Publication Abstract

Geographical variation in size-at-maturity and fecundity in Homarus gammarus: implications for management

J. Addison, O. Tully, A. L. Agnalt and J. Idoine

Effective fisheries management requires that management measures are applied on a geographical scale which appropriately reflects spatial variation in population parameters. The European lobster, Homarus gammarus, is distributed from Morocco to northern Norway and in the Mediterranean Sea, and thus Europe-wide management measures may not be appropriate. In this paper we review information on female size-at-maturity and fecundity in Homarus gammarus collected from studies carried out in a wide range of geographical sites primarily in the UK, Ireland and Norway. We discuss the possible environmental and fishery-induced causes of observed variation in these reproductive parameters across geographical locations, and for data on size-at-maturity, we discuss whether the observed variation is caused by true geographical variation or by differences in techniques for assessing size-at-maturity. Finally we use a life history model to investigate the impact on yield and egg-per-recruit levels of various management options. In particular, we examine the sensitivity of the model’s predictions to observed differences in size-at-maturity and fecundity in relation to management options such as prohibiting the landing of berried females, V-notching and minimum and maximum landing sizes.

Reference:

J. Addison, O. Tully, A. L. Agnalt and J. Idoine. (2004). Geographical variation in size-at-maturity and fecundity in Homarus gammarus: implications for management. International Conference and Workshop on Lobster Biology and Management, 8-13/2/04, Hobart, Tasmania.