What feeds the fish? Zooplankton abundance and productivity in the northern Baltic proper: implications for fish feeding conditions


Project leader


Funding source

Formas - The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning


Project Details

Start date: 01/01/2006
End date: 31/12/2008
Funding: 1150000 SEK


Description

There is growing evidence that changes in zooplankton population abundance and biodiversity are responsible for the decreasing fish stocks in the Baltic Sea. Zooplankton abundance and growth rates are directly linked to the variability in fish recruitment, and consequently in fish population abundance and condition. Despite this, zooplankton studies have been largely neglected in Swedish research and monitoring of eutrophication and fisheries, and there is no on-going research programme addressing the issue. In this project, we will take an advantage of archival samples collected during past 30 years at 3 monitoring stations; the analysis of these samples has however been discontinued in 1990s and no consistent data series are available for the past 15 years – i.e. the period of most dramatic changes in fish stocks. We will complete and summarize zooplankton data focusing on 3 interrelated questions: (1) if and how zooplankton in the western Baltic changed over the last three decades, (2) could these changes explain declined stocks in coastal fish, and (3) is zooplankton decline, if any, influenced by fish predation. To answer these questions, we will examine zooplankton stocks, biodiversity and growth rates in situ applying a recently developed biochemical method for zooplankton growth assessment. Relating zooplankton dynamics to fish stocks will provide understanding of zooplankton-fish linkage in western Baltic, a prerequisite for ecosystem approach to fish management.

Last updated on 2017-24-03 at 12:56