Polar

Front 1

What is the difference between the Berants and Bering Seas?

Back 1

Both are gateways to the Arctic, and serve as supplies of nutrients. Berants is E, shallower, more advection with Norwegian sea, more retention of phytoplankton blooms in surface, more recycling, more copepods, herring and cod fisheries productive. Bering is W, deeper iron depleted water crosses Bering strait, mixes with iron, blooms, sinks out, supports rich benthos, grey whale and walrus forage.

Front 2

Compare and contrast the Arctic and Antarctic regions.

Back 2

Arctic is shallower, more nutrients advected, sea ice coverage more seasonal, blooms more congruous, tend to be recycled in upper layers, more haline stratification, copepods important. Antarctic deeper, more ice, less land (nutrient and FW) influence, iron depleted, seasonal blooms more irratic, lots of mixing, temperature and light controled by sea ice, meltwater is important supply of nutrients. No land or riverine inputs of iron. Temp and light regulated by sea ice coverage.

Front 3

What does benthic-pelagic coupling usually refer to?

Back 3

Organic matter sinking to the seabed, decomposing and the delivery of inorganic nutrients to the water column from the seabed by diffusion and mixing.

Front 4

Name four examples of benthic-pelagic coupling.

Back 4

Subtidal pump
Planktonic larvae of benthos
Benthic resting stages of plankton
Benthic suspension-feeding

Front 5

How is primary production tied to benthos?

Back 5

Primary production is dominated by diatoms in the spring (cold, well mixed, nutrient rich), so vertical flux is high; shallower depths mean a higher proportion of primary production is delivered to the seabed, either directly or through zooplankton fecal pellets; earlier blooms result in less grazing and mineralizatino until water is warmer

Front 6

How does the size of the continental shelf impact shelf/slope exchange?

Back 6

Shelf width controls shelf/slope exchange. Where shelf is narrow, lots of organic matter is moved from shelf to the slope. On broader shelf, most of the organic matter is reworked in situ.

Front 7

How does winter temperature impact phytoplankton blooms?

Back 7

Small variations in winter temperature can have a dramatic effect on the size of the phytoplankton bloom and its fate. Under warmer conditions, zooplankton more easily keep up with primary productivity and bloom is diminished.

Front 8

According to Nixon (2009) what do warming winters mean for benthic-pelagic coupling?

Back 8

Reduction of benthic-pelagic coupling due to warming winters.

Front 9

How is organic matter remineralized in coastal sediments?

Back 9

Much of the organic matter is delivered to coastal sediments so much of the decomposition occurs there.

Front 10

What do organic matter mineralization rates depend on?

Back 10

The type of organic matter, temperature, delivery of electron acceptors.

Front 11

Do phytoplankton mineralize/decompose faster than seagrass?

Back 11

Yes. Phytoplankton mineralize in a few weeks. Seagrass detritus takes months/years to decompose and soil organic material takes centuries.

Front 12

How can decomposition be an example of trophic upgrading?

Back 12

Decomposition of nutritionally poor organic matter by some organisms can improve its nutritional quality- trophic upgrade.

Front 13

Under what conditions are high densities of small, tube-building animals found?

Back 13

If sufficient oxygen exists in overlying water, high densities of small, tube-building animals. Many tube dwellers can't feed and ventilate simultaneously- time budget.

Front 14

What is heterotrophy?

Back 14

Hetertrophs cannot fix carbon and use previously fixed C (organic matter from above benthos) for growth. Oxygen is a terminal electron acceptor for heterotrophs; in anoxic environment, other electron acceptors are used.

Front 15

What are the biological consequences of bacterial respiration?

Back 15

Bacterial activity uses up oxygen and produces some toxic waste products, especially ammonia and H2S.

Front 16

Can there exist both high organic carbon AND high oxygen levels in the benthos?

Back 16

No, bacteria deplete O2 when consuming OM. High organic carbon will be present when there is not sufficient O2 to support its decomposition.

Front 17

Where do we find sand?

Back 17

Continental shelves, shallow, water flow fast, little or no sediment accumulation, lots of sediment redistributino, low organic matter content, permeable

Front 18

Describe a muddy coastal seabed.

Back 18

Deeper or protected waters and estuaries, harbors, etc. Moderate to high sediment accumulation, high organic content, low permeability.

Front 19

What is the subtidal pump?

Back 19

Pressure gradients drive flow; permeable nature of sand allows flow through; flux of fluids and particles

Front 20

How can animals contribute to the subtidal pump?

Back 20

Some animals engineer the sediment with tubes, mounds, and pits, causing higher flux of food, oxygen and wastes. The bamboo worm creates dense fields of tubes connecting overlying water and permeable feeding zone.

Front 21

Give examples of planktonic resting stages.

Back 21

Diatoms, dinoflagellates, copepods. Mortality is still poorly understood.

Front 22

How does flow influence suspension feeding?

Back 22

Flow increases particle flux.

Front 23

What is a passive suspension feeder?

Back 23

Some suspension feeders are passive and require flow.

Front 24

What are active suspension feeders?

Back 24

Many suspension feeders actively pump water through particle-collection devices.

Front 25

Give examples of particle-collection devices that suspension feeders use.

Back 25

Gill, mucus web, setae

Front 26

Give examples of active suspension feeders. Which types are most successful?

Back 26

Bivalves, some polychaetes, sponges
Bivalves, clams, mussels, oysters, and scallops are some of the most successful suspension feeders using large, ciliated gills to make a current, then capture and sort particles.

Front 27

What do suspension feeders eat?

Back 27

Suspension feeders are omnivores and will eat microzooplankton, detritus, small macrozooplankton and their eggs, bacteria, and phytoplankton.

Front 28

What ecosystem services do suspension feeders provide?

Back 28

Estuarine benthic suspension feeders may be able to control algal blooms; oyster populations graze plankton, affect water clarity, benthic-algal coupling, and provide biogenic habitat for other species.

Front 29

Can some species switch between deposit feeding and suspension feeding?

Back 29

Yes, but depends on flow (particle flux).