Biological Oceanography Final
Gauno birds and anchovy fishery collapse
El Nino weakens the effect of upwelling in the E. Pacific, making the anchovy have to dive deeper in the water to reach the food source -"Guano birds" refers to diving birds that produce droppings that provide a source of nitrates and phosphates for primary production. The multiple variables affecting anchovy stocks (lack of food, lack of nutrients from birds & upwelling) caused a 20 year collapse in the fishery.
what are the zonation patterns on reefs
Reef flat: -on the sheltered side of the reef; shallow Reef crest: -the highest point on the outer reef; exposed to wave action; only few coral species grow there; exposed at low tide Seaward slope: -from low tide mark into deep water; dominance of large corals; maximum number of coral species at 15-20 m; below 30 m number of corals falls off rapidly
what are the 7 types of benthic communities?
Rocky intertidal shores, Kelp Forests, Estuaries (seagrass/marsh grass), Sand Beaches, Mangrove swamps, Deep-sea, Coral Reefs
What is the seasonal thermocline and how does it affect the biology of the surface ocean?
The STC represents a temperature gradient and causes stratification on the water column. Stratification keeps the phytoplankton in the sunlit surface but reduces the exchange of nutrients with the deeper ocean layer. The seasonal thermocline initially stimulates phytoplankton growth but will starve the surface ocean of nutrients later in the season.
what is the main benefit of DVM
a more efficient transfer of energy from the phytoplankton at the surface to the deep zones of the ocean.
______ are the largest and most diverse group of marine vertebrates.
fish
Two Virus Cycles
lytic (explodes) and lysogenic (replicates)
what forms hydrozoan colonies?
of unions of structurally and functionally different individuals. They can be seen on rocky substrates produce free swimming medusae
What are semidiurnal tides?
two periods of low and high tides daily, most common
what characterizes the intertidal envrionment? what are the different types?
"where the land meets the sea"= littoral; coastal areas which are periodically exposed to air during low-tide -These can be rocky shores, estuaries, sandy beaches or mud flats each with a specific benthic community
what are the food sources that sink from the surface to the deep benthic ecosystems
-"Detritus -•Fecal pellets and crustacean molts •Fecal pellets of zooplankton are relatively compact and reach the seafloor faster •Pellets and molts are hard to digest and most of that material ends up as microbial biomass which is an important food source for benthic deposit feeders.
Would you expect to find a greater biomass per unit area of benthic organisms in intertidal areas with a high tidal range or low tidal range?
-High tidal range should have higher biomass per unit area -•Greater water exchange brings in more nutrients and plankton •Increased nutrients lead to higher benthic primary production, and more food for grazing •More food increases the amount of benthic fauna, leading to a higher biomass
Why sandy beach species favor direct development as opposed to a pelagic larval phase
-Interstitial species are small, and have low numbers of offspring. -Direct development ensures that the progeny remains in a favorable environment. -A planktonic larval phase would make them vulnerable to pelagic predators or filter-feeders.
why do coral reefs have high species diversity? where in the world is coral reef specie diversity the highest?
-The high productivity of coral reefs supports a community with high species diversity. -Indo-Pacific reefs
what are the characteristics of polychaetes? how are the significant
-are segmented worms with multiple appendages -either epi- or infaunal -form a large fraction of benthic biomass
what are the characteristics of mangrove
-cover 60-75% of tropical coastlines. -They are euryhaline -are restricted to protected shores -leaf fall is source of detrius-based food chain
There are two main methods to determine the feeding rates of those "microheterotrophs",
-fluorescently labeled bacteria (FLP) method and the dilution series technique.
what is the ecology of deep sea environment?
-high percentage of endemic species -more than 80% of the fauna are deposit feeders -The number of suspension feeders decreases rapidly with depth
what features characterize the littoral zone?
-intertidal) lies between the tide marks .-part of the euphotic zone and supports algal and phytoplankton growth resulting in more species diversity and abundance.
The sperm whale Physeter macrocephalus range from cold polar regions to warm equatorial regions, traversing between low and high salinity waters, and diving for more than an hour at depths of 1,200 meters. Gestation of young requires 14 to 16 months, producing a single calf, and they can live 70 years or more. Is this species...
-k selected, Euryhaline, Eurythermic, Homoeothermic, Eurybathyl
what are the characteristics of benthic deep sea environments?
-largest benthic environment -no light; no photosynthesis. -Mostly soft bottom sediments -slow currents -buffered Seasonal variability by slow sinking rates of organic matter -most phyla represented
what are the characteristics of phylum Sipunculids worms?
