BSCI473 FINAL

Ecosystem-Based Approaches Summary

● Ecosystem-Based Management emerged within the last decade as a philosophy and approach to marine resource management that builds on and connects MPAs and MSP applications. ● Marine conservation requires a multi-disciplinary approach (social, economic, ecological, etc. ) in order to create a successful management plan of the ocean and its uses. ● Using zoning to designate certain human activities to certain areas allows for regulation of human use and avoids potential conflicts as well. ● There are a range of human activities (fishing, aquaculture, energy, etc.) that have an affect on marine life that need to be taken into consideration when creating a conservation management plan. ● It is important to further study both detrimental effects and resilience patterns in order to plan the best course of action for ecosystems.

community (dis)assembly rules in coral reefs

(a) assembly: - both past and present assemblages not a result of random processes - predictable: the composition of Pleistocene coral communities in Barbados, over time based on species specific growth rates - reef fish assemblages are adaptive to their respective environments (b) disassembly - non-randomly by environmental change - species that survive photobleaching tend to have thicket tissues and higher mass transfer - "champagne" reefs: persist in naturally acidic waters by percolating volcanic CO2 seeps, while branching corals are far less abundant on nearby reefs unaffected by the CO2 seeps

nitrogen fixation

- diazotrophy occurs mostly in warm oligotrophic waters and is performed by cyanobacteria - regulation depends on nitrogen-fixers and non-fixers - N fixation thought to carry a cost of lower growth rate --> diazotrophs prosper under extreme nitrogen limitation - a dominant competitor (N fixers under N limitation) facilitate the coexistence of an inferior competitor

population cycles and chaos

- "chaotic" dynamics: populations fluctuate irregularly with trajectories that are highly sensitive to initial conditions - boom bust dynamics: result in large blooms, leading to pulses in ecosystem processes such as carbon export from the photic zone

predicted changes in range and phenology

- "climate envelope" models (CEMs): statistical relationship between the abundance of a species and underlying climate variables, typically annual mean temperature; no assumptions about the processes driving this relationship; makes predictions about past and future change; null models against which observed shifts can be compared - velocity of climate change: ratio of the long-term trend in the climate variable to the local spatial gradient in that climate variable, and the direction is given by the direction of the local gradient; highly variable across the ocean

processes at seagrass patch edges

- "settlement shadow" of higher larval settlement at patch edges - increased nutrient uptake at patch edges; reduced physical disturbance within the canopy - seagrass growth and distribution patterns mediate predator-prey interactions - predator abundance does not always vary from patch edge to interior - seagrass landscape effects are best studied with bivalves, focusing on bivalve recruitment, growth, and survival

reef survival

- 3 factors that determine reef survival: rates of = (1) land subsidence, (2) sea level rise, (3) reef growth - depth of the granite mountaintop of Enewetak Atoll (Marshall Islands) is 4,158-4,610 feet beneath the carbonate cap--but Enewetak is still a living atoll - this means that the rate of coral growth has been able to keep up with the rise of land subsidence and/or sea level rise at Enewetak - if the reef "drowns" = a "drowned atoll" is called a "guyot" - dead coral heads found ~1,000 m deep in the NW Hawaiian & Emperor Chain

invasive species of seagrass communities

- 56 non-native species introduced to seagrass beds worldwide; contribute to seagrass decline - there was a relatively low number of introduced consumers which may be due to high abundance and diversity of native seagrass consumers - introduced consumers negatively affect seagrasses other than by consumption (disturbance) - more evidence for top-down control

trawling

- 75% of the ocean's continental shelf has been trawled or dredged at least once - modern trawls about 10-25 m wide and are used primarily to catch flatfish (halibut), groundfish (cod), shrimp, and crab - dredges cause significant damage as they dig into the substrate dislodging many of the benthic organisms and suspending sediment

types of fisheries

- 78.6 million metric tons reported (legal); ~11-26 million metric tons unreported (illegal) - reported landings of marine & freshwater fish increased more than fivefold between 1950 and 1998 - ~7 million metric tons of unintentional bycatch per year - conservative best estimate for total removal of marine life from ocean by all forms of fishing = ~100 million metric tons

threats to marine communities

- 96% of local extinctions in coastal environments involved fishing and hunting - 39% involved habitat degradtion - concepts and theories developed from terrestrial, freshwater and coastal ecosystems --> application to continental shelf and deepwater habitats - fisheries with a historically "single-species focus" require broader community context in order to fully understand impacts - EAF (ecosystem approach to fisheries): management framework incorporating interactions among marine organisms and fisheries

Mixotrophy

- An organism that is capable of being autotrophic and heterotrophic - Most phytoplankton are labelled as primary producers, when in reality the majority are classified as mixotrophs. - Unlike pure autotrophs or pure heterotrophs, mixotrophs are generalists. But this causes them to be at lower competitive ability when competing for a single resource

niche differentiation as a result of environmental gradients

- Central North Pacific can be divided into shallow, mid-level, and deep groups --> shows functional overlap between taxa - dominance of motile taxa in stratified conditions shows active depth regulation by swimming or buoyancy allows for layer formers

kelp forests

- found near shallow rocky coasts in cold marine waters - concentrates food, buffers against waves, regulates recruitment of species

Cumulative Impacts Planning

- Cumulative impacts- The collective impact of all stressors on a species or ecosystem. ○ Central concept in conservation and resource management. ● Emphasizes the importance of accurately assessing how multiple human stressors affect ecosystems so that strategic action can focus on the most important issues. ● Has been applied around the world in the last 5 years to inform conservation and management efforts in places such as The Great Barrier Reef, Europe, the Great Lakes, etc.

micro-borers or micro-bioeroders

- EX: cyanobacteria, unicellular and simple multicellular green algae, fungi, foraminifera - these bore into coral and reef basement for protection from predation/grazing - soften the substrate--facilitate invasion by internal bioeroders and grazing/chomping by external grazers

scrapers or external bioeroders

- EX: sea urchins, herbivorous and predatory fishes - create 3D microhabitat responsible for high reef diversity - scrape/chomp/crush calcium carbonate substrate in their feeding activities - create larger excavated holes, caverns, overhangs in reefs - allows refuges for larger organisms - further increase the structural complexity and diversity of microhabitats in the reef - may cause large scale erosion of the reef framework (i.e. during urchin outbreaks) * most important destroyers of reef substrate * most important sediment-producers on the reef--> favors reef cementation --> most important factor in reef growth

climate change and fishing

- East Australian Current (EAC) transports larvae and adults of numerous species, which establish themselves in Tasmania - warming of waters allows sea urchin C. rodgersii to develop - C. rodgersii forms extensive barrens along the open coast that have shown a loss of 150 species of seaweed and benthic invertebrates - predation interaction of lobsters with H. erythrogramma and C. rodgersii are size-specific - illustrates that functional attributes of food webs can be affected by fisheries - shift from kelp beds to sea urchin barrens in Tasmania represent a discontinuous phase shift

co-limitation

- Liebig's law of the minimum: growth is not controlled by the total resources available, but by the scarcest sources or limiting factors - it is possible for two species to coexist if each species has a lower requirement for one of the resources - adding either nitrogen or phosphorus to a community will result in greater biomass, but adding both causes an even greater increase

grazer driven die-offs

- North: experimental work on die-offs in southern New England in salt marshes is attributed to run-away herbivory by the native, nocturnal purple marsh crab - South: significant recovery began in marshes with the longest and most intensive histories of die-off; compensatory predation: the fear of being eaten by an invader is depressing the density and top-down effects of this problematic grazer and aiding in the recovery of Spartina in Cape Cod

Major Themes in Marine Conservation and Management in the Last Decade

- Social Ecological Systems - Ecosystem Function and Dynamics - Interdisciplinary Science to Support Management - Resilience

observed changes in ranges and phenology

- Sorte calculated a mean rate of range shift of 190 km per decade, much higher than the median value for velocity of climate change (21.7km/decade); could be due to the tendency for only positive or notable shifts to be reported in the scientific literature (publication bias) - phytoplankton and zooplankton show the most rapid shifts, at 400 and 100 km per decade on average respectively - climate-related changes in phenology in the ocean are much less well-reported (difficult to sample and sustain effort)

Marine Spatial Planning (MSP)

- Uses a big picture view of what is occurring in the ocean to make informed and coordinated decisions on how to use marine resources sustainably and minimize impacts on nature and conflicts among users. ● Built on idea that any human activity in marine water executed in a way that is economically, socially, and environmentally sustainable. ● Successful MSP can be attributed to: ○ Using planning approaches that are specific to a region, using ecology and scientific information to support management plans and regulations ○ Having a supportive legislative framework in place, a hierarchical system to clearly establish goals, objectives, and strategies for MSP. ● Guidance on how to best implement MSP has been limited due to the fact that most information is theoretical instead of practical, and because it is either so generic it provides little specific direction on how planning should proceed or it is so specific to a certain place that it can't be applied to other situations. ○ This lack of knowledge results in political resistance to the idea of MSP because it's believed that MSP is an added regulation with no clear benefit to people.

