Climate change and dams as threats to the World Heritage Shiretoko: response by coldwater salmonid fish and a possible conservation plan

2015 Fiscal Year Final Research Report

• Project/Area Number: 25281055
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Environmental and ecological symbiosis
• Research Institution: The University of Tokushima
• Principal Investigator: KAWAGUCHI Yoichi 徳島大学, ソシオテクノサイエンス研究部, 准教授 (20391617)
• Co-Investigator(Kenkyū-buntansha): TANIGUCHI Yoshinori 名城大学, 理工学部, 准教授 (30316145) ; URABE Hirokazu 地方独立行政法人北海道総合研究機構, さけます・内水面水産試験場, 研究主任 (30442669) ; SEKIJIMA Tsuneo 新潟大学, 自然科学系, 准教授 (10300964) ; SUMI Tetsuya 大同大学, 工学部, 准教授 (50303673)
• Co-Investigator(Renkei-kenkyūsha): KISHI Daisuke 岐阜県河川環境研究所, 下呂支所, 主任研究員 (80455526)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 温暖化 / 温度ストレス / ヒートショック蛋白 / オショロコマ / 砂防・治山ダム / スリットダム / 保全

Outline of Final Research Achievements

In the west coast of Shiretoko Peninsula, the water depth was shallow, velocity was low, and sunlight penetrated into the stream bed, all of which resulted in increasing the water temperature up to 25℃ in summer where dams were built densely along the stream course. The density of Dolly Varden in such a stream was low, and the fry was not confirmed.
Laboratory experiments showed that the Dolly Varden fries foraged less above 22℃, and they died at 26℃. Other experiments to clarify a defensive response of Dolly Varden to heat stress, the expression of
Hsp (heat-shock protein) 60s and 70 rose above 16℃. Field survey showed that the weight of ovaries were smaller as the expression of Hsp60 and 60s increased, and that the population density was low in the stream where the expression of Hsp60s and 70 was high. Thus, Hsp was shown to be an effective molecular index to detect the heat stress.

Free Research Field

生態工学