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| | a governance module involving adaptive management and stakeholder participation.finfish. By far the most numerous fish species, and those most important to aquaculture and fisheries, are teleosts, or bony fish, which in the sea extend from small "grazing" species such as anchovyto large active predatory fish such as tuna. A similarly wide range is also found in fresh water, with the most important species from a production point of view belonging to the carpfamily. These account for over half the total of inland waters fisheries production. Elasmobranchsor cartilaginous fish, such as sharksand rays, contribute much less to overall fisheries production. As well, although some primitive "jawless" fish such as lampreysand hagfishare also exploited, their significance is merely anecdotal. Likewise, other vertebrates do not feature prominently in the global aquatic harvest, particularly since the exploitation of whales and many other marine mammals has been curtailed.Among the invertebrates, the Mollusca, which includes squid and octopus as well as shellfish ( mussels, oysters, clams) and the Arthropoda, which includes crustacea such as crab, lobsterand shrimp, add substantially to fisheries. A number of aquatic plants, mainly algae such as Laminaria, are of great interest, both as food and as a source of additives widely used in the food and pharmaceutical industries.Detailed information on bio-ecological characteristics, fishing techniques, processing and trade of the main fishery species is collected by FAO and compiled by the Species Information and Data Programme (SIDP) of the FAO Fisheries Department in various forms and media. A list of the most important species for fisheries (around 600) has been established, based on annual landings (over 10 000 tonnes), regional interest from an economic or social point of view or because these species are endangered or threatened by fisheries. A series of fact sheets has been produced for these selected species, in collaboration with the FAO Fisheries Global Information System (FIGIS)using SIDP database material. The fact sheets provide brief, updated and comprehensive written and graphic species information including nomenclature, description, biology and ecology, geographical distribution and interest for fisheries.Definitions The FAO Glossary for Responsible Fisheriesindicates, inter alia, that from a pragmatic point of view, a stockis "the part of a fish population which is under consideration from the point of view of actual or potential utilization".In more biological terms, it is also a group of individuals in a species occupying a well-defined spatial range independent of other stocks of the same species.A stock can be affected by random dispersal movements and directed migrations due to seasonal or reproductive activity. It can be regarded as an entity for management or assessment purposes. A unit stockcomprises all the individuals of fish in an area, which are part of the same reproductive process. It is self-contained, with no emigration or immigration of individuals from or to the stock. On practical grounds, however, a fraction of the unit stock may be considered as a "stock" (or as a management unit) for management purposes as long as the results of the assessments and management remain close enough to what they would be on the unit stock. |  | | | | Stocks present a wide range of characteristics that affect the fisheries exploiting them: they can consist of fish, shrimp, clams, etc. and can be a multispecies stock. It can be highly migratory, straddling or shared; global, ocean-wide, regional, national and local - attributes that often have different implications for management.Stocks are units generally defined by scientists for assessment purpose and their indicators intend to describe their size, potential, health status and trends. | | | | The term "resources" is also often used when referring to vaguely defined "stocks". The FAO Glossary for Responsible Fisheriesindicates that aquatic resourcesare "biotic elements of the aquatic ecosystem, including genetic resources, organisms or parts thereof, populations, etc. with actual or potential use or value (sensu lato) for humanity. Fishery resources are therefore those aquatic resources of value to fisheries". | | | | Just like a stock, a fishery resource is defined by space and its geographical demarcation often has a political or jurisdictional connotation (e.g. Moroccan resources; EEZ or high seas resources). Potential or actual catch is a typical resources indicator reflecting the notions of use or value attached to the resource's concept. It could be local, national (e.g. the shrimp resource of Ghana), regional (e.g. Atlantic tuna) or global (cephalopod resources of the world). | | | | Stocks vary greatly in composition, size and other characteristics. They can include one or many species and be very large (e.g. Alaska Pollock) or rather small (e.g. the South African abaloneor the precious red coral of the Mediterranean).The total number of entities identified as "stocks" in the world in not known and no comprehensive classification exists. FAO has started compiling a catalogue. | | | | The Peruvian anchoveta, Eastern Pacific yellowfin tuna, Pacific Southern bluefin tuna, North Sea plaice, Canadian cod, Gulf of Mexico menhaden, Alaska pollock, Atlanto-Scandian herring, New Zealand orange roughy; Antarctic minke whale, Mauritanian black hake are among the more well-known stocks. It can however be assumed that the largest majority of the world stocks have hardly been mentioned in available literature. More than 1500 stocks and their population dynamic parameters are identified in FAO's POPDYN databasebut more comprehensive and detailed fact sheets are available in the Fisheries Global Information System (FIGIS). | | | | |
 | | | | | Fabio Carocci
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1076 Topics - 5135 Related Knowledge - 2534 Members - 34 Editors |
