Impacts of HABs on Marine Mammals

Just as human consumers of seafood contaminated with biotoxins of algal origin are at risk, many animals at higher levels of the marine food web are impacted by HABs. Some toxins are fat soluable and bioaccumulate in higher trophic levels. Others still transfer through successive stages, sometimes having lethal impacts where they are least expected, such as with this humpback whale, one of 14 that died near Cape Cod, MA in a one-month period due to saxitoxin in mackerel that they had consumed. Photo courtesy of G. Early.

dead humpback whale washed ashore on Cape Cod

It has now been confirmed that more than 150 deaths of the Florida manatees occurred in 1996 due to affects of algal toxins produced by G. breve. Estimates suggest that about 10% of the endangered population was wiped out. Both stomach contents and lung tissue contained the toxins suggesting that the toxins entered through the food web as well as from direct contact of the toxic aerosols when the animals broke the surface to breathe. Photo courtesy of Florida Department of Environmental Protection.

Dead Manatees piled up along the West Coast of Florida