larval dispersal and exchange in patchy, disturbed habitat

- active swimming may affect dispersal--some gastropods have been shown to actively swim downwards - eruptions may facilitate long distance transport of larvae

habitat loss and alteration

- affects primarily benthic habitat - fishing is one of the largest direct impacts on marine habitats alongside hurricanes and hypoxia - largest impacts caused by trawling - the use of explosive or poison to extract fish also causes significant damage to reef structure

ocean acidification

- approx. 25% of the CO2 emitted since the Industrial Revolution is now dissolved in seawater - when CO2 dissolves it forms H2CO3 - the pH of the ocean has fallen from 8.2 in 1750 to 8.1 in 2000 (30% increase in acidity)

extinction due to climate change

- depending on how quickly and by how much the oceans warm and acidify due to climate change, countless populations and some species will fail to adapt, acclimatize, or move and will simply go extinct - well over 100 species were predicted to be lost in the next few decades - paleontological record on how past regional and global climate shifts affected extinction rates and which taxa were most susceptible - extinction-prone coral species of the present are related to susceptible species from past geologic eras

herbivory in coral reefs

- as consumers of benthic algae, herbivores directly affect the structure and composition of benthic communities - fishing of herbivorous fishes alters the structure of the herbivore community by disproportionately reducing biomass of large bodied functional groups - main consumers of primary production include: fishes and urchins - herbivores function on reef depending on feeding mode: grazers, scrapers, bioeroders - herbivorous fishes consume benthic primary producers and regulate competition between fleshy algae and reef-building corals - diverse communities of herbivores are necessary to maintain important ecosystem functions on coral reefs

facilitation among plants

- at low marsh elevations, plant neighbors aerate oxygen-poor sediments within their aerenchyma, benefiting neighboring plants - at higher marsh elevations, plant neighbors shade the substrate and prevent evaporation of surface porewater, which causes salt to accumulate and stress plants - this facilitation is important in secondary succession after disturbance

evolutionary history of boring: bore into substrate for protection from predators

- began in Paleozoic in early non-scleractinian "reefs" as body size, activity level, and predation increased - intensified with the Mesozoic revolution--the rise of modern morphologically complex predators - predation drove epifauna (worms, sponges, bivalves, etc.) into relatively soft calcareous reef substrate--drilling/boring to make holes in substrate, refuge from predators - creates 3D microhabitat--responsible for high reef diversity * predation --> boring --> 3D microhabitat - after bioeroder dies, leaves empty hole - sessile and mobile epifauna crowd into empty bioeroded holes to avoid predation - competition for space drives morphological diversification in cryptofauna - constant predation pressure continues to drive morphological diversification in cryptofauna - restricted to small body size by size of available refuge space --> low fecundity, low dispersal --> high speciation

what are ecosystem services?

- benefits humans obtain from ecosystems - quantitative assessment: ecologists and economists map ecosystem structure and function to specific benefits - human impacts on ecosystems affect structure and function of an ecosystem, and can therefore impact ecosystem services

physical disturbance on benthic community structure

- benthic communities normally experience relatively low levels of disturbance - dominated by strong competitors that are larger, older and have long generation times - when these communities are disturbed intensely or frequently, the late-successional species are replaced by highly mobile demersal fishes and invertebrates - these animals, usually scavengers, attack the organisms displaced or damaged by fishing gear - these worm-like, nematodes are weak competitors with little defense but they are tolerant of pollution and hypoxia, which commonly occur in highly disturbed areas - 3 factors that determine the extent to which a benthic community is modified by bottom-disturbing fishing gear: (1) frequency of fishing disturbances, (2) frequency of natural disturbances, (3) the type of bottom substrate, not particle size

impacts of hypoxic events

- benthic mass mortality effects globally - as the habitat goes form normoxic to periodic hypoxic to persistent hypoxic, transfer of energy shifts from supporting mobile predators to supporting microbes - anaerobic respiration occurs in bacterial communities in the sediment --> produces H2S by sulfate reduction - sulfide production is normal mm to cm below sediment, but during hypoxic events, sulfide is produced at the sediment surface and into the water column once oxygen is depleted

microphytobenthos

- benthic unicellular eukaryotic algae and cyanobacteria that grow in the upper mm of soft sediments - ecosystem modifiers, primary producers, and nutrient processors - high productivity and accessibility makes them very important primary producers - enhance habitat restoration -important driver of food web dynamics, sediment stability, and ecosystem functioning - robust to a range of stressors that face these habitats

species interactions on hydrovents

- biotic interactions also important, but occur within livable abiotic environment - competition more frequent with more species, higher temperatures in center of habitat - facilitation more frequent with less species, lower temperatures at edge

types of hydrovents

- black smokers: abyssal and hadal zones because the water around these structures are rich in H2S which is black; hottest - white smokers: surrounding water contains barium, calcium, and silicon which are white; not as hot as black smokers

what happens when symbiosis breaks down? proximate causes

- bleaching - proximate causes of bleaching: zooxanthellae bails out, coral expels zooxanthellae, zooxanthellae dies

importance of coastal vegetation for climate change

- blue carbon (coastal carbon) covers small portion of Earth, but has a large effect on the global carbon cycle - sequesters carbon at a far greater rate (50-100X faster) and more permanently than terrestrial forests - coastal vegetation can spread rapidly via clonal propagation - marine wetlands release very little methane (unlike freshwater and bogs)

zonation

- borders are determined by stressors via latitudinal variation - high latitude: lower borders determined by waterlogging and anoxia; higher borders determined by competition - low latitude: borders determined by salinity stress from solar radiation evaporation

internal bioeroders or macro-borers

- boring sponges, clams, worms, barnacles - bore into coral and reef substrates for protection from predation (capable of excavating hundreds of kg/m^2/yr) - this is where much of the same on tropical beaches and lagoons comes from * internal bioeroders are the most important drivers of high diversity on coral reefs * most of the biodiversity on reefs is cryptofauna

population-level approaches: relocate and concentrate juveniles and adults

- can increase local population abundance - potential for disease introductions - reduces early post-settlement mortality, but not mortality for adults - these types of approaches only work if larval supply or early post-settlement mortality is the population bottleneck

geographic scope of small scale experiments

- canopy removal experiments increased barnacle survival by reducing predation - two studies indicate the strength and outcome of species interactions can vary over multiple scales

invasive species in soft sediments

- much more common in bays and estuaries than on open coastline - San Fran Bay has more than 240 non-native species - transfer of ballast water from around the globe and open ocean currents contribute to the lack of advection of bay larvae

community-level affects of climate change

- changes in community richness, composition, and functioning - prey will soon be introduced to new predators against which they have no evolved defenses - ocean warming will lead not only to new consumers, but also to hungrier ones: by increasing warming, activity and metabolic demands of predators will be higher - calcified structures are often used as a defense against predation, and a weakening of these structures may increase susceptibility to predators - growing number of documented examples in which water temperature and disease severity are positively related - altering the roles of mutualisms and other forms of facilitation

changes in geographic ranges and phenology

- climate change puts a proportion of the global population of a species outside their thermal range and bring new areas into the range of places where the species can live - notable exceptions are animals that control their internal body temperature which are mostly marine and birds - some organisms change their geographic distribution to remain in optimal thermal environment; changes the geographic location of the species fundamental niche

high-energy systems

- coarse sediment - physical forcing leads to sand ripples and waves - biogenic structures can also be formed in higher energy systems - topography-altering species that have positive effects on epifauna are considered foundation species - contribute to and are facilitated by abiotic processes, creating positive feedback networks

oceanographic drivers of rocky intertidal community structure

- coastal features influence propagule dispersal, recruitment intensity, and nutrient supply - nutrient "pulses" important where upwelling occurs --> nutrients brought onshore during relaxation events - in 1980s and 1990s most in field thought top-down and bottom-up did not occur simultaneously

salt marshes

- coastal wetlands that are flooded and drained by salt water brought in by tides - natural filters that intercept and process terrestrially derived runoff before it enters nearshore coastal systems

gradients of light vs. nutrient availability

- communities are vertically-structured due to light necessity - possibility of a functional trade-off between ability to compete for light or to compete for nutrients - two species can coexist if (1) light and a single nutrient are the limiting factors and (2) if each species is a better competitor for either light or the nutrient

competition: algae and coral

- competition common due to benthic location - algae effects are detrimental and physically cause shading and abrasion leading to tissue loss and mortality - aggressive mechanisms: chemical and biological warfare (release of allelochemicals that can cause bleaching), transfer microbes including pathogens directly to corals, and enhance microbial growth via water soluble compounds

human eutrophication

- competition: increased N switches dominant species hierarchy - invasives: more dominant when there is an increase in N - increase in N lowers diversity and increases palatability of plants; herbivory increases as the plants taste better

loss of habitat complexity

- complexity is lost when worm tubes, burrows, depressions and ripples on sediments and other structures created by emergent epifauna are destroyed by human activity - recovery rates in microhabitats are faster in coarse grained sediments - spatial extent and temporal disturbances influence species and habitat recovery dynamics in coastal marine ecosystems

prospects of conservation and management

- conservation efforts mainly driven by reef's economic contributions--global value estimated at US $30 billion annually - increasing reef resiliency is a major goal of conservation efforts--new growth and recruitment must exceed the rate at which coral death occurs - crucial parts of successful management: managing local stressors - many people look towards a singular fix for one problem: coral farming, assisted migration (moving fragments from healthy to desolate areas to try to increase recruitment), freezing coral gametes to repopulate if all reefs die off - in the end, we must address the root of the problem--increasing levels of atmospheric CO2

why are hydrovents important?

