EEB 109 Midterm 2

Tropic levels

-1st primary producer (plants, algae) -2nd primary consumer (grazer, herbivores) -3rd secondary consumer (carnivores) -4th tertiary consumer -at each level, detritivores and decomposers are turning biomass into nutrients

Ocean primary production (OPP)

-48.5 million kilotons C -Pacific Ocean has highest total OPP (because it's the biggest) -total OPP varies across oceans and ocean regions -disproportionate productivity among ecosystems, neurotic systems are more productive than planktonic -OPP/m^2 highest in Inland waters, Mediterranean and Atlantic

Nitrogen fixation

-N2 -> ammonium (NH4+), breaking of triple bond of N2 to produce ammonium (requires large amount of energy) -mainly fixed by bacteria, sometimes by lightning -ammonium used by primary producers

Rugosity

-a measure of small scale variations in the height of a surface -the bumpiness breaks up the laminar flow -coral reefs have high rugosity

Dynamic viscosity

-a measure of the resistance to flow of a fluid under an applied force -the stickiness -dynamic viscosity of water is 100x higher than air

Laminar flow

-a smooth pattern of flow -over sand flat -Re is low

Benthic feeding ecologies

-active suspension feeder: remove live/dead organic matter from water (barnacles extend cirri to capture suspended particles, clams siphon water to filter out particles) -passive suspension feeder: position themselves to remove live/dead organic matter from water (stalked tunicate bends in current to funnel water and particulates through body) -deposit feeding: eat organic matter from sediment -surface deposit feeder: eat organic matter from top of sediment (sand dollar) -burrowing deposit feeder: worms that burrow and eat sand and poop out long sand worms -herbivores and carnivores "surface" feed -scavenging: eating dead organism

Food chain efficiency (E)

-amount extracted from a trophic level/amount of energy supplied to that level -the proportion of energy that becomes biomass in the next trophic level -E is often ~10% -poilikotherms convert more energy into biomass than homeotherms

Turbulent flow

-an irregular, mixing flow pattern -eddies -increased turbulent flow = increased drag -over coral reef -Re is high

Nekton

-animals w/ sufficient swimming abilities to overcome the effects of ocean currents -have higher Re

Iron seeding

-artificially pumping iron into ocean to cause more primary production -trying to accelerate biological pump, however in order to be successful the phytoplankton has to sink into the deep ocean or may cause a dead zone -also uses a lot of energy to put iron into the ocean so not necessarily very effective

Soft sediments

-beach, marsh, mangroves, sea grass, mud flats, estuaries -minimal surface structure -almost no attached species -macroalgae and macro-herbivores are less common (b/c not much growing) -detritus is more important -lots of space but little food

Sea bird adaptations

-bills for catching fish and for withstanding impact -webbed feet -built for soaring

The biological pump

-biologically produced flux (flow) of organic carbon out of the euphoric zone -regulates atmospheric CO2 -determines nutrient content of deep sea -may change in response to changing atmospheric CO2, global C emissions exceed capacity of biological pump, leading to ocean acidification -productivity at surface -> marine snow (dead things) sinks to bottom and takes organic carbon w/ it -> brings nutrients into deep ocean -diving mammals can bring deeper carbon back up to the surface (poop)

Phytoplankton abundance is controlled by:

-biotic factors: competition from other species, predation -abiotic factors: temperature (function of depth and latitude), light (function of depth and latitude), salinity (function of evaporation/precipitation balance), nutrients (function of depth, distance from land, physical oceanography and biotic factors) -abiotic factors controlled by: geology (depth, nutrients), properties of water, sun (heat), spinning of earth (coriolis effect)

Osteichthyes

-bony fish -bony endoskeleton: calcium phosphate, cranium -fleshy finned fish: coelacanths, lungfish (closest relative of the tetrapods) -ray finned fish: tuna, lion fish, seahorse, eel -ray finned fish have: jaws w/ moveable elements, fins supported by bony rods, body covered w/ scales, gas filled swim bladder (buoyancy), gills covered by operculum, use counter current O2 exchange in gills to get lets of oxygen for lots of aerobic activity (water in through mouth and out through gills)

Top down vs. bottom up

-bottom up: something happens in abiotic world -> affects trophic levels @ bottom (phytoplankton) -> then affects trophic levels higher -top down: overfishing or something affects top of food chain -> affects lower trophic levels

