Fishermen

Distribution by Scientific Domains

Kinds of Fishermen

  • local fishermen


  • Selected Abstracts


    Fish and Fishermen in English Medieval Wall Paintings , By Frederick Buller

    INTERNATIONAL JOURNAL OF NAUTICAL ARCHAEOLOGY, Issue 2 2010
    JOE FLATMAN
    No abstract is available for this article. [source]


    Therapy of environmental mycobacterial infections

    DERMATOLOGIC THERAPY, Issue 3 2008
    Caterina Fabroni
    ABSTRACT: Environmental mycobacteria are the causative factors of an increasing number of infections worldwide. Cutaneous infections as a result of environmental mycobacteria are often misdiagnosed, and their treatment is difficult because these agents can show in vivo and in vitro multidrug resistance. The most common environmental mycobacteria that can cause cutaneous infections are Mycobacterium fortuitum and Mycobacterium marinum. All mycobacteria are characterized by low pathogenicity and they can contaminate affected or traumatized skin only in immunocompetent subjects (mainly in fishermen, swimming-pool attendants, and aquarium owners) whereas medical and esthetic procedures are at risk for the infections because of the quick-growing mycobacteria. Immunocompromised subjects can instead easily develop environmental mycobacterial infections of differing degrees of severity. [source]


    Morphometry and sexual dimorphism of the coastal spotted dolphin, Stenella attenuata graffmani, from Bahía de Banderas, Mexico

    ACTA ZOOLOGICA, Issue 4 2004
    Laura Sanvicente-Añorve
    Abstract External measurements and size differences between the sexes were examined in the coastal spotted dolphin, Stenella attenuata graffmani, in Bahía de Banderas, on the Mexican Pacific coast. The dolphins were collected by local fishermen and 29 external characteristics were measured by members of the Marine Mammals Laboratory, University of Mexico. The length of each characteristic with respect to total length was analysed through adjustment of the data to a power equation. A stepwise discriminant analysis was applied to the absolute values and to those expressed as proportions to analyse the differences between the sexes. Results indicate that growth in these dolphins is generally negatively allometric, and most of the characteristics measured were, in both absolute and proportional terms, greater in male dolphins than in female dolphins. As found in many species of odontocetes, the discriminant analysis showed that the main differences between the sexes for this coastal subspecies include the relative positions of the umbilicus, the genital aperture and the anus. The morphometric data provided by this study, corresponding to 29 specimens of S. a. graffmani collected in a restricted locality of the Mexican Pacific coast, are particularly interesting to studies documenting latitudinal morphological differences in the coastal spotted dolphin. [source]


    HIV and AIDS among fisherfolk: a threat to ,responsible fisheries'?

    FISH AND FISHERIES, Issue 3 2004
    Edward H. Allison
    Abstract Fishing communities are often among the highest-risk groups in countries with high overall rates of HIV/AIDS prevalence. Vulnerability to HIV/AIDS stems from complex, interacting causes that may include the mobility of many fisherfolk, the time fishermen spend away from home, their access to daily cash income in an overall context of poverty and vulnerability, their demographic profile, the ready availability of commercial sex in fishing ports and the subcultures of risk taking and hypermasculinity among some fishermen. The subordinate economic and social position of women in many fishing communities in low-income countries makes them even more vulnerable. HIV/AIDS in fishing communities was first dealt with as a public health issue, and most projects were conducted by health sector agencies and NGOs, focusing on education and health care provision. More recently, as the social and economic impacts of the epidemic have become evident, wider social service provision and economic support have been added. In the last 3 years, many major fishery development programmes in Africa, South/South-East Asia and the Asia-Pacific region have incorporated HIV/AIDS awareness in their planning. The HIV/AIDS pandemic threatens the sustainability of fisheries by eclipsing the futures of many fisherfolk. The burden of illness puts additional stresses on households, preventing them from accumulating assets derived from fishing income. Premature death robs fishing communities of the knowledge gained by experience and reduces incentives for longer-term and inter-generational stewardship of resources. Recent projects championing local knowledge and resource-user participation in management need to take these realities into account. If the fishing communities of developing countries that account for 95% of the world's fisherfolk and supply more than half the world's fish are adversely impacted by HIV/AIDS, then the global supply of fish, particularly to lower-income consumers, may be jeopardized. [source]


