Factors influencing choice of fishing location in Nankumba Peninsula: A case of study of gillnet and chilimira fisheries

This study was carried out to identify factors that influence choice of fishing location and carry out profitability analysis of Chilimira and Gillnet in different fishing locations. A survey using semi-structured questionnaire was administered to 99 Gillnet and 101 Chilimira fishers in Nankumba Peninsula in Mangochi District. The logit model was used to determine the factors influencing choice of fishing location among the fishers. The study showed that 92.1% of Chilimira fishers are operating in offshore areas while 69.7% Gillnet fishers are operating in inshore areas. Chilimira offshore fishers have higher daily average gross margins than their inshore counterparts and Gillnet fishers. However, they incurred more operating costs than the inshore Chilimira and Gillnet fishers. Furthermore, they find their fishing occupation more rewarding as evidenced by the higher returns to labour. The factors that influenced fisher’s choice of fishing location were Age of the fisher, type of fishing vessel and gear, possession of motor sail engine and access to information about previous day’s catch rates. Finally the study concluded that artisanal fishers in Malawi use different criteria in deciding where to fish. The criterion involves a complex interaction of biological, technological, personal and economical factors and time. However, the resource constrained artisanal fisher will need support to enable him exploit offshore fishery resources. Consequently the study recommends that appropriate fishery development interventions by the government and other stakeholders must adapt to the economics and lifestyles driving the artisanal fishers to fish in particular locations and therefore, build on this foundation to improve the existing fishing technologies.

Maryland commercial fisheries statistics, 1944-1945

This report presents a statistical analyses of the "fin" fisheries, as distinguished from the crab and oyster fisheries of Maryland, for 1944 and 1945. Comparative data on the catch by species, by area, and by gear, based principally on daily reports from the fishermen, are available for the first time as a result of a comprehensive statistical survey made by the Department of Research and Eduction to determine the results of the new management plan for the fisheries, referred to as the Maryland Management Plan. With the initiation in 1941 of a new system of fishery management in the State, a conservation plan based on the principle of stabilized fishing effort, it became obvious that a more accurate catch record system was needed for the proper administration of the program. The Management Plan stabilized the number of licensed fishermen at the 1939-1940 level, and provided for controlled expansion of the fishery to take place only when and where the industry warranted it as a result of increased fish populations. The text of the Plan may be found in Article 39, Section 60, Annotated Code of Maryland, 1943 Supplement. Publications 1, 2, 5, and 6 of the Educational Series of the Department of Research and Education explain the operating principles and the application of same to two important Maryland species, the shad and the rock or striped bass. Ocean fishery records only cover monthly gross landings.

A tree-ring perspective on the extreme wetness of the early 1900’s in the western United States [abstract]

Ring-width indices from 136 sites in the area from northern Montana to southern New Mexico between latitudes 103°W and 111°W were examined to infer periods of anomalous wetness for the years 1700-1964. Sites were grouped into north, central and south regions, and the gross regional tree-ring fluctuations were compared. The results indicate that the period 1905-1917 was unique in the 265-year record for the combined magnitude, duration, and north/south coherence of the growth anomaly of much lesser magnitude occurred in the 1830's-1840's [sic]. Both this and the 1905-1917 anomaly appear from time-series plots to be manifestations of low-frequency growth variations at wave lengths between about 20 and 60 years.

Latitudinal and seasonal egg-size variation of the anchoveta (Engraulis ringens) off the Chilean coast

The anchoveta Engraulis ringens is widely distributed along the eastern South Pacific (from 4° to 42°S; Serra et al., 1979) and it has also supported one of the largest fisheries of the world over the last four decades. However, there are few interpopulation comparisons for either the adult or the younger stages. Reproductive traits, such as fecundity or spawning season length, are known to vary with latitude for some fish species (Blaxter and Hunter, 1982; Conover, 1990; Fleming and Gross, 1990; Castro and Cowen, 1991), and latitudinal trends for some early life history traits, such as egg size and larval growth rates, have been reported for others clupeiforms and other fishes (Blaxter and Hempel, 1963; Ciechomski, 1973; Imai and Tanaka, 1987, Conover 1990, Houde 1989). However, there is no published information on potential latitudinal trends during the adult or the early life history of the anchoveta, even though this type of information may help in understanding recruitment variability, especially during recurring large scale events (such as El Niño or La Niña) that affect the entire species range.