- contain unusual organisms that have adapted extreme conditions - provide nutrients to surrounding ecosystem - sustain complex food webs - nutrient cycling - reservoir of knowledge

phase shifts

- continuous: systems exist in one state for a given environmental condition - discontinuous: systems can have alternative states for a given environmental condition

predation on coral reefs

- coral predators have the ability to greatly decrease coral populations - the Crown of Thorns Sea Star is the most notorious predator--responsible for almost half of the decline of coral cover on surveyed reefs - bottom up: nutrients made more abundant by agriculture cause initial outbreaks by increasing food force for sea star larvae - reductions in outbreaks associated with MPAs--suggesting that outbreaks are favored by sea star predators caused by overfishing - effects of predators are more common in the Pacific

local decline of corals: invasive species

- coral reef species are very specialized and resilient: very few non-native species found in diversity surveys - lionfish in the Caribbean reduce recruitment and abundance of native small fish - red algae in Hawaii forms large mats that block light

seagrasses as foundation species

- create entirely new types of substrate - structure above and below ground: allows support of a wide variety of invertebrates, fish, birds, and mammals - host higher animal densities than any other soft-bottom community - higher abundances, growth and survival or animals than unstructured habitats - considered "nursery" habitats: supporting many organisms only at early life stages

variation in sedimentation

- depend on grain size - coarse substrates (larger grain) tend to have more wave action, so more energy; long-lived suspension feeders - fine substrates (smaller grain) tend to occur in low energy areas; more deposition of organic materials --> deposit feeders

animal-sediment interactions

- deposit feeders: feed on matter that has settled to the bottom (haddock, eels, flounder, bass, crabs, shellfish, sea cucumbers) resuspend sediment, clogging suspension feeders' filtering apparatus and burying larvae - suspension feeders: above the sediment

Alfred Redfield

- described ontogeny of New England salt marsh: identified salt marshes as biogenic communities built and maintained by foundation species

population-level approaches

- different restoration approaches: restrict harvest, create spawning sanctuaries, introduce reared larvae, relocate and concentrate juveniles and adults, habitat conservation and restoration - the approach used depends on the current population bottleneck - EX: introducing reared larvae will have little to no effect if the population bottleneck is later post-settlement mortality

modification of the environment and of biotic interactions

- dominated by a small number of foundation species - many inhabitants facilitate other species --> facilitation cascades - reciprocal facilitation= form of mutualism - complex mutualisms involving third parties (including microbes)

soft sediments and structural complexity effects

- ecosystem engineers and foundation species play a dominant role - since soft-sediments don't have much complexity compared to other marine habitats, they are used to compare the effects of habitat complexity on species abundance, distribution, and interactions - at higher predator densities, habitat densities can reduce intra- and interspecific interference interactions among predators, increasing predation rates - complex habitats within soft sediments create a habitat mosaic with some areas rich in prey to others that have decreased growth - degree of connectivity of habitat patches can influence intraspecific interactions among predators

assessing marine ecosystem resilience

- ecosystem resilience is necessary for long-term persistence of a full range of ecosystem services - abrupt and unexpected shifts in an ecosystem state are known as "regime shifts"

regime shifts and feedback mechanisms

- ecosystems absorb disturbances up to a tipping point and shift rapidly into a new state that functions and responds to pressures differently - difficult to shift back to original state - feedback mechanisms tend to maintain the system in the undesired state - seagrass beds do not return to sediments from which they have already been lost - many coastal seagrass beds have been replaced by mats of ephemeral micro and macroalgae - nutrients released from decaying plant detritus accumulate in sediments to stimulate blooms of ephemeral algae even after conditions improve - two stable states are (1) seagrass beds or (2) benthic micro- and macroalgal beds

quantifying the role of biodiversity in supporting marine ecosystem services

- effects of human activities on marine ecosystems include loss of diversity - important services (such as productivity of fisheries and maintenance of water quality) decreased with declining diversity - more diverse large marine ecosystems (LMEs) had fewer collapsed fisheries and higher rate of recovery than less diverse LMEs

colonization and succession

- eruptions are volatile and violent, eradicate resident fauna, and alter the physical and chemical environment - eruption cycles of vents establishes the colonization and succession rotations of the community - vent H2S levels dip as in the months and years leading up to an eruption - foundation species facilitate the community growth around the vent - scientists still deliberating whether facilitation is a direct effect through surface bound chemical settlement or whether it's an indirect effect from the interaction with microbial biofilms - recovery is rapid and communities will return to full strength only 2-3 years after an eruption - eruptions give the opportunity for species previously unfound in that area to establish themselves and flourish in the community

coral biodiversity

- estimation methods are used to determine the number of species - extrapolation: calculations based on rate of discovery - coral reef diversity calculated based on estimated proportions of marine species living in or on coral reefs - varying results can imply smaller or larger numbers of reef-associated species

conservation of vent communities

- ever since its discovery, scientists have been exploiting these communities by harvesting and manipulation of vents in order to gain data - recently, mining of deep sea vents has become possible in order to extract precious earth like cobalt, gold, and copper to use in high-tech manufacturing - two main aspects of vent communities: (1) communities resiliences to disturbances, (2) connectivity to other locations - many strategies: (1) currently the Antarctic vents south of 60 degrees S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty; (2) MPAs are where most of the vents are located

distribution of vent species

- extreme environmental/abiotic gradients are a strong influence; especially temperature gradient - # microbes increases near center, decreases at edges

coral defenses against competing coral

- feeding tentacles of polyps can transform into enlarged sweeper tentacles up to 6.5 cm long - feeding tentacles are used to detect and repel competing corals - can cause damage to soft tissue and polyp mortality - response not rapid

direct effects: extinction risk

- few marine species driven to global extinction in modern times - IUCN Red List: most comprehensive source of information on threatened and extinct species - extinct marine species mostly birds, mammals, and molluscs - conceivable that significant numbers of marine invertebrates have gone extinct without anyone noticing - no truly marine fish species have gone extinct (multiple freshwater have) - particularly high for large bodied, slow-growing species: more vulnerable to fishing gear, lower population abundance, lower resilience

low-energy systems

- fine sediments - surface topography is structured by many species - ecosystem engineers: create emergent biogenic microhabitats - allogenic engineers: create structures by building tubes and making burrows; many taxa forage and seek refuge in structures built by allogenic engineers - marine mammals destabilize habitats by burrowing and creating depressions

Frederic Clements

- first described primary succession in New England salt marshes - (1) colonization of intertidal mudflats by cordgrass Spartina alterniflora (2) vegetative cordgrass growth and vertical accretion of peat and sediment (3) colonization by high marsh plants (4) woody plants

general patterns of distribution

- forests found between poles and warm, nutrient poor tropics - more diverse and abundant large brown algae at tropics - exception: cold-water currents and associated upwelling on western continental coasts allow forests to extend farther north - forests are rare in Arctic Circle - true kelps are not in Antarctic Circle, although extend as far south as Cape Horn - urchin barrens common at mid-latitude bands

ecosystem engineers

- foundation species (oysters, sea grasses, marsh plants, corals) change the above-ground structure - burrowing, tube building, etc. help to oxygenate deeper sediments allowing other organisms to survive - mud sediments: cohesive because of the ionic charges that hold them together; tends to be low water flow over muddy sediments; physical recovery rates are slower than in sandy areas - macrobenthic organisms are the first to recolonize chemically and physically

problems with restoration

- frame of reference: what time period do we choose to go back to? How do we know what the ecosystem was like before human disturbance? what site do we choose as a reference site? - accuracy of historical records or lack thereof - changes in the ecosystem that have occurred in the past and will continue to occur in the future - is it even possible to go back to older conditions given the new ecosystem?

what is climate change?

- greenhouse effect: caused by gases in the atmosphere absorbing infrared radiation - necessary for life on earth, but in moderation - atmospheric CO2 is expected to double in the next century from pre-industrial baselines - resulting warming of land is expected to be somewhere between 2 and 4.5C - sources of greenhouse gases: electricity use (29%), transportation (27%), industry (21%), commercial and residential (12%), agriculture (9%)

NCEs, food chains, ecosystem function

- growth efficiency is an important variable: can determine how much energy is transferred to higher trophic levels; can define the energetic status of organisms - found that green crab risk cues strongly reduce the flow of energy through food chain by reducing foraging and the conversion of energy once it is ingested - strong evidence that predation risk can shape prey energy budgets by increasing respiratory costs, production of heat shock proteins, and antioxidant enzymes

direct effects of fisheries on benthic habitats

- habitat alteration by fishing gear perhaps the largest yet least understood threat to marine habitats since most areas had been trawled or fished historically before adequate baseline data was collected - these areas are also affected by natural disturbances, such as storms, which makes it even hard to quantify the effects from fishing - removal of biogenic and physical habitat structure - direct mortality - increased abundance of mobile predators or scavengers that feed on organisms injured or killed by fishing gear - reduction in the average size and lifespan of benthic organisms - increased abundance of small-bodied invertebrate species - decrease in the secondary production of benthic invertebrates and fishes in the affected area

classic metapopulation model

- habitat occurs in discrete patches - all populations have a substantial risk of extinction - dispersal occurs among all patches - patch dynamics are asynchronous - ignore population dynamics within a patch

recovering marshes

- harnessing the positive effects of clonal integration of Spartina can clonally recolonize stressful (anoxic) bare substrate

positive interactions on coral reefs

- has equal influence on coral reefs as competition and predation - mutualism: engine that drives the growth of corals - EX: symbiodinium (dinoflagellates) found inside the tissue of all reef-building corals provides host with food in exchange for nutrients - EX: cleaners remove substantial numbers of ectoparasites from hundreds of fishes -facilitative relationships: one benefits at no cost to the other - EX: damselfishes defend territories to protect the algal resources and nest sites within them to benefit territory owners - crustose coralline algae (CCA): provide substrate for attachment of many coral larvae and the distribution of CCA species that confers the best survivorship on young corals is a good predictor of coral recruitment rates across habitats

population-level approaches: introduce reared larvae

- hatchery production of larvae released into environment - currently used in the Chesapeake for oyster restoration - there is little evidence that this approach is effective for most marine species as later post-settlement mortality tends to be the greater threat - potential for disease introductions

habitat-level approaches: seagrasses

- have been degrading at an accelerated rate over the last 20 years - limited success in restoration efforts - should only be attempted in places where the problem has already been addressed - it has become standard practice to test the restoration on a small scale plot first before starting a full blow restoration effort - much previous work is unpublished and/or difficult to access - hindered by site specific variables: unique herbivory, bioturbator community - since seagrass beds are almost exclusively monocultures, restoration attempts should maximize genetic variation because of the aforementioned benefits

predators in salt marshes

- having predator richness facilitates grasses and ecosystem functions - predator exclusion leads to marsh die offs

