GLOBEC: Growth and Survival of Juvenile Salmon

GLOBEC：幼鲑鱼的生长和存活

• 批准号: 0002725
• 负责人: Greg Rau
• 金额: $ 37.56万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-15 至 2006-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0002725&HistoricalAwards=false
• 关键词: GLOBEC; Growth; Survival; Juvenile; Salmon

RauSalmon populations in the California Current System (CCS), and coho salmon in particular, have been in severe decline since the 1980s, coinciding with the 1977 regime shift, and in contrast to record productivity in the Gulf of Alaska. The specific linkages between oceanographic changes and salmon survival in the marine.enviromnent are not well understood. GLOBEC has chosen to compare two regions of the Northern California Current divided by Cape Blanco, Oregon (43 degrees N) where an "upwelling jet" moves off the shelf. The regions north and south of Cape Blanco differ in intensity and stability of upwelling, temperature, and offshore transport. Evidence indicates that due to the physical conditions, the distribution and production of biota may differ north and south of Cape Blanco, providing the opportunity to compare and contrast the relationship between specific oceanographic processes and biological productivity. The investigators will use process oriented studies to examine mechanistic linkages between the physical and biological processes that are associated with habitat quality critical to recruitment of juvenile salmon. Juvenile coho (Oncorhynchus kisutch) and chinook (Oncorhynchus tshawytscha) salmon will be collected along transects between Eureka, CA to Newport, OR during May/June and September of 2000 and 2002. Sampling efforts will coincide with mesoscale and fine-scale surveys of physical (e.g., location of eddies, fronts, upwelling, offshore transport import; mixed layer depth, sea surface temperature, mixed layer depth) and biological (areas and density of primary and secondary productivity) features within the same regions conducted by other GLOBEC researchers. The salmon investigators will measure the growth rate, size variability, bioenergetic condition, pathogen prevalence and intensity in juvenile salmon as conditions of survival. By correlating indices in the Northern CCS with the trophic relationship studies, they will test the hypotheses that oceanographic features leading to high productivity of lower trophic levels translates to higher growth rates, condition and greater salmon recruitment through "bottom-up" forces. Also, the degree of correlation between these indices and variations in isotope natural abundances (14C, 13C, 15N) in juvenile salmon will be used to directly test the hypothesis that diet specificity and vertical ocean advection affect juvenile salmon health and condition. The investigators also will compare juvenile coho and chinook slamon growth and condition from different regions of the Northeast Pacific (e.g., Alaska, British Columbia, Washington and northern Oregon) and to the historical record (prior to the last regime shift) where available and applicable. These results will provide information on the relationships between ocean variability and juvenile salmon survival on temporal (interdecadal) and spatial (basin-wide, mesoscale, and local) scales.

自1980年代以来，加利福尼亚海流系统(CCS)中的劳哈鱼种群，特别是Coho鲑鱼数量一直在严重下降，恰逢1977年政权更迭，这与阿拉斯加湾创纪录的生产力形成了鲜明对比。海洋变化和海洋环境中鲑鱼生存之间的具体联系还没有被很好地理解。GLOBEC选择比较被俄勒冈州布兰科角(北纬43度)划分的北加州洋流的两个区域，在那里有一股上升流从大陆架上移开。布兰科角北部和南部地区在上升流、温度和近海输送的强度和稳定性方面存在差异。有证据表明，由于自然条件的原因，布兰科角北部和南部的生物群的分布和生产可能不同，这为比较和对比特定海洋过程与生物生产力之间的关系提供了机会。研究人员将使用面向过程的研究来检查物理和生物过程之间的机械联系，这些过程与栖息地质量有关，而栖息地质量对幼年鲑鱼的补充至关重要。幼年Coho(Oncorhynchus Kiutch)和Chinook(Oncorhynchus Tshawytscha)鲑鱼将在加利福尼亚州尤里卡至纽波特之间的横断面上采集，或在2000年至2002年的5/6和9月期间采集。采样工作将与GLOBEC其他研究人员对同一区域内的物理特征(例如，涡旋、锋面、上升流、近海输送输入；混合层深度、海表面温度、混合层深度)和生物特征(初级和次级生产力的面积和密度)进行的中尺度和精细调查相一致。鲑鱼调查员将测量幼体鲑鱼的生长速度、大小变异性、生物能量状况、病原体流行率和强度作为生存条件。通过将北部CCS的指数与营养关系研究相关联，他们将检验以下假设：海洋特征导致低营养水平的高生产力转化为更高的增长率、状况和通过“自下而上”的力量获得更大的鲑鱼补充。此外，这些指数与幼鲑鱼的同位素天然丰度(14C、13C、15N)的变化之间的相关程度将被用来直接检验食物特异性和垂直海洋平流影响幼鲑鱼健康和状况的假设。调查人员还将比较东北太平洋不同地区(如阿拉斯加、不列颠哥伦比亚省、华盛顿州和俄勒冈州北部)的幼年Coho和Chinook Slamon的生长和状况，并与可用和适用的历史记录(上一次政权更迭之前)进行比较。这些结果将提供时间(年代际)和空间(盆地范围、中尺度和局部)尺度上的海洋变异性与鲑鱼幼鱼存活率之间的关系的信息。