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Discrimination of the redfish ( S ebastes mentella ) stock components in the I rminger S ea and adjacent waters based on meristics, morphometry and biological characteristics
Author(s) -
Trella K.,
Podolska M.,
Nedreaas K.,
Janusz J.
Publication year - 2013
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/jai.12035
Subject(s) - sebastes , meristics , pelagic zone , biology , principal component analysis , fishery , fish measurement , oceanography , mesopelagic zone , deep sea , fish <actinopterygii> , geology , statistics , mathematics
Summary Redfish S ebastes mentella samples were collected in 2004 and 2005 during commercial cruises to the I rminger S ea on board the P olish vessel M / T ‘ W iesbaden’. I chthyological studies included length and weight measurements, sex, gonad maturity stages and age determinations. Meristic and morphometric measurements were performed on digital images of the redfish. Comparison of the pelagic redfish from the northeastern (depths deeper than 500 m) and southwestern (depths shallower than 500 m) fishing grounds of the Irminger Sea indicates a number of differences including spatial and vertical distribution, ambient temperature, length and age composition. Moreover, 12 morphometric and 4 meristic characters differed significantly between fish samples from these two areas. Results of C luster A nalysis showed the clear grouping of samples into that of the ‘oceanic’ component (depth 300–450 m) and the ‘deep sea’ component (depth 550–800 m). These results were confirmed by P rincipal C omponent A nalysis, which revealed the separation of samples into two catch depth groups. The share of fish allocated by D iscriminant A nalysis into the pelagic ‘deep sea’ component in the northeastern area was nearly 92%, while the ‘oceanic’ component was dominant in the southwestern area and comprised more than 88% of the fish. Cluster and P rincipal C omponent analyses suggest that the ‘oceanic’ component is a more homogeneous group than the ‘deep sea’ component. These results support the management units recently established by ICES .