Dynamics of bigeye (Thunnus obesus) and yellowfin (T. albacares) tuna in Hawaii’s pelagic fisheries: analysis of tagging data with a bulk transfer model incorporating size-specific attrition

Tag release and recapture data of bigeye (Thunnus obesus) and yellowfin tuna (T. albacares) from the Hawaii Tuna Tagging Project (HTTP) were analyzed with a bulk transfer model incorporating size-specific attrition to infer population dynamics and transfer rates between various fishery components. For both species, the transfer rate estimates from the offshore handline fishery areas to the longline fishery area were higher than the estimates of transfer from those same areas into the inshore fishery areas. Natural and fishing mortality rates were estimated over three size classes: yellowfin 20–45, 46–55, and ≥56 cm and bigeye 29–55, 56–70, and ≥71 cm. For both species, the estimates of natural mortality were highest in the smallest size class. For bigeye tuna, the estimates decreased with increasing size and for yellowfin tuna there was a slight increase in the largest size class. In the Cross Seamount fishery, the fishing mortality rate of bigeye tuna was similar for all three size classes and represented roughly 12% of the gross attrition rate (includes fishing and natural mortality and emigration rates). For yellowfin tuna, fishing mortality ranged between 7% and 30%, the highest being in the medium size class. For both species, the overall attrition rate from the entire fishery area was nearly the same. However, in the specific case of the Cross Seamount fishery, the attrition rate for yellowfin tuna was roughly twice that for bigeye. This result indicates that bigeye tuna are more resident at the Seamount than yellowfin tuna, and larger bigeye tunas tend to reside longer than smaller individuals. This may result in larger fish being more vulnerable to capture in the Seamount fishery. The relatively low level of exchange between the Sea-mount and the inshore and longline fisheries suggests that the fishing activity at the Seamount need not be of great management concern for either species. However, given that the current exploitation rates are considered moderate (10–30%), and that Seamount aggregations of yellowfin and bigeye tuna are highly vulnerable to low-cost gear types, it is recommended that further increases in fishing effort for these species be monitored at Cross Seamount.

Community metabolism, P/R ratio and photosynthetic efficiency of a brackishwater farm

The productivity level of a brackishwater fish culture farm consisting of 25 ponds, with a water spread area of 2.5 ha, was studied. Gross community photosynthesis of the farm was found to be 46.32 Kcal/m2/day, which is equivalent to the release of 13.23 of O2/m2/day, or the fixing of 4.10 gC/m2/day. Respiratory demand of the farm was estimated to be 44.66 kcal/m2/day, which is equivalent to the uptake of 12.76 g O2/m2/day or the utilization of 3.95 gC/m2/day. Photosynthetic efficiency of the farm was high at 2.26%. The P/R ratio was 1.04, showing eutrophic nature.

Polyculture of gulsha (Mystus cavasius Ham.) with rajpunti (Puntius gonionotus Bleeker) and silver carp (Hypophthalmichthys molitrix Val.) in earthen ponds

Culture of gulsha (Mystus cavasius) with rajpunti (Puntius gonionotus) and silver carp ( Hypophthalmichthys molitrix) was undertaken to assess the growth and production potential of these species under polyculture system. Fingerlings of gulsha, rajpunti and silver carp were stocked at a density of 18.000, 10.000 and 4.000/ha respectively. Two treatments were tested in this experiment. Treatment-I was conducted with rice bran and mustard oil cake and treatment-II with rice bran and duck weed. All the ponds were fertilized with urea and TSP at fortnightly intervals. After six months' rearing, the gross production was estimated to be 3,582 and 3,125 kg/ha from treatment-I and treatment-II respectively. Total yield showed non-significant differences (P>0.05) between the treatments.

Growth and production performance of red tilapia and Nile tilapia (Oreochromis niloticus Lin.) under low-input culture system

Comparative production potential of red tilapia (a mutant hybrid of Oreochromis mossambicus) and Nile tilapia (Oreochromis niloticus) under low-input aquaculture was studied in six ponds of 360 m² each with an average water depth of 90 cm. Three ponds were stocked with fingerlings of O. niloticus (average weight 11.4±3.48 g) while three other ponds were stocked with red tilapia (average weight 10.72±2.5 g) at a density of 20,000 fingerlings/ha. Supplementary feed consisting of rice bran was given daily at 4-6% of standing biomass. Ponds were fertilized at fortnightly intervals with cattle manure 750 kg/ ha. After six months of rearing, gross fish productions of 3,218 and 3,017 kg/ha were obtained from O. niloticus and red tilapia ponds, respectively. Of this, table size fish (>80 g in size) production amounted to 2,366 and 2,823 kg/ha from O. niloticus and red tilapia culture, respectively. Analysis of cost and benefits showed higher benefit from red tilapia culture.

Nutritional value of some small indigenous fish species (SIS) of Bangladesh

Twenty three small indigenous fish species (SIS) in the size range of 3-18 cm were analyzed for proximate composition and minerals (Ca and P) content to evaluate their nutritive value. The moisture content of different species ranged between 71.00 and 81.94%. In general, small sized fishes showed higher moisture content. The muscle protein content among the species varied widely (16.16-22.28%). In general, the muscle protein content of fishes showed higher value than the whole carcass protein content. The carcass lipid content varied between 1.87 and 9.55% and showed an inverse relationship with the moisture content. The gross energy content ranged from 19.51-27.30 KJ/g on dry matter basis. In the present study, the calcium and phosphorus contents ranged between 0.85-3.20% and 1.01-3.29% respectively. The calcium and phosphorus ratio (Ca/P) varied between 0.44 and 2.00. From the nutritional point of view, it shows that the SIS are good source of protein and minerals especially calcium and phosphorus

