methodology - Forest and Bird

Mid-water trawl - a trawl designed catch species in mid-water eg hoki and southern blue whiting. These
trawl nets can have 60 metre headline heights (top to bottom on net) and opening over 150m
wide.
Nautical mile - one nautical mile is the equivalent of 1.15 statute miles.
Overcapitalization - this occurs when there is more fishing capacity (ie, more boats, gear or investment in
equipment) than is needed to catch the available amount of fish in an economically efficient and
sustainable manner. Overcapitalization poses a threat to fish populations because it can easily lead
to over-fishing.
Over-fishing - over-fishing exists when the rate of fishing is greater than the level required to meet the
management goal or maximum sustainable yield. In other words, over-fishing occurs when a
population of fish is caught faster than it can replenish itself through reproduction. (Roberts et
al.,.)
Pelagic - an ancient Greek word for the open ocean or high seas, the area comprising most of the Earth's
surface.
Pelagic species - species found near the surface of the sea and not on or near the seabed, for example tuna
and kahawai.
Plankton - small plant and animal species that spend at least part of their time on the sea surface. They rely
in large part on ocean currents for distribution and transportation. As eggs and larvae, many
marine species, such as cod and Dungeness crabs, are planktonic for part of their life cycle. The
plankton provide food for many commercially important fish and form the basis of ocean food
webs. Some of the largest marine creatures, such as whale sharks and blue whales, eat plankton.
Zooplankton are animals and phytoplankton are plants.
Population - a group of interbreeding organisms that represents the level of organization at which
speciation begins. In other words, a population is a group within a species that shares common
ecological and genetic features compared to other individuals of that species.
Precautionary principle - a proactive method of dealing with the environment that places the burden of
proof on those whose activities could harm the environment rather than on the public. It is the
opposite of the wait-and-see principle; acting before scientific proof of deleterious effects is
applying a precautionary approach. (Norse)
Purse seine - a floating net designed to surround fish and can be closed at the bottom, or “pursed” by
means of a free-running line attached to the bottom of the net. The net may be of up to 1 km
length and 300 m depth and is used to encircle surface schooling fish such as kahawai, trevally and
skipjack tuna. During retrieval the bottom of the net is closed or pursed by drawing a purse line
through a series of rings to prevent the fish escaping.
Recruit - a fish entering the period in its life history when it is exposed to fishing. Related phrases include
pre-recruits, age or length at recruitment, recruitment failure.
Recruitment - recruitment is the general replacement of fish to a stock or population. In fisheries it is the
time when a fish grow to a size they become liable to be caught in fishing gear.
Recruitment failure - the failure of the fishstock to be replaced by recruits.
Recruitment over-fishing - occurs when the spawning stock has been reduced to a level at which
recruitment of young fish entering the exploited component of the fishery is significantly reduced.
Ring net - A modified lampara net with purse rings operated by two vessels.
Seamount - underwater volcanic mountain, ridges and plateaus that rise up several kilometres from the sea
floor, but do not reach the surface of the sea.
Seine - a type of fishing net that encircles a school of fish.
Set - to prepare and cast a net; one “set” is typically defined as the interval from the time the net is cast to
the time the net is hauled in.
Set net - a type of gill net that has been intentionally set, staked or anchored or otherwise fixed in
stationary position, as opposed to drift nets.
Stock - the technical definition of a stock is an interbreeding sub-population of a species, reproductively
isolated to some extent from other populations. Used as a unit for fishery management, however,
"stock" refers to a specific population or group of populations of one or more species.
Straddling stock – a stock which straddles two management jurisdictions eg Challenger orange roughy
stock which covers the NZ EEZ and the adjacent high seas area.
Territorial Sea - this is sea within 12 nautical miles from low-water line along the coast.
Trammel net - type of gill net with three panels suspended from a common surface line and attached to a
single bottom line. The two outside panels are of a larger mesh than the inside panel.
Forest & Bird Best Fish Guide 2012 – 2013: Criteria for Ecological Rankings 42