Predator-prey interactions and food web

These flashcards cover the key concepts discussed in the Marine Biology lecture regarding predator-prey interactions and food web dynamics.

What is marine ecology?

The study of how organisms interact with each other and their environment.

What constitutes a food chain?

A sequence of organisms, each of which is eaten by the next member in the chain, typically 2-3 steps long.

Define food web metrics.

Measures that include the number of links (L), linkage density (L/S), connectance (L/S²), and generality (n resource/taxa) in a food web.

What is bottom-up control in food chains?

A scenario where the population of higher trophic levels is regulated by resource availability.

What is a keystone species?

A species whose impact on its ecosystem is disproportionately large relative to its biomass, and whose removal can cause significant shifts in community structure.

What is the role of Euphausia superba in the Antarctic food web?

It is a crucial prey item that forms the base of the food web and is significant in nutrient cycling.

What factors affect krill density in the Antarctic food web?

Winter ice duration and changes in sea ice extent have positive correlations with krill density.

What does Diel Vertical Migration (DVM) refer to?

The daily migration of zooplankton between surface and deeper waters, known as the greatest migration on Earth in terms of biomass.

What are the proximate and ultimate causes of DVM?

The proximate cause is changes in light intensity, while the ultimate cause is primarily predator avoidance.

What ecological significance does DVM hold?

It plays a crucial role in transporting energy from surface waters to deeper food webs and supports global biogeochemical cycles.

What is marine ecology?

The study of how marine organisms interact with each other and their environment.

What constitutes a food chain?

A sequence of organisms, each of which is eaten by the next member in the chain, typically 2-3 steps long.

Define food web metrics.

Measures that include the number of links (L), linkage density (\frac{L}{S}), connectance (\frac{L}{S^2}), and generality (n resource/taxa) within a food web.

What is bottom-up control in food chains?

A scenario where the population of higher trophic levels is regulated by the availability of resources or primary production.

What is a keystone species?

A species whose impact on its ecosystem is disproportionately large relative to its biomass, and whose removal can cause significant shifts in community structure.

What is the role of Euphausia\ superba in the Antarctic food web?

It is a crucial prey item that forms the base of many food chains and is significant in nutrient cycling.

What factors affect krill density in the Antarctic?

Winter ice duration and changes in sea ice extent have positive correlations with krill density populations.

What does Diel Vertical Migration (DVM) refer to?

The daily migration of zooplankton between surface and deeper waters, representing the greatest migration on Earth in terms of biomass.

What are the proximate and ultimate causes of DVM?

The proximate cause is changes in light intensity, while the ultimate cause is primarily predator avoidance.

What ecological significance does DVM hold?

It plays a crucial role in transporting energy from surface waters to deeper food webs and supports global biogeochemical cycles.

What is top-down control?

A scenario where the populations and structure of lower trophic levels are regulated by the activities of predators at the top of the food chain.

Define a trophic cascade.

An ecological phenomenon triggered by the addition or removal of top predators, leading to reciprocal changes in the relative populations of predator and prey through a food chain.

What is the rule of energy transfer efficiency?

The principle that only about 10\% of the energy at one trophic level is transferred to the next, which limits the total number of feasible trophic levels.

What is the Biological Pump?

The process by which biologically produced organic matter in the surface ocean sinks to the deep sea, effectively sequestering carbon away from the atmosphere.

Define primary production in marine ecosystems.

The synthesis of organic compounds from aqueous CO_2 through photosynthesis or chemosynthesis, serving as the energy foundation for the entire food web.