Investigations on the structural and operational changes of Ring Seine Fishing Systems of Kerala and its Life Cycle Assessment (lCA)

The study covers theFishing capture technology innovation includes the catching of aquatic animal, using any kind of gear techniques, operated from a vessel. Utilization of fishing techniques varies, depending upon the type of fisheries, and can go from a basic and little hook connected to a line to huge and complex mid water trawls or seines operated by large fishing vessels.The size and autonomy of a fishing vessel is largely determined by its ability to handle, process and store fish in good condition on board, and thus these two characteristics have been greatly influenced by the introduction and utilization of ice and refrigeration machinery. Other technological developments especially hydraulic hauling machinery, fish finding electronics and synthetic twines have also had a major impact on the efficiency and profitability of fishing vessels.A wide variety of fishing gears and practices ranging from small-scale artisanal to advanced mechanised systems are used for fish capture in Kerala. Most important among these fishing gears are trawls, seines, lines, gillnets and entangling nets and traps The modern sector was introduced in 1953 at Neendakara, Shakthikulangara region under the initiative of Indo-Norwegian project (INP). The novel facilities introduced in fishing industry by Indo- Norwegian project accordingly are mechanically operated new boats with new fishing nets. Soon after mechanization, motorization programme gained momentum in Kerala especially in Alleppey, Ernakulam and Kollam districts.

Studies on Energy Requirement and Conservation in Selected Fish Harvesting Systems

Present work deals with the studies on energy requirement and convervation in selected fish harvesting systems.Modem fishing is one of the most energy intensive methods of food production. Fossil fuels used for motorised and mechanised fishing are nonrenewable and limited. Most of the environmental problems that confront mankind today are connected to the use of energy in one way or another. Code of Conduct for Responsible Fisheries (FAO, 1995) highlights the need for efficient use of energy in the fisheries sector. Information on energy requirement in different fish harvesting systems, based on the principles of energy analysis, is entirely lacking in respect of Indian fisheries. Such an analysis will provide an unbiased decision making support for maximising the yield per unit of non-renewable energy use, from different fishery resource systems, by rational deployment of harvesting systems. In the present study, results of investigations conducted during 1997-2000 on energy requirement in selected fish harvesting systems and approaches to energy conservation in fishing, are presented along with a detailed description of the fish harvesting systems and their operation. The content of the thesis is organised into 8 Chapters.

Dinâmica reprodutiva de Oligosarcus jenynsii e O. robustus (Characiformes, Characidae) na lagoa Fortaleza, Rio Grande do Sul, Brasil

Oligosarcus jenynsii (Günther, 1864) and O. robustus Menezes, 1969 are fish species distributed in Rio Grande do Sul, Brazil, Uruguay, and northern Argentina. The reproductive period and recruitment, sex ratio, absolute and relative fecundity, and body length at first gonadal maturation of the two carnivorous species from Fortaleza Lagoon were analized. The specimens were sampled monthly, from May 2000 to April 2001, with fishing effort of 24 hours/month, using stationary gillnets of different mesh sizes and seine net (three samples per edge). The records of each individual included total length, total weight, gonad weight, sex and gonadal maturity stage. The reproductive period of both O. jenynsii and O. robustus ranges from May/June to November/December, according to the bimonthly variation of the mean values of gonosomatic index, and the relative frequencies of the gonadal maturation stages. Recruitment of new individuals to the population occurs from November/December to March/April. The sex ratio is different from 1:1 for O. jenynsii and similar to 1:1 for O. robustus. The mean absolute fecundity, calculated by counting sub-sampled oocytes from mature females, was 14,483 oocytes for O. jenynsii, and 16,308 oocytes for O. robustus. The first maturation curve shows that O. jenynsii begins to reproduce between 84 mm and 104 mm (total length), and O. robustus between 126 mm and 146 mm, probably at similar ages.

Pesca exploratoria con redes chinchorro manual en la región Lambayeque

La pesca exploratoria se realizó del 26 de mayo al 5 de junio del 2009, efectuando 15 lances de pesca para evaluar el comportamiento del chinchorro manual. Se usó redes con copos convencionales de malla diamante de 50 mm y malla cuadrada de 60 mm y, una red con sobrecopo de 25 mm de malla. Del total de la captura el 73% fue bagre (Galeichthys peruvianus) y 12% lisa (Mugil cephalus). El bagre fue retenido en el copo (95%) con talla media de 27 cm y la captura de lisa fue por agallamiento en la sección de las alas de la red (92%) con talla media de 30 cm. El chinchorro es un arte de pesca que presenta baja selectividad debido a la diversidad de especies capturadas en estado juvenil y madurante (e.g. bagre).

