Maasvlakte 2's construction may mean a slight disturbance to bird species in the surrounding coastal area. In the construction phase, the noise could frighten timid bird species away. Many protected species in fact have a wide range of action: they simply seek out quieter spots. This is possible, because within the extensive Voordelta there are adequate opportunities to escape. The temporary effect on the habitat and foraging area of protected birds would therefore be limited, as appears from the EIA reports. There are no permanent effects, thanks also to the generous environmental compensation. There may well be temporary effects, because the silt concentration in the Voordelta may increase temporarily due to sand extraction. The water may become cloudier locally. This could have an effect on food supply for shellfish-eating ducks and fish-eating birds, including the eider duck, greater scaup, common scoter, and the sandwich and common tern, which could lead to a reduction in the population of these bird species between 2009 and 2011. This reduction will only be temporary and significantly smaller than the natural variation. All populations can recover fully after Maasvlakte 2's construction.
During dredging at sea, the dredgers suck up water and silt - small clay particles - along with the sand. The water and silt go back into the sea. A higher silt concentration makes the water cloudy and less translucent. As a result, the growth of algae is restricted. Algae serve as food for worms, snails and shellfish, which in their turn are food for fish and ducks. Too much silt could disrupt the food chain in the sea. For this reason, silt measurements are being carried out, not only in the area where Maasvlakte 2 is coming, but in one hundred places along the North Sea coast. By comparing the results of the measurements it becomes clear whether the silt is affecting life on and in the sea.
The eider duck, greater scaup and common scoter are happy to spend the winter in the Voordelta. These are shellfish-eating ducks. Cloudy water as a result of sand extraction might restrict these ducks' food supply. The cloudy water could also inhibit the growth of algae and thus of shellfish. However, the ducks are used to peaks and troughs in the food supply. It also appears from research that the effects of sand extraction will be very small and temporary. The calculated maximum reduction of these duck species is moreover significantly smaller than the natural variation in the size of the duck populations. The conclusion is therefore that the food chain will be neither substantially nor permanently disrupted.
During the sand extraction, a higher silt concentration may make the water cloudier. Fish-eating birds that hunt 'by sight', such as the common and sandwich terns, would be less able to see their prey fish. In the breeding season, this could be at the cost of their breeding success and consequently the size of the population. It is apparent from studies that this effect is temporary. And some scientists consider that prey fish in fact come closer to the surface in cloudier water, where they are more visible to the fish-eating birds.