A workshop to discuss the feasibility and practicality of developing ecological quality objectives for aggregate extraction areas Final report

File no.: CDEP 84/5/296. Workshop held at CEFAS Lowestoft Laboratory on 11 and 12 October 2001Available from British Library Document Supply Centre-DSC:m02/33483 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Monitoring the outcome of a seasonal dredging restriction A precautionary approach

SIGLEAvailable from British Library Document Supply Centre-DSC:8164.2675(no 115) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The coastal fisheries of England and Wales, part IV A review of their status 1999-2001

SIGLEAvailable from British Library Document Supply Centre-DSC:8164.2675(no 116) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Further identification and acquisition of bathymetric data for Irish Sea modelling

Produced for the DETRAvailable from British Library Document Supply Centre-DSC:m02/240089 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Genome-wide association and genomic prediction of growth traits in the European flat oyster (Ostrea edulis)

The European flat oyster (Ostrea edulis) is a bivalve mollusc that was once widely distributed across Europe and represented an important food resource for humans for centuries. Populations of O. edulis experienced a severe decline across their biogeographic range mainly due to overexploitation and disease outbreaks. To restore the economic and ecological benefits of European flat oyster populations, extensive protection and restoration efforts are in place within Europe. In line with the increasing interest in supporting restoration and oyster farming through the breeding of stocks with enhanced performance, the present study aimed to evaluate the potential of genomic selection for improving growth traits in a European flat oyster population obtained from successive mass-spawning events. Four growth-related traits were evaluated: total weight (TW), shell height (SH), shell width (SW) and shell length (SL). The heritability of the growth traits was in the low-moderate range, with estimates of 0.45, 0.37, 0.22, and 0.32 for TW, SH, SW and SL, respectively. A genome-wide association analysis revealed a largely polygenic architecture for the four growth traits, with two distinct QTLs detected on chromosome 4. To investigate whether genomic selection can be implemented in flat oyster breeding at a reduced cost, the utility of low-density SNP panels was assessed. Genomic prediction accuracies using the full density panel were high (> 0.83 for all traits). The evaluation of the effect of reducing the number of markers used to predict genomic breeding values revealed that similar selection accuracies could be achieved for all traits with 2K SNPs as for a full panel containing 4,577 SNPs. Only slight reductions in accuracies were observed at the lowest SNP density tested (i.e., 100 SNPs), likely due to a high relatedness between individuals being included in the training and validation sets during cross-validation. Overall, our results suggest that the genetic improvement of growth traits in oysters is feasible. Nevertheless, and although low-density SNP panels appear as a promising strategy for applying GS at a reduced cost, additional populations with different degrees of genetic relatedness should be assessed to derive estimates of prediction accuracies to be expected in practical breeding programmes