940 resultados para SEALED VESSELS


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A proportionate random sample survey of 10 percent of the driftnet and Payang seine fishers in West Sumatra was carried out in 1998. A total of 45 driftnet and 66 lampara fishers were interviewed to obtain socioeconomic data on the fisheries. About 40 percent of the driftnet and 76 percent of the lampara fishers owned and operated their fishing vessels and gears indicating a high level of ownership of fishing assets by these small scale fishers. The lampara catches consisted mainly of eastern little tuna, skipjack tuna, yellow fin tuna and mackerel, while the driftnets caught mainly Spanish mackerel, Indian mackerel, eastern little tuna and scad.

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To assess the impact of California sea lions (Zalophus californianus) on salmon fisheries in the Monterey Bay region of California, the percentages of hooked fish taken by sea lions in commercial and recreational salmon fisheries were estimated from 1997 to 1999. Onboard surveys of sea lion interactions with the commercial and recreational f isheries and dockside interviews with fishermen after their return to port were conducted in the ports of Santa Cruz, Moss Landing, and Monterey. Approximately 1745 hours of onboard and dockside surveys were conducted—924 hours in the commercial fishery and 821 hours in the recreational fishery (commercial passenger fishing vessels [CPFVs] and personal skiffs combined). Adult male California sea lions were responsible for 98.4% of the observed depredations of hooked salmon in the commercial and recreational fisheries in Monterey Bay. Mean annual percentages of hooked salmon taken by sea lions ranged from 8.5% to 28.6% in the commercial fishery, 2.2% to 18.36% in the CPFVs, and 4.0% to 17.5% in the personal skiff fishery. Depredation levels in the commercial and recreational salmon fisheries were greatest in 1998—likely a result of the large El Niño Southern Oscillation (ENSO) event that occurred from 1997 to 1998 that reduced natural prey resources. Commercial fishermen lost an estimated $18,031−$60,570 of gear and $225,833−$498,076 worth of salmon as a result of interactions with sea lions. Approximately 1.4−6.2% of the available salmon population was removed from the system as a result of sea lion interactions with the fishery. Assessing the impact of a growing sea lion population on fisheries stocks is difficult, but may be necessary for effective fisheries management.

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Reproductive data collected from porbeagle, shortfin mako, and blue sharks caught around New Zealand were used to estimate the median length at maturity. Data on clasper development, presence or absence of spermatophores or spermatozeugmata, uterus width, and pregnancy were collected by observers aboard tuna longline vessels. Direct maturity estimates were made for smaller numbers of sharks sampled at recreational fishing competitions. Some data sets were sparse, particularly over the vital maturation length range, but the availability of multiple indicators of maturity made it possible to develop estimates for both sexes of all three species. Porbeagle shark males matured at 140–150 cm fork length and females at about 170–180 cm. New Zealand porbeagles therefore mature at shorter lengths than they do in the North Atlantic Ocean. Shortfin mako males matured at 180–185 cm and females at 275 –285 cm. Blue shark males matured at about 190 –195 cm and females at 170–190 cm; however these estimates were hampered by small sample sizes, difficulty obtaining representative samples from a population segregated by sex and maturity stage, and maturation that occurred over a wide length range. It is not yet clear whether regional differences in median maturity exist for shortfin mako and

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Metal-framed traps covered with polyethylene mesh used in the fishery for the South African Cape rock lobster (Jasus lalandii) incidentally capture large numbers of undersize (<75 mm CL) specimens. Air-exposure, handling, and release procedures affect captured rock lobsters and reduce the productivity of the stock, which is heavily fished. Optimally, traps should retain legalsize rock lobsters and allow sublegal animals to escape before traps are hauled. Escapement, based on lobster morphometric measurements, through meshes of 62 mm, 75 mm, and 100 mm was investigated theoretically under controlled conditions in an aquarium, and during field trials. SELECT models were used to model escapement, wherever appropriate. Size-selectivity curves based on the logistic model fitted the aquarium and field data better than asymmetrical Richards curves. The lobster length at 50% retention (L50) on the escapement curve for 100-mm mesh in the aquarium (75.5 mm CL) approximated the minimum legal size (75 mm CL); however estimates of L50 increased to 77.4 mm in field trials where trapentrances were sealed, and to 82.2 mm where trap-entrances were open. Therfore, rock lobsters that cannot escape through the mesh of sealed field traps do so through the trap entrance of open traps. By contrast, the wider selection range and lower L25 of field, compared to aquarium, trials (SR = 8.2 mm vs. 2.6 mm; L25 =73.4 mm vs. 74.1 mm), indicate that small lobsters that should be able to escape from 100-mm mesh traps do not always do so. Escapement from 62-mm mesh traps with open entrance funnels increased by 40−60% over sealed traps. The findings of this study with a known size distribution, are related to those of a recent indirect (comparative) study for the same species, and implications for trap surveys, commercial catch rates, and ghost fishing are discussed.