    The artisanal fishery fleet of the lower Amazon

    FISHERIES MANAGEMENT & ECOLOGY, Issue 3 2008
    V. J. ISAAC
    Abstract, The present study analyses temporal trends in the characteristics of the artisanal fleet landing at ports in the city of Santarém (lower Amazon) from 1993 to 2003. A total of 2714 boats visited the city, accounting for more than 76 000 landings. Of these, 1952 were fishing boats; the others were buyer boats, specialised in the purchase of fish in rural areas for resale in Santarém. The activity involves more than 13 000 fishermen. Fishing boats are made of wood, are on average 11 m long and powered by a 20 hp outboard motor. Boats operate with an average of six to seven fishermen, spending 6 days per trip and catching between 300 and 800 kg of fish. Most variability in yield can be explained by the ice consumed (70%), the number of fishermen trip,1 (19%), fuel consumed (4%) and days spent fishing (3%). The yield changed according to the size, origin and type of boat. Fishing boats coming from more distant locations, in the state of Amazonas, performed better than those from Santarém. Total yield declined slightly during the study period. Mean age of fishing boats and fishing power is increasing. Consumption of ice and fuel by trip, number of fishermen trip,1 and mean days fishing showed positive trends. Financial subsidies from governmental agencies are criticised. Fleet performance and management options are discussed. [source]


    Fisheries of two tropical lagoons in Ghana, West Africa

    FISHERIES MANAGEMENT & ECOLOGY, Issue 6 2004
    H. R. Dankwa
    Abstract, The fisheries of two coastal lagoons, Keta and Songor, were studied as part of Ghana Coastal Wetlands Management Project (GCWMP) aimed at sustainable exploitation of wetland resources. Fish samples were obtained with seine nets and cast net as well as from local fishermen. Water quality parameters (pH, dissolved oxygen, temperature and turbidity) were similar in the two lagoons, except for salinity, which was significantly different (P < 0.001). Despite their close geographical proximity, the two lagoons supported different fish assemblages with the blackchin tilapia, Sarotherodon melanotheron Rüppell, and the redchin tilapia, Tilapia guineensis (Bleeker), being the most important commercial fishes in both lagoons. The number of individuals for each species in Songor Lagoon were far more abundant, with densities several orders of magnitude higher than in Keta Lagoon. However, both species were significantly larger (P < 0.01) in the latter [15,121 and 25,157 mm standard length (SL)] than in the former lagoon (30,102 and 15,95 mm SL) for S. melanotheron and T. guineensis respectively. Over-fishing, use of small-size mesh nets, limited mixing of marine and fresh water were some of the factors limiting fish production in both lagoons. [source]


    Developing co-management in an artisanal gill net fishery of a deep hydro-electric reservoir in Sri Lanka

    FISHERIES MANAGEMENT & ECOLOGY, Issue 5 2002
    S. NATHANAEL
    Abstract Victoria, is a recently (1984) impounded, deep, hydro-electric reservoir in Sri Lanka with an established commercial fishery. Participatory appraisal of the fishing community revealed decreasing reliance on fishing income with many fishermen moving away to supplementary occupations because of declining fish catches. Illegal fishing and theft of fishing gear resulting from open access, difficulties encountered in enforcing fisheries regulations and the need for fishermen to find alternative sources of income during low water levels are the major management problems. The top,down centralized management approach previously practised was ineffective in addressing any of these issues. Therefore, the possibilities and limitations for introducing co-management as an alternative management strategy were discussed. Financial hardship coupled with perceived benefits through state sponsored welfare schemes caused a positive attitude change among fishermen, making them respond favourably to fishery management. Establishing a licensing system for controlled access, ensuring greater user-group participation through equitable distribution of state sponsored benefits among members, attempting to enforce penalties for illegal fishing linked with surprise checks to enforce management regulations, and obtaining stakeholder perceptions regarding management issues are some of the recent steps taken by the Fishermen's Co-operative Society which would positively contribute towards developing effective co-management in this reservoir. [source]