Eutrophication

-buildup of organic matter (phytoplankton or macro algae) in aquatic systems (harmful algal bloom) -usually as a result of nutrient enrichment (sometimes natural but often anthropogenic)

Benthic movement

-burrowing: to escape predation or competition -hydromechanical burrowing: muscle contraction -thixotropy: decreasing viscosity w/ increasing shear rate (diff movement can change property of substance) -mechanical burrowing -bioturbation: the disturbance of sediment layers by biological activity (adds O2 to the system, makes space for other organisms)

Dead zones

-can be caused by eutrophication (bacteria decompose algae and consume O2) -hypoxia (low O2) and anoxia (no. O2)

Chondrichthyes

-cartilaginous fish -sharks, skates, rays -~800 species -all but 25 are marine and these are believed to be derived from marine ancestors -teeth specialized for different prey (great whites have serrated teeth, sand tigers have long skinny teeth)

Trophic cascade

-changes in food webs caused by changes in predators (top-down) or producers (bottom-up)

Oxygen technique of measuring primary productivity

-compare b/w light and dark bottles: have light bottle w/ water containing phytoplankton measuring O2 produced by photosynthesis and O2 consumed in respiration (NPP) and a dark bottle w/ water containing phytoplankton measuring O2 consumed in respiration (R), add them to get the total O2 produced by photosynthesis (GPP)

Anguiloform swimming

-eels -swimming like snakes

Nutrient pollution

-excess nitrogen and phosphorous leads to eutrophication -global nutrient inputs pre-1900s: bacterial fixation, lightning -global nutrient inputs post-1900s: bacterial fixation, lightning, cultivation of N-fixing crops, fertilizer production, burning fossil fuels, burning/clearing existing land (doubled!) -nutrients get cycled through water sheds

Food web

-feeding relationships among organisms within an ecosystem

Boundary layer

-forms if flow is regular and the bottom is level where water velocity decreases to 0 -thick boundary layer if water w/ small Re (slow flow) -thin boundary layer if water w/ high Re (faster flow creates more irregular movement) -affects: diffusion of nutrients, odor detection, delivery of food particles

Zooplankton

-free floating animals whose movements are largely determined by water movements -mostly heterotrophs -zooplankton abundance is related to phytoplankton abundance -greatest changes in zooplankton/phytoplankton abundance occurs at mid latitudes/temperate regions b/c of seasonal changes in light -distribution is patchy (from internal wave banding and turbulence)

Fish reproduction

-gonochronistic: separate sexes that never change -sequential hermaphroditism (start as 1 sex ten change): protogyny (sex change from female to male), protandry (sex change from male to female) -true hermaphrodites: have both male and female reproductive organs simultaneously

Assimilation efficiency

-growth -the percentage of what is initially consumed that becomes incorporated into the consumer -about 90% of biomass is "lost" (used for metabolism, excreted as waste, dissipated as heat) when transferred from be/w trophies levels (ecological efficiency = 10%) -therefore as trophic levels increase, biomass decreases

Red tides

-harmful algal bloom caused by high concentrations of dinoflagellates -associated w/ high surface sea temperatures, winds that concentrate blooms near the coast, bright, sunny weather, often following diatom blooms

Carbon cycling

-in the open ocean, planktonic algae and Cyanobacteria are the major primary producers -protists and small planktonic animals are primary consumers that feed on primary producers -bacteria decompose organic matter and, in turn, serve as food for many other organisms -fish and other secondary consumers move carbon through marine food webs

Internal wave banding

-internal waves: layers of water (cold nutrient rich water vs. warm, nutrient poor water) -organisms get caught up/trapped in layers, contributes to patchiness -when plume of low density water meets high density water -> high density water sinks below, plankton swim up to maintain depth, creating high concentration along front

Cnidarians

-jellies, corals, anemones ->9000 species (only some planktonic) -carnivorous w/ unique stinging cells (nematocysts): harpoon-like nematocysts are microscopic structures found in the epidermis of cnidarians, contact triggers the ejection of nematocysts, nematocysts of some cnidarians inject toxins into predators or prey -scyphozoans: true jelly fish, some of the largest zooplankton -hydrozoans: hydroids, Portuguese man of war -cubazoans: box jellies and sea wasps -ctenophores (comb jellies): 100-150 known species, characterized by iridescent rows (combs) of cilia used for locomotion, carnivorous of other zooplankton

