For a long time, biodiversity in Dutch rivers, streams and lakes has been improving. But that trend has stopped, warn the World Wildlife Fund (WWF-NL) and nature organizations VoegenNL and Sovon on Tuesday in the biennial Living Planet Report. According to the organizations, the recovery of biodiversity in Dutch freshwater nature has stagnated or is even declining in many places.
The organizations base their warning on research into the population trends of 176 animal species in “rivers, streams, swamps, ponds, fens and raised bogs”. In the twentieth century, these populations declined sharply due to environmental pollution. Thanks to successful environmental policy in the second half of that century, the animals returned: between 1990 and 2025, the total population of freshwater animals grew by 60 percent, according to nature organizations. Things were not going so well on land at the time: the number of animals decreased by about 30 percent.
However, biodiversity recovery in streams and rivers has now “turned into decline again”, the nature organizations write. This has several causes. In the streams and rivers, animals are struggling with a loss of natural banks and a surplus of poison; In ponds and ditches the water level is regularly too high or too low. Ditches also contain many pesticides.
Furthermore, the organizations mention “permanent and growing threats” such as pharmaceutical residues, PFAS and climate change as problems. Native species also suffer from invasive exotic species, such as the American crayfish and sunfish. Because these animals hardly have any natural enemies in Dutch nature, they occur in large numbers and empty ditches and (in the case of the sunfish) fens.
Low hanging fruit
The Netherlands is a water-rich country, but does not sufficiently cherish its freshwater nature, says Judy Koppenjan (Dutch nature expert at WWF-NL) in the announcement of the report. This is despite the fact that, according to Koppenjan, this nature “is the basis of our drinking water and our climate safety.”
According to Koppenjan, the question is not whether the Netherlands should protect freshwater nature more quickly, but how. “Decades ago, water quality was so poor that every measure yielded immediate benefits. This low-hanging fruit has now been picked. For real recovery, we need to restore an entire water system.”
Next year, the Netherlands must comply with the European rules for water quality (the Water Framework Directive or WFD). It seems unlikely that the Netherlands will meet that deadline: in most places the water quality is far below standard, and the situation has hardly improved for years.
“If we now tackle water quality, space, connection and management and implementation in a coherent manner, we can restart the faltering recovery,” write director of WWF-Netherlands Jelle de Jong and chair of BedrijvenNL Titia Wolterbeek in the introduction to the report. According to the two, waiting will lead to targets “feeling further out of sight and species that have found their way up will go down again.”
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