The effects of dietary Microcystis aeruginosa and microcystin on the copepods of the upper San Francisco Estuary

摘要: Summary 1. Increasing blooms of Microcystis aeruginosa have unknown impacts on the copepods Eurytemora affinis and Pseudodiaptomus forbesi, which are dominant zooplankters key prey species for endangered larval fish in upper San Francisco Estuary. 2. Laboratory feeding experiments were designed to measure effect copepod survival distinguish effects toxicity nutrition. In a series tests, fed mixed diet algae plus one two strains Microcystis, either producing (MC+) or lacking microcystin (MC−). 3. significantly reduced even when it was small proportion diet, indicating that major cause mortality. Contrary expectation, however, MC+ strain did not result higher mortality, suggesting non-MC metabolites can be toxic copepods. 4. Across treatments, P. forbesi greater than E. affinis, although responded differently both ratio their food. Survival inversely proportional dietary (MC+ MC−). contrast, E. affinis declined similarly across treatments related Microcystis. Results indicate coexist with while other cannot. 5. Regardless species, caused significant mortality copepods, may adverse potentially food-limited zooplankton community Estuary. These cellular MC concentration because contains negatively affect copepods.