    The effect of a closed area and beach seine exclusion on coral reef fish catches

    FISHERIES MANAGEMENT & ECOLOGY, Issue 2 2001
    T. R. McClanahan
    Fish landing data from the Mombasa Marine National Park (MNP) and a marine reserve exploited by various gears were studied over a 5-yr period to determine the influence of the closed area and different gears in fisheries. The number fishing and boats per landing site was constant, but total and catch per unit effort progressively declined in all sites on an annual basis irrespective of the existence of a marine reserve, exclusion of the beach seines or use of gear. Differences between landing sites were most pronounced when analysed on a catch per area as opposed to the more standard catch per fisherman, suggesting compensation in human effort when catches decline. A marine reserve next to a closed area that excluded beach seines had the highest catch per area (5.5 kg ha,1 month,1) despite having the highest density of fishermen (0.07 ± 0.02 fishermen ha,1 month,1). The annual rate of decline in the catch was lower than the other sites at around 250 g day,1 compared with 310,400 g day,1 in the other sites. One landing site, which excluded beach seine landings for more than 20 yrs, had a high catch per area (,5.3 kg ha,1 month,1), but after experiencing a doubling in the effort of other gears (line, speargun and trap), the catch per fisherman and area were reduced. Environmental or habitat degradation and excessive effort remain the most likely explanation for the overall declines in catch from 1995 to 1999. Closed areas and beach seine exclusion have the potential to increase catch rates, but the first often reduces the total fishing area and possibly leads to a loss of total catch, at least on a time scale of less than 10 yrs. The exclusion of beach seines can lead to an increase in other gear types that can also cause reductions in catch. [source]


    Can fishermen allocate their fishing effort in space and time on the basis of their catch rates?

    FISHERIES MANAGEMENT & ECOLOGY, Issue 1 2001
    An example from Spermonde Archipelago, Indonesia, SW Sulawesi
    Spatial and temporal patterns in catch rates and in allocation of fishing effort were analysed for the coastal fishery in Spermonde Archipelago, Indonesia, to assess whether fishermen can optimise their strategy from catch information, or whether they fish under great uncertainty and merely minimise risks. On average 517 fishing units operated in the 2800 km2 area, catching 21 t fish day,1. Major gear categories were hook and line (59% of total effort and 5% of total catch), and lift nets (16% of total effort and 70% of total catch). The size of individual resource spaces varied with gear type and was smaller in unfavourable weather conditions. Although spatial patterns in catch rates at the scale of the whole archipelago were evident, fishermen could not differentiate between locations, as catch variance within their individual resource spaces was high relative to the contrasts in spatial patterns. The aggregated distribution of fishing effort in Spermonde must be explained by factors such as the small scale of operations, rather than fish abundance. [source]


    Growth and mortality of the catfish, Hemisynodontis membranaceus (Geoffroy St. Hilaire), in the northern arm of Lake Volta, Ghana

    FISHERIES MANAGEMENT & ECOLOGY, Issue 1 2001
    P. K. Ofori-Danson
    Estimates of growth and mortality of the catfish, Hemisynodontis membranaceus (Geoffroy St. Hilaire), in Lake Volta were obtained from length composition data compiled in 1995 and 1996. The von Bertalanffy growth function (VBGF) estimates were: L,=44.5 cm standard length; K=0.62 year,1; and t0=,0.23 years. Natural mortality rate, M, was 1.20 year,1. Total mortality rate, Z, was computed as 4.39 year,1 and the exploitation ratio (E=F/Z) was 0.72. Although the fish is estimated to have longevity of about 5 years, those exploited are normally less than 2 years of age, which is indicative of growth over-fishing. In order to arrest over-exploitation of the species, there is a need to establish ,lake reserves'. In addition, the fisheries management should be devolved from the state to the local level to compel fishermen to take greater responsibility for the sustainability and conservation of the fisheries. [source]


    Trends in NE Atlantic landings (southern Portugal): identifying the relative importance of fisheries and environmental variables

    FISHERIES OCEANOGRAPHY, Issue 3 2005
    KARIM ERZINI
    Abstract Time series of commercial landings from the Algarve (southern Portugal) from 1982 to 1999 were analyzed using min/max autocorrelation factor analysis (MAFA) and dynamic factor analysis (DFA). These techniques were used to identify trends and explore the relationships between the response variables (annual landings of 12 species) and explanatory variables [sea surface temperature, rainfall, an upwelling index, Guadiana river (south-east Portugal) flow, the North Atlantic oscillation, the number of licensed fishing vessels and the number of commercial fishermen]. Landings were more highly correlated with non-lagged environmental variables and in particular with Guadiana river flow. Both techniques gave coherent results, with the most important trend being a steady decline over time. A DFA model with two explanatory variables (Guadiana river flow and number of fishermen) and three common trends (smoothing functions over time) gave good fits to 10 of the 12 species. Results of other models indicated that river flow is the more important explanatory variable in this model. Changes in the mean flow and discharge regime of the Guadiana river resulting from the construction of the Alqueva dam, completed in 2002, are therefore likely to have a significant and deleterious impact on Algarve fisheries landings. [source]


