Dolphin Ecology

Dolphin Life: What we’ve learned in 40 years

SDRP conducts the world’s longest-running study of a wild dolphin population, initiated in 1970. Information available from five decades of research on the multi-decadal, multi-generational, year-round resident community of individually identifiable bottlenose dolphins of Sarasota Bay established this as a unique natural laboratory for learning about the biology, behavior, ecology, social structure, health, and communication of dolphins, as well as the effects of human activities on them.

Long-term study is crucial for understanding the lives of members of long-lived species such as bottlenose dolphins, and for being able to detect trends in populations relative to changes in their environment. Knowing the long-term geographic range of a population unit allows the measurement of exposure to threats, which in turn facilitates mitigation, including direct interventions.

The ability to observe identifiable individual dolphins of known sex, age, and familial relationships through all of their life history milestones and associated transitions in behavioral and social patterns, to collect data on health and condition, and to then document their reproductive success and cause of death is rare in cetacean research.

Gaining a fuller understanding of dolphins also means studying how they interact with their environment, including other species in their environment (even humans).

Data are collected through a variety of techniques, including systematic photographic identification surveys, periodic catch-and-release health assessments, focal animal behavioral observations, tagging and tracking of dolphins and sharks, remote biopsy dart sampling, fish surveys, and passive acoustic monitoring of fish and dolphin sounds from shore-based listening stations.

As with most animals, there are two main ecological drivers for dolphin behavior: prey and predators.

Long-term catch-and-release purse-seining fish surveys provide information on the seasonal relative abundance of dolphin prey fish in Sarasota Bay.

Potential shark predators on dolphins are tagged and tracked through the Sarasota Coastal Acoustic Network (SCAN) array of acoustic tag tracking stations. A network of passive acoustic listening stations (PALS), facilitated by citizen scientists, provides measures of bioacoustics activity from fish, dolphins, and invertebrates, and measures of human activity from recordings of vessel sounds.

Research is conducted under a series of Scientific Research Permits issued by NOAA’s National Marine Fisheries Service, Special Activity Licenses from the State of Florida, and annual renewals of Institutional Animal Care and Use Committee approvals by Mote Marine Laboratory.