127
fishing effort
force in 1966 after the required minimum ratification by 22 countries. The
convention considers the development of modern techniques for the
exploitation of living resources of the sea, increasing man's ability to meet
the need of the world's expanding human population for food and the exposure of these resources to the danger of being over-exploited. Other bilateral and multilateral conventions on fishery rights outside the 12 miles' territorial sea exist.
fishery science fisheries research, field of research dealing with (a) the dynamics
of commercially exploited populations of fish and invertebrates (Le., fisheries
biology); (b) biological oceanography as far as relevant to a, and (c) fishing
techniques and materials and their possible improvement. The principle
aim of fisheries research is to determine the present effects of fishery on the
fish populations and, to indicate what management of the fisheries would
lead to maximum sustainable yields. The work of fisheries laboratories, therefore,
concentrates on the quantification of a number of properties of commercially important fish populations and their exploitation. The size and age
composition (-7age determination) are estimated from the commercial catches
(sound statistics of which are essential) and other sources like young fish surveys, acoustic surveys and tagging experiments. The production of fish populations is estimated on the basis of many different kinds of information, as
e.g., the fertility, egg production, survival of the early life stages, recruitment of
young fish to the exploited stock, growth rate as a function of age and size, and
on different kinds of mortality. The latter include natural mortality (estimation of which requires study of the population size, gut content and digestion
rate of all possible predators) and fishing mortality (estimated from the
catches and the discards). Mathematical models are an important tool of fisheries scientists; at present the conventional population dynamical models
are replaced by multispecies models in order to cope with the complexity of
the whole of mutually interacting fish populations under exploitation.
Because most fish resources in the open sea are exploited simultaneously by
different countries, and since single fish populations can inhabit or, by migration temporarily inhabit, different national waters, governmental fisheries
research activities have since the beginning of this century been coordinated by the International Council for the Exploration of the Sea (ICES), which
has its headquarters in Copenhagen.
fish farming commercial fish culture on a large scale. The farming can include
the production of brood in special hatcheries. -7fish culture.
fishing effort measure of the amount of time a specified (standardized) vesselgear combination spends fishing. Common measures are trawler hrs fishing,
horse-power days, trap days, hooknights, etc.
fishing effort
force in 1966 after the required minimum ratification by 22 countries. The
convention considers the development of modern techniques for the
exploitation of living resources of the sea, increasing man's ability to meet
the need of the world's expanding human population for food and the exposure of these resources to the danger of being over-exploited. Other bilateral and multilateral conventions on fishery rights outside the 12 miles' territorial sea exist.
fishery science fisheries research, field of research dealing with (a) the dynamics
of commercially exploited populations of fish and invertebrates (Le., fisheries
biology); (b) biological oceanography as far as relevant to a, and (c) fishing
techniques and materials and their possible improvement. The principle
aim of fisheries research is to determine the present effects of fishery on the
fish populations and, to indicate what management of the fisheries would
lead to maximum sustainable yields. The work of fisheries laboratories, therefore,
concentrates on the quantification of a number of properties of commercially important fish populations and their exploitation. The size and age
composition (-7age determination) are estimated from the commercial catches
(sound statistics of which are essential) and other sources like young fish surveys, acoustic surveys and tagging experiments. The production of fish populations is estimated on the basis of many different kinds of information, as
e.g., the fertility, egg production, survival of the early life stages, recruitment of
young fish to the exploited stock, growth rate as a function of age and size, and
on different kinds of mortality. The latter include natural mortality (estimation of which requires study of the population size, gut content and digestion
rate of all possible predators) and fishing mortality (estimated from the
catches and the discards). Mathematical models are an important tool of fisheries scientists; at present the conventional population dynamical models
are replaced by multispecies models in order to cope with the complexity of
the whole of mutually interacting fish populations under exploitation.
Because most fish resources in the open sea are exploited simultaneously by
different countries, and since single fish populations can inhabit or, by migration temporarily inhabit, different national waters, governmental fisheries
research activities have since the beginning of this century been coordinated by the International Council for the Exploration of the Sea (ICES), which
has its headquarters in Copenhagen.
fish farming commercial fish culture on a large scale. The farming can include
the production of brood in special hatcheries. -7fish culture.
fishing effort measure of the amount of time a specified (standardized) vesselgear combination spends fishing. Common measures are trawler hrs fishing,
horse-power days, trap days, hooknights, etc.