Marine Zoology

The complex networks of feeding relationships in ocean ecosystems, beginning with primary producers such as phytoplankton and passing energy through successive trophic levels to herbivorous zooplankton, small fish, larger predators, and apex predators.

The physiological process by which marine animals maintain the balance of water and dissolved salts in their body fluids despite living in a hypertonic (saltwater) or variable-salinity environment.

The production and emission of light by living organisms through chemical reactions, most commonly involving the substrate luciferin and the enzyme luciferase. It is widespread among deep-sea marine animals.

The study of the biological communities associated with coral reefs, which are calcium carbonate structures built primarily by colonial scleractinian corals harboring photosynthetic zooxanthellae. Coral reefs support roughly 25 percent of all marine species.

The vertical division of the open ocean water column into distinct depth zones, each characterized by different levels of light, temperature, and pressure: epipelagic (0-200 m), mesopelagic (200-1,000 m), bathypelagic (1,000-4,000 m), abyssopelagic (4,000-6,000 m), and hadopelagic (below 6,000 m).

The biological sonar used by toothed whales (odontocetes) and some pinnipeds to navigate and locate prey by emitting high-frequency clicks and interpreting the returning echoes.

Assemblages of organisms that live on or in the ocean floor (the benthos), including sessile filter feeders, burrowing infauna, and mobile epifauna. Benthic habitats range from intertidal mudflats to hydrothermal vents.

The process by which many marine invertebrates and fishes reproduce by releasing planktonic larvae that drift with ocean currents before metamorphosing and settling into adult habitats, a strategy that allows colonization of new areas.

Indirect ecological effects that ripple through a food web when the population of a top predator changes, causing reciprocal shifts in the abundance of organisms at lower trophic levels.

The ongoing decrease in ocean pH caused by the absorption of atmospheric carbon dioxide, which reacts with seawater to form carbonic acid. This reduces the availability of carbonate ions needed by many marine animals to build shells and skeletons.