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Fisheries agreements with the European Community (EC) are an important component of the fisheries sector in Cape Verde and São Tomé e Príncipe, constituting today a key source of income for the respective fisheries administration. In spite of this, and of the fact that these agreements have been renewed several times over the past decades, challenges remain in domains such as control and communication of fishing activities, follow-up of financial counterparts, and integration of European fleets’ operations with the Cape Verdean and Santomean economies. This paper analyzes the EC fisheries agreements with Cape Verde and São Tomé e Príncipe in terms of those domains, considering both the contents of the agreements and their practical implementation. The fisheries sector in each of these countries is reviewed, as are some of the fundamentals and criticisms of EC fisheries agreements. It is argued that the agreements with Cape Verde and São Tomé e Príncipe will not live up to the stated objectives of sustainability and responsibility in fisheries until improvements are made to the control of EC vessels, the follow-up of funds paid by the EC, and the size and diversity of benefits accruing to the fisheries and related sectors in the two countries

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Through the mid 1990’s, the bait purse-seine fishery for Atlantic menhaden, Brevoortia tyrannus, in the Virginia portion of Chesapeake Bay was essentially undocumented. Beginning in 1995, captains of Virginia bait vessels maintained deck logs of their daily fishing activities; concurrently, we sampled the bait landings for size and age composition of the catch. Herein, we summarize 15 years (1995–2009) of data from the deck logbooks, including information on total bait landings by purse seine, proportion of fishing to nonfishing days, proportion of purse-seine sets assisted by spotter pilots, nominal fishing effort, median catches, and temporal and areal trends in catch. Age and size composition of the catch are described, as well as vessel and gear characteristics and disposition of the catch.

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The implementation of Puerto Rican Regulation No. 6768, which overhauled the existing fishery management framework, generated considerable hostility towards local managers. Among the controversial management measures adopted in 2004 were the assignment of fishing licenses based on fishing income, the establishment of closed seasons, and new minimum size restrictions for commercially valuable species. Though tensions have subsided, considerable opposition to these regulations remains. This paper provides a characterization of the current population of active small-scale fishermen, discusses their perceptions about the biological and socio-economic condition of the fishery, and describes their attitudes towards the new management framework. This study revealed that the number of active fishermen decreased from 1,731 in 1988 to 868 in 2008. Although a declining resource base was one of the main drivers behind these waning participation statistics, rising fuel costs and burdensome regulations exacerbated the rate of attrition. The majority of the fishermen were middleaged men (50 years) with moderate levels of formal education and high levels of fishing dependence which limited their employment opportunities outside the fishery. Most of the vessels were small (20 ft) and outfitted with a single outboard engine (80 hp). Hook and line and SCUBA were dominant gears because of their versatility and cost effectiveness. Fishermen suggested that their opposition to the regulations would continue unless they were afforded greater regulatory flexibility and provided with a larger role in the decision-making process. Fishermen were adamant about the need to reconsider the income reporting requirements to secure a fishing license because of the potential for losing public assistance benefits. They also objected to increasing the minimum size of many deepwater snapper (Lutjanidae) and grouper (Serranidae) species because it forced them to discard dead fish, a practice they consider wasteful since these species do not survive the ascent to the surface once hooked.

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Bycatch in U.S. fisheries has become an increasingly important issue to both fisheries managers and the public, owing to the wide range of marine resources that can be involved. From 2002 to 2006, the Commercial Shark Fishery Observer Program (CSFOP) and the Shark Bottom Longline Observer Program (SBLOP) collected data on catch and bycatch caught on randomly selected vessels of the U.S. Atlantic shark bottom longline fishery. Three subregions (eastern Gulf of Mexico, South Atlantic, Mid-Atlantic Bight), five years (2002–06), four hook types (small, medium, large, and other), seven depth ranges (<50 m to >300 m), and eight broad taxonomic categories (e.g. Selachimorpha, Batoidea, Serranidae, etc.) were used in the analyses. Results indicated that the majority of bycatch (number) was caught in the eastern Gulf of Mexico and that the Selachimorpha taxon category made up over 90% of the total bycatch. The factors year followed by depth were the most common significant factors affecting bycatch.

