Sunday 11 May 2014

College of Science Postgraduate Seminar Series 15th May 2014

College of Science Postgraduate Seminar Series - Spring 2014
15th May 2014 - 1pm - Zoology Museum (Wallace 129)

Does the importation of live American lobster pose a threat to native European lobster populations? 

Charlotte Eve Davies

(PhD student, Swansea University, UK)

Charlotte is a third year bioscience PhD student under the primary supervision of Professor Andrew Rowley. After graduating from a BSc Biology at Swansea University in 2011, she is now studying the various diseases and parasites afflicting the European lobster.

Since 1989 there have been over 100 recorded incidences of American lobster (H. americanus) being found in European waters. Usually a result of escapees from ships, these ‘invasive’ lobsters may have serious implications for our native lobster (H. gammarus). European lobsters have an estimated value of £26.5 m to the U.K. lobster fishing industry therefore it is important to monitor the effect that these introduced species may have – there have already been reports of Homarus hybrids caused by inter-breeding and there are fears for the introduction of disease.

A form of shell disease, termed epizootic shell disease (ESD), has hampered southern regions of the North American lobster fishery for over a decade; however, there are recent signs of the syndrome spreading farther North. It is feared that this increasing prevalence of shell disease, plus American lobsters being found in European waters, could have serious implications for the health of native European lobster populations.

Our study examined the susceptibility of American and European lobsters to shell disease. Molecular techniques and scanning electron microscopy were used to identify differences between the cuticle structure of both species, as well as bacterial flora and subsequent structural modifications of the cuticle after induced damage.

The carapace and claws of American lobsters were found to be thinner and more vulnerable to abrasion damage than their European counterparts. The induced damage resulted in the formation of shell disease lesions on the claw and carapace of both species; however, American lobsters, unlike their European counterparts, had extensive bacterial colonisation on the margins of these lesions. It was deduced that the cuticle of the European lobster may be less susceptible to damage and resulting microbial colonisation.

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