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舟山渔场及邻近海域蟹类种类组成和时空分布 总被引：4，自引：0，他引：4
根据2006年8月、2007年1月、5月和11月4个季节在舟山渔场及邻近海域(29°30′N—32°00′N,127°E以西)开展海洋生态系统综合调查时所获得的蟹类调查资料,以渔获率作为蟹类数量指标分析该海域蟹类资源状况,包括种类组成、数量分布和时空变化。结果表明,本次舟山渔场及邻近海域调查共得蟹类种类43种,隶属于10科、21属。优势种类为细点圆趾蟹、双斑蟳、三疣梭子蟹、日本蟳、红星梭子蟹、红线黎明蟹,以上6种蟹类占蟹类总渔获量的94.58%。本次调查与20世纪90年代末在东海大陆架海域的蟹类资源调查结果相比,蟹类种类组成和优势种变化不大。从蟹类渔获率来看,秋季以舟山渔场最高,夏季以江外渔场最高,蟹类资源密集区主要位于长江口渔场和舟山渔场北部。 相似文献
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We used generalized additive models (GAM) to analyze the relationship between spatiotemporal factors and catch, and to estimate the monthly marine fishery yield of single otter trawls in Putuo district of Zhoushan, China. We used logbooks from five commercial fishing boats and data in government’s monthly statistical reports. We developed two GAM models: one included temporal variables (month and hauling time) and spatial variables (longitude and latitude), and another included just two variables, month and the number of fishing boats. Our results suggest that temporal factors explained more of the variability in catch than spatial factors. Furthermore, month explained the majority of variation in catch. Change in spatial distribution of fleet had a temporal component as the boats fished within a relatively small area within the same month, but the area varied among months. The number of boats fishing in each month also explained a large proportion of the variation in catch. Engine power had no effect on catch. The pseudo-coefficients (PCf) of the two GAMs were 0.13 and 0.29 respectively, indicating the both had good fits. The model yielded estimates that were very similar to those in the governmental reports between January to September, with relative estimate errors (REE) of <18%. However, the yields in October and November were significantly underestimated, with REEs of 36% and 27%, respectively. 相似文献
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