Other effects that have been linked to eutrophication are harmful algal blooms, but causal links to eutrophication are not yet proven. Nutrient abatement is recommended where eutrophication symptoms occur. Ciguatera, a disease affecting the nervous and cardio-vascular systems, is caused by eating tropical fish that have bioaccumulated toxins from natural algae. Other toxins produced by algal blooms affect coastal aquaculture and occasionally human health in both developed and developing countries. Marine litter is an increasing problem for marine life and tourism.
Turtles are particularly vulnerable to discarded litter.