A Review of Algal Toxin Effects on Freshwater and Marine Aquaculture Systems

摘要

Intensive aquaculture requires additional food resources to be added to ponds to increase primary and secondary production. The inherent efficiencies of feeding results in over half of the nitrogen being released to water and sediments through excretion, overfeeding, and feed sinking before consumption. These nutrients can increase dissolved nutrient concentrations and promote algal bloom development. While algal blooms are typically useful to decrease aeration requirements, on some occasions harmfulalgal species proliferate in ponds. These blooms can be either planktonic or benthic, the latter being sometimes difficult to recognize. A quick informed decision is critical for management of toxic harmful algal blooms (HABs) to prevent large financiallosses.Testing of ponds suspected of harboring toxic algae can be approached as a sequence after recognition of a change in feeding or presence of unusual activity, including mortality. If toxic algae are suspected, pond algal composition needs to be determined. It is advisable to collect samples of windrowed sediments, including algae, to have a complete picture of potential toxic species present. Samples should be examined live if possible within a few hours of collection, or alternatively preserved with a compatible preservative, such as Lugol's iodine, formalin or glutaraldehyde.