臺灣西南沿岸海域重要經濟蝦類之生態學研究-Ⅱ大鵬灣熊蝦之向海洄游

Ecological Studies on Commerically Important Prawns from the Coastal Waters of Southwest Taiwan-ⅡEmigration of Penaeus Semisulcatus from Dapong Bay

蘇茂森(Mao-Sen Su) ； 廖一久(I-Chiu Liao)

《臺灣水產學會刊》 14卷1期 (1987/06) Pp. 49-59

https://doi.org/10.29822/JFST.198706.0005

摘要

為長期利用本省週圍水域內之漁業資源，實施網目限制式之資源管理，乃一極為可行之對策。蝦類向為本省近海小型單拖網漁業之主要漁獲對象，本試驗卽針對綱目對其選擇作用之影響，採覆蓋網法(Covered net method)，於臺灣北部漁場，進行76網次之實驗，其結果如下：1.主要漁獲物種類有劍蝦、白鬚蝦、厚殼蝦、灰海鰻、烏賊、日本白口、錦鱗蜥魚等七種。2.蝦類的漁獲平均體長因應綱目規格之擴大而增加，但漁獲尾數則相對減少。3.同一網目規格對同體長之三種蝦類之選擇率甚為相近。4.厚殼蝦於本試驗漁期及漁場幼稚者佔很大之比率。5.50％選擇點體長（L0.5，in mm）與網目規格(Me,in mm)之關係：劍蝦：L0.5=4.9590 Me-122.3852白鬚蝦：L0.5=5.9836 Me-155.75416.就主要漁獲物劍蝦而言，其商業體長若以45～50 mm以上為對象時，以採行34.2 mm之網目限制為宜；若提高為80～85 mm以上之商業體長時，則以採行41.3 mm之網目限制為宜。

並列摘要

In order to study the mesh selectivity of shrimp otter trawl,cod-end of mesh size27.3 mm,33.3 mm,39.4 mm,45.5 mm,51.5 mm,57.6 mm and cover net of mesh size21.2 mm were made.All of experimental hauls were conducted around the water ofTung-Ting Island,250 miles from Keelung,during December,1982 and January,1983.Numbers and body lengths of shrimps retained in the cod-end and cover net wererecorded.The results obtained were as follows:1.When the mesh size increased,the mean body length of shrimps increased butthe numbers caught were reduced.2.When the same mesh size was used,the selection rates on various speciesof shrimps with same size were very similar.3.At this period and area of fishing,a majority of Metapenaeopsis barbata wereimmature.4.The relations between 50% point selection length(L0.5,in mm)and meshsize(Me,in mm)for shrimps were follow.Parapenaeopsis hardwickii:L0.5=4.9590 Me-122.3852Penaeus teraoi:L0.5=5.9836 Me-155.74155.Parapenaeopsis hardwickii was the major catch.If we considered two groupsof body length 45～50 mm and 80～85 mm as the major catching targets,the adoptivemesh size regulation then would be 34.2 mm and 41.3 mm,respectively.