Fisheries Science and Management Vocabulary

Vocabulary flashcards covering core fishery terminology, management concepts, stock assessment metrics, gear types, and governance terms from the lecture notes.

Catch per unit effort (CPUE)

Catch divided by effort; serves as a rough index of abundance where a falling CPUE signals falling biomass.

Maximum Sustainable Yield (MSY)

The largest average catch a stock can support indefinitely, occurring in simple models at about $50\%$ of unfished biomass.

Overfished

The state in which a fish stock has been depleted to levels lower than its most productive level.

Overfishing

The process in which the rate of fish harvest or catch is too high.

Stock Assessment

A model-based estimate of the size, status, and health of a population managed as a single unit.

Landings

The portion of total fish catch that is brought ashore, excluding discards and unreported fish.

Bycatch

Non-target marine organisms caught during fishing operations, which may either be kept or discarded.

Discards

Caught animals thrown back into the sea (alive or dead) during fishing activities.

Harmful Subsidies

Capacity-enhancing government support (such as fuel or vessel subsidies) that expands fishing effort beyond sustainable limits.

Beneficial Subsidies

Capacity-reducing financial support, including funding for fisheries science, Marine Protected Areas (MPAs), vessel buybacks, or fisher retraining programs.

Ecosystem-Based Management

An approach to managing the whole ecosystem (including predators, prey, habitat, and human activity) rather than focusing on a single target stock.

Fishing Down

The progressive shift of fishing catches from large top predators to smaller, lower-trophic-level species as top predators become depleted.

Marine Trophic Index (MTI)

The average trophic level of landed catch, where a declining trend over time indicates the signature of 'fishing down.'

IUU Fishing

Illegal, Unreported, and Unregulated fishing operations.

Distant-Water Fleets

Subsidized industrial fishing fleets that operate far from their home country's waters, into the high seas and developing nations' waters.

Collapse (Worm et al. definition)

A fishery status defined as catch dropping below $10\%$ of its historical peak catch.

Collapse (Edgar et al. definition)

A fishery status defined as stock biomass dropping below $10\%$ of its historical maximum.

Precautionary Principle

The rule stating that society should take protective action when there is potential for irreversible consequences, even in the absence of full scientific certainty.

Maximally Sustainably Fished

The optimal target state ('sweet spot') where a fishery catches as much fish as possible without reducing stock biomass below its most productive level.

Underfished

A status where fish catch is less than the reproduction rate of the population, missing out on potential food and income.

Spawning Stock Biomass

The total female biomass within a stock, tracked because total egg output depends primarily on females.

Social Trap

A situation where rational short-term individual decisions produce collective outcome consequences that are detrimental to all participants.

Landing Obligation

A policy requirement (such as in EU fisheries law) obligating fishers to bring all caught fish to land so that unwanted catch counts against allotted quotas.

Ministerial Discretion

Legal authority in EU and Canadian legislation enabling ministers to set catch quotas that exceed scientific advice.

Aquaculture

The farming of aquatic organisms, including fish, molluscs, crustaceans, and aquatic plants.

Pole and line

A low-bycatch method used to catch tuna and large pelagic fish one at a time using baited hooks and scattered bait fish.

Longline

A fishing gear method that trails a long main line with baited hooks attached at intervals, which can impact non-target fish, birds, and other marine life.

Gillnets

A hanging curtain or wall of netting in the water that entangles fish based on mesh size, presenting low seabed impact but high potential bycatch.

Purse seine

A vertical net used to surround dense schools of single-species fish that draws together at the bottom like a drawstring purse, having low bycatch and no seabed contact.

Pots and traps

Enclosed structures made of wood, wire, or plastic with cone-shaped entrances deployed on the seabed to capture crustaceans like lobsters and crabs.

Dredging

A gear type consisting of rigid structures towed along the seabed to dislodge and catch bivalves, often causing high ecological damage.

Pelagic trawl

A cone-shaped net pulled through midwaters using acoustic technology to locate target depth without touching the seabed.

Bottom trawl

A cone-shaped net pulled on or just above the seabed to capture large quantities of fish, causing significant seabed damage and high discard levels.