About one fourth of bloom-causing species produce toxins that may harm or kill higher forms of life such as zooplankton, shellfish, fish, birds, marine mammals, and even humans, that feed either directly or indirectly on the algae. In addition, some bloom-causing species do not produce toxins but affect organisms indirectly through other means, such as decreasing light penetration, oxygen depletion, etc. It feeds on zooplankton, eggs and fish larvae. The worm forms large mats that smother other sea life and it competes for food with native species. Introductions to the US are likely the result of ballast water or from crabs clinging to heavily fouled ship hulls.
Green crabs eat molluscs, crustaceans, polychaetes and green algae.
European, South African and California studies indicate the green crab has the potential to significantly alter the distribution, density and abundance of prey species, and thus profoundly alter the ecology where it has been introduced . Several species of invertebrates, plants, and fish have been introduced via the shipping industry, although their economic and ecological impacts may not quantified. Undaria pinnatifida, Antithamnionella hilgendorfi, Antithamnionella ternifolia, Sargassum muticum If less effective antifouling paints are used, additional species with similar life histories to those listed above could potentially be introduced via ship fouling in the future. More research on this topic is needed to quantify the potentially disastrous economic consequences of invasive species. Us - What's New Site constructed by Washington Web Site Services, Inc.