Qualitative and Quantitative Structure of Alosa Populations at the Romanian Black Sea Coast

George Tiganov

Abstract


The most important resource traditionally exploited for commercial purposes is the fisheryresource. Marine biological resources are essential for the survival ofhumanity, but, as it is well known, although they are renewable, they are notinfinite and therefore must be managed properly. Fishery resources are affectedboth by the changes occurring in natural environmental conditions and bychanges in environmental conditions as a result of human activities.In the past few years, the anthropogenic causes that led to severe changesin fish populations from the Romanian coast partly persisted, but some haveoccurred with less intensity, as follows:- the environmental conditions in the coastal area are still quite poor,reflected by fishing clusters traveling offshore during the warm season;- the influence of hydrotechnical structures on the Danube on sturgeonbreeding and shad, in general, and Pontic shad, in particular, is maintained; - the use of inappropriate fishing gear and techniques;- illegal fishing of breeding clusters.In the Romanian marine sector, the species structure of catches partlyreflects the fish fauna composition, as the ratio of fished species isconditioned primarily by two factors: the type of fishing gear and the seasonalconditions of forming and maintaining fishing clusters.Fishery research conducted in 2011-2012 mainly aimed at reaching thecorrect knowledge and estimation of the dynamics of the Black Sea potential, inorder to ensure the necessary data volume for stock management and exploitationunder sustainable conditions. This research focused on collecting data andinformation on environmental conditions that directly affect fisheries,seasonal distribution of exploitable clusters, the qualitative and quantitativecomposition of catches, the biology of the main Alosa species caught in the Romanian marine area.The research works performed are meant to lead to the knowledge of thecurrent state of Alosa populationsand were conducted along the entire Romanian Black Sea coast, in almost allfishing points, by organizing both expeditions along the coast (gillnetfishing) and sea surveys (pelagic trawl fishing).The paper refers to the qualitative and quantitative composition ofcatches, as well as the length and weight class structure, age, sex ratio,degree of maturation, length/weight relationship for the Alosa species which populate the Romanian coast, underhydroclimatic conditions specific or the analyzed period.

Keywords


Black Sea, Pontic shad, Caspian shad, catches, C.P.U.E., length, weight, age, sex, maturation degree

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DOI: http://dx.doi.org/10.15835/buasvmcn-asb:70:2:9525




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