    Freezing of lakes on the Swiss plateau in the period 1901,2006

    INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 4 2008
    H. J. Hendricks Franssen
    Abstract Data of ice cover for deep Alpine lakes contain relevant climatological information since ice cover and winter temperature are closely related. For the first time, ice cover data from 11 lakes on the Swiss plateau have been collected and analysed for the period 1901,2006. The ice cover data used stem from systematic registration by individuals or groups (fishermen, an ice club and lake security service) and from several national, regional and local newspapers. It is found that in the past 40 years, and especially during the last two decades, ice cover on Swiss lakes was significantly reduced. This is in good agreement with the observed increase in the winter temperature in this period. The trend of reduced ice cover is more pronounced for lakes that freeze rarely than for the lakes that freeze more frequently. This agrees well with the stronger relative decrease in the probability to exceed the sum of negative degree days (NDD) needed for freezing the lakes that rarely freeze. The ice cover data are related with the temperature measurements such as the sum of NDD of nearby official meteorological stations by means of binomial logistic regression. The derived relationships estimate the probability of a complete ice cover on a lake as function of the sum of NDD. The sums of NDD needed are well related to the average depth of the lake (rNDD,Depth = 0.85). Diagnosing lake ice cover on the basis of the sum of NDD is much better than a prediction on the basis of a climatological freezing frequency. The variance of lake ice cover that cannot be explained by the sum of NDD is important for judging the uncertainty associated with climate reconstruction on the basis of data on lake ice cover. Copyright © 2007 Royal Meteorological Society [source]


    Ancient Remotely-Operated Instruments Recovered Under Water off the Israeli Coast

    INTERNATIONAL JOURNAL OF NAUTICAL ARCHAEOLOGY, Issue 2 2008
    Ehud Galili
    Underwater archaeological investigations in Israel have recovered instruments intended to be operated under water from a vessel on the surface, at depths and times beyond the ability of free divers. Some of these remotely-operated devices, including salvaging-rings, coral-harvesting devices, and grapnels, are described, classified and discussed. These humble but efficient instruments, the prototypes of sophisticated modern instruments, fulfilled necessary tasks in antiquity and are still being used today by traditional fishermen. © 2008 The Authors [source]


    Fishing near sea-cage farms along the coast of the Turkish Aegean Sea

    JOURNAL OF APPLIED ICHTHYOLOGY, Issue 1 2010
    O. 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]


    Multidimensional analysis of fishery production systems in the state of Pernambuco, Brazil

    JOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2009
    R. P. Lessa
    Summary A total of 17 fishery systems covering gillnets, traps and seines targeting fish and crustaceans as well as hand-collected mussels in the state of Pernambuco (Brazil) were compared and analyzed in the present study using the RAPFISH method and 57 attributes to qualify five evaluation dimensions: economic, social, ecological, technological and management. The aim was to determine the sustainability of each field from the fishery (i.e. stocks) and social standpoint (i.e. fishermen). With regard to sustainability, it was generally apparent that the fisheries analyzed are far from any ideal that would permit long-term exploitation, but are nonetheless also distant from the extremes of non-sustainability in the environments investigated. The low degree of organization demonstrated in most fisheries of Pernambuco and the low level of schooling among the fishermen contribute toward maintaining the status quo, with an increase in situations of conflict and a lack of valorization regarding the activities. The shrimp system is the least sustainable, mainly due to its environmental impact; however, this is compensated by the relatively higher quality of living provided stakeholders through its exploitation. The evaluation dimensions showed the most sustainable system in Pernambuco to be the stationary ,uncovered pound net', followed by the line system. Alternative procedures for integrated fishery management, such as an increase in statistical data, coastal zoning to limit shrimp farms and establishing protected areas are proposed and discussed. Such procedures may contribute toward the formulation of public policies for the fishery industry of the state, which is essentially made up of artisanal fisheries with low yields and exercised by the 11 926 fishermen affiliated with coastal fishing colonies. [source]


    Ecology and exploitation pattern of a landlocked population of sand smelt, Atherina boyeri (Risso 1810), in Trichonis Lake (western Greece)

    JOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2001
    I. D. Leonardos
    Age, growth, mortality and exploitation pattern of sand smelt, Atherina boyeri (Risso 1810), in Trichonis Lake (western Greece) were studied from samples taken from catches of local fishermen. Individuals ranged between 44 and 109.53 mm in total length (TL). Age determinations based on scale readings show that the population has a 4-year life cycle. Sand smelt grows allometrically (b=3.18) and relatively rapidly, achieving 52.3% of the growth during the first year; thereafter the annual growth rate drops quickly. The von Bertalanffy growth parameters for all individuals are: L,=112.40 mm, k= 0.42 years,1,,, to=,0.40 years. The total mortality rate was Z=1.65 years,1 and the natural mortality rate M=1.07 years,1. The exploitation rate indicates that the population is rather underexploited (E=0.35). [source]


    Reproductive cycle of female Brazilian codling, Urophycis brasiliensis (Kaup 1858), caught off the Uruguayan coast

    JOURNAL OF APPLIED ICHTHYOLOGY, Issue 2 2000
    By A. Acuña
    Between August 1993 and September 1995, aspects of reproduction of female Urophycis brasiliensis (Phycidae), a euryhaline species found in the Western Atlantic between 23° and 40° S, were studied. A total of 2500 specimens (23,60 cm; 113,2400 g) were obtained from artisanal fishermen at two locations on the Uruguayan coast: Piriápolis, influenced by the discharge of the Río de la Plata, and La Paloma, a marine site. The ovaries of 900 fish, analysed according to standard histological techniques, revealed eight maturity stages, including one virgin ovary obtained from the catch of a research vessel. The gonadosomatic index ranged from 0.13 to 8.7. Its maximum was determined in the autumn in La Paloma, whereas a shift towards the winter was observed in Piriápolis. In both capture areas, resting stage 2 was present in the samples throughout the year, reaching 67% of the total. At no time were hydrated ovaries observed. The histological cycle is described and compared with macroscopic features of the female gonad. Maturity stages determined in the field had to be confirmed by histological analysis in order to avoid erroneous classification. Although the two ports are only 150 km apart, data indicate different and extended reproductive periods, between June and December for Piriápolis, and March to May for La Paloma. Data indicate synchronous group spawning, possibly as a reproductive strategy in a highly variable environment. The results are compared with scarce information available on U. brasiliensis in its distribution area and data on other species of the same genus. [source]


    Prediction and verification of possible reef-fish spawning aggregation sites in Los Roques Archipelago National Park, Venezuela

    JOURNAL OF FISH BIOLOGY, Issue 4 2010
    J. Boomhower
    This study attempts to predict and verify possible spawning aggregation sites and times in the Los Roques Archipelago National Park, Venezuela, based on physical reef characteristics and the knowledge of experienced local fishermen. Three possible aggregation sites were selected for monitoring based on satellite images, low-cost bathymetric mapping and interviews with experienced local fishermen. Abundances and sizes of 18 species that are known to form reproductive aggregations were monitored at these sites using underwater visual census for 7 days after each full moon from February to August, 2007. While spawning events were not observed, possible indirect evidence of spawning aggregations was found for Lutjanus analis at Cayo Sal and Boca de Sebastopol, Lutjanus apodus at Cayo Sal, Lutjanus cyanopterus at Cayo Sal and Piedra La Guasa and Epinephelus guttatus at Bajo California and Cayo de Agua. Additionally, indirect evidence was identified for the past existence of a spawning aggregation of Epinephelus striatus in the northern part of the archipelago, which may have been eliminated by overfishing c.15 years ago. Bathymetric mapping showed that the shelf edge at sites monitored in this study was shallower than at spawning aggregation sites in other parts of the Caribbean, and that sites were not proximal to deep water. While this study does not prove the existence or locations of spawning aggregations of reef fishes in the archipelago, it does add insight to a growing understanding of generalities in the relationship between seafloor characteristics and the locations of transient reef-fish spawning aggregations in the Caribbean. [source]


    Pathology associated with retained fishing hooks in blue sharks, Prionace glauca (L.), with implications for their conservation

    JOURNAL OF FISH DISEASES, Issue 9 2002
    J Borucinska
    Fishing hooks retained from previous capture events were found in 6 of 211 blue sharks, Prionace glauca (L.), landed in the summers of 1999 and 2000 by recreational fishermen off Long Island (New York, USA). The hooks were embedded within the distal oesophagus (n=3), or perforated the gastric wall (n=3) and lacerated the liver (n=2). The hooks were surrounded by excessive fibronecrotic tissue which ablated the normal anatomical structures and in the three sharks with oesophageal hooks caused partial luminal obstruction. Accompanying lesions included oesophagitis, gastritis, hepatitis and proliferative peritonitis. Aeromonas sp. and Vibrio sp. were isolated from the peritoneal fluid of one shark with peritonitis and intralesional bacteria were seen on histological examination in all sharks. This is the first report of the prevalence and pathology of retained fishing hooks in a large number of wild-caught sharks. [source]


