Plankton, Productivity, and Food Webs Flashcards

Flashcards based on lecture notes about Plankton, Productivity, and Food Webs.

What are Plankton?

Organisms that drift or wander in the ocean with limited mobility with respect to currents.

What are Phytoplankton?

Photosynthesizing plankton.

What are Zooplankton?

Heterotrophic plankton.

What are Bacterioplankton?

Bacteria in the water column.

What are the most common groups of phytoplankton?

Diatoms, Dinoflagellates, Coccolithophorids, Cyanobacteria, and Green, Brown, Red Algae.

What are Diatoms?

Cell wall made of silica; abundant in high-nutrient areas; can reproduce asexually or sexually.

What are Dinoflagellates?

Cell wall of cellulose, can be armored or naked; can be auto-, mixo-, or heterotrophic; some are bioluminescent

What are Coccolithophorids?

Scales of calcite (coccoliths); can form large blooms visible from space.

What are Cyanobacteria?

Prokaryotic photoautotrophs; can fix nitrogen; common in nutrient-poor waters.

What are Harmful Algal Blooms (HABs)?

Uncontrolled algae growth that unbalances the ecosystem.

What are Holoplankton?

Spend their entire life as plankton.

What are Meroplankton?

Spend part of their life cycle as plankton.

Name some examples of Holoplankton Crustaceans

Copepods and Krill.

Name some examples of Meroplankton Crustaceans

Crabs, Lobsters, Shrimp, and Barnacles

What are Foraminiferans?

Amoebas with calcium carbonate shells; useful environmental indicators.

What are Radiolarians?

Amoeba-like protozoans with tests (shells) of silica.

What are Scyphozoans?

Jellyfish with stinging cells (cnidae); planktonic medusa stage and benthic polyp stage.

What is the role of Bacterioplankton?

Drive biogeochemical cycles; convert DOM into biomass; critical in recycling energy/biomass.

What is the Microbial Loop?

Convert Dissolved Organic Matter into biomass for other organisms to use.

What is the role of primary producers?

Use pigments to convert light and inorganic matter into organic matter.

What is Gross Primary Production (GPP)?

Total organic material made by photosynthesis.

What is Net Primary Production (NPP)?

Gross production minus respiration of photosynthesizers.

What is Bottom-up control?

Primary productivity is controlled by temperature, nutrients, and light levels.

What is Top-down control?

Abundance of autotrophs are controlled by the grazing pressure of consumers.

What is a food chain?

Linear depiction of predator-prey interactions

What is a food web?

Interlinked food chains

What is Trophic Efficiency?

Percentage of energy that transfers from one trophic level to the next, ~10% on average.

What is the Biological Pump?

Composite of food web processes that result in a draw-down of CO2 from the atmosphere to the ocean.