-peanut worm -unsegmented worms -borrow in the mud
What characterizes phylum cnidaria ?
-phylum benthic anemones and coral species -most live as epifauna -radial symmetry -suspension feeders.
what phylum does the group Enteropneusts belong to? what are the characteristics of the Enteropneusts group?
-phylum hemichordata -intertidal to the deep sea sediment
what are the characteristics of phylum Echiurids worms?
-similar to sipunculids -unsegmented -found in deep water sediments
what is "Benthic-Pelagic Coupling"
-spatial distribution and trophic structure of benthic fauna significantly influences the physical and chemical characteristics of the sediments and sediment-water exchange -The strong interactions between pelagic primary production, benthic communities and detritus are crucial in defining the trophic conditions and ecosystem health in coastal regions
what are the characteristics of coral reefs?
-stenohaline -polikiotherms -stenothermic -confined to the tropics -cover about 0.2% of the ocean -need lots of light -restricted to the upper 25 m and is limited by the lowest tide levels
what benthic communities occupy the lower or seaward region of estuaries? what type of food-chain dominates this region?
-the mudflat or sand-bar community -rich with Meiofauna species -low primary production (diatoms, cyanobacteria, dinos), consumed by flatfish, crabs, bivalves, polychaetes and mud shrimp. birds are large consumers
what is kelp? how does its production impact the the food chain?
-very large brown algae; the fastest growing plant overall (The giant kelp Macrocystic 2 ft a day) - (90%) of production is not directly consumed, but enters the detritus food chain.
How do human impact the marine biota?
-•Domestic and industrial pollution (refineries, mega city) •Eutrophication with nutrients contained in sewage, domestic discharge (detergents) and agricultural runoff (fertilizer) •Changes in the chemical composition of the atmosphere and sea level rise •activities may lead to change of species composition, loss of habitats, disrupt entire marine ecosystems
what are the three main patterns of zooplankton migration
1.nocturnal, 2.twilight, and 3.reverse migration
how N-input impacts ocean
1.the input of new nitrogen will determine the amount of sustainable fish harvest from the ocean (removal of fish also removes nitrogen). 2.It is also only the new nitrogen that can help to take up the excess CO2 that enters the ocean due to human activities.
what are the habitat found in the benthos?
1.•Rocky substrates provide opportunities for attachment of sessile organism 2.Soft bottom substrates (burrow and food)
what is the largest know tidal range on earth?
15 m in the Bay of Fundy (Nova Scotia) in eastern Canada.
what are semidiurnal mixed tides?
2 highs and two low tides of different sizes every day.
only ____of the deep Atlantic species are also found in the deep Pacific
20%
If you consider the bacterial carbon demand (production and respiration), what share of the primary production is processed by bacteria in the ocean?
30-50 %
bacteria growth rate
: Nfinal = Nstart e(µ*∆t)
There are 3 taxonomic classes of fish found in the ocean, what are they and which one is the most important in terms of fisheries?
Agnata (jawless), Chondrichthyes (cartilage fish), Osteichthyes (bony fish). Bony fish have the most species and contribute the most important fisheries species.
what are the main primary consumers in the intertidal region?
Algae are grazed by mollusks, sea urchins phytoplankton consumed by benthic filter feeders (mussels, barnacles, clams, tunicates, polychaetes and sponges).
why is the species diversity low in the seaward estuarine mudflat and sand bar communities?
Although we find high biomass and high abundances of organisms in estuaries the species diversity is actually lower than in other systems. - Only few species are able to deal with the large salinity fluctuations in this system
What factors contribute to the large difference in total fish production between the oligotrophic ocean and upwelling regions?
Amount of PP, number of trophic transfers, transfer efficiency; fish production in upwelling areas >>> than in oceanic areas.
Anadromous/catadromous
Anadromous fish (salmon, sturgeon, shad, smelt) breed in freshwater. Then young migrate to sea and return to freshwater to breed -•Catadromous fish (eels) breed in the ocean and their young return to freshwaters where they spend most of their lives before returning to the sea to spawn and die.
what is formula for Assimilation efficiency
Assimilation efficiency = Ration of food - Egestion in faeces x100 Ration of food ingested
What do you know about the uptake mechanisms of gases, nutrients and organic matter by bacteria?
Bacteria can only use dissolved substrates (< 600 Da). There are 3 main uptake mechanisms: Diffusion, passive uptake, active uptake
what is the most prominent group in phylum Ectoprocta? what are the characteristics of this group?
