Fisheries Glossary O-R
OY - See advisory panel.
Pelagic - Refers to fish and animals that live in the open sea, away from the sea bottom.
Population Dynamics - The study of fish populations and how fishing mortality, growth, recruitment, and natural morality affect them.
Possession Limit - The number and/or size of a species that a person can legally have at any one time. Refers to commercial and recreational fishermen. A possession limit generally does not apply to the wholesale market level and beyond.
Predator - A species that feeds on other species. The species being eaten is the prey.
Predator-Prey Relationship - The interaction between a species that eats (predator) another species (prey). The stages of each species’ life cycle and the degree of interaction are important factors.
Prey - A species being fed upon by other species. The species eating the other is the predator.
Primary Productivity - A measurement of plant production that is the start of the food chain. Much primary productivity in marine or aquatic systems is made up of phytoplankton, which are tiny one-celled algae that float freely in the water.
Pulse Fishing - Harvesting a stock of fish, then moving on to other stocks or waiting until the original stock recovers.
Put and Take Fishery - The placing of hatchery-raised fish in waters to be caught by fishermen. There are few marine fisheries that fit this description. Most cases are found in inland streams and lakes.