Large-scale distribution of three deep-water squaloid sharks: Integrating data on sex, maturity and environment
|Author(s)||Moura Teresa1, Jones Emma2, Clarke Maurice W.3, Cotton Charles F.4, Crozier Paul5, Daley Ross K.6, Diez Guzman7, Dobby Helen8, Dyb Jan E.9, Fossen Inge9, Irvine Sarah B.10, Jakobsdottir Klara11, Lopez-Abellan Luis J.12, Lorance Pascal13, Pascual-Alayon Pedro12, Severino Ricardo B.14, Figueiredo Ivone1|
|Affiliation(s)||1 : Inst Portugues Mar & Atmosfera, Div Modelacao & Gestao Recursos Pesca, P-1449006 Lisbon, Portugal.
2 : Natl Inst Water & Atmospher Res, Auckland Cent 1010, New Zealand.
3 : Inst Marine, Galway, Ireland.
4 : Florida State Univ, Coastal & Marine Lab, St Teresa, FL USA.
5 : World Wildlife Fund New Zealand, Wellington 6141, New Zealand.
6 : CSIRO Wealth Oceans Flagship, Hobart, Tas 7001, Australia.
7 : AZTI Tecnalia, Div Marine Res, Sukarrieta 48395, Bizkaia, Spain.
8 : Marine Scotland Sci, Marine Lab, Aberdeen AB11 9DB, Scotland.
9 : More Res, Sect Fisheries, N-6021 Alesund, Norway.
10 : Irvine Consulting, Sandford, Tas 7020, Australia.
11 : Marine Res Inst, IS-121 Reykjavik, Iceland.
12 : Inst Espanol Oceanog, Ctr Oceanog Canarias, Santa Cruz De Tenerife 38180, Spain.
13 : IFREMER, F-44311 Nantes 3, France.
14 : Univ Porto, Ctr Invest Marinha & Ambiental, CIMAR Lab Associado CIIMAR, P-4050123 Oporto, Portugal.
|Source||Fisheries Research (0165-7836) (Elsevier Science Bv), 2014-09 , Vol. 157 , P. 47-61|
|WOS© Times Cited||15|
|Keyword(s)||Commercial fishery data, Deep-sea, Life stage, Population structure, Survey data|
|Abstract||Deep-water sharks exhibit species-specific reproductive strategies, which include segregation by sex, size and reproductive stage. However, due to the wide spatial distribution of most species, available information, usually collected at a regional scale, is usually not adequate to infer species reproductive spatial dynamics. This study draws together information on the distribution of reproductive stages of three species of squaliform sharks: Portuguese dogfish Centroscymnus coelolepis (Somniosidae), leafscale gulper shark Centrophorus squamosus (Centrophoridae) and birdbeak dogfish Deania calcea (Centrophoridae), gathering data from several geographical areas from the Atlantic, Indian and Pacific Oceans. For each species we analysed the sex ratio and the spatial patterns of reproductive stages within regions, considering the influence of geographical area, depth, season, temperature and salinity. The combination of statistical methods used in this study successfully identified a number of life history patterns which reflect different use of habitats by sex and life cycle stage. Pregnant females of the three species are spatially segregated, inhabiting shallower and/or warmer waters. In the case of the leafscale gulper shark this segregation might be associated with large scale migrations. In contrast, in Portuguese dogfish all adult maturity stages occur in the same geographical area. Pregnant female birdbeak dogfish were rare in all samples. Larger immature specimens of all the three species distribute deeper than the remaining maturity stages in most of the regions analysed. Mature males of leafscale gulper shark and birdbeak dogfish were more broadly distributed than mature females, supporting the possibility of sex-biased dispersal. Neonates and small sized specimens were scarce in the Northeast Atlantic potentially explained by their concentration in nurseries, and/or by gear selectivity. Management measures will benefit from considering the geographic scale of demographic variation between species. However, standardized collaborative approaches will be needed for comprehensive assessment.|