"Ecoogical Study on sustainabel fisheries management based on the ecosystem conservation"

太平洋鲑鱼(Oncorhynchus spp.)表明北太平洋的周期为30或40年，与长期气候条件相吻合。我们用Ricker‘s Recruiting t曲线的替换水平估算了北太平洋红鲑鱼、鲑鱼和粉鲑鱼的负荷量(K)，并定义了剩余负荷量(RCC)：RCC=(负荷量-生物量)/(负荷量)x100。在物种水平上观察到阿留申低压指数(ALPI)与负荷量呈显著正相关。影响种群水平承载能力的因素，如繁殖制度(如早期海洋生物时期的存活率和海面温度以及孵化技术)，因北海道鲑鱼种群而异。北海道鲑鱼种群的RCC与体尺呈显著正相关，与成熟龄呈显著负相关。鲑鱼的生物量将会是…20世纪90年代更多的d种群比20世纪30年代减少了50%，尽管孵化场种群的生物量显著增加。在基于生态系统水平的太平洋鲑鱼生产可持续管理中，野生种群和孵化场种群之间的生物相互作用是一个重要的考虑因素。基于胃内容物和碳、氮稳定同位素的分析，研究了气候事件对阿拉斯加湾中部近海太平洋鲑鱼摄食生态和营养动态的影响。除了大马哈鱼外，所有鲑鱼物种的主要猎物都是钩吻乌贼(Berryteuthis Anauchus)。在1997年厄尔尼诺事件和1999年拉尼娜事件期间，所有太平洋鲑鱼的食物中鱿鱼数量急剧减少，但副北冰洋的Choho鲑鱼除外，鲑鱼的食物从胶状浮游动物转变为更多样化的浮游动物物种。δ13C和δ15N分析表明，在1999年至2000年期间，所有三文鱼物种都占据了食物链的同一分支。我们假设公海鲑鱼通过在营养水平内或营养水平之间改变食物来适应气候引起的猎物资源的变化。营养损失(营养不良)和随之而来的低生产力对生态系统中的生物多样性和生产力的影响最近引起了研究人员的兴趣，因为城市化的加速和自然河岸生态系统的恶化，如堤坝建设、栖息地破坏和人工孵化计划，导致野生淡水鱼(太平洋鲑鱼)的损失。在日本，鲑鱼已经通过孵化计划大量生产，而大量的野生太平洋鲑鱼由于城市化和河岸生态系统的恶化而几乎灭绝。滨河鱼类是维持河岸生态系统生产和生物多样性的关键物种。对于河岸生态系统的可持续保护管理，野生鲑鱼种群、物质循环系统和自然河流的恢复是日本至关重要的问题。较少

The change in biomass of Pacific salmon (Oncorhynchus spp.) indicates a 30- or 40-year periodicity in the North Pacific Ocean coinciding with long-term climate conditions. We estimated the carrying capacity (K) of sockeye, chum, and pink salmon in the North Pacific Ocean using the replacement level of the Ricker's recruitment t curve, and defined residual carrying capacity (RCC): RCC=(Carrying capacity-Biomass)/(Carrying capacity)x100.A significant positive correlation between Aleutian low pressure index (ALPI) and the carrying capacity was observed at the species level. Factors affecting carrying capacity at the population level, such as reproductive regimes (e.g. survival rate and sea surface temperature (SST) in the early marine life period and hatchery technology), differed by population in Hokkaido chum salmon. The RCC was significantly positively correlated with body size and negatively related to age at maturity in Hokkaido chum salmon populations. The biomass of chum salmon wil … More d populations in the 1990s decreased 50% below that of the 1930s, despite the significant increases in the biomass of hatchery populations. Biological interaction between wild and hatchery populations should be an important consideration in the sustainable management of Pacific Salmon production based at the ecosystem level.The effects of climate events on the feeding ecology and trophic dynamics of Pacific salmon in offshore waters of the central Gulf of Alaska were investigated during early summers (1994-2000), based on analyses of stomach contents, and carbon and nitrogen stable isotopes. Gonatid squids (mainly Berryteuthis anonychus) were the dominant prey of all salmon species except for chum salmon. During 1997 El Nino event and the 1999 La Nina event, squids decreased sharply in the diets of all Pacific salmon except choho salmon in the Subarctic Current, and chum salmon diets changed from gelatinous zooplankton to a more diverse array of zooplankton species. Aδ13C and δ15N analysis indicated that all salmon species occupied the same branch of the food web in 1999-2000. We hypothesize that high-seas salmon adapt to climate-induced changes in their prey resources bye switching their diets either within or between trophic levels.The consequences of nutrient loss (oligotrophication) and attendant low productivity on biodiversity and productivity in the ecosystem have recently invoked the interest of researchers, as result of loss of wild anadromous fish (Pacific salmon) by acceleration of urbanization and deterioration of natural riparian ecosystem such dam construction, habitat destruction, and artificial hatchery program. In Japan, chum salmon have been mass-produced by hatchery program, while numerous wild Pacific salmon have been almost extinguished by a combination of the urbanization and the deterioration of riparian ecosystem. Anadromous fish are key species for sustaining production and biodiversity in the riparian ecosystem. For sustainable conservation management of riparian ecosystem, the rehabilitations of wild salmon population, system of material cycle, and natural rivers are critical important issued in Japan. Less