EOSC 373 Unit 2: Food Webs

Holoplankton

Entire life as plankton

Meroplatnkton

Part of life as planktokn

Groups in heterotrophic protists

flagellates, ciliates, foraminifera, radiolarans

Groups in chordates

appendicularia, salps

heterotrophic protists characteristics

unicellular, up to 3 mm, iregular shape

what environment are heterotrophic protists important to

oligotrophic regions

how to flagellates eat

generate currents with flagella and trap prey with cytoplasmic extensions

how do ciliates eat

capture prey with cilia

What are Tintinnids

ciliates with vase like external protein shell

What are special about Tintinnids

can eat up to 60% of primary production

foraminiferan characteristics

amoeboid, bacteriavores, calcareous shell

How do foraminiferans eat

Use pseudopodia, cytoplasm filled projections of cell wall

Radiolarian characteristics

Amoeboid, silicate capsule, gelatinous colonies

How do radiolarians eat

Use pseudopodia, cytoplasm filled projections of cell wall

what do ctenophores eat?

copepods

What are special about ctenophores

can eat up to 1000% of their body weight per day

Chaetognath characteristics

predatory marine worms, hermaphroditic

Heteropod characteristics

swimming snails with eyes and fin

What do heteropods eat

gelatinous zooplankton

What are pteropods

sea slugs

what are thecosomes

main type pteropods with shell

what are gymnosomes

pteropods without shell

how do thecosomes eat

secrete mucus web

how do gymnosperms eat

tentacles with chitinous hooks

Euphausiids

krill

amphipod characteristics

carnivores or scavengers, often live within a jellyfish

copepod feeding

generate current with legs and mouthparts, most are herbivores

Appendicularia characteristics

mucous house pumps water and sieves particles

salp characteristics

massive aggregations, fast growing, pump water through mucous nets in body

coastal mean zooplankton ml/1000m³

120

oligotrophic mean zooplankton ml/1000m³

12

N Atlantic Winter zooplankton ml/1000m³

200-300

N Atlantic Summer zooplankton ml/1000m³

700-800

Where does zooplankton abundance decline at depth

OMZ at 500m

Where is diel vertical migration most common

thermally stratified seas

triggers of DVM

light, pressure, hunger, temp

North Atlantic copepod life cycle

2 month life span, overwinter at 300m, need to feed before breeding

North Pacific copepod life cycle

one generation per year, overwinter at 500m, don’t feed before breeding

N Atlantic copepod species

Calanus

N Pacific copepod species

Neocalanus

Is there a fall bloom in the Pacific or Atlantic

Pacific because copepods migrate to deeper waters

In which ocean are copepod populations high at the onset of the spring bloom

Pacific

what is bacteria growth efficiency

C metabolized used towards growth

what are the main bacteriavores

heterotrophic protists

trophic transfer efficiency

10%

what is the microbial loop

flow of energy from phytoplankton to DOC to bacteria to protozoans to zooplankton

how much primary production is channeled into the microbial loop

50%

role of viruses

recycling nutrients through lysing bacteria and regulates community structure

how much C production is destroyed by viruses

20-40%

regenerated production

fraction of net primary production sustained by recycled nutrients

f-ratio

new primary production / new and regenerated primary production

oligotrophic f ratio

0.1

upwelling f ratio

up to 0.8

Sustainable fish catch (FYE)

Fish production efficiency * sustainable harvest fish production

sustainable harvest fish production

25-45% of annual fish produced