Bryozoa (moss animals) -calcium carbonate shell -colony forming -
What happens to CO2 after it enters the ocean from the atmosphere - chemically and biologically?
CO2 to carbonate (CO2 - H2CO3 - HCO3- - CO3=); Biological production converts CO2 to organic carbon and CaCO3; biology modulates the distribution of C between the ocean and the atmosphere.
The assimilation efficiency is different in different trophic levels- How? Why?
Carnivores consume prey with similar biochemical composition, herbivores have difficulty digesting plant material (i.e. cellulose), and much of the detritus is indigestible/hard to break down, better to eat meat/protien
Name the different mammals that belong to Nekton in the ocean
Catacaea - whales dolphins, porpoises Pinipeds - seals, walruses, sea lions; Sirenia - manatees an dungongs
How can you measure primary production in the surface ocean?
Change in biomass (i. e. cell numbers, chlorophyll a; direct or remote sensing, many downsides); Oxygen production (bottle incubations, account for respiration); radioactive bicarbonate (or 14C) additions/incubations (most commonly used method)
Salps are tunicates that are mostly transparent and gelatinous. They filter feed by pumping seawater into their mouth and form long colonies in the water column. What Phylum do they belong to?
Chordata
What is the fate of primary production in the euphotic zone - compare the coastal and open ocean?
Coastal/open ocean: 25 or 10% leave euphotic zone; 6 or 1% reach sediment surface; <1 or < 0.1% are buried -From the net production about 10% are excreted in the form of DOC. Most of the organic particles and DOC produced in the surface ocean will serve as food source for the rest of the food web. Most of the growth and respiration of plants, bacteria, zooplankton, fish etc. takes place in the surface ocean leaving only about 10% of the organic carbon to escape the euphotic zone. The "rain" of organic particles is highly variable and depends on the overall production in the surface, the species composition of the food web, and physical parameters.F
What is the significance of the critical depth (light related) and how is it estimated?
Critical depth is where the water column production equals water column respiration. The depth level of the critical depth relative to the mixing depth determines if there is net primary production at a certain location or not. It can be calculated by dividing the light intensity at the surface by the product of the light extinction coefficient and the compensation light intensity
Which biological processes convert inorganic N to organic nitrogen, which biological processes convert organic nitrogen back to inorganic nitrogen, and how did humans change the global nitrogen cycle ?
DIN - ON: N-fixation, photosynthesis/biosynthesis ON - DIN: degradation of ON (digestion, bacterial decomposition; (NH4), nitrification (NO3), denitrification (N2)
Pennate shapes live within sea-ice, asexual division forms one small daughter cell and on regular size cell, external skeletons made of silica, deposits of siliceous oozes what am I?
Diatom
Why are phytoplankton abundance and zooplankton abundance not similar in many regions of the ocean?
Different generation times; dynamic nature of predator-prey relationship The North Atlantic shows a clear peak in phytoplankton biomass during the spring and fall blooms indicating that zooplankton is not as efficient and cannot keep up with the rapid growth of phytoplankton. More dead phytoplankton will reach the seafloor to feed benthic organisms.
What are the major points you remember from the most recent IPCC report on oceans and the cryosphere?
Different models predict different outcomes; -Temperature rise in the ocean is continuing faster, - biological production, including fish harvest is predicted to decline; - ice caps and glaciers are melting faster and are hard to predict; - Atlantic Meridional Ocean Circulation (AMOC) has likely declined over past 150 years; -ocean heat content is increasing causing marine heat waves; - sea level rise is increasing, - permafrost melt is accelerating causing further GHG release, - ocean pH is declining to dangerous levels in polar oceans; -ocean oxygen is declining; -Arctic sea ice and snow cover decreasing leading to weaker albedo - even more heating of the Arctic region.
what are differences and similarities between benthic and pelagic environments?
Different: •larger number of species found in the benthic environment Similar: -organisms distributed based on light, temperature, and salinity -ecological divisions of the seafloor are based on topography and depth and represent
Have 2 flagella and are motile, Classified in the division Pyrrophyta, responsible for red and brown tides,and Some have the ability of bioluminescence What am I?
Dinoflagellate
what are the characteristics of estuaries?
Estuaries are Partially enclosed systems "where the river meets the sea". -among the most productive of marine systems - contain high biomass of benthic algae, sea grasses, and phytoplankton supporting a large number of fish and birds -they retain waters enriched by nutrients from the rivers -
Which of the following are examples of the Phylum Arthropoda? A. Mysids D. Euphausiids B. Amphipods C. Copepods E. B & C Only F. All of the above A, B, C, D
F. all of the above
how to track diets
Fatty acids are source-specific and are transferred conservatively from producer to consumer
Growth of larval and juvenile fish is generally a factor of?
