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首页> 外文期刊>Fisheries Research >A validation of short-duration scientific tows as a representation of longcommercial-length tows: comparing the catch rates, size composition andspecies composition of prawn trawler bycatch in the far northern GreatBarrier Reef, Australia
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A validation of short-duration scientific tows as a representation of longcommercial-length tows: comparing the catch rates, size composition andspecies composition of prawn trawler bycatch in the far northern GreatBarrier Reef, Australia

机译：验证了短时科学拖缆作为长商业拖缆的代表：在澳大利亚大堡礁北部，比较虾拖网渔船兼捕的捕获率，大小组成和物种组成

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摘要

The duration of tows for scientific trawl surveys in northern Australia is generally 30 min. Commercial trawls may be up to 200 min long. In this study we compare the catch rates, size of fish and species composition for 10 short (30 min) tows paired with 10 commercial length (165 min-not in a straight line) tows at both an inshore and an offshore location in the far northern Great Barrier Reef. Evaluations of this kind have not been reported in tropical Australian multi-species fisheries. Overall, catch rates of fish and invertebrates differed between short and long tows both inshore and offshore. Inshore, the mean catch rate for the fish and the invertebrates was significantly greater in short duration tows (P < 0.05). Offshore, the mean catch rate for all fish, and all invertebrates was not significantly different between short and long tows, although higher catch rates of invertebrates were recorded in long tows. Inshore, 12 fish species out of 49 had significantly different catch rates, most being greater in short tows. Only 2 invertebrates out of 16 had significantly different catch rates (P < 0.05). The combined weight of species showing significant differences in catch rates represented less than 10% of the total weight in both inshore and offshore samples. Principal component analysis indicated that catch composition was similar between short and long tows both inshore and offshore. The results from our sampling are that the species composition of 30-min trawls is similar to that of commercial length tows, and that size frequencies are equivalent. The implications are that short tows (30 min) can be used in scientific surveys to give a true representation of both size and species composition of commercial length tows, but may overestimate catch rates.
机译：在澳大利亚北部进行科学拖网调查的拖缆时间通常为30分钟。商业拖网可能长达200分钟。在这项研究中，我们比较了近岸和近海地点的10个短（30分钟）拖丝与10个商业长度（165分钟，非直线）拖丝的捕获率，鱼的大小和种类组成大堡礁北部。在澳大利亚的热带多物种渔业中尚未进行这种评估。总体而言，近岸和近岸的短拖和长拖的鱼和无脊椎动物的捕获率不同。在近岸，短时拖曳的鱼类和无脊椎动物的平均捕获率明显更高（P <0.05）。在近海，短和长丝束中所有鱼类和所有无脊椎动物的平均捕获率没有显着差异，尽管长丝束中无脊椎动物的捕获率更高。在近岸，49种鱼类中有12种的捕捞率有很大不同，大多数在短拖曳中更大。 16个中只有2个无脊椎动物的捕获率差异显着（P <0.05）。在近岸和近海样本中，总捕获量差异显着的物种总重量不足总重量的10％。主成分分析表明，近岸和近海的短拖和长拖之间的渔获物组成相似。我们采样的结果是，30分钟拖网的物种组成与商业长度拖网的物种组成相似，并且大小频率相同。这意味着短的丝束（30分钟）可用于科学调查中，以真实地代表商业长度丝束的大小和种类组成，但可能会高估捕获率。

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