Staff and students at The Centre for Research on the Ecological Impacts of Coastal Cities have been working on aspects of the small prawn issue. We hope to continue working with NSW Fisheries in 2001. Near any coastal city, nutrients such as sewage, fertilizers, organic and inorganic wastes, drain into waterways and eventually into the sea. When blooms are not massive, seaweeds are washed up patchily in space and time. When blooms are extensive, they can blanket large areas.
Macroalgal blooms can alter types and numbers of animals living in sediments - benthic animals.
Animals in sediments represent important food that may be affected through a variety of pathways. Initially, the algal mats may cause an increase in numbers of individuals and species. They can form localised deposits of fine particles that provide food or the algae can be a direct source of food for herbivores. Seaweeds can, however, also provide a refuge for or from predators. Then, numbers of individuals and species are reduced and the whole assemblage is impoverished.