Re-introduction of allis shad to the River Rhine System: Netherlands, Germany & France

Summary

Allis shad (Alosa alosa), an anadromous herring once so abundant in the Rhine that hundreds of thousands were caught annually, has vanished from Germany and most of Western Europe over the past century, with large surviving populations now found only in France; it is listed as extinct or threatened with extinction on Germany's Red List. A tri-national re-introduction project spanning the Netherlands, Germany, and France ran a feasibility study from 2003 to 2005 covering genetics, spawning and stocking site mapping, and breeding trials, drawing on techniques developed for the successful re-introduction of the closely related American shad along the US Atlantic coast. The project, coordinated by North Rhine-Westphalia's State Office for Nature, Environment and Consumer Protection with French partners CEMAGREF and MIGADO, secured EU LIFE co-funding in 2006, one of only 61 proposals selected from 229 applicants, and launched formally on 1 January 2007 for a 2007-2010 term. The plan calls for producing and stocking five million marked allis shad larvae, sourced and bred in France, into the Rhine system between 2007 and 2010, backed by drift-netting and electro-fishing surveys to evaluate stocking success and cooperation with Dutch fishermen to track juvenile distribution. A complication emerged when the French donor populations in the Garonne and Dordogne rivers showed unexplained low return rates in 2006 and 2007, possibly linked to fishing pressure, hydrology, or climate change. Since allis shad take three to six years to mature, the project rated itself Partially Successful, stating that true success can only be assessed five to fifteen years after the first releases in 2008.