Food availability and temperature
what are food chains
Food chains or webs are arrangements showing the transfer of energy and organic matter through various trophic levels of marine organisms. Each trophic level is composed of organisms that are similar in the way they acquire energy.
Explain the "Ocean Carbon Pump"?
Gradient in DIC; soft tissue pump (70%), CACO3 pump (20%); solubility pump (10%)
What parameters would you have to know to estimate secondary production by zooplankton?
Grazing rates (G), defecation rates (D) Respiration (R), molting (E), mortality (M),
what controls the diversity and composition of intertidal species?
Grazing, competition and predation amoung intertidal plants and animals
List the different types of heterotrophic Bacteria and Achaea in the ocean and sediments
Heterotrophic bacteria: Aerobic respires, denitrifiers, sulfate reducers, fermenting bacteria
How does increased nitrogen from humans affect carbon transport? will the balance spiral? if not how will it be balanced?
If N- fixation or human N-input in the ocean would increase, so would primary production and the vertical transport of carbon as long as the other essential nutrients are available. N-fixation and denitrification are likely held in balance by other elements like O, P and Fe
How do negative feedback loops control the concentration of Nitrogen in the ocean? what are the two loops?
If denitrification increase, N-fixation decreases and so does the concentration of fixed N in the ocean. This decreases production, oxygen consumption, and decreases vertical transport organic matter. This would increase oxygen concentration in the water column and lead to lower denitrification rates. -The second feedback loop is based on a small excess of P in low latitude surface ocean. If nitrate becomes limiting in the surface ocean N-fixation would take its place until all the excess phosphorus is used up. This would add additional fixed nitrogen to the ocean until N-fixation is back in balance with denitrification.
Where do Kelp forests develop?
In cold temperate regions, intertidal rocky-shore communities merge subtidally into kelp forests.(california) -Kelp prefer upwelling areas with fast currents, and require a hard substrate to attach to, with depths of 20-40m.
how do benthic communities change as you go from shallow water to deep sea trenches?
In shallow water phytoplankton and benthic plants contribute to primary production. Phytoplankton and zooplankton are consumed by shallow water filter feeders. Recycled organic matter and detritus supply nutrients to the water column, and currents along the seafloor may cause a resuspension of sediments, making benthic microphytes and bacteria-covered sediment particles available as food sources for zooplankton. fish and mammals rely on shallow-water benthos for food. Deep water: -•Benthic communities located in the aphotic zone - depend on food produced in the water column (except chemosynthetic bacteria). The marine snow brings food and forms the sediments in which the benthic organisms live. -Deep waters decompose organic matter that later resupplying nutrients to the surface to be used by phytoplankton
Why is fish activity high at certain parts of the day?
Incoming/Outgoing tides move water, nutrients, and plankton, and the fish tend to follow.
what are the two ecological categories in the benthic zone
Infauna - live within the substrate (clams, worms); usually in soft substrate in subtidal regions and also live in hard substrate (e.g. rock-boring clams) Epifauna-live on or attached to the seafloor; represent 80% of the zoobenthos; include corals, barnacles, mussels, starfish, sea urchins, sea cucumbers, sponges
what latitude is intertidal PP the highest?
Intertidal PP is highest in the temperate regions
Describe an enclosed ecosystem experiment and its advantages over laboratory experiments
Larger (>100m3) enclosure and allows to study several trophic levels at the same time. -An example of experimental manipulation in large enclosures is shown below where small additions of copper had a dramatic effect on the species composition during the experiment. Large diatoms died off after copper additions and were replaced by smaller microflagellates with a trickle down effect on higher trophic levels.
Which human impact has the greatest impact on marine biota?
Largest impact of humans is the removal of 100 million tonnes of fish per year affecting the species composition of fish and the nutrient levels in the ocean -size of targeted fish species gets smaller and smaller because larger individuals are preferentially removed.
There is also a classification based on size for benthic animals, what are the different sizes for macro, meio, and microfauna
Macrofauna - larger than 1 mm include starfish, mussels, clams Meiofauna - 0.1 - 1 mm; mostly living in the interstitial spaces of sand and mud; includes small moluscs, worms (nematods) Microfauna: smaller than 0.1 mm mostly protozoans (ciliates)
how are marine macrophytes different that intertidal species?
