2009 Fiscal Year Final Research Report
Impact of the newly introduced trident goby on the littoral community in Lake Sikotsu
| Project/Area Number |
19710029
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Environmental impact assessment/Environmental policy
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| Research Institution | Tokai University (2008-2009)
Hokkaido Tokai University (2007) |
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Principal Investigator |
HIROMI Saito Tokai University, 生物理工学部, 講師 (50433454)
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| Project Period (FY) |
2007 – 2009
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| Keywords | 国内外来種 / 湖沼 / 生態系 / 底生無脊椎動物 / ヌマチチブ |
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| Research Abstract |
Alien species often have strongly negative impact on the abundance and diversity of lotic community. The trident goby (Tridentiger brevispinis) is one of successful intra-national alien fishes in pond and lake ecosystem of Japan. To clarify the impact of alien trident goby on littoral lake ecosystem, density, body size and diet of trident goby were investigated at three distinct sites in littoral lake during July to November 2007 and enclosure experiment were conducted in July 2008. Field research in 2007 revealed that density of trident goby showed highest in summer, while body size was constant over season. Dietaly composition mainly consisted of algae. The enclosure experiment indicated that high density of alien goby reduced algal abundance. This predation of alien goby for algae led to change in species composition of invertebrate assemblage through the reduction of chironomid abundance. The result suggested that alien goby had negative impact on abundance and diversity on littoral ecosystem in Shikotsu Lake.
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