593
Glossary
Shear dispersion the differential movement of water or particles along a shear line.
Shifting baseline a term used to describe the way signifi cant changes to a system
are measured against previous baselines, which themselves may represent
signifi cant changes from the original state of the system (Pauly 1995 )
Sneaking the situation where a male does not take part in courtship activities, but
ries to surreptitiously release sperm at the site of gamete release after other fi sh
have spawned, probably in hope of fertilizing some of the eggs. Similar to streaking
Spawning aggregation is a repeated concentration of conspecifi c marine animals,
gathered for the purpose of spawning, that is predictable in time and space. The
density/number of individuals participating in a spawning aggregation is at least
four times that found outside the aggregation. The spawning aggregation results
in a mass point source of offspring. Sometimes referred to as FSA
Sperm competition Sperm competition is competition between sperm of two or
more males for the fertilization of an ovum. Species that have sperm competition
are typically characterized by large male testes (and high reproductive GSI )
Sperm limitation a situation in which there may be insuffi cient males (sperm) to
fertilize all available viable eggs (oocytes); this might be brought about by heavy
fi shing selectivity for males which great imbalances the reproductive sex ratio
Staging area an area where migration pathways begin to converge and certain
aggregating fi sh species rest, feed or visit cleaning stations during the spawning
season and in the vicinity of the spawning site
Standard length (SL) refers to the length of a fi sh measured from the tip of the
snout to the posterior end of the last vertebra or to the posterior end of the midlateral portion of the hypural plate; SL excludes the length of the caudal fi n
Stock a part of a fi sh population usually with a particular migration pattern, specifi c
spawning grounds, and subject to a distinct fi shery. A fi sh stock may be treated as
a total or a spawning stock. Total stock refers to both juveniles and adults, either
in numbers or by weight, while spawning stock refers to the numbers or weight
of individuals which are old enough to reproduce. There may or may not be a
specifi c genetic structure associated with a stock; extrinsic factors (immigration
and emigration) are considered to be insignifi cant
Streaking similar to sneaking , but an individual rushes upward near simultaneously
with a spawning rush by a pair or more of fi sh and releases gametes, usually
sperm, at the site of gamete release by other fi sh. Often the streaking individual
is attacked by spawning males
Sustainable fi shery one in which the harvesting of the target species is conducted
in such a way, and at a rate, that it does not threaten the long-term health of the
stock (by exceeding the natural ability of the fi shed population to replace itself)
and the ecosystem on which it depends, or does not inhibit recovery of the stock
or the ecosystem if it has previously been reduced below appropriate levels
Swath width strictly speaking this refers to the strip of the Earth’s surface from
which data are collected by a satellite. The longitudinal extent of the swath
is defi ned by the motion of the satellite with respect to the surface, whereas
the swath width is measured perpendicularly to the longitudinal extent of the
swath. In relation to underwater visual censuses, the longitudinal component is
the transect while the total width surveyed about the transect is the swath.
Glossary
Shear dispersion the differential movement of water or particles along a shear line.
Shifting baseline a term used to describe the way signifi cant changes to a system
are measured against previous baselines, which themselves may represent
signifi cant changes from the original state of the system (Pauly 1995 )
Sneaking the situation where a male does not take part in courtship activities, but
ries to surreptitiously release sperm at the site of gamete release after other fi sh
have spawned, probably in hope of fertilizing some of the eggs. Similar to streaking
Spawning aggregation is a repeated concentration of conspecifi c marine animals,
gathered for the purpose of spawning, that is predictable in time and space. The
density/number of individuals participating in a spawning aggregation is at least
four times that found outside the aggregation. The spawning aggregation results
in a mass point source of offspring. Sometimes referred to as FSA
Sperm competition Sperm competition is competition between sperm of two or
more males for the fertilization of an ovum. Species that have sperm competition
are typically characterized by large male testes (and high reproductive GSI )
Sperm limitation a situation in which there may be insuffi cient males (sperm) to
fertilize all available viable eggs (oocytes); this might be brought about by heavy
fi shing selectivity for males which great imbalances the reproductive sex ratio
Staging area an area where migration pathways begin to converge and certain
aggregating fi sh species rest, feed or visit cleaning stations during the spawning
season and in the vicinity of the spawning site
Standard length (SL) refers to the length of a fi sh measured from the tip of the
snout to the posterior end of the last vertebra or to the posterior end of the midlateral portion of the hypural plate; SL excludes the length of the caudal fi n
Stock a part of a fi sh population usually with a particular migration pattern, specifi c
spawning grounds, and subject to a distinct fi shery. A fi sh stock may be treated as
a total or a spawning stock. Total stock refers to both juveniles and adults, either
in numbers or by weight, while spawning stock refers to the numbers or weight
of individuals which are old enough to reproduce. There may or may not be a
specifi c genetic structure associated with a stock; extrinsic factors (immigration
and emigration) are considered to be insignifi cant
Streaking similar to sneaking , but an individual rushes upward near simultaneously
with a spawning rush by a pair or more of fi sh and releases gametes, usually
sperm, at the site of gamete release by other fi sh. Often the streaking individual
is attacked by spawning males
Sustainable fi shery one in which the harvesting of the target species is conducted
in such a way, and at a rate, that it does not threaten the long-term health of the
stock (by exceeding the natural ability of the fi shed population to replace itself)
and the ecosystem on which it depends, or does not inhibit recovery of the stock
or the ecosystem if it has previously been reduced below appropriate levels
Swath width strictly speaking this refers to the strip of the Earth’s surface from
which data are collected by a satellite. The longitudinal extent of the swath
is defi ned by the motion of the satellite with respect to the surface, whereas
the swath width is measured perpendicularly to the longitudinal extent of the
swath. In relation to underwater visual censuses, the longitudinal component is
the transect while the total width surveyed about the transect is the swath.