evaluating cumulative impacts

- helps managers to access the cumulative impacts of diverse human activities on ecosystem health - uses considered included renewably energy, sand and gravel mining, commercial shipping, commercial and recreational fishing, telecommunication infrastructure, and aquaculture - resources considered included both species and habitats of concern, particularly those that were unique and sensitive to human impacts - the five services most strongly affected by cumulative human impacts are: biodiversity, marine harvested species, aesthetic values, habitat and recreational values

landscape-level approaches

- high importance of these landscapes to predator-prey dynamics, recruitment, competitive interactions - these habitats tend to enhance each other

analysis of pattern at multiple scales

- higher variation occurs at small spatial scales, but the importance of large-scale variation is more species-specific - large scale variation becomes important as the spatial scale of sampling approaches the geographic limits of species distribution - important broad-scale spatial trends in the abundances of several algal and invertebrate species and changes in the spatial extent of key foundation species -

the state of coral reefs

- historical accounts suggest modern reefs are shadows of their former selves - decline from about 50% coral cover in the mid-1970s to just 10% at the turn of century in Caribbean) - corals can retain their structure for some time after their death - local and global stressors: overfishing, runoff, invasive species, CO2

habitat-level approaches: mangroves

- historically exploited for lumber and organisms associated with them - cleared from coastlines to make room for resorts and aquaculture - mangrove restoration efforts historically focus on just a few types of vegetation - mangrove planting on previously unvegetated mudflats usually fails - loss of mangroves is often associated with lower fin fish fisheries success and lower wild shrimp harvest success - success of mangrove restoration efforts can be roughly measured by relative health of benthic assemblages - heavy consumption of mangrove faring invertebrates (crabs, prawns) is often correlated with negative effects in offshore food webs - symbiotic relationships can promote mangrove growth

loss of ecosystem services

- human disturbances are negatively impacting salt marsh coverage and the structure of these ecosystems - no longer can marshes be championed as systems that can and should be used to buffer human impacts

introduction to hydrovents

- hydrovent: a hydrothermal vent; a crack in the planet's surface where geothermally heated water can leave - deep sea hydrovents arise in all ocean basins and usually form at mid-ocean ridges--where two tectonic plates diverge and a new crust is being formed and on volcanic arcs made at subduction zones--where two tectonic plates meet and one plate is forced below another - water that is issued out from hydrovents consists mostly of the ambient seawater that is drawn into the hydrothermal system at mid-ocean ridges or subduction zones - the cold water is heated by magma and reemerges as well as porous sediments - when the superheated water hits the near-freezing water of the ocean, the minerals dissolved into the fluid will precipitate out to form particles and accumulates

zonation and community organization of intertidal rocky shores

- importance of strong vertical, horizontal gradients caused by physical forces - physiological, morphological, behavioral adaptations to stressful conditions - trade-offs are accepted as creators of max lift and drag organisms can withstand

ecosystem services provided by seagrass communities

- improve water quality and reduce erosion - blue carbon and nutrient sequestration - constitute a critical nursery and feeding habitat for economically important species of fish and shellfish

sea-level rise

- in many areas, marshes are blocked in with no way to expand landward due to human development - top-down predator depletion are eliminating the foundation species that build marshes

challenges to quantification

- inadequate knowledge of link between ecosystem structure/function and production of goods and services - some services are direct, easily measurable - others are harder to estimate, benefit humans without input

marine protected areas

- incorporate extensive areas of undisturbed terrestrial borders to buffer marshes from extensive eutrophication via runoff and allow for their landward migration as sea levels rise - must allow for the inclusion of positive interactions at all levels of biology

deforestation: human interference

- increase in sea urchin populations - humans have overexploited the predators of sea urchins (otters, large fish, lobsters) disrupting the trophic balance and increasing urchin populations on shorelines - these disturbances to predators in kelp forests cause trophic cascades; sea otters were close to extinction which caused collapse in kelp forests

temporal or seasonal variation affects vertical gradients

- increased turbulence and decreased light during winter in higher-latitude systems leads to light limitation of growth - summer stratification allows phyto to use nutrients

the community consequences of predation risk

- inducible defenses are common in rocky shore species and have been documented in a number of traits - EX: snail shell thickness, shell color, adductor muscle size, byssal thread production, barnacle shell shape, chemical defenses of algae

size-structured phytoplankton community

- is co-limited by grazers and nutrient supply - as nutrients increase, phyto size increases which allows for grazer class to feed on them

hydrothermal vent paradox

- it was observed that the palm worm had a homogeneous genetic structure across many hydrothermal vent sites, despite having an extremely limited dispersal potential - using general metapopulation models that include extinction and recolonization, scientists were able to find that the character of dispersal, interacting with habitat dynamics, determines the extent of genetic divergence between populations

Maine's kelp forest-coralline community

- large scale herbivore removal caused a change of ecosystem function that persisted long enough to meet persistence stability - no sea urchins survived to adulthood due to algal succession to densely branched morphologies - cascading sequential processes of herbivory, recruitment, and predation created reinforcing feedback, locking this ecosystem into the kelp forest state

grazers and pathogens

- larger organisms tend to eat smaller organisms, with the ratio of predator size to prey typically between 10:1 and 100:1 on a linear scale - grazers use chemical cues to select prey based on nutritional quality or toxicity

cell size

- larger-celled species become relatively more abundant and small-celled species become relatively less abundant as system productivity (approximated as total chlorophyll a) increases

traits of individual plants

- leaves, rhizomes, and roots of seagrasses modify currents and waves = traps and stores sediments and nutrients

kelp highway hypothesis

- lines of kelp forests may have provided food, holdfasts, and other ecosystem services for first colonizers of the Americas 10,000 years ago

effects of removing blue carbon sites

- loss of blue carbon habitats means loss of their sequestration function - conversion of blue carbon sites --> releases stored carbon in the form of greenhouse gases - aeration may lead to the release of carbon that has been locked up for centuries or millennia - aeration leads billions of tons of carbon emissions annually

climate change and ocean ecosystem services

- loss of species and entire ecosystems - loss of income from lack of tourism - loss of reefs especially adjacent to coastal community means reduced buffering from waves and increased shoreline erosion - direct and indirect effects on fishery production

other forms of habitat disturbance

- loss of wetlands by land reclamation, coastal development, pollution, and eutrophication - rocky shore habitats and coral reefs threatened by sedimentation from terrestrial runoff, beach development, dredging - species invasions, tourism, shipping affects most habitats - aquaculture, the most rapidly growing food sector, involves some degrading practices such as replacing mangroves with shrimp farms - result of all these activities is that the marine environment is becoming less heterogenous and there's less structurally complex physical habitat

herbivory

- low latitudes: more intense predator-prey interactions lead to an increase in defense through palatability - higher chemical defense in southern plant species; grazers prefer northern vegetation - increase in rodent grazers increases plant diversity - tunneling by field mice slows down secondary succession of bare patches and inhibits growth of invasive animals

quantifying and valuing marine ecosystem services

- mangrove forest conversion to shrimp farms has led to considerable loss of valuable ecosystem services in Thailand - Louisiana Master Plan for Coastal Restoration and Protection - local investment in building resilient coastal communities in California

experiments

- marsh plant transplant experiments that examined mechanisms maintaining the distinct patterns of plant zonation aligned perpendicular to incoming tides showed that salt marsh plants did not necessarily live where they grew best, as if physical or bottom-up processes were in control - instead, transplant experiments in New England revealed interspecific competition largely dictated the conspicuous segregation of different plant species across marsh zones - new explanation for plant zonation in which intense competitive interactions hierarchically organize plant species along environmental gradients according to interspecific differences in competitive ability and stress tolerance - later experiments revealed that both intra- and interspecific positive interactions esp. facilitation among plants is also important

trophic cascades on coral reefs

- may be difficult to detect - "fear effect" predators cause shifts in prey behavior through the risk they impose (spend more time hiding, find less risky habitats) - behavioral change in herbivores can result in changes in their demography - trophic cascades may ultimately be context dependent at sites: can be top-down or bottom-up control

coral defenses against algae

- mesenterial filaments - filaments loaded with nematocyst, that are used to digest prey - may occasionally allow corals to inhibit algal growth - also used with competitive interactions when neighboring coral of different species comes too close

metacommunity dynamics of vents

- metapopulation: a group of geographically separated populations, each of which is subject to extinction and connected to others by migration, so that dynamics in one population can potentially affect dynamics in others - metacommunity: an expansion of the metapopulation concept to include multiple species and their interactions - global species distributions are important for understanding diversity among vents - all biogeographical provinces of vents host a characteristic fauna that describes their general appearance

mixotrophy and interactions with heterotrophic bacteria

- mixotrophy: the use of both photosynthesis and organic sources of energy or nutrients - osmotrophy: the direct uptake of organic molecules from the environment - phagotrophy: the ingestion of prey or other food particles - mixotrophs are one source of coupling between phytoplankton and the "microbial loop" in which dissolved organic matter enters the food web via heterotrophic bacteria and their predator's pathogens

