The objective of the study was to develop and compare information on diet from stomach content analysis of stranded specimens of two dolphin species that are known to use offshore habitats. Data were available from eight Risso’s dolphins and 17 offshore bottlenose dolphins, stranded along the Gulf of Mexico, on the east coast of Florida [...]

January, 2012 In Sarasota Bay, the occurrence of a severe red tide in 2005 was followed by increases in dolphin depredation behaviors, declines in body condition, decreased abundance (through temporary and permanent movements to neighboring waters or disappearances), and increased mortality of weaning and newly independent calves. These changes in the dolphin population correlated with [...]

January, 2012 Bottlenose dolphins within southern Georgia estuaries have been exposed to extremely high levels of persistent organic pollutants (POPs). Dolphins in this region have the highest polychlorinated biphenyl (PCB) levels recorded for any marine mammal, and these levels are related to distance from a known EPA Superfund point-source in the Turtle/Brunswick River Estuary (TBRE). [...]

Do Sarasota dolphins all have the same “lifestyle?” Do some prefer different prey, or forage in the different habitats, like grass flats as opposed to open bays? We know a lot about the Sarasota dolphin community, but we actually know little about how individuals “make a living” in their environment. Do individuals specialize by hunting [...]

Dolphins in Sarasota Bay eat a variety fish species. The most common prey are those that make sounds.  Dolphins have excellent hearing, and they use it to help catch sound-producing fish . Common prey fish include pinfish, pigfish, spot, and mullet. But when the opportunity presents, dolphin exhibit a preference for sea trout, toadfish, ladyfish, [...]

By Elizabeth Berens McCabe, MS, Chicago Zoological Society Natural disturbances such as harmful algal blooms can greatly affect the community dynamics of estuaries and nearshore environments.  In Florida, red tides are a type of harmful algal bloom caused by the dinoflagellate Karenia brevis.  This naturally occurring alga produces brevetoxins (PbTx), lethal neurotoxins which affect the [...]

These data indicate that at the population level resident bottlenose dolphins of Sarasota Bay select soniferous prey. These results lend further support to the hypothesis that bottlenose dolphins use passive listening to locate sound-producing fishes.

We have been using the ratios of stable isotopes in dolphin tissues to examine feeding patterns of bottlenose dolphins along Florida’s west coast. Results from the stable isotope analyses suggest that differences exist at the population level, which allow us to distinguish offshore and various inshore dolphin populations, and we have started to examine potential [...]