• abiotic factor
    • Physical, chemical and other non-living environmental factors, including climate, soil parent material and sediment lithology.

  • abyssal
    • Relating to ocean depths from 2000 to 5000 m.

  • abyssal hill
    • Relatively low-relief hill rising up from an abyssal plain.

  • abyssal zone
    • Applied to the deepest part of the ocean, below about 2000 m. The abyssal zone lies seaward of, and deeper than, the bathyal zone, and covers approximately 75% of the ocean floor. It is the most extensive Earth environment, cold, dark, with slow-moving currents (less than a few centimetres per second), supporting fauna that are typically black or grey, delicately structures and not streamlined. (cf. neritic. See also bathyal zone, hadal zone.)

  • Invasive species
    • An invasive species is a plant, fungus, or animal species that is not native to a specific location (an introduced species), and which has a tendency to spread to a degree believed to cause damage to the environment, human economy or human health.

  • Lateral line
    • A sensory organ of fishes which consists of a canal running along the side of the body and communicating via sensory pores through scales to the exterior; functions in perceiving low frequency vibrations and pressure differences in general.