EAPSI: Characterization of dissolved free amino acids in hatchery system water - a salmon hatchery case study

几十年来，太平洋西北部的鲑鱼因多种原因而受到追捧。由于每年返回其出生河流产卵的成鱼数量在区域性下降，孵化场鲑鱼的饲养和释放已经使用了几十年。不幸的是，孵化场饲养的鲑鱼已经显示出家庭溪流保真度的显著下降，并且由于与野生种群的相互作用增加而带来了各种各样的生态问题。对孵化场鲑科鱼类缺乏家乡溪流保真度的一种解释是对纳塔尔河水中的化学线索了解不足。本研究的目的是确定简单的日常孵化场操作是否改变了纳塔尔河水的化学性质。这项研究将与日本北海道大学的溶出游离氨基酸（DFAA）专家Hiroshi Ueda博士合作进行。众所周知，当鲑鱼游到它们的出生河流产卵时，它们利用嗅觉来识别出生河流中不同的化学物质。然而，鲑鱼产生这种现象所使用的化学物质的独特组合或“气味”尚未被确定。最近，相当多的注意力集中在DFAA作为一组分子，鲑鱼使用它来导航和识别它们的出生河流。研究表明，鲑鱼具有根据DFAA成分区分某些水源的能力。采用高效液相色谱法（HPLC）对河水中DFAA的含量进行分析。通过分析从孵化场设置的某些地点收集的水，将确定当前孵化场的操作是否可能显著改变其源河水的化学性质。NSF EAPSI奖是与日本科学促进会合作资助的。

For many decades, salmon in the Pacific Northwest have been sought after for a multitude of reasons. Due to regional declines in adults returning to their natal rivers to spawn every year, the rearing and release of hatchery salmonids has been utilized for many decades. Unfortunately, hatchery raised salmon have shown a significant decrease in home stream fidelity and impose an assortment of ecological issues due to increased interaction with wild populations. One proposed explanation for the lack of home stream fidelity in hatchery salmonids is inadequate learning of chemical cues in natal river water. The purpose of this study is to determine if the chemical nature of natal river water is altered by simple, daily hatchery operations. This research will be conducted in collaboration with Dr. Hiroshi Ueda, an expert in dissolved free amino acids (DFAA's) in salmonid imprinting and homing, at the Hokkaido University in Japan.It is well understood that salmon use olfaction to identify distinct chemical cues of natal river water when navigating to their natal rivers to spawn. However, the distinct set, or "bouquet" of chemicals that salmon use for this phenomenon has yet to be identified. Recently, considerable attention has been directed towards DFAA's as a set of molecules that salmon use to navigate and identify their natal rivers. Research has shown that salmonids possess the ability to distinguish between certain water sources based on their DFAA compositions. High-performance liquid chromatography (HPLC) will be used to analyze the content of DFAA's in river water. By analyzing water collected from certain locations within a hatchery setting, it will be determine if current hatchery operations may significantly alter the chemical nature of their source river water. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.