Georgia Sea Islands

- modern salt marsh ecology began here - bottom-up energy flow in salt marshes controlled the function and structure of these systems - major paradigm: the abundance, distribution, and productivity of organisms in ecosystems were regulated by energy flow within a food web and that physical forces (nutrients, physical factors, tides) mediated the production of that energy at the bottom of the web (bottom-up)

biodiversity and ecosystem functioning

- more diverse assemblages more resistant to invasion by invasives - functional group diversity more important than species diversity - more diverse assemblages recovered from stress more quickly - more richness led to less nutrient uptake by algal species - herbivory promoted recovery and succession - increasing richness inhibited succession when abundance was high - global warming causes species ranges to expand toward the poles - literature is probably biased in favor of a positive response to global warming

comparing predictions and empirical observations

- more rapid range shifting has occurred in areas where the velocity of climate change is greater - the majority (68%) of shifts have lagged behind the rates expected from shifting climate - species may adapt to the new thermal regime in their existing geographic range - climate debt = distance between the expected shift and the observed shift

direct effects: changes in composition and diversity

- more skewed fishing pressure = more pronounced shift in species composition - fished community over time will lose species with high catchability or low resilience to additional mortality - skewing of trophic structure - declining species richness

community dynamics under variable resource supply

- more species can coexist when phosphorus is supplied in pulses vs. supplied at a constant rate

direct effects: changes in age and size structure

- most are size selective: large bait, large hooks = large mouthed fish - individual size correlated with age: some species' sizes correlate with other attributes such as longevity, growth rate - uneven exertion of fishing pressures across size classes drastically alters size and age structures: larger, older fish becoming more rare - size structure desirable from MSY perspective: smaller, faster-growing fish may be more productive and may survive better when larger predators are depleted

population-level approaches: restrict harvest

- most common conservation measure to rebuild stocks of overexploited fish - directly reduces fish mortality - does not work if the target species is not directly exploited - hard to accomplish because of public resistance and the potential economic losses to fishermen

nutrient limitation

- most important element limiting production - nitrogen, iron, and phosphorus

invasive species

- naturally, salt marshes are difficult to invade due to high salinity - intentional planting of invasives is the main issue - EX: Spartina alterniflora planted for erosion control in China and California lead to displacement of migratory birds, bivalves, and native grasses

ocean solutions to climate change

- need to reduce our emissions of greenhouse gases - develop policies and technologies to remove those already emitted - reducing solar radiation would do nothing to mitigate ocean acidification

biogeographical diversity

- northern hemisphere: Laminariales have higher diversity here - true kelp evolved here 15-35 million years ago - southern hemisphere: lower diversity of Laminariales; recently colonized ~10,000 years ago

size-productivity relationship

- nutrient limitation appears to be a primary driver of the size-productivity relationship - high turbulence = high nutrient supply - small-celled phyto in low turbulence and low nutrients - large-celled phyto in high turbulence and high nutrients

early experiments on biological interactions of intertidal rocky shores

- observed importance of consumer pressure, competition, biotic/abiotic control of distribution across gradients - important consumer removal experiments - manipulative experiments reveal patterns generated by disturbance - a "mosaic" of patches in different stages of succession - challenged Connell's view of "intermediate disturbance hypothesis" --> ecological systems are not at equilibrium, and more extreme disturbance levels promote diversity

ocean warming

- occurring at all levels since 1980s - West coast of America has actually cooled slightly - Southwest Pacific is heating quicker than global average

causes of deforestation

- oceanographic anomalies (change in water quality, sediment and nutrient levels, salinity, temp, El Niño) - human-caused variation (predator abundances, community composition) - sea-urchin overgrazing - climate change

habitat-level approaches: salt marshes

- oldest/first marine restoration effort - usually require large scale efforts to restore hydrology - planting of halophytic vegetation - some ecosystem conditions return quickly after restoration, while others take a much longer time to become established - plant species richness can be as low as 50% less than comparable undisturbed marsh, decades after restoration - well planned restoration takes into account complex relationships among species - restoring high native species diversity is a common goal - salt marshes are naturally resistant to plant invaders due to their hostile nature, but still have invasive problems

assessing trade-offs of ecosystem services

- one can use the ecosystem services lens to assess trade-offs among different management objects or human activities - MSP (marine spatial planning) could prevent over a million dollars in losses to the fishery and whale-watching sectors and could generate more than $10 billion in extra value for the wind energy sector - people in MA had a one-year intensive planning process to develop the first ever comprehensive ocean plan for the state's waters

kelp forest dynamics

- only ecosystems to exhibit rapid shifts between community states - alternative stable states: runaway change propels the system to a contrasting state that is self-stabilizing; usually occurs from trophic cascade (removal of a top predator) - overgrazing by urchins leads to alternative states called "barrens" - deforestation sources can create "algal turfs" which accumulate sediment, preventing kelp recruitment

origins of modern kelp forest biogeography

- paleocene (65 mya): Fulcares and Laminariales diverged - miocene (23 mya): separation of the two orders - today: both orders have radiated to create unique hemispheric phylogenies - kelp species diversity seems to reflect global evolutionary history rather than a specific area's ecological history

latitudinal variation on mudflat pans

- pan: marsh patch continually without any dominant plant species - low latitude: pans with evaporated salt surface from intense hot climate - high latitude: pans are waterlogged suppressing plant growth

patch fragmentation

- patches range in size and shape due to clonal growth and sexual reproduction, biotic forces (grazing, bioturbation), and physical forces (hydrodynamics)

kelp beds and turf

- phase shifts to turf involve a different mechanism - kelps and turf compete for space - eutrophication tips the competitive balance - the replacement of kelp beds by turf communities associated with eutrophication and sedimentation will be exacerbated by climate change - sediment trapping turfs can create lethal environments by forming anoxic layers and preventing small rock-dwelling organisms from attaching - kelp forest deforestation and shifts to turf communities may be discontinuous phase shifts but unsure

non-equilibrium dynamics

- phytoplankton environment is constantly in flux due to periodic abiotic variation at diurnal and annual scales, mesoscale eddies, and Rossby waves

diseases on coral reefs

- play a more prominent role in the Caribbean--White Band Disease: presumed bacterial infection causes segments of bare skeleton, bordered by narrow bands of disintegrating, necrotic coral tissue - pathogens are more difficult to study than predators due to diversity of disease syndromes and causative agents of most diseases remain unknown - potential causative agents: nutrients and polysaccharides released by seaweeds & warm temperatures

ecological interactions of coral reefs

- predation - diseases - competition - herbivory - positive interactions - trophic cascades - community (dis)assembly rules

biotic interactions

- predation: variable distribution in prey species, which might predictably congregate - armored species sit atop the sediment and therefore receive more handling time and more predator exposure, but are harder to eat - competition for space: exploitative competition which results in reduced feeding and growth - suspension feeders experience less exploitative competition than deposit feeders since their food resources can be replenished by currents

community ecology

- primary succession in salt marshes is limited by substrate instability, anoxia, and physical disturbance - both plant-plant and plant-animal positive interactions facilitate the initial establishment or successional development of salt marshes - at high marsh elevations, interspecific plant community structure becomes a major driving force

the intermittent upwelling hypothesis

- propagules and food only reach shore during relaxation events - relaxation events (when upwelling stops, brings warm water to areas it does not reach during upwelling) brings more food --> prey population grows --> predator populations grows and exerts top-down control - both strong, persistent upwelling and persistent downwelling seem ineffective in replenishing rocky intertidal areas - Menge & Menge propose hump-shaped relationship where rates of ecological processes highest with intermediate upwelling - suggests that when switches between upwelling and downwelling are too frequent there is not enough food and recruits get to the coast

snail transplants

- recent research into the formation of these snail fronts indicate that snail grazing alone did not initiate salt-marsh die-off; instead suggests that following drought-induced dieback in distinct, yet extensive areas, allow for snail fronts to form on the disturbance edges and propagate through the landscape to cause cascading vegetation loss - synergistic effects of both bottom-up and top-down forces are causing the massive die-offs in southern marshes

drivers of kelp forest dynamics

- recruitment: seasonal, strong after storms; difficult due to spores being unable to travel large distances - growth regulation: light, nutrients, temperature, waves; dispersal differs among species but typical in colder months - competition: interspecific within same canopy level; intraspecific between canopy levels

invasive species: retentive environment

- reduces advection, which contributes to non-native establishment - density-dependent inhibition of reproductive success of one group of adults (due to exotics) heavily affects the next generation and the survival of the species - invasive species alter prey abundance, native predator foraging, and sediment deposition

local decline of corals: overfishing

- reduction in fish abundance, density, and diversity - removing herbivores triggers trophic cascade--shifts balance in favor of algae - sometimes use dynamite to stun or kill fish: this damages the physical structure of the coral

direct effects: change in abundance and biomass

- reduction in the abundance of target species & bycatch species - "fishing down" of accumulated biomass = major manipulation - strategy to move populations away from carrying capacity: desired because population growth rate is higher at low to medium abundance - maximum sustainable yield (MSY): obtained at a low to intermediate population biomass (~30-50% of biomass prior to fishing)

hysteresis

- reflects the fact that once a system "flips" from one state to another, it can be difficult to return to its original state - tipping point: the minimum level of sea urchin biomass that is required for the kelp forest to convert to a sea urchin barren - recovery point: the maximum level of sea urchin biomass that is required to allow kelp regrowth converting a sea urchin barren to a kelp forest

seagrass communities

- relatively resistant to grazing - consumed mostly by large vertebrates - large vertebrate herbivores are relatively uncommon in seagrasses - understanding seagrass ecosystems and predicting stress responses is increasingly urgent due to their steep decline in recent decades

deforestation: sea urchin grazing

- remove vegetation that is used as habitat and food for kelp forest communities - creates "barrens" = decrease in species diversity - keystone predators maintain sea urchin populations - encourage people to eat them, but when urchins have no vegetation they become cannibalistic which inhibits their gonad development (the edible part)

phase shifts and tipping points of corals

- replacement of corals by other sessile organisms and algae - rapid transition and hard to shift back - species extinction: no reef species globally extinct; 1/3 are at risk due to global warming + local stressors

taxonomic groups of marine phytoplankton

- represented by four taxonomic supergroups (Rhizaria, Archaeplastida, Chromalveolata, and Excavata) - eukaryotic plankton arose as a result of endosymbiotic events in which a photosynthetic organism was engulfed by a heterotrophic protist (~1.8 billion years ago) - secondary and tertiary endosymbiotic events, in which eukaryotes were engulfed by heterotrophs, occurred many times and gave rise to all other major phytoplankton groups

ecosystem-level approaches

- required to address problems such as: changes in hydrology of watersheds and estuaries, chronic pollution and nutrient input, shoreline development - most projects focus on restoring connectivity between estuaries and nearshore marine environments - smaller scale habitat restoration efforts can work together to solve ecosystem-level goals

socioeconomic consideration in marine restoration

- restoration projects quickly lose support when relocation of property owners becomes an objective - reactions to natural/ecological disasters is usually engineering-first - an engineering approach to natural disaster prevention can result in: increased erosion around building site, loss of nutrient regulation, reduced foraging and nursery habitats - this reactionary approach to disaster prevention can be avoided if conservation and sustainability become the objective for any restoration initiatives

what is restoration?

