『ECOSYSTEM ANALYSIS AND RESTORATION POTENTIAL OF BRACKISH LAKES: SHINJI AND NAKAUMI (JAPAN)』
話題提供：Hugo Coops 博士 島根大学汽水域研究センター
Hugo Coops 博士は、オランダ the Institute of Inland Water Management and Waste Water Treatment (RIZA) の senior aquatic ecologist で、今年1月より1年間の予定で Visiting Professor として島根大学汽水域研究センターに勤務されます。
This presentation will outline the approach that I intend to follow during my stay at the Center in 2005. The particular interest of this study lies in the restoration or rehabilitation of brackish lakes, an issue attracting interest in many places; exemplified by the efforts to restore transitional water bodies in the EU, as well as the issue of changed freshwater inputs to estuaries in the Mediterranean countries, North America and Australia.
Lakes Shinji and Nakaumi form a very interesting study area as they represent a gradient of a freshwater river (River Hii and other tributaries), a moderately brackish lake (Shinji), and a saline lagoon (Nakaumi). Although the water system has been modified in various ways and is currently under a high eutrophication pressure, it still has unique estuarine features supporting a profitable fisheries and is regarded of high value for the local and regional societies.
Ecosystems of freshwater shallow lakes have been investigated throroughly in the past decades. Current understanding of foodweb interactions has led to management practices incorporating both external nutrient control as well as internal measures, including manipulation of foodwebs. However, brackish lakes are much less well understood; they probably respond differently to nutrient supply and control than their freshwater counterparts.
The main issue I want to address is the potential for ecological restoration of the Shinji-Nakaumi lake system. This will include:
- Reference state
- Towards a conceptual model of lake ecosystems
- Use of monitoring data for hypothesis generation
- Focus on keystone organisms: experiments
- Littoral; pelagial interactions
- Restoration targets and scenarios
- Valuation of ecosystem attributes