Ecosystem services provided by a non-cultured shellfish species: The common cockle Cerastoderma edule.

Coastal habitats provide many important ecosystem services. The substantial role of shellfish in delivering ecosystem services is increasingly recognised, usually with a focus on cultured species, but wild-harvested bivalve species have largely been ignored. This study aimed to collate evidence and data to demonstrate the substantial role played by Europe's main wild-harvested bivalve species, the common cockle Cerastoderma edule, and to assess the ecosystem services that cockles provide. Data and information are synthesised from five countries along the Atlantic European coast with a long history of cockle fisheries. The cockle helps to modify habitat and support biodiversity, and plays a key role in the supporting services on which many of the other services depend. As well as providing food for people, cockles remove nitrogen, phosphorus and carbon from the marine environment, and have a strong cultural influence in these countries along the Atlantic coast. Preliminary economic valuation of some of these services in a European context is provided, and key knowledge gaps identified. It is concluded that the cockle has the potential to become (i) an important focus of conservation and improved sustainable management practices in coastal areas and communities, and (ii) a suitable model species to study the integration of cultural ecosystem services within the broader application of 'ecosystem services'.

What does three years of hunting great cormorants, Phalacrocorax carbo, tell us? Shooting autumn-staging birds as a means of reducing numbers locally.

BACKGROUND: The population of great cormorants, Phalacrocorax carbo, has increased markedly in Europe in the last 30 years, creating conflicts primarily with fisheries' interests. Some advocate that there should be a reduction in bird numbers on anything from local to regional and pan-European levels. The effect of attempts to reduce cormorant numbers by shooting to kill and by shooting to reinforce the scaring of birds in two Danish fjords was studied. RESULTS: A total of 308, 364 and 459 cormorants were shot in the two fjords during each of three annual hunting seasons. When shooting was intensive over a series of days near the birds' main roosting and sleeping place, numbers dropped significantly compared with non-shooting years. No significant scaring effect was detected when shooting was carried out only at random along the shores of the fjords. None of the shooting treatments had an effect on the number of cormorants occurring in subsequent years. CONCLUSION: These results indicate that large efforts can be invested in shooting to scare and kill cormorants without reaching any desired reduction in numbers, in particular when the shooting is not coordinated in time and space and not undertaken at key roosting sites.

Similar estimates of population genetic composition and sex ratio derived from carcasses and faeces of Eurasian otter Lutra lutra.

Collecting faeces is viewed as a potentially efficient way to sample elusive animals. Nonetheless, any biases in estimates of population composition associated with such sampling remain uncharacterized. The goal of this study was to compare estimates of genetic composition and sex ratio derived from Eurasian otter Lutra lutra spraints (faeces) with estimates derived from carcasses. Twenty per cent of 426 wild-collected spraints from SW England yielded composite genotypes for 7-9 microsatellites and the SRY gene. The expected number of incorrect spraint genotypes was negligible, given the proportions of allele dropout and false allele detection estimated using paired blood and spraint samples of three captive otters. Fifty-two different spraint genotypes were detected and compared with genotypes of 70 otter carcasses from the same area. Carcass and spraint genotypes did not differ significantly in mean number of alleles, mean unbiased heterozygosity or sex ratio, although statistical power to detect all but large differences in sex ratio was low. The genetic compositions of carcass and spraint genotypes were very similar according to confidence intervals of theta and two methods for assigning composite genotypes to groups. A distinct group of approximately 11 carcass and spraint genotypes was detected using the latter methods. The results suggest that spraints can yield unbiased estimates of population genetic composition and sex ratio.