The occurrence of Norway lobster (Nephrops norvegicus) larvae off the Portuguese coast

Abstract

Norway lobster (Nephrops norvegicus) larvae have been investigated in northern European waters, particularly in the Irish Sea where biomass estimation studies are used for the annual larval production method. However, nothing is known of their distribution in southern European waters, off the Portuguese coast or in the Mediterranean Sea. From zooplankton sampling off the Portuguese coast between October 1986 and March 2001, planktonic larvae of this species were known to occur from January to April off the north-west and south coasts. In the north, larvae were only observed over the shelf, shoreward of the upper limit of the adults' distribution. Larvae were never collected off the south-west coast of Portugal, even though this is one of the largest fishing grounds for this species off the Iberian Peninsula. The absence of larvae from all surveys in this region may relate to the local oceanographic conditions and shelf width.