    EFFECT OF STORAGE TEMPERATURE ON HISTAMINE FORMATION IN SARDINA PILCHARDUS AND ENGRAULIS ENCRASICOLUS AFTER CATCH

    JOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2007
    PIERINA VISCIANO
    ABSTRACT Histamine formation in Sardina pilchardus and Engraulis encrasicolus as a function of storage temperature was studied. Fish were caught off the Adriatic Coast and were carried immediately to the laboratory. A portion of dorsal muscle from each fish was soon analyzed, while two other portions were examined after storage at two different temperatures (25 and 4C) for 24 and 72 h, respectively. The analyses were carried out by high-performance liquid chromatography (HPLC)-UV and confirmed by HPLC-diode array detector. Histamine concentrations were always higher than the European Community admissible levels in samples stored at 25C. In fish stored at 4C, histamine was detected only in E. encrasicolus. PRACTICAL APPLICATIONS Time experiments were conducted to quantify the histamine formation in scombroid species at two different temperatures. The first assay (24 h, 25C) could reproduce the modality of sale adopted by fishermen or retailers in summer on the one hand, and the maintenance at ambient temperature of semipreserved sardines or anchovies during salting and ripening on the other hand. The second experiment (72 h, 4C) was based on the domestic cold preservation of fish before the consumption, which sometimes occurs some days after purchasing. Even if ice storage is recommended, time/temperature abuse conditions often occur in the fish merchandising chain. The results of this research showed that high histamine concentrations could be found in the analyzed species not only at an abused temperature, but also at a common storage temperature of fish at home. [source]


    INTERACTIONS BETWEEN THE INDIAN RIVER LAGOON BLUE CRAB FISHERY AND THE BOTTLENOSE DOLPHIN, TURSIOPS TRUNCATUS

    MARINE MAMMAL SCIENCE, Issue 4 2002
    Wendy D. Noke
    Abstract Anecdotal reports from blue crab fishermen in the Indian River Lagoon (IRL), Florida suggested that bottlenose dolphins (Tursiops truncatus) followed their boats, and stole bait fish from crab pots soon after they were deployed. To investigate these reports, we made biweekly observations from IRL commercial crab boats from January 1998 to January 1999 (670 h). Only 2.8% of the 18,891 crab pots surveyed revealed evidence of dolphin/crab pot interaction. Dolphin interactions included: (1) begging at boats, (2) feeding on discarded bait fish, (3) engaging in crab pot tipping behavior, and (4) dolphin mortality from crab pot float line entanglement. Overall, 16.6% of the 1,296 dolphins sighted interacted with fishing boats. Seasonal trends were evident, with fishery interactions peaking in the summer. Crab pot interactions ranged from 0% to 36% of the traps checked daily. Different methods of securing the bait-well door and the role of trap locality were tested using a replicated experimental design. Results showed significant differences in successful bait removal by dolphins, among the degrees of door security (P < 0.001) and between trap location (P < 0.01). Thus, increased door security may help to reduce the negative impacts to the fishery and dolphins involved. [source]


    CREATION OF MARINE RESERVES AND INCENTIVES FOR BIODIVERSITY CONSERVATION

    NATURAL RESOURCE MODELING, Issue 2 2010
    QUACH THI KHANH NGOC
    Abstract Despite a number of benefits, marine reserves provide neither incentives for fishermen to protect biodiversity nor compensation for financial loss due to the designation of the reserves. To obtain fishermen's support for marine reserves, some politicians have suggested that managers of new marine reserves should consider subsidizing or compensating those fishermen affected by the new operations. The objective of this paper is to apply principal,agent theory, which is still infrequently applied to fisheries, to define the optimal reserve area, fishing effort, and transfer payments in the context of symmetric and asymmetric information between managers and fishermen. The expected optimal reserve size under asymmetric information is smaller than that under symmetric information. Fishing efforts encouraged with a transfer payment are always less compared to those without payment. This reflects the fact that as the manager induces the fishermen to participate in the conservation program, the fishermen will take into account their effects on fish stock by decreasing their effort. Examples are also supplied to demonstrate these concepts. [source]