Harmful algal blooms

-large blooms of toxin-producing phytoplankton that negatively impact marine or human populations

Mollusks

-largest marine phylum, ~23% of all named marine species -most are not planktonic -many have a planktonic larval stage -nudibranchs: gastropod mollusks (sea snails) without shell, ~3000 species, some can be planktonic -pteropods, "winged foot": sea angels, sea butterflies and others, at risk for ocean acidification

Compensation irradiance

-light too low for photosynthesis to be greater than respiration

Order Sirenia

-manatees, sea cows, dugongs -most closely related to hyrax and elephant -slow moving shallow water species, puts them at greater risk

Coccolithophores

-marine phytoplankton, eukaryote -representative species: Emiliana huxleyi -calcium carbonate scales -fix CO2 gas into CaCO3 -important in global carbon cycling (carbon sink) -source of carbonate sediments to sea floor

Cyanobacteria

-marine phytoplankton, prokaryote -size: pico and nano plankton -representative species: synechococcus (unicellular) and trichodesmium (filamentous, trichomes, perform Nitrogen fixation)

Prochlorophytes

-marine phytoplankton, prokaryote Cyanobacteria -one of the most abundant organisms on the planet -representative species: prochlorococcus -size: picoplankton

Reynolds's number

-measure of relative importance of inertial and viscous effects of a fluid and on objects in a fluid -Re < 1, viscous forces dominate (stickiness of the fluid) -Re > 1000, inertial forces dominate (tendency to keep moving) -velocity x size, Re increases w/ velocity and/or size -when Re is high, a fluid encountering an object (ex: tube) may change velocity rapidly and inertia may cause the fluid to break up into complex vortices (higher drag/turbulence)

Drag

-mechanical force, function of shape -drag is reduced w/ streamlined shape of fish (move fast/long distances), less work the organism has to do -drag is greater w/ boxier fish (good for living in coral reef and being small/maneuverable) -higher drag when higher Re

Diel vertical migration

-movement up and down in the water column on 24 hr cycle -pelagic shrimp, copepod -come up to surface at night to eat and descend to depth during the day to avoid predation

Fishes

-nekton -simplest and oldest of all vertebrates -500 million years old lineage -extant fishes include some lineages separated by ~400 million years -half of all vertebrate species -24,000+ species -anatomy adapted to ecology: acceleration specialist, cruising specialist, maneuvering specialist

Cephalopods

-nekton, mollusks -700+ species -octopus, squid, nautilus, cuttlefish -carnivorous -typically high fecundity -many are annual species so live fast and die young -hunt by sight and use tentacles to capture prey -have beak that can exert powerful biting forces -move by jet propulsion, fins, tentacles -predator defense w/ jet of ink -sexual reproduction: spermatophores from male, females uses to fertilize her eggs, female lays egg sacks and protects eggs and gives them all her resources then dies after they hatch

Nutrients

-nutrients and primary production are typically highest in coastal waters -nutrients decrease moving away from shore -pycnoclines (thermo and halo) limit water replenishment from below -warm low-density water, low nutrient concentration -cold high-density water, high nutrient concentration -mostly, mixing of nutrients from bottom sediments occurs in shallow depths -neurotic environments generally have more water movement and less volume than oceanic environments so there are more nutrients and nutrient cycling in shallow, coastal environments -thermoclines limit mixing w/ deeper nutrient laden waters -upwellings bring deep nutrient rich waters back to the surface

Fish reproductive modes

-oviparous pelagic: release gametes into the water column (external fertilization) and lay eggs -oviparous demersal: lay eggs on the sea floor or other substrate (teleost, condrichthyes) -ovoviviparous: eggs laid into oviduct (internally) where they develop, results in live birth (coelacanth, most sharks) -viviparous: internal fertilization (benefit of having more selective mate, greater reproductive success and more efficient use of resources), gestate young w/ placenta and give live birth (bull and tiger sharks)

Pinnipeds

-phocidae: earless seal -otariidae: eared seals and sea lions

Dinoflagellates

-phytoplankton, eukaryote -cellulose walls -2 flagella -unicellular, sometimes colonial -size: nanoplankton -marine and freshwater habitats but much more abundant in marine waters (90%) -130 genera w/ ~2,000 species

