Meiobenthos of the Shelf Waters of West Coast of India With Special Reference to Free-Living Marine Nematodes

Department of Marine Biology, Microbiology and Biotechnology, Cochin University of Science and Technology

Harvesting the sea: the exploitation of marine resources in the Roman Mediterranean

Harvesting the Sea provides the first systematic treatment of the exploitation of various marine resources, such as large-scale fishing, fish salting, salt and purple-dye production, and oyster and fish-farming, in the Roman world and its role within the ancient economy. Bringing together literary, epigraphic, and legal sources, with a wealth of archaeological data collected in recent years, the book shows that these marine resources were an important feature of the Roman economy and, in scope and market-oriented production, paralleled phenomena taking place in the Roman agricultural economy on land. The book also examines the importance of technological innovations, the organization of labour, and the use of the existing legal framework in defence of economic interests against competitors for the same natural resource.

The relationship between community-based organisations and the effective management of coastal and marine resources in the Western Indian Ocean region

This study examines the relationship between community based organisations and marine and coastal resource management in the Western Indian Ocean Region.

Multiyear predictability of tropical marine productivity

Phytoplankton is at the base of the marine food web. Its carbon fixation, the net primary productivity (NPP), sustains most living marine resources. In regions like the tropical Pacific (30°N–30°S), natural fluctuations of NPP have large impacts on marine ecosystems including fisheries. The capacity to predict these natural variations would provide an important asset to science-based management approaches but remains unexplored yet. In this paper, we demonstrate that natural variations of NPP in the tropical Pacific can be forecasted several years in advance beyond the physical environment, whereas those of sea surface temperature are limited to 1 y. These results open previously unidentified perspectives for the future development of science-based management techniques of marine ecosystems based on multiyear forecasts of NPP.

Dispersal in free-living, marine, benthic nematodes : passive or active processes?

Meiofauna, and especially marine nematodes are common in sediments around the world. Despite very wide ranging distributions in many nematode species, little is presently known about their dispersal mechanisms shaping these patterns. Rafting, and perhaps ballast water transport has been suggested as viable means for nematode long-range transport. On a much smaller scale other processes have been suggested for their dispersal. They generally include some form of passive suspension into the water column and later on a passive, haphazard settling back towards the bottom. Small-scale phenomena in nematode dispersal were studied by conducting a series of studies at Askö field station, Trosa Archipelago, Baltic proper. Studied aspects were one case of macrofaunal influence on nematode dispersal rate, using an amphipod, Monoporeia affinis as disturbing agent, and three different studies on mechanisms related to settling. The experiments were conducted both in laboratory and field settings. The amphipod Monoporeia affinis did not exert any influence on the dispersal rate in the nematodes. The nematode dispersal was only an effect of time, in the aspect that the more time that past, the more nematodes dispersed from their place of origin. The settling experiments revealed that nematodes do have an active component in their settling behaviour, as they were able to exert influence on the spot where they were to settle. They were able to choose settling spot in response to the food quality of the sediment. It also became evident that contrary to common belief, nematodes are able to extend their presence in the water column far beyond the times that would be predicted considering settling velocities and hydrodynamic conditions alone.

Demersal communities in the Mediterranean Sea: a case study of Triglidae (Osteichthyes, Scorpaeniformes) on the conservation and sustainable use of marine resources

An appropriate management of fisheries resources can only be achieved with the continuous supply of information on the structure and biology of populations, in order to predict the temporal fluctuations. This study supports the importance of investigating the bio-ecology of increasingly exploited and poorly known species, such as gurnards (Osteichthyes, Triglidae) from Adriatic Sea (Mediterranean), to quantify their ecological role into marine community. It also focuses on investigate inter and intra-specific structuring factor of Adriatic population. These objectives were achieved by: 1) investigating aspects of the population dynamics; 2) studying the feeding biology through the examination of stomach contents; 3) using sagittal otoliths as potential marker of species life cycle; 4) getting preliminary data on mDNA phylogeny. Gurnards showed a specie-specific “critical size” coinciding with the start of sexual maturity, the tendency to migrate to greater depths, a change of diet from crustaceans to fish and an increase of variety of food items eaten. Distribution of prey items, predator size range and depth distribution were the main dimensions that influence the breadth of trophic niche and the relative difference amongst Adriatic gurnards. Several feeding preferences were individuated and a possible impact among bigger-size gurnards and other commercial fishes (anchovy, gadoids) and Crustacea (such as mantis prawn and shrimps) were to be necessary considered. Otolith studies showed that gurnard species have a very fast growth despite other results in other areas; intra-specific differences and the increase in the variability of otolith shape, sulcus acusticus shape, S:O ratios, sulcus acusticus external crystals arrangement were shown between juveniles and adults and were linked to growth (individual genetic factors) and to environmental conditions (e.g. depth and trophic niche distribution). In order to facilitate correct biological interpretation of data, molecular data were obtained for comparing morphological distance to genetic ones.