Ecomare

Environmental care in aquatic sports deserves special attention. Before much attention was paid to this, the influence of aquatic recreation had a substantial influence on the environment. Dumping oil (bilge water), and PAHs (coal-tar on the ship hulls) had negative effects for seals and birds. The organotin compounds which used to be applied a lot to fight algae growth on those outer parts of the ships under the water surface appeared to be extremely poisonous for many benthic animals, among which the common dogwhelk and the whelk. The much applied alternative used later on, a copper-containing underwater paint, also led to unacceptable accumulation of toxic copper compounds in the environment.
The aquatic recreationists have taken many measures to limit the inconveniences. Yacht harbours are required to purify the wastewater from the rinsing areas. Oil remnants are no longer allowed to be thrown overboard. Underwater paint containing tar, organotin or copper are not allowed to be used. All yacht harbours have facilities for collecting chemical wastes from aquatic sporters since April 1996. As of 2009, there will be a ban on dumping wastewater from pleasure boats.
The Dutch Automobile Association (ANWB) awards yacht harbours that have a good environmental management with a blue flag. Skippers that treat nature and the environment well are also allowed to sail with a blue pennant. They are required to sign a document with the golden rules of behavior.

In the whole wadden region, fast motor boats are not allowed to go faster than 20 km per hour. Exceptions are the reinforced navigational channels from sea to Den Helder, Harlingen and Lauwersoog and the navigational routes from and to the islands. Faster than 20 km per hour is also permitted at some places in the Texelstroom and in the Marsdiep.

A thick layer of aquatic animals and plants grow rapidly on an untreated ship hull. The ship will use more fuel and velocity will decrease. In order to prevent the growth, the hull can be treated with toxic anti-fouling paint. The paint slowly dissolves in the water. Traditionally, one often used tin-holding paint, until it was discovered that tin compoundsare extremely damaging for some species of aquatic snails. Paint containing copper was then used, but this kind of paint has also been banned for ships in freshwater because the copper concentrations remain too high. Modern anti-fouling paint that does not damage the freshwater environment is presently on the market. Because this paint does not adhere as well, the hull must be treated more often, which is unfavorable for the amount of waste products.

After using non-stick coating, growth can be removed with a spongeOne is therefore desperately looking for really good alternatives. One hopeful development is the so-called non-stick coating. This paint system contains no toxic materials. It fights growth by producing an extremely smooth surface: organisms have great difficulty in attaching to the surface, and those that do manage are easily brushed off. The second important development is the mechanical cleaning method, whereby the underside of the vessel is mechanically brushed clean.

The 'Clean Ship Underwater' project began in 1998. In this project, a number of (combinations of) alternative solutions are compared to each other in a practical experiment. A number of ships and stationary underwater panels are treated with a special 'non-stick coating', another group with a simple non-toxic metallic paint and another group with copper-holding anti-foul paint. These ships and objects lie in three different kinds of harbours: a saltwater environment, a freshwater environment and a freshwater harbour from where one often heads out to sea. And the last variant in the investigation concerns the maintenance: do nothing, regularly brush off manually or use the mechanical cleaning facility. Coordination of the investigation is the province of North Holland.