An ecosystem is a community of living organisms and the nonliving components of the environment. Energy flows in an ecosystem in one direction through food chains, and a food web is made up of all the food chains within a community of organisms. Biodiversity refers to the variation in species found within an ecosystem, and it is measured in two ways: (1) species richness, which is the total number of different species in an ecosystem; and (2) relative abundance, which is a measure of how common each species is within the ecosystem. Biodiversity and complex feedings relationships within an ecosystem help maintain sustainability.

Question

Question 1

Choose the food web model that illustrates a high degree of biodiversity that in turn contributes to the sustainability of an ecosystem.
Responses
A
B
C
D
Question 2

Consider this Arctic marine environment.

Fishing has long been a way of life in this area. Natives to the area have utilized the riches of the oceans for generations. Recently a commercial fishing company has entered this area and begun bottom trawling for small fish such as sardines and Arctic cod. How would such a fishing technique impact the ecosystem? All BUT one statement could apply.
Responses

A Top level predators may leave the area.Top level predators may leave the area.

B Once prey species are caught, the food web in the area will be disrupted.Once prey species are caught, the food web in the area will be disrupted.

C Predators from other regions will move in to replace absent polar bears and seals.Predators from other regions will move in to replace absent polar bears and seals.

D The trawl net will scoop up everything in its path, including marine life and seafloor structure

Answer 1

Question 1

To choose the food web model that illustrates a high degree of biodiversity contributing to ecosystem sustainability, consider the following guidelines:

• A model showcasing a variety of species at multiple trophic levels (producers, consumers, and decomposers).
• A complex network of interconnections between these species.
• A balance of species richness and relative abundance.

Responses:

• Since the specific food web models (A, B, C, D) are not provided here, you would select the one that displays these characteristics best.

Question 2

In the context of the Arctic marine environment affected by commercial bottom trawling:

Responses:

• A: Top level predators may leave the area. (This statement likely applies as predators may leave due to reduced prey availability.)

• B: Once prey species are caught, the food web in the area will be disrupted. (This statement applies because removing prey species disrupts the food web.)

• C: Predators from other regions will move in to replace absent polar bears and seals. (This statement is the least likely to apply, as ecosystems generally do not see an influx of new top-level predators replacing specific ones that are extirpated from their current habitats.)

• D: The trawl net will scoop up everything in its path, including marine life and seafloor structure. (This statement applies, as bottom trawling is known to massively disrupt seafloor habitats and captures non-target species.)

The statement that could NOT apply is C.