2012-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/712809摘要：1980年代開始，東海的漁業資源急遽減少，除了過漁之外，最主要的原因是輸入東海的營養鹽大量增加，引發近岸優養化與底部大範圍缺氧，生物多樣性亦因此降低，禁漁區內的漁業資源也無法恢復。自2008年底，長江三峽大壩運作之後，長江輸入東海的沉積物通量顯著降低，營養鹽含量及比例也在改變，故本研究將持續研究東海營養鹽狀態對底棲魚類群聚的潛在影響。藉由研究船的調查，我們將能分析各測站的種類豐富度，生物多樣性，均勻度等群聚因子，配合其他子計畫所取得的環境與水文資料，進行生物與環境因子的相關性分析。另外，陸域顆粒態有機物輸入至東海，亦可能貢獻到近岸的底棲食物鏈，本研究將利用穩定性碳、氮同位素分析，評估長江的有機物及無機營養鹽分別對東海生態系統的貢獻及影響。研究成果將有助於了解東海陸棚上的底棲魚類資源在環境變遷與人為活動影響的影響下，是否能夠逐漸恢復。 深海底部是個低溫、高壓、黑暗並缺乏食物的極端環境，能生存於此類環境的底棲性魚類必定也演化出獨特的生活史策略，受限於採樣與直接觀察的困難度高，科學界對於深海底棲性魚類的了解一直相當有限。本研究的目的是以耳石的微細構造與穩定性碳氧同位素組成解析深海底棲性魚類的生活史，有些種類可能具有【個體發育垂直洄游行為】，而有些種類則可能是終身棲息於深海底部，若是屬於前者，本研究將探討其幼魚與稚魚階段所棲息的深度，經過多久之後沉降到深海底部，之後的階段是否又有垂直遷徙行為?研究成果可以了解不同魚種所採取的生活史策略，用以適應或是克服海洋深度對各魚類的生存限制。<br> Abstract: The fishery resource in the East China Sea (ECS) has significantly decreased since the 1980’s, due to intensive fishery exploitation and excessive anthropogenic nutrient input. The latter factor causes eutrophication, hypoxia, anoxia and low bio-diversity. Therefore, fishery resource cannot recover even in the fishing prohibited areas. Construction of the Three Gorges Dam (TGD) was completed at the end of 2008 and TGD has changed the ratios of the nutrients discharging into the ECS. This study aims to evaluate the effects of nutrient levels (eutrophic, mesotrophic and oligotrophic) on community structure of demersal fish in the ECS. The biological data for biodiversity, evenness, biomass and abundance will be analyzed. Environmental factors, nutrients, oxygen levels and primary production, will be also measured and collected during the same cruise by other researchers. The biological and environmental data will be analyzed to clarify their interactions. In addition, the particulate organic matters discharged into the ECS may be used by marine organisms. We will use stable isotope analysis to evaluate the relative contribution of inorganic nutrients and POM to marine food web. These results will enable us to better understand the interactions and responses of the demersal fish community to environmental change, especially in continental shelf areas which are largely disturbed by anthropogenic activities. The deep-sea floor is a harsh environment characterized by low temperature, high pressure, darkness and lacks of food supply. The demersal fish living in such environment have evolved special and successful life history strategies. However, scientists have very limited knowledge about the life history of deep-sea demersal fish due to the difficulties of sampling and field observation in the deep seas. This project aims to reconstruct the life history of deep-sea demersal fish by otolith microstructure and stable isotopic analysis. Some species may show ontogenetic vertical migration and some species reside at the deep-sea floor for all of their life. For the migratory deep-sea fish, we will further reveal the important events of their migratory life history such as the timing and depth for the larvae or juvenile to sink and settle on the deep-sea floor, and any possible vertical migration occurring during the adolescent and adult stages. The outcomes of this project can provide further insight into the life history strategies used by different fish species to overcome the restriction of ocean depth in order to survive on the deep-sea floor.東海底棲性魚類生活史穩定性同位素East China SeaDemersal fishLife historyStable isotope