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The 19th century commercial ship-based fishery for gray whales, Eschrichtius robustus, in the eastern North Pacific began in 1846 and continued until the mid 1870’s in southern areas and the 1880’s in the north. Henderson identified three periods in the southern part of the fishery: Initial, 1846–1854; Bonanza, 1855–1865; and Declining, 1866–1874. The largest catches were made by “lagoon whaling” in or immediately outside the whale population’s main wintering areas in Mexico—Magdalena Bay, Scammon’s Lagoon, and San Ignacio Lagoon. Large catches were also made by “coastal” or “alongshore” whaling where the whalers attacked animals as they migrated along the coast. Gray whales were also hunted to a limited extent on their feeding grounds in the Bering and Chukchi Seas in summer. Using all available sources, we identified 657 visits by whaling vessels to the Mexican whaling grounds during the gray whale breeding and calving seasons between 1846 and 1874. We then estimated the total number of such visits in which the whalers engaged in gray whaling. We also read logbooks from a sample of known visits to estimate catch per visit and the rate at which struck animals were lost. This resulted in an overall estimate of 5,269 gray whales (SE = 223.4) landed by the ship-based fleet (including both American and foreign vessels) in the Mexican whaling grounds from 1846 to 1874. Our “best” estimate of the number of gray whales removed from the eastern North Pacific (i.e. catch plus hunting loss) lies somewhere between 6,124 and 8,021, depending on assumptions about survival of struck-but-lost whales. Our estimates can be compared to those by Henderson (1984), who estimated that 5,542–5,507 gray whales were secured and processed by ship-based whalers between 1846 and 1874; Scammon (1874), who believed the total kill over the same period (of eastern gray whales by all whalers in all areas) did not exceed 10,800; and Best (1987), who estimated the total landed catch of gray whales (eastern and western) by American ship-based whalers at 2,665 or 3,013 (method-dependent) from 1850 to 1879. Our new estimates are not high enough to resolve apparent inconsistencies between the catch history and estimates of historical abundance based on genetic variability. We suggest several lines of further research that may help resolve these inconsistencies.

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Commercial trawling on the Atlantic slope areas off Brazil intensified in the late 1990’s owing to the expansion of coastal trawling areas and the operations of a chartered foreign fleet. Between 2000 and 2003, 59 fishing trips conducted by 10 chartered trawlers were intensely monitored by observers and satellite vessel monitoring systems, totaling 9,069 tows and 30,085.2 trawling hours. Fishing operations occurred in northern, northeastern, southeastern, and southern sectors of the Brazilian coast in 60–1,173 m depths. Total retained and processed catch were 8,074.6 t and 6,479.8 t, respectively. Argentine hake, Merluccius hubbsi; and Argentine shortfin squid, Illex argentinus, were the primary species taken contributing to 41.1% and 28.6% of the overall catch, respectively. The silver John dory, Zenopsis conchifera; monkfish, Lophius gastrophysus; Brazilian codling, Urophycis mystacea; and the black grouper, Epinephelus nigritus, composed 23% of total processed catch, and the remaining 7.2% was composed of deep-sea shrimps (family Aristeidae) and other teleosts and elasmobranches. The occupation of slope areas included an early exploratory phase, followed by directed phases of the upper slope (300–500 m), aiming principally at the Argentine hake, and the lower slope (>700 m), targeting valuable concentrations of deep-sea aristeid shrimps. The role of chartering for slope trawling development was critically addressed. We conclude that chartered vessels were efficient explorers and were particularly important in areas not available to the technologically limited national fleet. Because the charters were market-oriented and had elevated profit demands, however, those vessels quickly turned from exploration to exploitation and competed with national trawlers in shallower areas and produced significant impacts on Brazil’s modest deep-sea resources.

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The U.S. Atlantic coast and Gulf of Mexico commercial shark fisheries have greatly expanded over the last 30 years, yet fishery managers still lack much of the key information required to accurately assess many shark stocks. Fishery observer programs are one tool that can be utilized to acquire this information. The Commercial Shark Fishery Observer Program monitors the U.S. Atlantic coast and Gulf of Mexico commercial bottom longline (BLL) large coastal shark fishery. Data gathered by observers were summarized for the 10-year period, 1994 to 2003. A total of 1,165 BLL sets were observed aboard 96 vessels, with observers spending a total of 1,509 days at sea. Observers recorded data regarding the fishing gear and methods used, species composition, disposition of the catch, mortality rates, catch per unit of effort (sharks per 10,000 hook hours), and bycatch of this fishery. Fishing practices, species composition, and bycatch varied between regions, while catch rates, mortality rates, and catch disposition varied greatly between species.