    GROWTH AND MEASUREMENT UNCERTAINTY IN AN UNREGULATED FISHERY

    NATURAL RESOURCE MODELING, Issue 3 2009
    ANNE B. JOHANNESEN
    Abstract Complete information is usually assumed in harvesting models of marine and terrestrial resources. In reality, however, complete information never exists. Fish and wildlife populations often fluctuate unpredictably in numbers, and measurement problems are frequent. In this paper, we analyze a time-discrete fishery model that distinguishes between uncertain natural growth and measurement error and in which exploitation takes place in an unregulated manner. Depending on the parameterization of the model and at which point of time uncertainty is resolved, it is shown that expected harvest under ecological uncertainty may be below or above that of the benchmark model with no uncertainty. On the other hand, when stock measurement is uncertain, expected harvest never exceeds the benchmark level. We also demonstrate that the harvesting profit, or rent, under uncertainty may be above that of the benchmark situation of complete information. In other words, less information may be beneficial for the fishermen. [source]


    RANDOM PENALTIES AND RENEWABLE RESOURCES: A MECHANISM TO REACH OPTIMAL LANDINGS IN FISHERIES

    NATURAL RESOURCE MODELING, Issue 3 2009
    FRANK JENSEN
    Abstract Recent literature considers illegal landings a moral hazard problem that arises because individual landings are unobservable. The literature proposes incentive schemes to solve the information problem. However, most of the proposed schemes raise huge information requirements and social budget balance is not secured. In this paper, we suggest a random penalty mechanism that reduces the information requirements and secures budget balance in the case of a given number of licensed vessels. In the random penalty mechanism, aggregate landings are measured through stock sizes and the natural growth function. If aggregate landings are below optimal landings, each fisherman receives a subsidy. If aggregate catches are above optimal landings, the mechanism works such that either the fisherman is randomly selected and pays a fine or the fisherman is not selected and receives a subsidy. The fine and subsidy can be designed such that budget balance is secured. Provided risk aversion is sufficiently large and the fine is high enough, the random penalty mechanism will generate optimal individual landings. The budget balance combined with risk aversion drives the result for this advanced tax/subsidy system that does not exhaust the resource rents. The budget balance creates interdependence between fishermen that secure optimality. [source]


    ENTRY AND EXIT OF LABOR AND CAPITAL IN A FISHERY

    NATURAL RESOURCE MODELING, Issue 2 2005
    ASGEIR DANIELSSON
    ABSTRACT. Exit and entry of fishermen, as well as vessels, is modeled explicitly. If the speed of exit and entry of fishermen is less than instantaneous the wage rate varies with the fortunes of the fishing firms and affects the endogenous labor supply creating a second transmission mechanism from profits to effort. There are realistic cases where this mechanism has important effects on the stability of the dynamic system and on the effects of taxes (subsisdies) on the size of the fish stock. If labor supply depends negatively on the wage rate, the immediate effect of an increase in the tax rate is to increase effort and harvest. This condition makes it also more probable that the dynamic system is unstable. In those cases where the dynamic system is unstable the increase in the tax rate increases overexploitation not only in the short-term but also in the long-term. [source]


    Ergonomic risk factors for low back pain in North Carolina crab pot and gill net commercial fishermen

    AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 4 2009
    Kristen L. Kucera PhD
    Abstract Background The objective of this research was to determine the association between LBP that limited or interrupted fishing work and ergonomic low back stress measured by (1) self-reported task and (2) two ergonomic assessment methods of low back stress. Methods Eligible participants were from a cohort of North Carolina commercial fishermen followed for LBP in regular clinic visits from 1999 to 2001 (n,=,177). Work history, including crab pot and gill net fishing task frequency, was evaluated in a telephone questionnaire (n,=,105). Ergonomic exposures were measured in previous study of 25 fishermen using two methods. The occurrence rate of LBP that limited or interrupted fishing work since last visit (severe LBP) was evaluated in a generalized Poisson regression model. Results Predictors of severe LBP included fishing with crew members and a previous history of severe LBP. Among crab pot and gill net fishermen (n,=,89), running pullers or net reels, sorting catch, and unloading catch were associated with an increased rate of LBP. Percent of time in forces >20 lb while in non-neutral trunk posture, spine compression >3,400 N, and National Institute of Occupational Safety and Health lifting indices >3.0 were associated with LBP. Conclusions Tasks characterized by higher (unloading boat and sorting catch) and lower (running puller or net reel) ergonomic low back stress were associated with the occurrence of severe LBP. History of LBP, addition of crew members, and self-selection out of tasks were likely important contributors to the patterns of low back stress and outcomes we observed. Based on the results of this study, a participatory ergonomic intervention study is currently being conducted to develop tools and equipment to decrease low back stress in commercial crab pot fishing. Am. J. Ind. Med. 52:311,321, 2009. © 2009 Wiley-Liss, Inc. [source]