- returning a system to a close approximation of its condition prior to disturbance, with both the structure and function of the system recreated - goals of restoration based on the historical context - manipulation of populations or habitats for the primary purpose of increasing human exploitation is not restoration

vent habitats

- right above seafloor is cold, dense, oxygen-rich seawater: chimneys are physical habitat where organisms live at 40-80C - underneath the seafloor are hydrothermal fluids: nothing lives here because temp over 400C - primary producers: microbes called "chemolithoautotrophs" used energy from H2S - herbivores: grazers and suspension feeders - predators: mobile species like crabs, octopods, fish, sea stars - foundation species: usually have symbiosis with microbes (polychaetes, tubeworms, clams, shrimps, amphipods)

other consequences of climate change

- rising sea level and declining sea ice threatens coastal, benthic, and arctic communities - changing salinity because of more evaporation - due to spatial differences in temperature increase, gradients that drive storms become more intense - stronger upwelling - warmer water holds less oxygen; also can be a result of upwelling

spatial variation

- salt marsh plants survive best in freshwater or low salinity

effects of scale in manipulative experiments: scale within a single site

- scale effects the outcome of field experiments - field experiments involve small experimental units - algal canopies dominate sheltered shores; mussel bed and barnacles dominate more wave-exposed shores

patterns of species diversity

- scleractinian corals (stony corals) contribute little to reef diversity - molluscs, fishes, arthropods are mostly comprised of small, cryptic species - diversity dominated by small, cryptic, and rare species - the coral triangle: identified high-diversity reef sites based on corals, fishes, snails, and lobsters - the diversity of the region is the best predictor of diversity at a specific site - diverse tropical regions lay farther to the west and are correlated with tectonic activity

seagrass management and restoration

- seagrass species are at elevated risk of extinction, including 3 species now considered endangered - major increases in the number of marine protected areas that include seagrasses - seagrass indicators are used to assess the quality of ecosystems in many national policies aiming to improve the health of marine ecosystems - common strategy worldwide to halt the loss of seagrass habitats is the process of seagrass restoration, in which seagrasses are planted, via transplants or seeds, to restore a degraded habitat

ocean acidification effects on seagrass communities

- seagrasses are actually expected to benefit from increases in water column CO2 levels because they can be limited by carbon - there is hope that seagrasses may help alleviate the stress of acidification for associated calcifying organisms

bottom-up control in seagrass communities

- seagrasses universally have high light requirements (11% of surface irradiance) - unlike most vascular plants, seagrasses can take up nutrients from both their leaves and roots - sediment nutrient enrichment has positive overall effects on aboveground and below-ground biomass, whereas water column nutrient enrichment has negative effects on these responses - the roots and rhizomes of seagrasses are often situated in anoxic sediments containing high levels of toxic metabolites, esp. H2S - providing oxygen to their below ground tissues carries a large energetic toll and possibly explains why the minimum light requirements for seagrasses are much higher than those of micro and macroalgae

local decline of corals: poor water quality

- sediment, nutrients, and pollutants runoff from areas developed by humans - eutrophication linked to prevalence and severity of coral diseases - fish abundance is 60% lower in polluted areas compared to pristine areas

indirect effects of degradation

- sedimentation on rocky coastlines increased sediment-tolerant turf algae that provided habitat for invertebrates and sea cucumbers - coral declines from bleaching, storms, or over-predation by sea stars leads to a shift to macroalgae communities which slow or stop coral recovery - fishing in NE increased herbivorous crab populations, decimating the foundation species, cordgrass, by 40-90%

population-level approaches: create spawning sanctuaries

- setting aside no-take areas for species of interest to reduce juvenile mortality - protects habitat by reducing harvest and has the potential to increase disease resistance - blue crab spawning sanctuary in the Chesapeake

characteristics of soft sediments

- simple structure: baseline habitat in which many other habitats (sea grass beds, mangrove forests, bivalve reefs) are embedded - eutrophication alters sediment biogeochemistry and has chronic effects - microphytobenthos (benthic microalgae and cyanobacteria) stabilize sediments, produce a basal energy source, and process nutrients

dimensions of expansion

- spatial expansion and intensification (coastal and estuarine --> continental shelves --> open ocean and deep sea) - continual rise of fishing effort, global CPUE decline - increasing concern because CPUE decline is a proxy for declining fish abundance - newly exploited species allow increase in the fraction of marine biodiversity used for human purposes

grazer control

- strong role that grazers and top-down forces play in regulating marsh population - goes against Odum doctrine which states that bottom-up control of marsh ecosystems through nutrients, temperature, anoxia, and salinity are the only important processes occurring

consequences of seagrass genetic structure

- studies have found that higher allelic diversity increased vegetative shoot production and sexual reproduction in transplanted seagrasses - increased genetic diversity can be important in the buffering of seagrasses against multiple perturbations

effects of other habitat-degrading activities

- substantial increase in sedimentation and a related increase in turbidity from human activities - sedimentation on rocky substrates can prevent the settlement of larvae of hard-substrate organisms - increased mortality of adults by smothering foundation species thereby affecting any associated species - sedimentation removes late-successional, large-bodied, and long-lived species which are then replaced by opportunistic flora and fauna - kelp forests, mangroves, and seagrasses can control sedimentation, but for the most part sedimentation controls community composition and structure - steamships have been dumping burnt pieces of coal, called clinker, into deep water which makes up 50% of the hard substrate available for attachment by brachiopods across large areas of the abyssal plain

Menge and Sutherland model

- synthesized previous experiments to create model comparing importance of stress, disturbance, and recruitment on assemblages of rocky intertidal systems - model focused on top-down control of community structure by consumers - research today recognizes that both top-down and bottom-up processes are influenced by environmental factors and recruitment

role of temperature in bottom-up control

- temperature can influence light limitation (high temp = high respiration rates = faster plant growth) - temperature can affect the rate of nutrient uptake; optimal temperatures for nutrient uptake are not necessarily identical to those for photosynthesis and growth - warmer temps tip the balance of grazing vs. production toward a stronger top-down control on algae

habitat-level approaches: coral reefs

- temperature rise and ocean acidification - restoration attempts for coral reefs are especially time sensitive - restoration of coral reefs after disturbance events is especially labor intensive: rectifying overturned corals, removal of sediment coverage - characterized by transplant - first step in restoration: restore vertical relief - establishment of diverse reef habitat can take decades - conservation efforts are often much more cost effective than restoration

biodiversity

- terrestrial plants show species richness enhances ecosystem functions through primary production and nutrient cycling - typical of early stages of marshes, but in later years, ecosystem functioning relies on species identity over richness

communities around hydrovents

- the areas around hydrovents are biologically more productive, containing complex communities fueled by dissolved chemicals - the mixing of vent and ambient fluid causes coexistence of hydrogen and oxygen that doesn't usually occur; this provides energy for microbial production called chemosynthesis

non-consumptive predator effects and trait-mediated indirect interactions

- the central idea is that the presence of one species modifies a trait of a second species with a third species - NCE: non-consumptive effect - TMII: a trait-mediated indirect effect or interaction - predators have a positive effect on producing by relaxing grazing pressure

habitat destruction

- the marshes that remain are threatened by invasive species, large scale oiling, run-away consumer effects, eutrophication, global warming, drought, and sea-level rise

top-down control in seagrass communities

- the mutualism between mesograzers and seagrasses is context dependent: the outcome is sensitive to environmental conditions and to the species composition an structure of the food web, and the relationship can turn antagonistic - some mesograzer taxa feed on seagrasses even when there are alternative food sources available - studies have found a negative effect on algal blooms and positive effect on seagrasses

measuring management effectiveness

- the ocean health index (OHI) assesses the benefits of healthy oceans, with explicit focus on humans as part of coastal and marine ecosystems - an OHI score was calculated for every coastal country in the world; highest scoring country is Germany and uninhabited Jarvish Islands in the Pacific - OHI can be used as a retrospective tool to assess the effectiveness of past management actions or as a forward-looking tool to examine how future policy option may affect multiple dimensions of ocean health

the "biological pump" solution

- the oceans naturally remove CO2 from the atmosphere via diffusion and that CO2 is taken up by phytoplankton via photosynthesis - when phytoplankton die they sink to the seafloor where CO2 is effectively transferred from atmosphere to seafloor - these processes remove roughly 1/4 of anthropogenic carbon emissions from the atmosphere - enhancing pump by fertilizing the surface of the ocean with iron fillings to spur plankton blooms - problems: only a small fraction of phytoplankton sink to the seafloor; very inefficient

trophic cascades in seagrass ecosystems

- the potentially strong effects (positive and negative) of mesograzers on seagrasses highlight the importance of factors controlling their abundance which leads up the food - extending mutualistic mesograzer model by connecting it to higher trophic levels, by proposing that the present lack of grazer control of algal biomass in many seagrass ecosystems is due to a trophic cascade caused by overfishing of large coastal fish predators worldwide - overfishing of top predators should lead to a cascading effect in which mesopredators increase and in turn decrease the abundance of mesograzers that consume algae, thereby releasing epiphytic algae from grazer control

what is "reef growth"?