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In late October of 1966, an imposing ship steamed quietly through the placid waters of the Suez Canal. Clad in drab industrial gray, and flying a Soviet hammer and sickle flag at her masthead, the vessel was accompanied by a large fleet of smaller craft. Any observer able to decipher Cyrillic script could have read, in rusting metallic letters on her bow, the name Sovetskaya Ukraina. The more experienced would perhaps have identified her as a whaling factory ship, traveling with her attendant fleet of catcher boats and scouting vessels on a transit that would take them south into the Red Sea and beyond.

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Fishery observers collected data from 307 tows during 96 trips aboard skimmer trawl vessels in Louisiana’s coastal waters from September 2004 through June 2005 to estimate catch rates of target and nontarget species, including sea turtles (Cheloniidae and Dermochelyidae), by area and season during commercial shrimping operations. About 16,965.7 kg of total catch were recorded during 517.0 hours of fishing operations. Based on weight extrapolations from species composition samples, penaeid shrimp (Penaeidae) dominated the catch at 66%, followed by finfish at 19%, nonpenaeid shrimp crustaceans at 7%, discarded penaeid shrimp at 6%, and debris at 3%. Noncrustacean invertebrates comprised less than 1%. Catch rates in kilograms per hour by category was 21.6 for penaeid shrimp, 6.2 for finfish, 2.2 for nonpenaeid crustaceans, 1.8 for discarded penaeid shrimp, and 0.9 for debris. White shrimp, Litopenaeus setiferus, other penaeid shrimp, and Gulf menhaden, Brevoortia patronus, were the top three dominant species by weight. Seasonally, a higher catch rate was observed from May through August 2005 for penaeid shrimp as compared with the September through December 2004 period. Conversely, the September through December 2004 period experienced a higher catch rate for finfish than during May through August 2005. No sea turtle interactions were documented.

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Due to a lack of data on vessel costs, earnings, and input use, many of the capacity assessment models developed in the economics literature cannot be applied in U.S. fisheries. This incongruity between available data and model requirements underscores the need for developing applicable methodologies. This paper presents a means of assessing fishing capacity and utilization (for both vessels and fish stocks) with commonly available data, while avoiding some of the shortcomings associated with competing “frontier” approaches (such as data envelopment analys

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Data collected by fisheries observers aboard U.S. pelagic longline vessels were examined to quantify and describe elasmobranch bycatch off the southeastern U.S. coast (lat. 22°–35°N, long. 71°–82°W). From 1992 to 2000, 961 individual longline hauls were observed, during which 4,612 elasmobranchs (15% of the total catch) were documented. Of the 22 elasmobranch species observed, silky sharks, Carcharhinus falciformis, were numerically dominant (31.4% of the elasmobranch catch). The catch status of the animals (alive or dead) when the gear was retrieved varied widely depending on the species, with high mortalities seen for the commonly caught silky and night, C. signatus, sharks and low mortalities for rays (Dasyatidae and Mobulidae), blue, Prionace glauca; and tiger, Galeocerdo cuvier; sharks. Discard percentages also varied, ranging from low discards (27.6%) for shortfin mako, Isurus oxyrinchus, to high discards for blue (99.8%), tiger (98.5%), and rays (100%). Mean fork lengths indicated the majority of the observed by-catch — regardless of species — was immature, and significant quarterly variation in fork length was found for several species including silky; dusky, C. obscurus; night; scalloped hammerhead, Sphyrna lewini; oceanic whitetip, C. longimanus; and sandbar, C. plumbeus; sharks. While sex ratios overall were relatively even, blue, tiger, and scalloped hammerhead shark catches were heavily dominated by females. Bootstrap methods were used to generate yearly mean catch rates (catch per unit effort) and 95% confidence limits; catch rates were generally variable for most species, although regression analysis indicated significant trends for night, oceanic whitetip, and sandbar sharks. Analysis of variance indicated significant catch rate differences among quarters for silky, dusky, night, blue, oceanic whitetip, sandbar, and shortfin mako sharks.