Diatoms

-phytoplankton, eukaryote -size: nanoplankton -SiO2 cell walls -found in all aquatic systems (past + present) -main component of open water marine flora -planktonic or benthic -autotrophs, heterotrophs, symbionts -seasonal abundance keyed to nutrients

Simple southern ocean food chain

-primary producer -> primary consumer (krill) -> secondary consumer (baleen whale) -short, more energy efficient

Photosynthesis

-primary production (rate at which organic matter is produced) -most important chemical process on earth -metabolic process by which solar energy is trapped, converted to chemical energy and stored -base of the oceanic/coastal food web -CO2 + H2O -> (sunlight and chlorophyll) C6H12O6 + O2 -performed by photoautotrophs -whole process (reducing power) is driven by light -oxygen is a byproduct -carbon dioxide is fixed = changes from a gas to a high energy solid (inorganic CO2 into organic C)

Chemosynthesis

-primary production in the deep ocean and anaerobic marsh sediments -chemical reducing power comes from reduced inorganic compounds such as H2S and NH3

Dinoflagellate bioluminescence

-produce light w/ chemical reaction: Luciferin + O2 -> (luciferase affected by mechanical sheer) oxyluciferin + light

Hard bottoms

-rocky shores/reefs, kelp forest, coral reefs -lots of 3D structure -sessile invertebrates, macroalgae attached -very few deposit feeders -competition for attachment space and light on rocks -generally more food, but competition for space

Echinoderms

-sea urchin, sea cucumber, sea star -planktotrophic (eats plankton) -many echinoderms have amazing planktonic larval stages

Hagfish and lampreys

-simplistic fish -brains protected by a cranium but lack jaws -hagfish: lack any sort of vertebral column, marine, bottom dwelling, scavengers -lampreys: have cartilage along the dorsal hollow nerve cord, freshwater and marine, parasites

Nutrient distribution vs productivity

-southern ocean is high nutrient but low productivity b/c iron is limiting

Holoplankton

-species of zooplankton that remain in a planktonic stage their entire lives

Meroplankton

-species of zooplankton that spend only part of their lives as plankton

Amnesiac Shellfish Poisoning

-species: pseudonitzchia multiseries -producer of Dominic acid -filter feeding shellfish obtain P. Multiseries from marine waters -ingestion is biomagnified by birds, marine mammals, and humans resulting in ASP -effects in humans: memory loss, abdominal cramps, disorientation, death -blooms in CA have resulted in seal illness and stranding, possibly involved in beaching of whales and porpoises

Crustaceans

-subphylum of arthropods -exoskeleton of chiton and calcium that is molted ->40,000 marine species (only some planktonic) -have complex life cycles: sexual reproduction w/ internal fertilization, eggs are retained by the female until they hatch, most species pass through several larval stages -copepods: most abundant zooplankton, have set of really long antenna -krill: most abundant animal on earth by weight, important food source for whales -barnacles: include 2 distinct larval stages (nauplius dispersing stage and capris settling stage), adults are attached to a rock, hermaphroditic, internal fertilization

Specialized feeding ecology of fish

-suction feeding -opercula movement: open and close opercula to pull food in -piscivore: long skinny teeth good at capturing slippery prey -coral polyp specialist: tweezer like mouth for capturing small prey -scrapers: scrape algae off rocks and corals, eat lots of CaCO3 and poop a lot of sand

Sea bird modes of feeding

-surface feeding (catch zooplankton/juvenile fish on surface) -pursuit diving (penguins, streamlined body shape w/ flippers like fins) -plunge diving

Why is primary production so high in the North Pacific?

-thermohaline circulation -water is rising in north due to thermohaline circulation, deep ocean water w/ nutrients rises to surface

How do we measure primary productivity?

