Nectonema species are parasites of decapod crustaceans and the only known representatives of the otherwise freshwater/terrestrial taxon Nematomorpha. We report the American lobster, Homarus americanus, as a new host for Nectonema agile, a first record among astacidean decapods. A female, about 590 mm long, was found in the body cavity of one female lobster specimen. We assume lobster to be a very rare host for Nectonema.

Studies of marine reserves typically focus upon differences in the size and abundance of target organisms inside versus outside reserve borders, but they seldom provide spatially explicit measurements of how reserves influence mortality rates. This study investigated mortality rates for female California spiny lobster (Panulirus interruptus) at multiple sites inside and outside of three marine reserves at the Santa Barbara Channel Islands, California, USA. Mean total mortality (Z) of female lobsters was lower at sites inside reserves (Z = 0.22 [± 0.05 SE]) than at sites outside reserves (Z = 0.59 [± 0.02 SE]). Mean mortality at all sites inside reserves, and among sites near reserve centres (where Z = 0.17 [± 0.05 SE]), was similar to estimates of natural mortality for other temperate spiny lobster species. Among sites inside reserves, there was a positive relationship between mortality and proximity to reserve borders, but this relationship was absent among sites outside reserves. Mortality estimates were much more variable among sites inside reserves than at sites in fished areas. This variation is probably due to differential emigration rates from the three reserves, as well as site-specific ecological factors that influence population structure, demonstrating the importance of spatially explicit reserve sampling and understanding how ecological heterogeneity influences fisheries models.

The natural (226Ra, 228Th, 232Th and 40K) and anthropogenic (137Cs) radionuclides concentrations in three crustaceans species (Penaeus monodon, Metapenaeus monoceros and Panulirus versicolor), collected from the bay of Bengal, were determined with an aim of assessing any internal radiation hazard due to consumption of the shell fishes and establishing a database for radioactivity levels of the species. Very low level of radioactivity was observed in all the species. The average activity of 226Ra observed in P. monodon was 1.21 ± 0.27 Bq kg–1 fw; in M. monoceros was 0.70 ± 0.08 Bq kg–1 fw, and in Panulirus versicolor was 1.04 ± 0.09 Bq kg–1 fw. The activity of 232Th observed in these species was 1.30 ± 0.37, 0.76 ± 0.34 and 1.32 ± 0.70 Bq kg–1 fw, and 228Th was 0.55 ± 0.26, 0.31 ± 0.14 and 0.74 ± 0.22 Bq kg–1 fw, respectively. The average activity of 40K observed in these species was 12.56 ± 1.18, 6.38 ± 1.02 and 10.07 ± 1.52 Bq kg–1 fw, respectively. The activity of radiocaesium (137Cs) was below detection limit. The results indicate that the natural and artificial radionuclides observed in three crustaceans species are safe for human health. A significant relationship was observed between 226Ra and 232Th in both the P. monodon (r = 0.839, p ≤  0.05, df = 4) and the Panulirus versicolor (r = 0.906, p ≤  0.05, df = 4).

Marine fisheries and the ecosystems that sustain them are increasingly beset by environmental deterioration, and the problem is particularly acute in coastal zones where human populations are increasing. In the best of circumstances, fishery managers are faced with the multiple, often conflicting, demands of resource users, politicians, and scientists when considering strategies for resource management. A further challenge is that management decisions must be made against a backdrop of a deteriorating environment and the shifting status of coastal ecosystem integrity. Traditional tools for single-species management may be inadequate in these settings. Furthermore, the necessary empirical data to appropriately parameterize models with vital rates representative of an altered environment are often lacking. Thus, we need approaches that better approximate the complicated dynamics between environmental conditions, fishery impacts, and multi-species interactions. Spatially-explicit, individual-based simulation modeling potentially permits this kind of integration, but it has seen limited use in marine resource management, especially with respect to benthic resources. My colleagues and I have used this approach, combined with targeted experimental work, to explore the impacts of nursery habitat deterioration, coastal freshwater management, and fishery activities on Caribbean spiny lobster populations and sponge community structure in the Florida Keys, Florida (USA). Although not applicable for all resource management situations, our experiences provide an example of the potential use of spatially-explicit, individual-based modeling and targeted empirical science in predicting resource conditions in a dynamic environment.

This presentation describes a series of experiments designed to study the biology and fisheries of decapod crustaceans in the Western Mediterranean in the framework of research programmes carried out by Instituto de Ciencias del Mar (CSIC) in Barcelona. The results have been used to highlight the importance of bio-ecological studies on commercial species in instituting fisheries management programmes. A series of examples are used to demonstrate how integrating knowledge of the effects of biological and ecological aspects (growth, reproduction, migrations, aggregations, environmental factors, sexual dimorphism, behaviour, etc.) in the fisheries, is essential to avoid sampling errors and errors in stock assessment. Finally, potential directions for future research in this area are discussed.