Jamaica
Trinidad

Droits : All rights reserved by the source institution.

Éditeur(s) : Elsevier Science Bv
Résumé : Coastal and estuarine systems provide nursery grounds for many marine fish species. Their productivity has been correlated with terrigeneous inputs entering the coastal-estuarine benthic food web, thereby favouring the establishment of fish juveniles. Studies in these ecosystems often describe the nursery as a single large habitat without verifying nor considering the presence of contiguous habitats. Our study aimed at identifying different habitats based on macrozoobenthic communities and morpho-sedimentary characteristics and assessing the trophic interactions between fish juveniles and their benthic preys within these habitats. It included 43 sampling sites covering 5 habitats in which we described taxonomically and quantitatively the invertebrates and fish communities with stable isotopes and gut contents. It suggested that the benthic common sole Solea solea displayed feeding plasticity at the population level, separating the juveniles (G0) from the older fish (G1) into different "feeding sub-populations". Size-based feeding plasticity was also observable in the spatial occupancy of that species in the studied bay. The demersal pouting, Trisopterus luscus, equally used the different habitats but displayed low feeding plasticity across and inside each habitat. Stable isotopes proved to be powerful tools to study the spatial distribution of trophic interactions in complex ecosystems like the bay of Vilaine and to define optimal habitats for fish that use the coastal-estuarine ecosystem as nursery grounds.
Journal Of Sea Research (1385-1101) (Elsevier Science Bv), 2013-08 , Vol. 81 , P. 40-48

Droits : 2013 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/00151/26226/24327.pdf
DOI:10.1016/j.seares.2013.03.013
http://archimer.ifremer.fr/doc/00151/26226/

Éditeur(s) : Elsevier Science Bv
Résumé : The overexploitation of fishery resources has led to a major fisheries crisis. In this context, artisanal fisheries, and in particular small-scale coastal fisheries, appear as relevant alternatives for a sustainable use of coastal resources. Marine Protected Areas (MPA) are more and more used as management tools for these fisheries, as protection effects and targeted access regulations may benefit to commercial fishers. Managers and scientists need then quantitative information not only to adapt their management to the fishing activity present on their territory, but also to estimate the effects of MPA management on it. This study provides catch and effort estimates that are essential for appraising and managing the artisanal fishery in the Côte Bleue Marine Park (CBMP), a French Mediterranean MPA including two No-Take Zones of different age and size. A field protocol was defined and implemented between July 2009 and June 2010 within the CBMP. Seven métiers were identified and characterized by target species, gear type, fishing grounds and fishing periods. During the one-year studied period, 3512 fishing trips and 4645 fishing operations were performed by 30 active boats in the Côte Bleue fishing territory, amounting to 9500 km of immersed nets. In total, approximately 130 tons of catch were landed in the six CBMP harbors, out of which 58% depend on the three main species caught on the Côte Bleue: hake (Merluccius merluccius), gilthead seabream (Sparus aurata) and common sole (Solea solea). The presented methodology could be part of a long term monitoring requiring close collaboration with local fishers. It enables adaptive management with respect to changes in fishing pressure (from inside and outside the MPA) that may impact the environment and its resources.
Fisheries Research (0165-7836) (Elsevier Science Bv), 2014-06 , Vol. 154 , P. 93-101

Droits : 2014 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00180/29120/29367.pdf
DOI:10.1016/j.fishres.2014.02.006
http://archimer.ifremer.fr/doc/00180/29120/

Éditeur(s) : Springer
Résumé : The French Atlantic coast contains large highly productive intertidal mudflats that are colonised by juveniles of numerous flatfish species, including the common sole (Solea solea, L.). These ecosystems are also heavily exploited by the shellfish farming industry. Intensive bivalve culture is associated with substantial biodeposition (1-6 t-dw ha(-1) day(-1)), which directly or indirectly contributes to increase exopolysaccharide (EPS) concentrations at the interface between water column and seabed. EPS are long-chain molecules organised into colloids, which influence rheological properties of water, particularly viscosity. Increased water viscosity had consequences for ventilatory activity of juvenile flatfish, whereby the minimal pressure required to ventilate the medium increases directly with EPS concentration. Moreover, the critical EPS concentration ([EPS](crit)) at which water was no longer able to flow through the branchial basket ranged from almost nil to over 30 mg l(-1), depending on species and size. [EPS](crit) was lower in small individuals and individuals from species with high metabolic rates (turbot and plaice). These differences may depend upon gill and bucco-branchial cavity morphometrics. The ventilatory workload of sole increased with viscosity to a maximum at 2 mg EPS l(-1). Viscosity might, therefore, be a limiting factor for flatfish post larvae, which colonise the intertidal mudflats, depending upon their size and species. EPS concentrations in the field can reach 15 mg l(-1). A selective effect is conceivable but remains to be estimated in the field.
Marine Biology (0025-3162) (Springer), 2007-09 , Vol. 152 , N. 4 , P. 803-814

Droits : 2007 Springer
http://archimer.ifremer.fr/doc/2007/publication-2801.pdf
DOI:10.1007/s00227-007-0731-z
http://archimer.ifremer.fr/doc/00000/2801/

Éditeur(s) : Elsevier Science Bv
Résumé : Estuaries and coastal waters are essential nursery habitats for many marine species, and especially for flatfishes. Thus, investigating how anthropogenic disturbances affect the quality of these habitats is of major importance to understand their consequences on the population renewal of marine species. The aim of the present study was to analyse the effects of estuarine habitat degradation on the population of the common sole in the Eastern Channel, a key species in the fish community and fisheries in this area. We especially focused on the drastic drop in the surface area and on the low water quality of the Seine estuary, the main river of the Eastern Channel. A geographic Information System (GIS) was used to develop quantitative maps of sole nursery habitats in the Eastern Channel by using a habitat suitability model based on bathymetry and sediment structure. This approach indicated that juvenile densities are low in the Seine estuary with regards to other nursery sectors. Then, thanks to historical maps of the Seine estuary, habitat suitability maps were built for key dates in the modifications of this estuary since 1850. This backward predictive approach suggests that habitat loss in the Seine estuary has led to a 42% decrease of its nursery capacity. As the density of juvenile sole in the Seine estuary is low in comparison to other sectors, this represents only a 3% loss at the sole population scale, in the Eastern Channel. However, when we assumed that prior to anthropogenic disturbance the juvenile density in the Seine estuary might have been equivalent to the current density of adjacent sectors with higher quality, the loss in abundance could be nearly 23% (8-36%). Results suggest that the loss in habitat surface combined with habitat degradation has led to an important loss in the contribution of the Seine estuary nursery to the whole sole population in the Eastern Channel. (C) 2009 Elsevier BM. All rights reserved.
Journal Of Sea Research (1385-1101) (Elsevier Science Bv), 2010-07 , Vol. 64 , N. 1-2 , P. 34-44

Droits : 2009 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/00008/11921/9799.pdf
DOI:10.1016/j.seares.2009.08.003
http://archimer.ifremer.fr/doc/00008/11921/