- the rate of rise of cemented reef basement - corals then can settle on top of the basement 1. reef growth must be sufficient to keep corals near the lighted surface despite: (a) land/island subsidence and (b) sea level rise

indirect ecosystem effects

- the removal of high trophic-level predators through fishing initiates trophic cascades (2+ trophic levels) eventually altering community and habitat structure - effects of apex predators on mesopredators often powerful - "trophic triangles" can shift the roles of predator and prey - the importance of apex predator removal in pelagic, open-ocean habitats, which cover 2/3 of the planet, is more uncertain - low trophic level foragers constitute 30% of global fishery production, while also channeling photosynthetic energy from plankton to higher trophic levels - changes in biomass, species composition, and diversity loss make ecosystems more vulnerable to external processes - loss of "response diversity" lessens communities' ability to adapt - overall decline in ecosystem production and services - through MPAs, all this is (partially) reversible

reproduction and dispersal of seagrass

- there is a better understanding of vegetative processes not sexual reproduction - there are high levels of genetic diversity which indicate that sexual reproduction and dispersal may be more prevalent

global change

- there is trouble with prediction - many abiotic factors are changing simultaneously - global ecosystem models predict a decrease in oceanic production, BUT data shows a decadal increase in production - positive feedback loop: reduced production will lower carbon export to ocean so higher carbon levels

phytoplankton

- they are microscopic marine plants - phytoplankton are major primary producers in the ocean, responsible for almost half of global photosynthetic carbon fixation - they form the base of most pelagic food webs and ultimately fuel fishery production

population-level approaches: habitat conservation and restoration

- this approach is used when the bottleneck to the population is post-settlement mortality - hard to protect international waters

the mutualistic mesograzer model

- this model proposes that the dominance of seagrasses in temperate systems is facilitated by small herbivorous invertebrates, notably amphipod and isopod crustaceans and gastropod molluscs, collectively referred to as mesograzers - suggests that productivity and even the existence of some seagrass ecosystems depends on facilitation by mesograzers

adaptation and acclimatization

- tolerances for abiotic change vary within species: interpreted as evidence of genetic potential for population persistence despite changing environmental conditions via organisms' physiological plasticity or genetic variation that can enable natural selection - coccolithophore populations exposed to elevated CO2 grew and calcified faster than control populations when both populations were subsequently exposed to acidified conditions - existence of standing variation in thermal tolerance within a population suggests that natural selection drives thermal adaptation - corals display among-clone and among-population variation for thermal sensitivity and are able to physiologically acclimatize to natural and experimental warming * key question: which (if any) taxa will adapt or acclimatize fast enough to keep up with abiotic conditions?

grazer diversity and trophic processes

- top-down control should be stronger in more diverse consumer assemblages - diverse grazer assemblages better resist establishment of newly introduced invaders and maintain a low and stable algal biomass in the face of experimentally induced warming, nutrient loading, and pulses of freshwater runoff

subsidies from seagrass to other habitats

- two pathways by which seagrass production is transferred to other ecosystems: (1) passive export of seagrass detritus and dissolved organic matter; (2) active transport of seagrass-derived biomass in the form of mobile organisms - seagrasses also link other habitats through non-trophic mechanisms by providing safe corridors through which organisms can move between habitats

habitat-level approaches: oyster reefs

- unlike salt marshes and seagrasses, oyster reefs are exploited as a fishery - they have a large impact on nutrient availability - can facilitate vegetation - they have faced a century long period of over-harvesting - recruitment favors settlement on the shells of other bivalves - over-harvesting of oysters therefore causes a decrease in recruitment - majority of restoration efforts have focused on improving the fishery - few studies have tracked long-term fate of restoration efforts

using comparative experimental approach

- used to examine oceanographic processes over large scales - focuses on recruitment rates, colonization, and growth of major space holders (barnacles + mussels), predation, and competition - colonization and succession measured by clearing an area and watching recovery - recruitment recorded monthly - tests "upwelling hypothesis": large-scale upwelling intensity drives benthic processes - both showed compelling evidence for link between oceanographic and benthic processes

spatial variation in ecological production of coastal landscapes

- valuation of the value of how an ecosystem service varies across an ecological landscape is rare - studies of coastal systems indicate that it is possible to track how ecological functions that underlie some ecosystem services vary spatially - mangrove forests and salt marshes both influence abundance, growth, structure of fish and invertebrate populations

quantifying ecosystem services

- valuing ecosystem services: quantifies the benefits in terms of human welfare that ecosystem services provide - economic valuation: measures gains or losses in human welfare from changes in ecosystem services caused by human impacts - human drivers of ecosystem change --> ecosystem structure and function --> ecosystem goods and services --> values --> back to human drivers

recruitment variation and community dynamics of intertidal rocky shores

- variation in settlement and recruitment determine order of importance of predation, grazing, and competition - may be caused by spatial, temporal variation in propagule supply from water column to shore; also influenced by postsettlement mortality - "supply-side ecology" became major focus of marine ecology: analyzes importance of variation

impacts of hydrovent mining

- vents are in fact resilient enough to withstand mining based on the claim that there is a quick relocalization of the community after an eruption - mining leaves behind rubble and the substrate change could alter how quickly a destroyed vent could be recolonized by vent species

eutrophication and bottom water hypoxia

- vulnerable when water column stratifies and biological oxygen demand exceeds amount of available oxygen - nutrient loading results in estuarine eutrophication and bottom-water hypoxia - low levels of dissolved oxygen are a threat to many estuaries globally - effects epifaunal animals and sediment biogeochemistry and infaunal organisms - stressors: increased sediment runoff, overfishing of filter feeding bivalves, toxin loading - denitrification: bacteria conversion of nitrates (NO3-) to gases (N2 and N2O) - hypoxia will increase until microbes generate toxic H2S

deforestation: El Niño

- warm water and no upwelling - deforestation of Macrocystis in California occurs after an event - kelps become stressed and susceptible to disease - brown algae move northward following an event in Chile showing stressors are greater at lower latitudes

physical and chemical effects of climate change

- warming: infrared radiation is reflected back to the surface - acidification: CO2 is dissolved in the oceans to form H2CO3 - sea level rise and ice loss - salinity - winds and upwelling - reduced oxygen

global decline of corals: increased CO2 concentrations

- warming: rise of 0.74 degrees C in sea surface temperature - temperatures of 1-2 degrees C above seasonal maximum triggers bleaching - acidification: carbonic acid H2CO3 inhibits corals from creating and maintaining skeletons

habitat restoration

- wherever prevention of degradation is not feasible, restoration can reverse some damaging trends - working with ecological feedback loops, trophic cascades, and environmental disturbances can help restoration efforts succeed

valuation of coral reef benefits

- widespread loss of coral reefs prompted investigations into benefits they provide - support for nearshore fisheries, supply aquarium trade, provide valuable shoreline protection, recreational benefits, buffer shorelines from severe weather - reef ecosystem services function better with connectivity between other reefs, mangrove forests, seagrass beds, etc.

principles underlying phytoplankton community structure and the maintenance of diversity

-cell size and community co-limitation by resources and predators -gradients of light vs nutrient availability -nutrient limitation -co-limitation -nitrogen fixation -non-equilibrium dynamics -variable resource supply -temporal fluctuation in relative ability -population cycles and chaos -grazers and pathogens -mixotrophy

effects on community

-human society (climate, fishery production, global biogeochemistry) -challenge: predicting how they will change to anthropogenic global change -multitude of effects from CO2 (increases in temperature, photosynthesis, stratification and acidity of oceans; regional variation in terms of effects) increased temp. promotes stratification, stratification increases light penetration and decreases nutrient input

troubles with prediction

-many abiotic factors are changing simultaneously -global ecosystem models predict decrease, but data shows decadal increase -future dangers: positive feedback loop

picophytoplankton advantages

-prok. and euk. picophytoplankton have a high surface-area-to-volume ratio due to their small size and thus are good competitors for nutrients and light -favored by strong stratification bc of their low sinking rates

Climate Change Summary

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Soft Sediment Summary

1) Soft-sediment communities have received a lot of scientific attention within the past 50 years, which has led to the establishment of general accepted principles 2) Anthropogenic effects have a significant impact on soft-sediment communities through introduction of invasive species 3) The reduction of habitat complexity, as caused by human activities, has led to deterioration of both structures and relationships in soft-sediment communities 4) Denitrification and permanent burial of sediments are primary causes of current nitrogen removal. Recent research over the past 30 years unveiled the significance of microphytobenthos in consistent nitrogen production as a ecosystem modifier

fishing methods

1. "fixed gear": remain in place while fishing; fish trap, net, hook-and-line methods, wire fish traps, bottom longlines, gill nets 2. "mobile gear": dragged over the sea floor or through the water column; bottom trawls, mid-water trawls, dredges 3. pelagic (open-ocean): target either schooling foraging fish, squid, and top predators; drift nets, seines, pelagic longlines

Ecosystem Servies Summary

1. Marine ecosystem services are the goods and services that humans stand to gain from a particular ecosystem 2. Ecosystem service quantification can help managers assess the total impact of diverse human activities on human health 3. Conservation must involve sustainable fishing practices 4. There are many challenges left to conquer regarding ecosystem services since many do not know how to quantify the value of these services

importance of bioeroders

1. all facilitate the development of complex 3D reef structure--responsible for high reef diversity 2. destroy reef substrate, cause corals to dislodge (esp. in storms) --> death 3. produce sand, sediment, some of which is cemented --> affects reef growth ***know how/when each evolved

why quantify ecosystem services?

1. assessing trade-offs 2. evaluating cumulative impacts 3. measuring management effectiveness

productivity... where?

1. coral reefs and algal beds (kelp forests) = 2,500 g/m^2/year

what happens when symbiosis breaks down? external causes

1. excessive temperature: this is why there is concern about global warming (corals already live at near the upper end of their temperature tolerance) 2. UV: volcanoes erupt, particles in stratosphere serve as nuclei for break down of ozone, or extra low tides in El Niño 3. Pollution: high organic material in water, bacterial action = low O2 4. Low light: volcanoes; soot clouds from burning oil wells during Persian Gulf War in the Middle East

how do corals feed?

