People fishing on the Wadden Sea (Picture: Wikimedia Commons/Weefemwe) - Source: Fishing boat on the North Sea (Picture: Wikimedia Commons/Weefemwe) at
Thursday, April 10, 2014 - 11:01
Fewer fish in the Wadden Sea
The state of fish populations in the Wadden Sea has seen a significant decline in the last 50 years. The Wadden Association announced on Wednesday that the number of fish in the sea is "only a fraction of what it was in the 60s." The nature organization backs up their claim with figures from the Royal Dutch Institute for Sea Research (NIOZ) which has been counting fish populations for almost 50 years with a bow net near Texel. "In the 60s there were still, for example, twenty eels per day in the net, but now you're happy if you get one in ten days" says marine biologist Wouter van der Heij who works with the Wadden Assiciation. Thicklip grey mullet, which used to be caught six times a day, is now caught once a day. Some fish species have actually grown over the last years. "The Wadden Sea has warmed up a few degrees and the sea bass enjoys swimming in that, for example", Van der Heij states. The exact cause of the overall population decline is not entirely clear. Over-fishing and warm sea water, or the blocking off of the Ijsselmeer could be blamed. It could also be the replacement of sand from one place to another. All details of this phenomenon have been published by the Wadden Association, the NIOZ and Sport Fishing Netherlands on the website Waddenzeevismonitor.nl, which makes these figures available to the general public for the first time. "The difficulty is that the bow net has been used for a long time already. Most other researches don't take this long", says the biologist.