@article {9657, title = {Oil Spills and Dispersants Can Cause the Initiation of Potentially Harmful Dinoflagellate Blooms (\“Red Tides\”)}, journal = {Environmental Science \& Technology}, year = {2018}, abstract = {ABSTRACT: After oil spills and dispersant applications the formationof red tides or harmful algal blooms (HABs) has been observed, whichcan cause additional negative impacts in areas affected by oil spills.However, the link between oil spills and HABs is still unknown. Here,we present experimental evidence that demonstrates a connectionbetween oil spills and HABs. We determined the effects of oil,dispersant-treated oil, and dispersant alone on the structure of naturalplankton assemblages in the Northern Gulf of Mexico. In coastalwaters, large tintinnids and oligotrich ciliates, major grazers of\ phytoplankton, were negatively affected by the exposure to oil and\ dispersant, whereas bloom-forming dinoflagellates (Prorocentrum\ texanum, P. triestinum, and Scrippsiella trochoidea) notably increased\ their concentration. The removal of key grazers due to oil and\ dispersant disrupts the predator-prey controls ({\textquotedblleft}top-down controls{\textquotedblright}) that normally function in plankton food webs. This\ disruption of grazing pressure opens a {\textquotedblleft}loophole{\textquotedblright} that allows certain dinoflagellates with higher tolerance to oil and dispersants\ than their grazers to grow and form blooms when there are no growth limiting factors (e.g., nutrients). Therefore, oil spills and\ dispersants can act as disrupters of predator-prey controls in plankton food webs and as indirect inducers of potentially harmful\ dinoflagellate blooms.}, url = {https://pubs.acs.org/doi/abs/10.1021/acs.est.8b00335}, author = {Almeda, Rodrigo and Sarah Cosgrove and Edward J. Buskey} }