Composição e abundância da ictiofauna de duas lagunas costeiras da América do Sul Austral: lagoa do Peixe (31ºS; 51ºW), Brasil e laguna Mar Chiquita (37ºS; 57ºW), Argentina

This article describes and compares the shallow water fish-fauna from two coastal lagoons (Peixe Lagoon, in Brazil, and Mar Chiquita Lagoon, in Argentina). Peixe Lagoon was sampled between 2000 and 2001 using a 9 m beach seine net (12 mm bar mesh in the wings and 5 mm in the centre 3 m section) totalizing 125 samples, which yielded 33,848 individuals and 32 species. Mar Chiquita Lagoon was sampled from 1995 to 1998 using a 21) m beach seine net (12 mm bar mesh) totalizing 232 samples resulting in 31,097 individuals of 28 species. A total of 47 species were observed in both lagoons and 13 were shared. The "marine-estuarine-related" species were similar and dominate the fish assemblages in both lagoons. The remaining species were similar to the species collected along the southern Brazil, Uruguay and Argentina estuaries. The number of species observed in Peixe Lagoon (S = 32) was higher than in Mar Chiquita Lagoon (S = 28) and is probably associated with a strong latitudinal gradient of species richness increasing from north to south. Considering that the Peixe Lagoon and Mar Chiquita Lagoon are isolated by the large estuaries of Patos Lagoon and Prata River, the composition of the species with low abundance and occasional occurrence were different for each local studied. These results expand the knowledge for the fauna of both sites and help conservation and management from both lagoons.

The value of patches of intertidal seagrass to prawns depends on their proximity to mangroves

Penaeid prawns were sampled with a small seine net to test whether catches of postlarvae and juveniles in seagrass were affected by the distance of the seagrass (mainly Zostera capricorni) from mangroves and the density of the seagrass in a subtropical marine embayment. Sampling was replicated on the western and eastern sides of Moreton Bay, Queensland, Australia. Information on catches was combined with broad-scale spatial information on the distribution of habitats to estimate the contribution of four different categories of habitat (proximal dense seagrass, distal dense seagrass, proximal sparse seagrass, distal sparse seagrass) to the overall population of small prawns in these regions of Moreton Bay. The abundance of Penaeus plebejus and Metapenaeus bennettae was significantly and consistently greater in dense seagrass proximal to mangroves than in other types of habitat. Additionally, sparse seagrass close to mangroves supported more of these species than dense seagrass farther away, indicating that the role of spatial arrangement of habitats was more important than the effects of structural complexity alone. In contrast, the abundance of P. esculentus tended to be greatest in sparse seagrass distal from mangroves compared with the other habitats. The scaling up of the results from different seagrass types suggests that proximal seagrass beds on both sides of Moreton Bay provide by far the greatest contribution of juvenile M. bennettae and P. plebejus to the overall populations in the Bay.

Temporal variation in habitat use by nekton in a subtropical estuarine system

Utilisation by fish of different estuarine habitats is known to vary at many different temporal scales, however no study to date has examined how utilisation varies at all the relevant times scales simultaneously. Here, we compare the utilisation by fish of sandy, intertidal foreshore habitats in a subtropical estuary at four temporal scales: between major spawning periods (spring/ summer and winter), among months within spawning periods, between the full and new moon each month, and between night and day within those lunar phases. Comparisons of assemblage composition, abundance of individuals and of fish in seven different,ecological guilds' were used to identify the temporal scales at which fish varied their use of unvegetated sandy habitats in the lower Noosa Estuary, Queensland, Australia. Fish assemblages were sampled with a seine net at three different regions. The most numerically dominant species caught were southern herring (Herklotsichthys castelnaui: Clupeidae), sand whiting (Sillago ciliata: Sillaginidae), weeping toadfish (Torquigener pleurogramma: Tetraodomidae), and silver biddy (Gerres subfasciatus: Gerreidae). Considerable variation at a range of temporal scales from short term (day versus night) to longer term (spawning periods) was detected for all but one of the variables examined. The clearest patterns were observed for diurnal effects, where generally abundance was greater at night than during the day. There were also strong lunar effects, although there were no consistent patterns between full moon and new moon periods. Significant differences among months within spawning periods were more common than differences between the actual spawning periods. The results clearly indicate that utilisation of sandy, unvegetated estuarine habitats is very dynamic and highly variable in space and time. (c) 2006 Elsevier B.V. All rights reserved.

Stomach content records for pelagic fish (herring, mackerel, blue whiting, albacore and bluefin tuna) in the northeast Atlantic

Fish stomach content records extracted from the DAPSTOM 4.5 database (held at the UK Centre for Environment, Fisheries and Aquaculture Science - CEFAS). Data collated as part of the EU Euro-Basin project and specifically concerning herring (Clupea harengus), mackerel (Scomber scombrus), blue whiting (Micromesistius poutassou), albacore (Thunnus alalunga) and bluefin tuna (Thunnus thynnus). The data set consist of 20720 records - collected throughout the northeast Atlantic, between 1906 and 2011 - mostly during routine fisheries monitoring research cruises.

Preliminary interpretation of growth ring on the otolith of Boops boops off Gran Canaria (Canary Islands)

Máster en Gestión Sostenible de Recursos Pesqueros