Effect of mixed feeding schedule on growth and nutrient utilisation in Rohu, Labeo rohita (Ham.) fingerlings

Studies on nutrient utilisation and growth of rohu (Labeo rohita) fingerlings (3.13-4.09 g) raised on seven feeding schedules under laboratory conditions (26.3-33.5°C) showed that two days regular feeding on Diet B (high protein, 38.90%) resulted in maximum growth and protein retention efficiency. While regular feeding on low protein diet (Diet A) resulted in poor nutrient utilisation and growth of fish, high protein diet (Diet B) did not show any significant difference in growth from the mixed 2A-3B schedules but exhibited comparatively low protein retention efficiency. The other feeding schedules were 1A-2B, 1A-3B, 2A-2B and 2A-4B, where the numerical value refers to the number of days for continuous feeding of a particular diet. The diets A and B served as the controls which contained 3.40 and 3.67 kcal/g gross energy respectively. The 2A-3B feeding schedule was also found to be highly economic as an expenditure of Rs.11/- only was required for raising the body weight by one kilo as against Rs.17/- with high protein diet (Diet B) as calculated

Comparison of growth and conversion efficiency of the freshwater prawn Macrobrachium malcolmsonii (H. Milne Edwards) juveniles fed with formulated and commercial feeds

A nutritional study was carried out to know the feasibility of formulated and commercial feeds on the growth of juveniles of the freshwater prawn Macrobrachium malcolmsonii. Best relative growth rate was observed for feed 1 followed by feeds 2 and 3. Animals fed with feed 1 showed higher production than the other feeds. Higher assimilation efficiency was noticed in the animals provided with feeds 5 and 4. Higher gross and net growth efficiencies were observed in the animals offered feed 1. Among the commercial feeds, feed 3 may considered to be suitable alternative to feed 1.

Drift-net fishing in Ceylon waters

Fishing with drift-nets beyond the continental shelf was more profitable than fishing within the continental shelf. Fishing operations conducted over the year beyond the shelf yielded an average catch approximately 1000 lbs. per operation while fishing within the shelf yielded an average catch of 400 lbs. per operation. The seas off the south-west and south coasts were found to be much richer in pelagic fish than the seas off the east coasts. There was a seasonal abundance of fish off the south-west, south and east coasts of Ceylon. On the south-west and south coast fish were more abundant during the months of the south-west monsoon while on the east coast fish were more abundant during the months of the north-east monsoon. Drift-net fishing proved to be a more lucrative method of capturing fish than trolling, longlining and trawling in the seas off Ceylon, and has contributed to an increase in the gross catch in Ceylon waters.

Feed utilization and wastage in semi-intensive pond culture of mahseer, Tor putitora. (Ham.)

Mahseer, Tor putitora with 12.75, 12.11, and 12.02g of initial weight were fou · J to attain a net weight gain of 12.0 kg, ll.5 kg, and 11.4 kg respectively in pond-1 (commercial feed), pond-2 (farm-made feed), and pond-3 (farm-made feed), respectively against 78.2 kg, 70.3 kg, and 68.1 kg feed fed. Gross energy contents in fish were 1359.3 Kcal/kg, 1281.5 Kcal/kg and 1266.6 Kcal/kg, respectively in pond-1, pond-2, and pond-3 against 3630.4, 3876.9 and 3570.5 Kcal/kg energy in the feed fed. Only 9.4%, 10.5% and 13.7% of the protein, and 8.9%, 3.4% and 3.3% of the lipid fed to fish were converted into muscle respectively in pond-1, pond-2 and pond-3. It was observed that the higher the protein content in feed, the lower the rate of conversion in muscle; the same was also true for lipid. It is supposed that feed derived wastes contribute potentially to water quality deterioration and eutrophication. Lower feed conversion, higher nitrogenous and phosphatic concentrations and higher plankton biomass in the ponds are all supportive to this observation.

An empirical study on income and efficiency of pond fish and nursery fish production in some selected areas of Pabna, Bangladesh

The study was designed to determine the costs, returns and relative profitability of pond fish and nursery fish production. In order to attain this objective, a total of 70 producers: 35 producing pond fish and 35 producing nursery fish were selected on the basis of purposive random sampling technique from 6 villages under two Upazilas (Sujanagar and Santhia) of Pabna district. It was estimated that per hectare per year gross cost of pond fish production was Tk 65,918 while gross return and net return were Tk 91,707 and Tk 25,789 respectively. Per hectare per year gross cost of nursery fish production was Tk 87,489 while gross return and net return were Tk 1,39,272 and Tk 51,783 respectively. The findings revealed that nursery fish production was more profitable than pond fish production. Cobb-Douglas production function was applied to realize the specific effect of the factors on pond fish and nursery fish production. It was observed that most of the included variables had significant impact on pond fish and nursery fish production. Out of five variables included in the function, all the variables had positive impact on return from pond fish production but stock value of pond, material cost and pond area had positive impact on return from nursery fish production.