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  • 1. We conducted a preliminary study of the effects of a shrimp beam trawl and prawn traps on sea whips (Halipteris willemoesi (Cnidaria: Octocorallia: Pennatulacea)) at two bays on Clio Channel, south central coast of British Columbia, Canada. Video and grabs surveys were conducted to estimate abundance and make observations on sea whips and their habitat.
  • 2. No adult sea whips were caught in six beam trawls. In 600 prawn (Pandalus platyceros) trap sets at Turnour Bay, 30 sea whips were found entangled in the gear and of these 50% of the colonies were damaged. The length of broken sea whips ranged from 0.09 to 1.03 m. At Turnour Bay, the density of adults observed in video surveys ranged from 7.1 to 14.3 m?2. Juvenile density in grab samples ranged from 53 to 123 m?2 and a few adults were also caught. The lengths of intact adult sea whips caught in traps and grabs ranged from 0.20 to 1.98 m and juveniles from 0.3 to 0.7 cm.
  • 3. Fewer adult sea whips (<0.1 m?2) were seen in Bones Bay, where sediments were muddier (grain size <0.25 mm: 84.6 to 97.2%) relative to Turnour Bay (grain size <0.25 mm: 71.4 to 85.9%). Bottom water characteristics at the two bays were similar. Seasonal temperature range was 7.5–8.4°C, salinity 30.63–31.49 psu, and dissolved oxygen 2.76–5.97 mg L?1. Differences in sediment characteristics and food availability may have been a factor influencing differences in abundance of sea whips between the two bays.
  • 4. Further data are needed to investigate the effects of trawling and trapping on sea whips, as sample sizes were small in the present study and only two gear types were evaluated. Studies of effects of otter trawling and heavier traps, such as those used for Dungeness crab (Cancer magister), are warranted.
Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

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Evaluating historical changes in the exploitation of marine organisms is a key challenge in fisheries ecology and marine conservation. In the Eastern Pacific, marine turtles were exploited for millennia before systematic monitoring began <50 years ago. Using ethnographic and historical data, we generated a detailed reconstruction of the East Pacific green sea turtle (Chelonia mydas) fishery in Mexico's Baja California peninsula from 1700 to 1990. Sea turtles from the region's important feeding areas were a staple food source from the earliest phases of human occupation, dating back at least 12,000 years. In contrast with regions such as the Caribbean, small human populations and limited market access resulted in apparently sustainable turtle harvests until the second half of the 20th century. We found that the estimated annual catches between 1960 and 1980 exceeded the estimated annual catches of the previous 250 years by an order of magnitude, leading to the collapse of the fishery and the depletion of the green turtle population. A total ban on sea turtle captures in 1990, comprehensive nesting beach protection, and significant conservation efforts resulted in increases in breeding females on nesting beaches and catch rates in scientific monitoring on main feeding grounds since the early 2000s. This provides a positive outlook for this once‐depleted population segment. Although further research is needed to evaluate current conservation status, we have identified a date, between 1950 and 1960, which can serve as a reliable temporal reference for future evaluations of historical baseline abundance in this region.  相似文献   

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This paper offers a socio‐historical study of the Prud'homie de pêche (the “Prud'homie”), a common‐pool institution (“CPI”) that has managed the fishery commons at Marseille since the Middle Ages. The evidence presented here sheds light on specific challenges faced by the Prud'homie during the early stages of globalization: one challenge is the import of a new fishing technique (the madrague) in the early 17th century, and another challenge is the arrival of migrant fishermen from Catalonia throughout the 18th century. On this basis, this paper explores the ways in which globalization has impacted the Prud'homie and identifies the mechanisms through which these challenges might threaten the functioning of CPIs.  相似文献   

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Marine scholars have come to realize the importance of including historical perspectives as part of comprehensive assessments made of the social–ecological systems involved in sustainable fisheries management. In particular, there is increasing recognition of the value in examining information contained within historical anecdotes as a prelude to implementing current conservation actions as well as setting future restoration objectives. The present study demonstrates that careful parsing of eyewitness accounts of unidentified marine objects which at the time were purported to be sea serpents—of the “many‐humped” or “string‐of‐buoys” typology—actually reveals that marine fauna in the British Isles have been victims of entanglement in fishing gear for a much longer period than is customarily assumed. The temporal baseline for the onset of entanglement in this region certainly predates, by more than a century, the advent and widespread use of plastic in fisheries and other maritime operations.  相似文献   

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