1. feed on zooplankton using nematocysts on tentacles 2. symbiotic zooxanthellae: only in reef-building corals; dinoflagellates live inside coral cells, lose flagellae, may either invade from outside seawater or be passed on in egg; accelerate CaCO3 production (10X); provide organic molecules (carbs, amino acids) 3. mucous and ciliary entrapment of detritus (filter feeding) 4. direct absorption of organic molecules through epidermis

how do corals benefit?

1. gets photosynthetic products (carbs, amino acids) for food 2. can grow faster (lay down CaCO3 10x faster)--critical for competition for space

challenges to linking ecosystem services to action

1. many people are skeptical of model-based results 2. developing rules of thumb that describe ecosystem provision shifts are important in order to guide societal decisions about how to manage different marine ecosystem services 3. need to assess whether managing with an ecosystem lens has improved outcomes 4. some people do not see the value of quantifying nature's benefits as "services"

how is coral skeleton destroyed and what is the significance of this?

1. micro-borers or micro-bioeroders 2. macro-borers = internal bioeroders 3. scrapers, macro-bioeroders, external bioeroders

how does zooxanthellae benefit?

1. protection from predators (herbivores) grazing on phytoplankton up in the water column 2. abundant source of N from host's metabolism

alternative stable states

1. transitions between states must occur quickly relative to the potential longevity of each state in the same physical habitat 2. Shifts must result from a pulse (temporary) perturbation rather than a press (chronic) perturbation, and when environmental conditions return to their initial state, the system must not return to its original state 3. Study must be long enough that the alternative state is self-sustaining beyond the turnover time of its dominant constituents

Other Threats: Overfishing and Habitat Degradation Summary

Although the issues of impacts being made on marine ecosystems are daunting, some are reversible ● It is important to change fishing practices to be more sustainable and less destructive on the environment ● More research is required to create a more sustainable fishing practice ○ It is not yet known which fishing practice is more efficient in preserving marine ecosystems (fishing through vs fishing down) ● Overfishing will cause many issues in the future and should be reduced as much as possible ○ Global fishing communication, persecution of those that illegally fish, etc.

Ecosystem-Based Management (EBM)

EBM recognizes the complex interactions within an ecosystem (including humans) rather than focusing on single issues, species, or ecosystem services in isolation ● EBM considers resource tradeoffs in ecosystems ● The three general phases of EBM are: visioning, planning, and implementation/adaptive management

Marine Protected Areas (MPAs)

MPA is a term that encompasses a variety of conservation and management methods ● MPAs are created to protect patches of ocean and coastal habitat (and in some cases a particular marine species) ● Objectives vary and can include: enhanced conservation, increased tourism, and increased fisheries production ● In the last 15 years, science behind MPA design/effectiveness has grown exponentially

types of effects fisheries have on marine communities

a. direct effects on targeted fish populations b. collateral damage to bycatch species c. transformation and destruction of bottom habitats d. indirect effects - alter abundance, biomass, age, and size structure - affect species composition and diversity - selective removal of certain species and size classes - changes amplified by species interactions

distribution of kelp

kelp forest biome defined by: - high density of tall brown algae forming closed/semi-closed canopy - subcanopies and understory seaweeds - associated animals - temperate or cold waters, depths of 30-40m - grow on shallow rocky reefs - true kelp (order Laminariales) and other brown algae (Fucales and Desmarestiales) - all canopies are brown algae because they have trumpet hyphae (specialized cells that move around photosynthates)

Phytoplankton (general)

microscopic marine plants -major primary producers in the ocean, responsible for almost 1/2 of global photosynthetic carbon fixation -major players in the nitrogen, phosphorous, and silicon biogeochemical cycles -affect climate in several ways (take up CO2 and decrease its conc. in atmosphere, and produce DMSP) -major food source for zooplankton -base of most pelagic food webs

Picoplankton

the fraction of plankton composed by cells

Challenges in managing for thresholds

○ Lack of knowledge about tipping points ○ Social tipping points connected to ecosystem status ○ Two types of tipping points - achieve and avoid

Difficulties with Cumulative Impacts Planning

○ Quantitatively assigning each stressor a certain amount of impact (translating the huge diversity of stressors into a common "currency" of impact on ecosystems) ■ Requires a vulnerability weight for each habitat and stressor combination (Little to no empirical data exists for most of these combinations, requiring some form of expert judgment to be used.) ■ Difficulty deciding how to combine these stressors into a cumulative impact "score" ○ Major data gaps for many of the stressors and many habitats

Salt Marshes Summary

● Balance of positive and negative biotic interactions are necessary for the maintenance of salt marsh communities ○ plant-plant//plant-animal positive interactions facilitate initial establishment of successional development of marshes ● Nature of salt marsh plant interactions varies with latitude and seasonal climate ● Humans have had many impacts on salt marsh ecosystems with new implementation of conservation efforts ● Future studies should focus on: ○ Population Biology ○ Role of recruitment ○ Biodiversity ○ Sea-level rise

Ecosystem Function and Dynamics

● Connected through larval dispersal, adult movement, and species physiology and interaction ● Understanding in marine ecosystem function has lagged behind terrestrial ecology ○ Interactions among species, drivers behind changes in functioning and productivity, and critical thresholds

Coral Reefs Summary

● Coral reefs are the most diverse (per unit area), serving countless functions, but they are the most threatened of all marine ecosystems ( no pristine reefs are left) ● Most diverse sites are in the tropical western Pacific: Coral Triangle ● Ecological interactions such as predation and disease, competition, herbivory, biotic interactions, and trophic cascades are essential to the biodiversity found within coral reefs ● Anthropogenic activities such as predator fish fishing is a threat to coral as their biggest predator (starfish) increase in abundance (trophic cascade) ● There has been a documented overall decline since the mid 1970's attributed to both local and global stressors

Why study communities?

● Different functional traits among genotypes, species, and taxonomic groups ● Results in distinct biogeochemical signatures and food web effects

Social Ecological Systems

● Humans as part of the system ● Changes in Scientific research agendas ○ Conservation NGO priorities ○ Paradigm shift in conservation and resource management ● Two realizations ○ Managing for the absence of human influence on nature is no longer possible ○ Natural and human systems are intertwined

Benefits of salt marshes

● Intertidal habitats → essential for healthy fisheries, coastlines, and communities ● Protect shorelines from erosion and shore damage ● Reduce flooding ● Buffer shoreline ecosystem from human activities ● They and estuaries known as "Natural filters" ○ Intercept and process runoff (with sediments, nutrients, polluants) ● Used as water purification and sewage treatment facilities ● Sequester and store carbon

Interdisciplinary Science to Support Management

● Marine conservation is no longer only doing ecological assessments ● New considerations ○ Social science, economics, decision science, geography, oceanography, conservation planning, anthropology, and other fields ● Increase in multidisciplinary nature ○ Shift towards multiple-objective planning ● Example: When MSP is implemented as zoning

Marine Restoration Summary

● Marine restoration ecology is a fast growing field that has gained prominence in the last few decades ● It seeks to restore functionality and structure to a system that has encountered a disturbance ● The field can be subdivided into 4 major approaches ○ Population level restoration ○ Habitat level restoration ■ Salt marshes, seagrasses, oyster reefs, coral reefs, and mangroves ○ Landscape level restoration ○ Ecosystem level restoration ● Social attitudes towards beach re-engineering need to be addressed in order to create adequate restoration plans

Phytoplankton Summary

● Phytoplankton community composition influences ecosystem processes because different species of phytoplankton have differing functional traits ● Phytoplankton community structure is influenced by light, nutrient availability, and competitive interactions ● Phytoplankton success and community equilibrium require a precise ratio of certain nutrients and elements in the ecosystem, mainly nitrogen and phosphorus. Interacting with each other, phytoplankton species can increase or decrease the ratios of those nutrients to reach equilibrium. ● Phytoplankton and other microbes have a very crucial role in the lives of humans due to their impact on fisheries, climate and their role in global biogeochemistry.

Kelp Forest Summary

● Sea urchin/kelp predator-prey dynamics are complex, influenced by water turbulence, predation of sea urchins, fishing, and trophic cascades ● Alternative Stable States are present in kelp forests but present some controversy ● Kelp species need to compete with each other and other communities to prominently reside in ecosystems ● Climate change, accompanied by anthropogenic factors are contributing to loss of kelp bed communities

Seagrasses Summary

● Seagrass provides to the ecosystem as a food for herbivores as well as habitat that provides shelter ● Seagrasses are a genetically diverse foundation species crucial to marine communities ● Seagrass health and growth is regulated by light, nutrients, temperature, and the presence of mesograzers ● Seagrass meadows can beneficially impact other habitats in close proximity, and provide critical ecosystem services. ● Animals inhabiting seagrass beds often have a bigger influence on the structure and productivity of seagrasses

Resilience

● The capacity of a natural system to resist perturbation or spring back to normal following a disturbance. ○ Large scale disasters ○ Low-level but chronic changes ■ More responsible for regime shifts ● Need to identify resilience factors ○ Help avoid reaching "thresholds" or "tipping points"

Hydrothermal Vents Summary

● These communities are highly specialized and unique given their abilities to thrive in such hostile environments ● Different species thrive under different specific conditions (gradient dictates) ● Several factors contribute to whether there is larval dispersal and if so what direction they will be moved ● Metapopulation theory can help us determine the diversity levels of vent populations

Rocky Intertidal Summary

➢ RIC is a harsh environment where organisms need to... ○ Avoid desiccation ○ Regularly compete for space (competition is responsible for where organisms are vertically on the landscape) ○ Thermal stress impacts where the organism needs to live ➢ Spatial patterns are studied numerous times in RIC ➢ Inducible changes in prey can have strong e ects on the ecosystem ➢ Predation pressure can shape the flow of energy through trophic levels ➢ Species ranges may be altered by increasing surface temperatures as a result of climate change, including spread of invasive species ➢ Need to further study the impact of multiple anthropogenic stressors