Los crustáceos decápodos Brachyura del litoral bonaerense (R.Argentina)

In this work the taxonomy of the Brachyura Decapod Crustacea from fthe shelfwaters of the Province of Buenos Aires, Argentina (South Atlantic Ocean) is described, with particular reference to the biology and zoogeography. The material and methods are described and various zoogeographical problems are considered. A total of 25 species were encountered, and each one is briefly described together with its ecological and biological data. In many cases the geographical distribution has been extgended. Keys are given for the identification of the more common Brachyura from Argentina, as also for the sub-divisions of the Brachyura, including ffamilies, subfamilies and genera. The so-called "cangrejal" community (community composed of semiaquatic crabs) of the river Salado was studied, which was composed of Chasmagnathus granulata crabs. The species Uca uruguayensis formed the outer limit of the "cangrejal" community.

Pour les vingt ans du C.R.O.

Founded in 1959, the Centre de Recherches Océanographiques is now twenty years old. During its existence, its administrative structure and its internal organization have considerably changed. It is now a research center placed under the supervision of the State Secretary for Scientific Research but, for management, it has been committed to the care of Orstom, a French organization specialized into scientific and technological research in the developing countries. Orstom also partially finances the research work, whose aims are decided by special commissions, which in their choices take into account the fundamental options of the plans of development of the government of Côte d'Ivoire.

Méthodes des mesures des biovolumes, poids secs, poids secs sans cendres et des éléments C, N, P du mésozooplancton utilisées au C.R.O. d'Abidjan

Methods for the estimation of zooplankton biomasses, used in the Oceanographic Research Center of Abidjan are presented. They deal with settled and displacement volumes, dry weight and ash-free dry weight, elementary carbon, nitrogen and phosphorus composition. The dry weight method is detailed: elimination of salt by a fresh water stream, preservation of dry samples at -20 degrees Celsius, rehydration during weighing. A few comments on the 'CHN' analysed values are made: at 1,100 degrees Celsius, most of the carbon is organic, only 10% of the mineral fraction being analysed.

Introduction of boulders to the R. Ribble: a short geomorphological evaluation

The placement of artificial in-channel structures (including large cobbles / boulders) into any fluvial system needs to be considered carefully. This brief report summarises considerations for boulder introductions into the River Ribble from a geomorphological perspective. This includes boulder placement and shape. Bagnold's Excess Stream Power Method is used to calculate the boulder sizing.

Use of telemetric tracking to examine environmental influences on catch/effort indices. A case study of Atlantic Salmon (Salmo salar L.)in the R. Tywi, S. Wales

A case study of Atlantic Salmon runs into the R. Tyvi (S. Wales) is presented. Radio tracking of over 200 salmon in 1988 and 1989 has demonstrated that flow is an important factor in modifying both run timing and migratory success. Entry of salmon into the river is typically in response to flow events, and periods of low falling flows delay entry and may directly result in reduced runs into the river. Delayed entry may also increase the proportion of the run migrating after the end of both rod and net fishing seasons. The implications of these results for net and rod catch and catch/effort data are discussed, using both statutory reported catch data and data from specific catch/effort studies. Flow is demonstrated to be a dominant factor in determining the within-season distribution of rod catch and catch/effort during low-flow years. Estuarial seine net catch and catch/effort tend to be controlled more by time of return than by flow although low flows may delay runs. Annual reported rod catch is correlated with flow, which controls in season availability, catchability and consequently the amount of fishing effort. Use of catch or catch/effort data should take account of inter-year variations in flow and other environmental factors. Although catch and catch/effort are valuable indicators of fishery performance, they are inadequate to represent changing stock levels.

A computer software package for assessing and managing risks posed by experiments with genetically modified fish and shellfish

Assessment and management of risk is needed for sustainable use of genetically modified aquatic organisms (aquatic GMOs). A computer software package for safely conducting research with genetically modified fish and shellfish is described. By answering a series of questions about the organism and the accessible aquatic ecosystem, a researcher or oversight authority can either identify specific risks or conclude that there is a specific reason for safety of the experiment. Risk assessment protocols with examples involving transgenic coho salmon, triploid grass carp and hybrid tilapia are described. In case a specific risk is identified, the user is led to consider risk management measures, involving culture methods, facilities design and operations management, to minimize the risk. Key features of the software are its user-friendly organization; easy access to explanatory text, literature citations and glossary; and automated completion of a worksheet. Documented completion of the Performance Standards can facilitate approval of a well designed experiment by oversight authorities.

Population dynamics and exploitation of Metapenaeus affinis in Kuwaiti waters

Length-frequency data of Metapenaeus affinis collected from the trawl catches of R/V Bahith in Kuwaiti waters from 1985 to 1989 were combined with estimates of monthly total catch by the commercial and small-scale fleets operating in Kuwait, and analyzed using the Compleat ELEFAN software package. A major recruitment pulse of M. affinis occurs in spring and a minor one in autumn. Optimum relative yield per recruit (Y'/R) is obtained with the length-at-first capture (L sub(c)) of 24.4 cm CL for females and < 17.6 m CL for males. Virtual population analysis results indicated that the biomasses have decreased during the last three-year period for which data were available.

Diversification of aquaculture for empowerment to fisheries through institution village linkage programme (IVLP) in Kerala, India

Technology Assessment and Refinement through the Institution Village Linkage Programme (IVLP) is the latest participatory extension model successfully undertaken by the Indian Council of Agricultural Research in India. The Central Marine Fisheries Research Institute has been implementing IVLP since 2001 to assess and refine the technologies of the coastal agro ecosystems at Elamkunnapuzha village (Vypeen Island) in the Ernakulam District of Kerala. A series of need based location specific technology intervention plans have been introduced to overcome the social and biological constraints on farming practices in fisheries, livestock and agriculture, and implemented with the active participation of the stakeholders. The inferences drawn from IVLP ultimately form a package suitable for enhanced production in the costal agro ecosystem for replication to other areas with similar characteristics. This paper gives a brief account of the treatment packages applied in fisheries through various technological interventions and discusses the consequent yield and benefits obtained. The ‘integrated whole village development’ through the involvement of multi institutional teams and a participatory approach was accorded prime importance in the IVLP of Elamkunnapuzha, with a greater emphasis on marginal and small farmers and specifically focusing on women for poverty alleviation and equity under the coastal agro ec

Rangia and Marsh Clams, Rangia cuneata, R. flexuosa, and Polymesoda caroliniana, in Eastern México: Distribution, Biology and Ecology, and Historical Fisheries

Rangia and marsh clams, Rangia cuneata, R. flexuosa, and Polymesoda caroliniana, occur in brackish waters along México’s eastern coast from the northern State of Tamaulipas to the southern State of Campeche. The clams were important to the prehispanic people in the southern part of the State of Veracruz, where they were used as food and as construction material. In modern times, they are harvested for food. The fishermen wade in shallow water and harvest the clams in soft sediments by hand. Annual landings of whole clams during a recent 5-yr period, 1998–2002, were 1,139–1,695 t. The only area with a substantial ongoing clam fishery is in the Lower Papaloapan River Basin, including Alvarado Lagoon, where as many as 450 fishermen are licensed harvesters. This fishery for the Rangia and marsh clams is the most important clam fishery along México’s Gulf Coast.