De Steur

The sturgeon is the largest fish you could find in the Netherlands and also one of the largest in the world. Once plentiful, this fish faced overfishing in the middle ages and by the 1930s no longer swam in the Dutch or German waters. It is currently categorized as a critically endangered animal. So what are the Dutch doing to help them before it's too late? 

In 1971, the Haringvlietdam was installed at the mouth of the Haringvliet, the mouth of major rivers like the Rhine and Maas. This installation became a significant problem for the remaining wild sturgeon around. These fish spend most of their time in the saltwater but come back into the freshwater rivers to reproduce due to the unique conditions like clear and deep channels with gravel beds that are favorable. The closing of the Haringvliet prevented them from being able to enter the Netherlands waterways in this area. 

Recognizing that this fish is important to the history of this country, organizations have started to come together and aid in their restoration. One major aspect of this was slightly opening the dam in 2018, allowing fish to freely swim between the sea and the rivers again. 

Reintroducing the sturgeon to the Rhine again is no easy feat. Sturgeons take a long time to reach maturity, with males being able to spawn after about 10 years and females reaching maturity between 15 and 22 years. This slow process is further lengthened by the females only being able to reproduce every 3-5 years. 

Saving this species will take a long time and is something that would benefit from human intervention. Tagging and tracking adults and babies will be necessary to measure the population and ensure that it is growing. Additionally, strict fines should be placed on people who illegally fish these animals, as there are other methods like buying from a sustainable sturgeon fishery. I think the Dutch are off to a good start righting their wrongs but it will be a joint effort between the fish, people, and international governments to make sure that these efforts continue. 

Sign about the sturgeon and Haringvliet in the Rotterdam Zoo inspired me to look into this conservation further.