Restored wetlands see an increase in pike coming to spawn and the hope is that their contribution to the ecosystem will lead to a reduction of algal bloom plaguing the Baltic Sea's brackish waters. Amy Pollcok reports.
Swedish pike are being given a boost in the wetlands close to the capital, Stockholm. Shrubs have been cleared and a dam built to keep the habitat saturated for three months of the year - creating the perfect conditions for pike to spawn. SOUNDBITE (English) OSCAR OLSERYD, SWEDISH ANGLERS ASSOCIATION, SAYING: "This is what we call a pike factory and this is a really shallow area with lots of vegetation that actually warms up really quickly during the spring and that is the reason why pike actually migrate here from the Baltic Sea. Anglers and conservationists installed a corral to monitor numbers of pike migrating to the Baltic They are measured and weighed, the sex determined and photos taken of the unique colouring on their cheeks before being released. SOUNDBITE (English) OSCAR OLSERYD, SWEDISH ANGLERS ASSOCIATION, SAYING: "Now in 2017 there has been 350 pikes that have come up here to spawn and the biggest fish they are, well they are huge. It's fish about 10 kilos - almost as long as I'm tall, basically." And more pike heading into the Baltic means less algae in the brackish water. Nitrates run off farmland on the shore into the sea, causing algal bloom, which kills off plant and animal life on the sea bed - a process called eutrophication. But pike eat smaller fish, allowing smaller organisms to decompose the algae without being eaten themselves. SOUNDBITE (English) TOM ARNBOM FROM THE WORLD WIDE FUND FOR NATURE, SAYING: "When the pike goes from the wetland out to the Baltic again they start eating fish. They eat the fish which are the ones who really eat the zooplankton which means that eutrophication can then disappear because the zooplankton is the one keeping the eutrophication down, very low number...So the pike is a tool to decrease the eutrophication - it will not take away the basis for it but will help to decrease the eutrophication in the Baltic." The project has caught the eye of conservationists and fishing enthusiasts alike. They're angling for more wetlands to be restored.