    Water-related occupations and diet in two Roman coastal communities (Italy, first to third century AD): Correlation between stable carbon and nitrogen isotope values and auricular exostosis prevalence,

    AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010
    Fiona Crowe
    Abstract The reconstruction of dietary patterns in the two Roman imperial age coastal communities of Portus and Velia (I,III AD) by means of stable isotope analysis of bone remains has exposed a certain degree of heterogeneity between and within the two samples. Results do not correlate with any discernible mortuary practices at either site, which might have pointed to differential social status. The present study tests the hypothesis of a possible connection between dietary habits and occupational activities in the two communities. Among skeletal markers of occupation, external auricular exostosis (EAE) has proved to be very informative. Clinical and retrospective epidemiological surveys have revealed a strong positive correlation between EAE development and habitual exposure to cold water. In this study, we show that there is a high rate of occurrence of EAE among adult males in both skeletal samples (21.1% in Portus and 35.3% in Velia). Further, there is a statistically significant higher prevalence of EAE among those individuals at Velia with very high nitrogen isotopic values. This points to fishing (coastal, low-water fishing) as the sea-related occupation most responsible for the onset of the ear pathology. For Portus, where the consumption of foods from sea and river seems to be more widespread through the population, and where the scenario of seaport and fluvial activities was much more complex than in Velia, a close correlation between EAE and fish consumption by fishermen is less easy to establish. Am J Phys Anthropol 2010. © 2009 Wiley-Liss, Inc. [source]


    European Nature Conservation and Restoration Policy,Problems and Perspectives

    RESTORATION ECOLOGY, Issue 4 2009
    Jozef Keulartz
    Abstract The implementation of Natura 2000 has met with considerable resistance from farmers, fishermen, foresters, and other local residents in most European Union Member States. In response to the rural protest, the majority of governments have gradually abandoned their centralist, top-down approach and increasingly switched over to methods of participatory and interactive policy-making. However, this "democratisation" of European nature conservation policy is not without its problems and pitfalls. The inclusion of an ever-growing group of stakeholders with different and often diverging interests, ideas, views, and values will more often than not lead to conflicts over the future of nature and the landscape. The causes and consequences of these conflicts need to be examined to improve the policy process. [source]


    The influence of human disturbance on California sea lions during the breeding season

    ANIMAL CONSERVATION, Issue 6 2009
    K. Holcomb
    Abstract California sea lions Zalophus californianus occupy 26 islands in the Gulf of California (GoC), Mexico. Although human presence is prohibited on these islands without a government permit, the law is not enforced and tourism to the islands is increasing. Tourists, along with local fishermen, often come ashore to get close to the animals, which may disrupt behaviors critical for reproduction. In this paper, we report the results of an experimental study on the behavioral effects of human disturbance on California sea lions in the GoC. To document effects, we recorded sea lion behavior immediately before and in 10-min intervals for up to an hour after experimental human disturbance. Our results showed few behavioral responses of sea lions to human disturbance. Adult females and juveniles demonstrated immediate responses, but these were not consistent between years, apparent an hour after disturbance, or evident across other age and sex classes. These results suggest that California sea lions may be resilient to human disturbance and a possible flagship species for ecotourism, but further studies of the physiological and population-level effects of human disturbance are needed. [source]


    Using Oral History Techniques in A NOAA Fisheries Service (NMFS) Education and Outreach Project: Preserving Local Fisheries Knowledge, Linking Generations, and Improving Environmental Literacy

    ANNALS OF ANTHROPOLOGICAL PRACTICE, Issue 1 2007
    Susan Abbott-Jamieson
    Oral historical interviews are a core activity in a successful outreach and education project piloted by the National Oceanic and Atmospheric Administration (NOAA)'s National Marine Fisheries Service (NMFS) in two Maine high schools between 2003 and 2005. Through interviews with local fishermen and others in fishing-related industries, Local Fisheries Knowledge (LFK) Pilot Project students have explored the connections between fisheries, the marine environment, their communities, and their own lives, while documenting and preserving the knowledge and experiences of local residents for future generations. This article describes the pilot project's use of oral history methods, and discusses the project's role in three agency interest areas: (1) public outreach, (2) education, and (3) documenting fishing communities' lifeways and local fisheries knowledge. [source]