ABSTRACT
Entrainment causes the loss of a large number of eggs, larvae and plankton organisms. The question however is if this represents a significant, additional source of mortality for the affected species, which negatively affects the ability of the species to sustain their populations, and which may affect the productivity of coastal ecosystems. These secondary ecosystem effects are difficult to quantify [39]. Plankton organisms are generally prevalent in coastal surface waters and have rapid reproductive cycles. Fish and invertebrate species produce large numbers of eggs and larvae to compensate for a high natural mortality rate as part of their reproduction strategy. The mortality caused by entrainment in a single facility therefore seems unlikely to have a substantial negative effect on population and ecosystem dynamics. The situation is different when cumulative sources of mortality (other power or desalination plants) exist and when endangered species, species of commercial interest, or marine protected areas are potentially affected by the intakes. While it is relatively straightforward to estimate the levels of entrainment for a single desalination project, it is difficult to evaluate the indirect impacts on the ecosystem, especially in places where cumulative sources of mortality are involved.
