Biology Marine Biology & Aquatic Ecosystems Flashcards

What is the main cause of ocean acidification?

Answer: Increased absorption of atmospheric CO2 forming carbonic acid

The ocean absorbs excess atmospheric CO2, which reacts with seawater to form carbonic acid, lowering ocean pH.

Mangrove forests provide which key ecological service in coastal ecosystems?

Answer: Coastal stabilization, nursery habitat, and carbon sequestration

Mangroves anchor coastlines against erosion, serve as nurseries for juvenile fish and invertebrates, and sequester large amounts of carbon in their soils.

Which term describes organisms that live suspended or swimming in open water, unable to overcome currents?

Answer: Plankton

Plankton are organisms that drift with ocean currents and include both phytoplankton (photosynthetic) and zooplankton (heterotrophic).

The thermohaline circulation (global ocean conveyor belt) is driven by differences in:

Answer: Water density due to temperature and salinity

Thermohaline circulation is driven by density differences caused by varying water temperature (thermo) and salinity (haline) across ocean basins.

Eutrophication in aquatic ecosystems is most directly caused by excess:

Answer: Nitrogen and phosphorus from agricultural runoff

Excess nitrogen and phosphorus trigger algal blooms; when algae die and decompose, bacterial respiration depletes dissolved oxygen, creating hypoxic dead zones.

Which structural feature distinguishes bony fish (Osteichthyes) from cartilaginous fish (Chondrichthyes)?

Answer: A swim bladder for buoyancy regulation

Bony fish possess a gas-filled swim bladder that allows them to adjust buoyancy at various depths without continuous swimming.