Glossary of Fisheries and Aquaculture Terms

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Glossary of Fisheries and Aquaculture Terms
Aquaculture Cultivation or farming of any aquatic species marine or freshwater,
plant or animal.
Beam trawl
Benthic
Biomass
B MSY
Bottom trawl
Brood stock
Bycatch
Cetacean
CITES
A type of bottom trawl in which the horizontal opening of the net is
provided by a heavy beam mounted at each end on guides or skids
which travel along the seabed. On sandy or muddy bottoms, a series
of tickler chains are strung between the skids ahead of the net to stir
up the fish from the seabed and chase them into the net. On rocky
grounds, these tickers are replaced with chain matting. Used mainly
for flatfish and shrimp fishing.
Bottom-dwelling.
The total weight of a group (or stock) of living organisms or of some
defined fraction of it (e.g. spawners), in a given area, at a particular
time.
Biomass corresponding to maximum sustainable yield (MSY).
Often used as a biological reference point in fisheries management, it
is the long-term average biomass expected if fishing at the rate of
F MSY (see Fishing mortality).
A trawl designed to work at the sea bottom. The lower edge of the net
opening drags along the seabed, and is normally protected by a thick
ground rope and ballasted with chains, sinkers, rubber discs, bobbins,
etc. Bottom trawls include low-opening trawls for demersal species
such as beam trawls and shrimp trawls, and high-opening demersal
otter trawls for semi-demersal or pelagic species.
Eggs, juveniles or adults of a species, from which a first or
subsequent generation may be produced in captivity, whether for
growing in aquaculture or for release to the wild for stock
enhancement.
The part of a catch other than the adults of the target species, which
is taken incidentally. Some or all of it may be returned to the sea as
discards, usually dead or dying.
A marine mammal of the order Cetacea, including whales, dolphins
and porpoises.
Convention on International Trade in Endangered Species of Wild
Fauna and Flora.
Common Fisheries Policy (CFP). The policy under which the EU manages all fisheries within the
European EEZ.
Cold seep
Critically Endangered
Danish seine
An area of the seabed where hydrogen sulphide, methane and other
hydrocarbon-rich fluid-seepage occurs, often in the form of a brine
pool.
Facing an extremely high risk of extinction in the wild in the immediate
future (IUCN definition).
A fishing net with a conical net bag with two relatively long wings. Two
long heavy ropes, one attached to each wing, are used to encircle a
Glossary of Fisheries and Aquaculture Terms 1

Data Deficient
Demersal
Demersal otter trawl
Dredge
Endangered
EU
large area of the seabed to herd the fish into the net and then to haul
the net in. Used for benthic fish such as flatfish.
Presumed to be at some risk of extinction, but there is inadequate
information to make a direct, or indirect assessment of this risk based
on its distribution and/or population status (IUCN definition).
Of a fish or other organism: living near or on the seabed. Of a fishery,
etc: operating within this zone. Demersal fish include species such as
haddock and cod and flatfish.
A type of bottom trawl with rectangular 'doors' or 'otterboards' to
keep the mouth of the cone-shaped net open horizontally while the
net is being towed. A vertical opening is maintained by weights on the
bottom and floats on the top. The net is dragged along the sea bed
with the aid of bobbins, rollers and rockhoppers which can roll across
or dig into the bottom or bounce over obstacles.
Gear used in fishing for shellfish, consisting of a rugged triangular
steel frame and tooth-bearing bar, behind which a mat of linked steel
rings is secured. A heavy netting cover joins the sides and back of
this mat to form a bag in which the catch is retained. Shellfish such as
scallops are raked out of sand or gravel and swept into the bag.
Several dredges are towed together from a tow bar and larger vessels
generally tow two bars.
Not Critically Endangered, but facing a very high risk of extinction in
the wild in the near future (IUCN definition).
European Union.
Exclusive economic zone (EEZ). The maritime zone under national jurisdiction (up to 200
nautical miles from the coast), within which a coastal state has the
right to explore and exploit, and the responsibility to conserve and
manage, the living and non-living natural resources.
FAO
Fishing mortality
Fishmeal
Forage fish
Food and Agriculture Organisation of the United Nations.
(F). The total rate of deaths of fish directly due to fishing. Usually
expressed as the proportion of the entire population caught in a year.
F MSY is the rate which, if applied constantly, results in the maximum
sustainable yield (MSY) of fish. F lim is the rate above which
recruitment will decline substantially, usually set as the F MSY . F pa is
the precautionary approach limit set to allow for uncertainty in survey
data and to ensure F lim is not reached accidentally.
Protein-rich meal derived from processing whole fish (usually small
pelagic forage fish, and bycatch) as well as by-products from fish
processing plants. Used mainly as feeds for poultry, livestock, and
aquaculture species.
Abundant, schooling species (such as sardines, herrings, Alaska
pollock, menhaden, krill, and squid) that are described as fuel for the
food web because they are the food that sustains diverse
assemblages of larger predators higher up in the ocean food chain
seabirds, marine mammals, and other fish species. 1 Although highly
abundant, their populations fluctuate widely under various
environmental influences. Forage fish were once a relatively small
share of the global marine fisheries, but industrial fishing technologies
have enabled the removal of ever-growing quantities from the oceans,
with little thought as to the impacts on marine ecosystems. The
Peruvian anchoveta fishery is now the largest in the world (10.7
million tonnes in 2004), and seven of the top ten fisheries (by weight)
target forage fish. 2 Most of these fish are processed directly into
Greenpeace Red Grade Criteria for Unsustainable Aquaculture 2