-units: energy/area/time = kcal/m^2/yr, biomass/area/time = g/m^2/yr -gross primary productivity (GPP): total rate of photosynthesis or the energy assimilated by autotrophs -net primary productivity (NPP):rate energy is stored as organic matter after respiration/growth of new biomass, energy available to consumers (NPP = GPP - R) -measure changes in O2 and CO2 levels -measure wavelengths of light from space to see where there is chlorophyll a

How does the seemingly uniform ocean environment support high phytoplankton diversity? (Paradox of the plankton)

-variation in growth rate across phytoplankton species -phytoplankton species vary in light requirements (depth and latitude) -high light species thrive in surface waters during high light periods of the year -low light species thrive at depth or at surface during low light periods of the year -individual growth rate increases w/ light -species and strains can vary in light tolerance -phytoplankton can occur in massive blooms, compete for light so distribution of individual species will be impacted by abundance of other species -phytoplankton species vary in temperature and salinity requirements (varies by depth, latitude, and time of year) -phytoplankton species vary in nutrient requirements (vary in surface waters) -answer: niche differentiation!, ocean is not uniform (varies in temperature, light, salinity, nutrients)

Plankton

-wanderer/drifter; can't swim against current -free floating organisms whose movements are largely determined by water movements -phytoplankton: photosynthetic micro algae, Cyanobacteria and prochlorophytes -exceptionally diverse, many species compete for the same basic resources (light, nutrients) -more in coastal areas -> affects location of zooplankton and other consumers

Cetaceans

-whales and dolphins -odontocetes/toothed whales: sperm whales, beaked whales, orca, dolphins -mysticetes/baleen whales (filter feeding): humpbacks, grey whales, blue whales -bubble feeding in mysticetes: work together to swim around in circles and make a bubble net trapping fish in center then go through the middle and scoop up fish -most recent common ancestor w/ hippo, vestigial traits reduced or incompletely developed structures w/ little/no function and not adaptive -whale strandings: human produced sounds or consumption of domoic acid possibly confusing whales

Food chain efficiency, or transfer of energy to the next trophic level, is generally around

10%

The depth at which oxygen production by photosynthesis equals oxygen consumption by respiration in a phytoplankton cell is called the:

Compensation depth

What physiological mechanism ensures that oxygen will diffuse efficiently into the blood via the gills of bony fishes?

Countercurrent gas exchange

Which taxa of phytoplankton includes species that can transform gaseous nitrogen (N2) into ammonium (NH4+)

Cyanobacteria

Scavenging is much more common in the benthos than in the plankton. Why?

Dead animals don't maintain buoyancy (sink)

Which of the following taxa produce domoic acid?

Diatoms

Identify the taxa of phytoplankton that has the following characteristics: cellulose cell walls flagella may produce light

Dinoflagellates

Which of the following organisms can form red tides?

Dinoflagellates

Given loss of energy among trophic levels, how can low primary producer biomass support high biomass at higher trophic levels

Fast turnover rate

How do zooplankton get their energy?

Feeding on phytoplankton and/or other zooplankton

Which of the following is an example of meroplankton?

Fish larvae

Transfer among trophic levels

G = I - E - R -G: energy translated into growth (2nd, 3rd, etc. production) -I: energy ingested -E: energy egested (excreted) -R: energy lost in respiration (CO2)

Organisms that only consume organic matter are

Heterotrophs

Wind is moving south down the CA coast, how will seasonal increases in this wind impact zooplankton abundance in coastal waters?

Increases b/c of upwelling (more phytoplankton)

Which of the following crustacean zooplankton are an important food source for whales?

Krill

Zooplankton biomass decreases sharply beyond 200m. Why?

Light decreases

Plankton that spend only part of their lifetime in a planktonic stage are called:

Meroplankton

In which area of an ocean are nutrient concentrations typically the highest?

Neritic zones

Thermohaline circulation delivers deep water nutrients to the surface in the:

North Pacific

The biological pump is sending ___________ downward to the deep ocean.

Organic carbon

When nitrogen levels are high, the nutrient that limits primary production is typically:

Phosphorous

Which of the follow could explain why there could be low phytoplankton concentrations at the very surface of the ocean even when nutrients are plentiful?

Photoinhibition

Why are nutrient concentrations typically low at the surface relative to deeper depths?

Phytoplankton use the nutrients during photosynthesis

Which factor would be least affected by high localized diatom concentrations?

Salinity

One way that inorganic carbon is transferred to deep water is via the

Solubility pump

Which season begins to stabilize the water column by creating a thermocline, thus keeping more phytoplankton in the zone of active photosynthesis?

Spring

Fish may aggregate for any of these reasons, EXCEPT

To stay warm

T/F: Coastal areas with upwelling typically have high concentrations of zooplankton compared to non-upwelling areas.

True

Odobenidae

Walruses

Many zooplankton undergo a twice daily migration in the water column. They go:

up towards the surface at night and down during the day