Marine: -seaweeds -rootless -include brown algae (kelp), red algae, green algae. -Seaweeds are also known to produce significant amounts of dissolved organic matter. Intertidal:; -roots
what characterizes the bathyl zone?
Marks where benthic habitats are below euphotic zone bathyal extents down the continental slope representing 16% of the seafloor. The rain down of Organic matter and detrius supplies the benthos with nutrient.
Some in this group are known for their exoskeletons made of calcium carbonate plates (coccolithophore), Some form colonies and produce oozes that smell like dimethyl sulfide (DMS) what am i?
Microflagellate
Was the management of fisheries successful over the last decade? Explain why and name recent global trends in fish harvest
No, did not consider ecological and biological variations. Trend goes towards overexploitation, shift in species composition to less desireable species.
What are the products of photosynthesis?
O2 + carbohydrates
What happens during the light reaction of photosynthesis?
Photons are harvested by pigments in the chloroplasts of the algae cells the light energy is passed through the electron transport chain converting the energy of the sun into biochemical energy in form of ATP and NADPH, making use the proton gradient generated by the electron transport chain. Oxygen is also produced during the light reaction.
What is PAR? How deep does light penetrate into the ocean - for photosynthesis and for optical orientation, respectively?
Photosynthetically active radiation. Penetrates max. 200m for photosynthesis and about 1000m for optical orientation
How does the growth of phytoplankton influence the global carbon cycle?
Phytoplankton convert CO2 to organic carbon. If enough CO2 is consumed in the surface ocean it needs to be replaced by CO2 from the atmosphere therefore phytoplankton growth reduces the CO2 concentration in the atmosphere. Some organic carbon produced by phytoplankton is settling to the sediment on the bottom of the ocean and gets buried. This carbon is considered CO2 sequestration for millenia. In order for phytoplankton growth to have a net effect on atmospheric CO2 the produced organic carbon needs to be transported to the deep ocean and stored away for a long time (more than several 100 years).
Some in this group are known as "blue-green algae", Some organisms in this group are Prokaryotes, Trichodesmium sp. Can use dissolved N2 gas as a nutrient source, The very small sized Chlorphyta, or "green algae" belong to this group what group am I?
Picoplankton
what are the three groups in phylum nematode?
Platyhelminthes, Sipunculids, Echiurids
Name the different trophic levels of the marine food web. How do you determine the transfer of energy from one trophic level to the next and how large is the ecological efficiency on average?
Primary producers Herbivores Carnivores1 Carnivores2 Top predators (piscivores) Measuring how much biomass is in each trophic level, on average transfer efficiency is 20% lower trophic levels and 15% upper trophic levels
what is the PP of coral reef communities?
Primary producers of coral reefs include phytoplankton, benthic algae, and zooxanthellae. Gross primary productivity is very high nutrients well-recycled
What are the most important representatives of holoplankton?
Protozoans (foraminifera, radiolaria, ciliates,...), Cnidaria, Ctenophora, Chaetognaths, Annelida (polychaetes), Mollusca (Heteropods, thecosomes), Arthropoda (Copepods, Cladocera, Euphausids, Amphipods, Decapod,..), Chordata (Appendicularia, Salps)
what is the keystone species of kelp forests? what other species thrive there?
Sea otters (predation on sea urchins regulates the ecological balance between kelp production and the destruction) Epifauna and epiflora; sea urchins; fish; sea otters.
what benthic communities occupy the middle region of estuaries? what type of food-chain dominates this region?
Seagrass beds grow in the intertidal and subtidal areas in the middle of the estuary -dominated by detritus-based food chains.
What are possible reasons for dial vertical migrations by zooplankton?
Search for food, avoid predators, more efficient transfer of energy from the phytoplankton at the surface to the deeper zones of the ocean, advection into new feeding regions
Evaluation of secondary production:
Secondary production is the rate of change in the biomass of herbivores. -P = GA - R - E - M
What kind of tide do we have today in Galveston?
Semidiurnal / Semidiurnal Mixed
What determines the survival of fish larvae into the adult stage (recruitment). We mentioned 4 hypotheses.
Starvation, Predation, Advection, and Growth hypothesis
what are remedies for overfishing?
Sustainable fishing plans Regulation of fishing Bycatch reducing devices Marine reserves Mariculture (also creates problems)
how are epipelagic fish different from mesopelagic ones
The mesopelagic species are smaller and are less numerous and belong either to the stomiatoids or the myctophids (lantern fish). Bioluminescence
what are the differences between zooplankton in the epipelagic and those in the mesopelagic?