Hydrothermal vent
ICES
Industrial fisheries
IUCN
IUCN Redlist
IUU fishing
Minimum landing size
fishmeal and fish oil to be used in poultry, livestock, and aquaculture
feeds.
A fissure in the seabed from which geothermally heated water issues.
International Council for the Exploration of the Sea. Scientists working
through ICES gather information about the marine ecosystem. ICES
Advisory Committee develops this information into advice which is
used by the 20 member countries to help them manage resources in
the North Atlantic Ocean and adjacent seas.
Fleets of large vessels, using highly mechanised means to catch and
process fish and shellfish, particularly for purposes other than human
consumption (e.g. fishmeal, fertilizer).
World Conservation Union (formerly the International Union for
Conservation of Nature and Natural Resources).
The world's most comprehensive inventory of the global conservation
status of plant and animal species. It is widely considered to be the
most objective and authoritative system for classifying species in
terms of the risk of extinction. Classification groups are: Data
Deficient, Near Threatened, Vulnerable, Endangered, Critically
Endangered, Extinct in the Wild, or Extinct.
Illegal, unreported and unregulated fishing. Also known as pirate
fishing.
(MLS). A fishery management control on size at landing (or in the
market). Intended to minimize the catch of small fish or juveniles to
give them a better chance to grow and reproduce before being
vulnerable to fishing.
Maximum sustainable yield (MSY). The highest theoretical yield that can be continuously taken
from a stock under existing environmental conditions without
significantly affecting recruitment.
NAFO Northwest Atlantic Fisheries Organization. NAFO is an
intergovernmental fisheries science and management body. NAFO
Scientific Council gives advice on the status of fish stocks in the
NAFO Convention Area to the Fisheries Commission and Coastal
States.
Near Threatened
Nursery
OSPAR
Overfished
Overfishing
Pair trawl
Pelagic
At a lower risk of extinction in the wild but close to qualifying for the
Vulnerable category (IUCN definition).
An area where juvenile fish live and grow.
Oslo and Paris Convention for the Protection of the Marine
Environment of the North-East Atlantic
In fisheries science, a stock is considered to be in an overfished state
when it has reached an explicit limit set by management, below which
the population may fall to a level too low to ensure reproduction at a
rate sufficient to maintain it. (Exact definitions vary between
management systems).
In fisheries science, overfishing is occurring when the fishing
mortality has reached an explicit limit set by management, above
which the stock is expected to decline towards an overfished state.
(Exact definitions vary between management systems).
A large pelagic trawl towed between two boats. Associated with
bycatch of marine mammals.
Of a fish or other organism: spending most of its life in the mid-water,
with little contact with or dependency on the seabed. Of a fishery, etc:
Greenpeace Red Grade Criteria for Unsustainable Aquaculture 3

Pelagic trawl
Quota
Recruitment
Reproductive capacity
operating within this zone. Pelagic fish include species such as
herring and sardine.
A trawl designed to work in mid-water, targeting pelagic fish. The
front net sections are often made of very large meshes or ropes,
which herd the fish towards the back of the funnel-shaped net.
Pelagic trawls may be towed by one or two (pair trawl) boats.
Associated with bycatch of cetaceans and other marine mammals.
A share of the total allowable catch (TAC) for a given fishery,
allocated to an operating unit such as a country, a vessel, a company
or an individual fisherman (individual quota), depending on the system
of allocation. Quotas may or may not be transferable, inheritable or
tradable.
The rate at which a population is added to each year. Recruitment to
an exploitable (i.e. mature) stock is generally through growth of
juvenile individuals and/or migration into the stock area.
(RC). A measure of a stock s ability to maintain its SSB at a level
below which recruitment will decline substantially. RC is determined
by comparing the SSB to the biomass limit reference point (B lim ) and
the biomass precautionary approach reference point (B pa ).
Spawning stock biomass (SSB). The total weight of all fish in the population which contribute to
reproduction.
Seamount
Stock
Stock status
A mountain rising from the seabed that does not reach to the water's
surface.
A population from which catches are taken by a fishery. A stock is
usually defined in terms of a particular population more or less
isolated from other populations of the same species and hence selfsustaining.
Assessment of the situation of a stock. The FAO express this as:
protected, under-exploited, intensively exploited, fully exploited, overexploited,
depleted, extinct or commercially extinct.
Suction/hydraulic dredge Water is shot into sediments and displaced shellfish are collected the
in a mesh bag (hydraulic) or sucked to the surface through a pipe
(suction).
Total allowable catch
Trawl
Tropic level
Vulnerable
(TAC). The catch allowed to be taken from a resource in a specified
period (usually a year), as defined in the management plan. The TAC
may be allocated to the stakeholders in the form of quotas, as
specific quantities or proportions of the TAC.
A funnel-shaped net that is towed through the water by one or more
vessels.
The position that an organism occupies in a food chain, i.e. what it
eats, and what eats it.
Not Critically Endangered or Endangered, but facing a high risk of
extinction in the wild in the medium-term future (IUCN definition).
1 Marine Fish Conservation Network (2008). Forage Fish. www.foragefish.org website. Marine Fish Conservation
Network, Washington, DC, USA. Accessed April 2008 at: http://www.foragefish.org/index.html
2 FAO (2007). The state of world fisheries and aquaculture 2006 (SOFIA). Biennial report. Food and Agriculture
Organization of the United Nations (FAO), Rome, Italy. Accessed April 2008 at:
http://www.fao.org/docrep/009/A0699e/A0699e00.htm
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