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Underwaterpark Zoetermeer / The Zebra mussel


In 2010 our Dive Team (Time2Dive) has created a new underwater park in Zoetermeer. More than one reason led to this. The primary reason for the people who took the initiative was reason that a dive site close to home is nice for fun and for conducting courses.

When I heard about these plans I immediately started thinking about the possibilities to add an ecological twist to this underwater park.

In the lake the site is located in we have trouble with the visibility and the lack of abundance of marine life and underwater plants. There are fish, but you didn’t see them very often because the place where the dive site is located was not very appealing to the marine life. There was mainly a sandy bottom with no interesting objects to look at, or to make it your home when you are a fish. This is all the situation before the park was created.

As soon as we got all the permits form the municipality and the water management institute we started making the plans. This has resulted in a park where we sunk four boats, concrete sewer pipes, two platforms for exercises and a large amount of concrete slabs. We added ropes for easy navigation for the divers. This especially for the times the visibility is so poor that navigating is challenging for many divers.

ll this is very nice but where does Project Aware come into this picture. My input in these plans was mainly the ecological aspect. I started doing research on how we could improve the visibility. Greater visibility means more plants, more plants means more marine life and probably a greater biodiversity. All the objects that were sunk also add to a good surrounding for marine life. They have places to hide and hunt and thus more marine life will be found in and in the neighbourhood of the park.

So, what more could we do. My research led to the ecological bureau Waardenburg. They have quite extensive experience with the zebra mussel and what is can do for the water quality. This mussel was already present in the lake but I was looking for ways to give the population a good boost. Together with dr W. Lengkeek of the bureau Waardenburg we harvested about 300 kilos of zebra mussels form a place where they are very abundant (the visibility at that site is also remarkable for a Dutch sweet water site). On May 5, 2010 we harvested these mussels and transported them to our dive site.

In the months since then the mussels are moving slowly through the park. You see them creeping up the concrete sewer pipes and the concrete slabs. Because of the warm temperatures and the very poor visibility during the summer months we have seen not so much progress since July. But based on the first weeks since we planted the population we are confident that next year the mussel will conquer the objects in the park and thus make this park a pleasant dive site. The evidence from this year is that we see much more marine life on the dive site. It is hard to say if the visibility has been favourably affected so far.

I am quite happy with the outcome so far. Next year I am planning to add reefballs to the park. Than it will be even more attractive for marine life and we can use the park as educational tool for creating ecological awareness by showing people what difference a small group of people can have for the environment. It is proof that we can make a change and that we can help preserving nature and in some cases (as in this case) can even improve the water quality and with that create a favourable environment for the marine life in a Dutch sweet water lake.

More information can be found on (only in Dutch)

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