The mesopelagic species tend to be larger than epipelagic counterparts -permanent pycnocline
What is microbial ecology and which organisms does it involve?
The study of the ecology of microbes and their role in biogeochemical cycles; Viruses, Bacteria, protozoans, microalgae
what characterizes the sublittoral zone?
The sublittoral (subtidal) extents from low tide mark to the outer edge of the continental shelf -about 8% of the total sea floor area -Benthic plants disappear at the outer edge of the sublittoral, as do rocky surfaces
What benthic organisms inhabit the supralittoral zone?
The supralittoral is inhabited by encrusting black lichens (symbiosis of algae and fungi) blue green algae, certain species of snails (Littorina), and isopods
how will global warming impact kelp forests and urchin larval success rates?
The survival rate of larval sea urchins seems to increase with increases in average temperatures, representing a potential problem for kelp forest systems with a warming climate.
what benthic communities occupy the upper parts of estuaries? what type of food-chain dominates this region?
The upper parts of estuaries are occupied by saltmarsh communities dominated by detritus-based food chains.
what process determine the zones within the intertidal zone?
The upper, shore ward, border of the intertidal zone is determined by physical processes, while the lower border is determined by biological processes like competition for space and predation.
List the different types of autotrophic Bacteria and Achaea in the ocean and sediments
There are 3 general groups of prokaryotic chemoautotrophs. Methanogens, sulfur oxidizing bacteria, and nitrifying bacteria. These are either anaerobes or aero tolerant organisms (need oxygen and reduced chemical substrates). Photoautotrophic bacteria (cyanobacteria),
Explain the outcome of the biomass of phytoplankton and zooplankton based on different light extinction coefficients
These model runs predict the biomass of phytoplankton and zooplankton based on different light extinction coefficients. Low k (high light) produces lots of PP fast, but leads to collapse after nutrients are depleted and zooplankton don't consume a large share of PP; Medium light produces elevated PP over longer time scale, zooplankton consume a larger share of PP and build up more biomass than under high light. Large k (low light) does not allow for much PP as well as zooplankton production.
why zooplankton migrate
To reduce vulnerability to visual predators 2. To conserve energy -If animals feed in the warmer surface waters and descend to cold water to digest, they can use less energy for respiration and have more available for growth and reproduction. 3. To enhance horizontal advection
What is ocean acidification, where in the global ocean will it become a problem first?
With each additional molecule of CO2 added to ocean surface waters you generate 2 protons which lowers the pH of ocean water. Over a century time scale this could lower the pH of ocean surface waters enough to affect calcium carbonate saturation values. This will affect all CaCO3 forming organisms. In polar regions.
what are the characteristics of group Pogonophora?
abundant in deeper sediments (up to 10,000m -live near deep thermal vents - source energy from symbiotic chemosynthetic bacteria
Which of these hypotheses explains the fluctuation of adult fish abundance due to currents and physical oceanographic movements?
advection
two nitrifying bacteria
ammonium oxidizing bacteria and the nitrite oxidizing bacteria
what are characterics of the ecological subgroup epibenthos?
animals that live associated with the seafloor but also swim from time to time; flatfish, crabs, prawns
what are the Characteristics of the sandy beach environment?
beach sand is formed from quartz particles mixed with a high proportion of shell fragments, coarser sands on exposed beaches that have higher wave action
what are macrophytes?
bethic plants that attach to the seabed. restricted to the intertidal and shallow subtidal regions. -indigestible
what adaptions do intertidal benthic communites use to resist changes in the intertidal environment?
burrowing rigid exoskeletons (shells) high tolerance for changing water content attachment. -crowding in sessile organisms to keep moisture
What causes tides on Earth?
by gravitational forces of Sun and Moon as well as centrifugal forces from the rotation of the Earth-Moon complex.
how does the nitrogen cycle change with glacial-interglacial cycles?
changes in ratio of denitrification and N-fixation - more denitrification during interglacial periods - less denitrification during glacial periods.
