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Fish Farmers (fish + farmer)
Selected AbstractsAccess to and Legal Protection of Aquaculture Genetic Resources,Norwegian PerspectivesTHE JOURNAL OF WORLD INTELLECTUAL PROPERTY, Issue 4 2006G. Kristin Rosendal A central socio-economic challenge in fish breeding arises from issues relating to access to and exclusive rights of genetic resources. Breeding companies need legal or biological protection measures to assure revenues from genetic improvement and investment in genetic material. Fish farmers and fish breeders need access to genetic resources for food production and further development and sustainable use of fish genetic material. How can a balance be created between the need for unencumbered and free access, on the one hand, and, on the other hand, the need to ensure a right to the results from breeding and research? First, we provide a brief outline of the rationale for ensuring access to and for using legal measures for protection of breeding materials in aquaculture. Secondly, we examine how technological developments and biological features present options and barriers that will affect choices relating to access and property right issues to fish genetic resources. [source] Fishing near sea-cage farms along the coast of the Turkish Aegean SeaJOURNAL OF APPLIED ICHTHYOLOGY, Issue 1 2010O. Akyol Summary This study reports on the yield of commercially important species captured intentionally around and under fish-cage farms using specific types of gear from both sea-cage farmers and artisanal fishermen, and to identify the species composition of these catches. The 2004,2008 research was carried out in 21 fish farms, randomly chosen along the coast of Izmir Province on the Aegean Sea. A total of 91 persons were interviewed, including directors, fishers from the fish farms and artisanal fishermen. The technical characteristics of a special trap used by some fish farmers were diagramed. Total wild fish catch quantities as well the species raised in the sea-cages were recorded. A total of 34 finfish and four invertebrate species were identified from the sea-cage farm fishery. Eight fish species according to the descending quantities raised were bogue (Boops boops), grey mullet (Mugil spp.), blackspot seabream (Pagellus bogaraveo), salema (Sarpa salpa), common two-banded seabream (Diplodus vulgaris), annular seabream (Diplodus annularis), striped seabream (Lithognathus mormyrus) and gilthead seabream (Sparus aurata). Mean quantities of wild fish caught from 2004 to 2008 in a sampled farm were 13 998 ± 210, 34 434 ± 482, 30 116 ± 529, 27 893 ± 429, and 32 366 ± 808 kg, respectively. There were significant differences between fish amounts and years (P < 0.05). [source] Economic Analysis of Nile Tilapia (Oreochromis niloticus) Production in TanzaniaJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2006Aloyce R Kaliba In Tanzania, Nile tilapia culture is a promising aquaculture enterprise. Information on production costs could assist fish farmers in economic and financial planning. Economic profitability of small-scale Nile tilapia production in Tanzania is analyzed using a model that simulates individual fish growth and takes into account fish population dynamics in the pond. The results suggest that the current practiced mixed-sex tilapia culture without predation is not economically sustainable. Extension efforts should be geared toward developing a Nile tilapia production system that is based on a hand-sexed all-male tilapia. Meanwhile catfish can be introduced in ponds to control overcrowding in mixed-sex tilapia culture without predation. Studies to determine optimal pond sizes, availability of feed, and a quality fingerling supply chain are also fundamental for developing a sustainable Nile tilapia production system in Tanzania. Under improved Nile tilapia production systems, returns are high enough to justify investment through borrowed capital from formal institutions. [source] Investigations on the digestibility and metabolizability of the major nutrients and energy of maize leaves and barnyard grass in grass carp (Ctenopharyngodon idella)AQUACULTURE NUTRITION, Issue 3 2010E.B. DONGMEZA Abstract In the uplands of northern Vietnam, culture of grass carp contributes significantly to income and household food security of Black Thai farmers. Maize is one of the most important upland crops and barnyard grass is the most important weed in the paddy rice fields. Thus, these are frequently used by small-scale fish farmers as fish feed. An 8-week feeding trial was conducted simultaneously in a recirculation and in a respirometric system to determine the digestibility and metabolizability of the nutrients of maize leaves and barnyard grass, to assess their crude protein, lipid and energy conversion and to estimate the energy allocation in grass carp. The following diets were used: diet ,A' (reference diet) containing 39% crude protein with 19.8 MJ kg,1 gross energy; diets ,B', ,C' and ,D', which contained the same amount of the reference diet as the control diet, supplemented with a known amount of dried barnyard grass, dried maize leaves or fresh maize leaves, respectively. Five fish were assigned to each treatment in each experimental unit. Reference and test diets were fed to fish and faecal samples were collected and the oxygen consumption was measured in order to set up an energy budget of the fish over the whole experimental period. The weekly development of the body weight was recorded. The body weight gain of the fish fed diet D was significantly higher than that of the group fed diet A, which also in turn was significantly higher than that of fish fed diet B or C. The apparent digestibility coefficients (ADC) of nutrients and gross energy for the different experimental diets in fish kept in the aquaria were, for diets A, B, C and D respectively, 94.1%, 60.9%, 70.5% and 84.7% for protein, 91.3%, 60.7%, 76.8% and 71.8% for lipid; 95.9%, 44.5%, 60.6% and 69.1% for gross energy. The partial ADC of plant leaf ingredients were determined and barnyard grass and dried maize leaves were found to be not only poorly digestible but having negative impact on the digestibility of the reference diet, while fresh maize leaves were well digested. The results of the present study indicated that fresh maize leaves have a good potential to be used as supplement in diets for grass carp. [source] Aquaculture information sources for small-scale fish farmers: the case of GhanaAQUACULTURE RESEARCH, Issue 13 2009Kwamena K Quagrainie Abstract The Ghana ministry of fisheries and the ministry of Agriculture provide free extension services and other technical services to fish farmers in Ghana, e.g. producing fingerlings at government-operated fish hatcheries for sale to farmers. Non-governmental organizations and universities have also provided some technical assistance to fish farmers in efforts towards the development of aquaculture in Ghana. The study identified the various sources of aquaculture information to Ghanaian fish farmers and examined the factors that affected their decision to utilize these alternative sources of information. Using choice modelling techniques, the study found that the probability of farmers seeking information on aquaculture from the Ghana government increases with literacy by about 43% more than with illiteracy and by about 34% with an increase in total size of ponds. The probability that a literate farmer will choose to obtain aquaculture information from a non-governmental organization decreased by about 10% compared with an illiterate farmer. The probability of choosing ,other sources' for aquaculture information increased by about 27% for farmers residing in Ashanti region compared with farmers in the Brong-Ahafo region but the probability of farmers seeking information from ,other sources' decreased with literacy and number of years farming. [source] Timing and duration of constant light affects rainbow trout (Oncorhynchus mykiss) growth during autumn,spring grow-out in freshwaterAQUACULTURE RESEARCH, Issue 13 2009John Taylor Abstract Photoperiod enhancement of growth is becoming an area of increasing interest as a means of enhancing rainbow trout production efficiency in commercial practice. This paper examines the possible implications of shortening periods of constant light (LL) exposure on rainbow trout growth during autumn,spring grow-out under ambient water temperatures in freshwater to portion size. Triplicate groups of juvenile all-female rainbow trout were permanently exposed to LL in October, November, December or January. Growth was monitored and compared with those maintained under a simulated natural photoperiod (SNP) until the following May. Permanent exposure to LL (all treatments) resulted in significantly greater weight gain of rainbow trout than those under SNP. Furthermore, greatest growth was achieved when fish were left permanently exposed to LL from October. These findings suggest there may be implications for fish farmers if the period of photoperiod exposure is reduced, or timing of application is not considered with regards to ambient water temperatures. [source] | ||||||||||