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中文摘要：
为研究长江口鳗苗捕捞量与生态因子的相互关系,于2012年汛期对长江靖江段鳗苗的捕捞量进行了监测,采用广义可加模型（GAM）对日捕捞量与水温、潮差、气压、浑浊度等生态因子之间的相关性作了分析。结果显示,靖江段鳗苗汛期为1月下旬—4月上旬,单船总捕捞量为221～443尾,平均（344.8±83.4）尾。1月均值仅0.4尾/d,且空网率高达90.9%;4月为旺汛期,均值10.4尾/d,空网率仅为10.0%。GAM模型显示,潮汐周期—月份交互项、水温和潮差对鳗苗日捕捞量的影响显著,而气压、浊度和月相周期对鳗苗日捕捞量的影响不显著。潮汐周期—月份交互项、水温和潮差对鳗苗日捕捞量的偏差解释率分别为42.4%、19.1%和13.1%,均呈现正相关关系。统计也显示,日捕捞量表现出上、下弦月较低、新月或满月前后较高的半月周期波动。鳗苗捕获的最低水温为6.3℃,而10～15℃为适宜捕捞水温。高潮期和低潮期分别占总捕捞量的76.8%和23.2%。研究表明,长江口鳗苗在借助潮汐流而快速溯河的过程中,部分在口门水域即被捕获,部分滞留在了长江河口段,而影响鳗苗溯河的重要生态因子是潮汐和水温。
英文摘要：
To analyze daily variations in Anguilla japonica glass eel catch as related to ecological factors at Jingjiang section of the Yangtze River, we conducted daily monitoring program at Jingjiang section of the Yangtze River during the 2012 fishing season. A generalized additive model（GAM） was applied to evaluate the relationships between daily catch and their ecological variables, including water temperature, the tidal range,turbidity, lunar phase, tide phase and pressure. Fishing was performed at Jingjiang section of the Yangtze River from late January to early April. The total fishing period catch per boat ranged from 221 ind. to 443 ind. with a mean±SD of（344.8±83.4） ind. The daily catch differed by month. The mean daily catch was only 0.4 ind./d in January, and the abortive haul rate was 90.9%; while mean daily catch was up to 10.4 ind./d in April, and the abortive haul rate was only 10.0%. Stepwise GAM building using the AIC and adjusted pseudo-R～2 showed that turbidity, pressure and lunar phase did not affect daily catch of A. japonica glass eels significantly, but three predictor variables, tide phase-month interaction, water temperature and tidal range were highly significant. In addition, tide phase-month interaction, water temperature, and tidal range account for 42.4%, 19.1% and 13.1% of the variance in the data, respectively, and these three variables also showed a positive relationship with the daily catch. Statistical results also showed that the daily catch fluctuated with tide phase, since high catches appeared at times corresponding to the spring tide of the full moon or the new moon, while, low catches appeared at times corresponding to the neap tide during quarter moons. Moreover, glass eels were caught when the minimum water temperature was 6.3 ℃, and a greater catch was found in optimal water temperature ranging between 10 and 15℃. Overall, the proportion of total catches for spring or neap tide period was 76.8% and 23.2%, respectively.Furthermore, our results suggested that duri
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