Which benthic environment is the most diverse and ecologically complex?
coral reef environments
why do different microphyte species occupy different tidal levels?
determined by their preferences for different wavelengths of light. -Green algae (Ulva) grow in shallow water -brown algae live somewhat deeper, -red algae are typically subtidal.
how does a major oil spill impact the marine biota? Historically, what are the largest oil spills ?
elimination of benthic fauna (30% reduction has been documented), killing large number of birds (in the 10 thousands). The recovery time for ecosystems after major oil spills typically takes few decades. -Gulf of Mexico Macondo Oil Well (BP-spill) 675,500 2010 -Gulf of Mexico Natural oil seeps ~140,000 every year
Rocky areas support mainly _______, while soft substrate sand and mud flats have a higher proportion of _______ species
epifauna; infaunal
how to study microbes
epifluorescence microscopy, with acidrine orange stain
what are the characteristics of phylum Platyhelminthes worms?
flatworms; -live in sand, mud
what are the three groups in phlyum mollusk?
gastropods (snails,naudibranchs) , bivalvia (clams and mussels), Chitons (polyplacophora, sometimes octopus, scaphopods, aplacophorans
what factors limit primary productivity in intertidal regions?
harsh conditions, high temperature and sun light in the tropics and ice in the Arctic and subarctic regions
how will a high salinity, low temperature water mass move in the water column,
high density, the water mass will sink
oxygen minimum layer.
in the mesopelagic, permanent pycnocline which represents a density gradient that leads to accumulation of particles coming from above. This leads to elevated respiratory activity in this layer due to the consumption of organic matter
why are hydrothermal vents and cold-seeps unique? how diverse are these environments?
independent of solar energy and photosynthesis. The chemosynthetic bacteria are the primary producers in theses communities. they instead utilize the presence of hydrogen sulfide to form organic compounds from carbon dioxide. -and species diversity is low
what are the major scavengers of the intertidal zone
isopods and crabs
The Irradiation at the surface ocean and at 50m depth is 200 µEm-2s-1, and 60 µEm-2s-1, respectively. Calculate the light extinction coefficient k.
k = (ln200uE - ln60uE)/50m = 0.0241 m-1 k=light at surface-light at depth)/depth
You go out on your boat in Galveston bay and toss your light and depth meter over the side. You record the Irradiation at the surface as 100uE. The radiation at 10m is 50% of the surface radiation. What is the extinction coefficient, k?
k = ln(I0) - ln(ID)/ depth (m)
increased fish production in upwelling reion because
larger PP, less trophic levels thus more efficient energy transfer, high nutrients from upwelling supports large phytoplankton growth and enables larger fish biomass.
what are spring tides? when and why do they occur?
maximum tidal range, twice each month when Earth, Sun, and Moon line up
why are ciliates important?
members of the microbenthic community representing the major trophic link between bacteria, diatoms and larger invertebrates living in the benthos
what phylum does foraminifera belong to? where do they live?
micro and meiobenthos, particularly in deep sea sediments Feed on diatoms in shallow water and bacteria in deep water sediments
what are stromatolites?
microphytes; photosynthetic cyanobacteria form rock-like reefs by secreting calcium carbonate
what are neap tides? when and why do they occur?
minimal tidal range, twice a month when planets are not aligned
what type of fauna thrive in the sandy beach environment?
mobile infaunal organisms.
what are mystecti
mysticeti which are characterized by their baleen -Some baleen whales feed on larger fish (humpback and finback) or on benthic animals (grey whales).
what benthic worm phylum is most abundant? what is there classification? how much so?
nematodes (meiofauna) -One square meter of sand or mud can have 4.5 million nematodes
What are diurnal tides?
one high tide and one low tide
why are sessile benthic organisms excellent orgamisms to study?
organisms of interest don't move and can be observed over a long period of time and insitu experimental manipulations are also possible as long as the wave action is not too strong.
what phylum does the group Tunicates (ascidians) belong to? what are the characteristic of this group?
phylum Chordata -intertidal zone but also down to several -suspension feeders -but can pump 170 liters of water per day
which is the most diverse group under phylum annelid?
polychaetes
what groups belong to phylum annelid, which is most diverse?
polychaetes (most diverse), Pogonophora
when there is low evaporation and high precipitation, what happens to salinity and density? will the water mass rise or sink in the water column?
salinity and density will decrease, and the water mass will "rise"
when there is high evaporation and low precipitation, what happens to salinity and density? will the water mass rise or sink in the water column?
salinity and density will increase, the water mass will sink
what benthic species dominate sublittoral zones?
sea anenomes, seaweed
Marine Reptiles include
sea snakes, saltwater crocodiles, marine iguanas and sea turtles
Brachipoda (phylum)
similar to bivalves and have a calcareous shell. Mostly on the continental shelf on hard substrate.
what adaptions enabled meiofauna species to be the most abundant and diverse in sandy beach environments?
small size, wormlike shape, flattened bodies, strengthened body walls, or high ability to contract -98% meiofauna in sand do not produce planktonic larvae
What is Phylum Porifera? what are its characteristics?
