GLOSSARY OF MARINE BIOLOGY
Abyssal plain. The deep ocean floor, an expanse of low relief at depths of 4,000 to 6,000 m
Abyssopelagic zone. The 4,000 to 6000-m-depth zone, seaward of the shelf-slope break
Acclimation. Given a change of a single parameter, a readjustment of the physiology of an organism, reaching a new steady state
Accuracy. Is the correctness of a measure when comparing to a known standard. See also resolution and precision.
Age structure. The relative abundance of different age classes in a population
Aggregated spatial distribution. A case where individuals in a space occur in clusters too dense to be explained by chance
Ahermatypic. Non-reef-building (referring to scleractinian corals)
Allele. One of several variants that can occupy a locus on a chromosome
Allopatric speciation. The differentiation of geographically isolated populations into distinct species
Allozyme. A variant of an enzyme type. These may be variants of a specific enzyme (e.g., cytochrome c) that are the products of a single genetic locus.
Amensal. Negatively affecting one or several species
Amino acids. Basic structural unit of proteins
Anadromous fish. Fish that spends most of its life feeding in the open ocean but that migrates to spawn in fresh water
Anoxic. Lacking oxygen.
Arrow worms. Members of the phylum Chaetognatha, a group of planktonic carnivores
Asexual reproduction. Reproduction of the individual without the production of gametes and zygotes
Assimilation efficiency. The fraction of ingested food that is absorbed and used in metabolism
Assortative mating. The mating of a given genotype mates with another genotype at a frequency disproportionate to that expected from random
Atoll. A horseshoe or circular array of islands, capping a coral reef system perched around an oceanic volcanic seamount
Attenuation (of light). Diminution of light intensity; explained, in the ocean, in terms of absorption and scattering
Autotrophic algae. Algae capable of photosynthesis and growth using only dissolved inorganic nutrients
Auxotrophic algae. Algae requiring a few organically derived substances, such as vitamins, along with dissolved inorganic nutrients for