sponges -very primitive -large fraction of macrobenthos in rocky regions
Nektonic Cephalopods
squids, cuttlefish and octopods
What species make up the carnivores in intertidal regions?
star fish, snails , barnacles, mussels
what is the keystone species in intertidal regions?
starfish
what is Xenophyophoria
subgroup of foraminifera; abundant in hadal zone; largest off all protozoa (25cm)
what are the zones in rocky intertidal shores?
supralittoral littoral
what are the 6 benthic zones and their depths?
supralittoral (0-only during storms) littoral (0-200) sublittoral (0-200) bathyl (200-2000) abyssal (2000-6000) hadal (>6000)
when there is less heat from the sun at the poles, what happens to temperature and density? will the water mass rise or sink in the water column?
temperature decreases and density increases, water mass will sink
when there high heat, what happens to temperature and density? will the water mass rise or sink in the water column?
temperature increases and density decreases, water mass will rise
what phylum does the Crustacea group belong to? what are examples of meiofauna and macrofauna Crustacea?
the phylum Arthropoda -Macrobenthic crustaceans include isopods and amphipods -Meiobenthic forms include ostracods, copepods, and tanaids
Stock/recruitment theory-
the recruitment of new fish stock is a function of the number of eggs produced and subsequent survival of young.
what are Sponge skeletons made of?
the sponge skeleton is made of calcium carbonate, siliceous spicules, or spongin fiber.
odonticeti
toothed whales two bloehole
what are microphytes?
unicellular algae that live on the sand grains or form algal mats on mud surfaces -) include diatoms, cyanobacteria, and dinoflagellates -important source of OM in shallow waters
how do sandy beach macrofaunal communities change as you move shoreward?
upper beach: low number of macrofauna and is dominated by polychaetes, bivales and crustaceans . At mid and lower tidal zone: -the diversity of macrofauna increases and is dominated by clams and snails. mid-tidal levels: -Crabs of the genus Emerita The lower tidal levels: - inhabited by echinoderms like sea cucumbers, heart urchins and sand dollars
how are benthic orgamisms zoned in the littoral (intertidal) zone?
upper- limpets, Littorina snails below the littoral- zone of barnacles followed by a zone of densely packed mussels
Does the sand beach environment have high or low PP?
very low, depends to a large degree on detritus imported from the outside.
what is the microbial loop
which starts with the production of dissolved organic matter and ends up with respiration and the consumption of bacterial cells by bacterivores, which in turn are consumed by zooplankton. -, transferring DOM to higher trophic levels via the activity of heterotrophic bacteria
Can any corals grow below the euphotic zone? if so, what type of coral?
yes, non-reef building corals Ahermatypic (non-reef building; soft) corals that don't have a symbiotic relationship with zooxanthellae do not require light for nutrition and growth.
which species has a symbiotic relationship with stony (carbonate shell) corals? how do they aid one another?
zooxanthellae -zooxanthellae use CO2 and waste products from the coral to grow, and in return the coral is provided with organic compounds such as glucose and glycerol as a food source
what are other human causes of fish and shellfish decline?
•Dams make it difficult for anadromous fish (salmon, steelhead trout) to migrate to spawning grounds. •Loss of spawning ground and coastal nurseries because of land development •Trawling destroys the habitat of demersal fish -Bycatch
what are the three different types of reef formations?
•Fringing reefs- band along the coast or around an island. (e.g. Caribbean sea) •Barrier reefs- Attached to the edges of a volcanic island, but separated from the land by a lagoon of open deep water. (e.g. Great Barrier Reef) •Atolls- When a volcanic island subsides below sea level, the coral reef is left as a ring around a central lagoon.
how much of global production does benthic primary production account for?
•On a global scale benthic production is about 10% of total primary production in the ocean.
what are the common characteristics of all mangrove plants
•Salt tolerance •Aerial roots •Excrete excess salt •Many are viviparous •Zonation: above-tide forest and intertidal swamp represent two very different habitats for different communities.
What physical and biological factors determine the number and type of animals living withing benthic communities (8)
•Substrate type •Bioturbation and colonization •Tidal levels •Wave action •Salinity and temperature variations •Competition and predation •Life history •Success of larval recruitment
how can you measure benthic primary production
•The production of small benthic plants (microphytes) can be measured by carbon or oxygen exchange by benthic chambers. •Production of macrophytes are usually measured by harvesting and weighing the plants.
What Environmental conditions impact intertidal environments
•air exposure •temperature •salinity •ice formation and scouring •wave action and current motion
