Scientific representation on the Bottlenose Dolphin Take Reduction Team
By Brian Balmer, MS, PhD Student, University of North Carolina Wilmington

      The Bottlenose Dolphin Take Reduction Team (BDTRT) was established to limit the number of serious injuries and deaths of bottlenose dolphins along the east coast of the U.S. from incidental fishing practices. In 2002, the BDTRT submitted a report to the National Marine Fisheries Service with regulatory and non-regulatory recommendations for management of Western North Atlantic coastal bottlenose dolphins. The BDTRT has met several times since 2002 to review and discuss bottlenose dolphin stock structure in relation to fisheries interactions. In September 2009, I had the opportunity as Randy Wells’ alternate to participate in the BDTRT meeting in Wilmington, North Carolina. The meeting consisted of approximately 40 participants including commercial fishermen, federal and state biologists, as well as researchers from academia and non-profit organizations.

     The National Marine Fisheries Service (NMFS) has recently updated the Stock Assessment Report (SAR) for Western North Atlantic bottlenose dolphins, dividing the coastal and estuarine ecotypes into separate stocks. The primary goal of this year’s BDTRT meeting was to identify the conservation measures necessary for the new stock divisions recently defined by NMFS. The meeting itself consisted of short presentations by various researchers, followed by round table discussions and small break-out groups for more in-depth consultation. After three days of meeting, several key points were clear:

• Data suggest multiple, resident estuarine bottlenose dolphin stocks from North Carolina to Florida.
• There is geographic overlap between coastal and estuarine stocks.
• Classifying an individual into a given stock requires a multi-faceted approach using photo-identification and genetic analyses; currently, if an individual dolphin is considered a fisheries' take, identifying the stock it is from is extremely difficult.
• Data suggest two estuarine stocks in North Carolina with relatively low abundance estimates; even a few fisheries’ takes may result in exceeding potential biological removal (PBR) for the stocks.
• The majority of abundance estimates for Western North Atlantic bottlenose dolphin stocks are either out-of-date or non-existent. Mark-recapture, photo-identification studies are necessary to determine abundance for all newly defined estuarine stocks before any management recommendations can be identified.

     For my first experience with a TRT, I was extremely impressed with the professionalism of all participating stakeholders. The issues being discussed affect the livelihoods of fishermen as well as the conservation of bottlenose dolphins along the east coast of the U.S. This meeting offered the opportunity for participants to be kept up to date on recent research in this field as well as express their own opinions on management decisions. The common theme that all participants repeatedly emphasized was the lack of data in understanding the population structure of bottlenose dolphins along the east coast of the U.S. This point illustrates how important the Sarasota Bay bottlenose dolphin community is to marine mammal research as a whole. It is easy to take for granted that the Sarasota Bay community has approximately 160 individuals, and over 96% of these individuals are seen on a regular basis. However, if not for the hard work of so many over the past 40 years, this would not be possible. Along the east coast of the U.S., there are regions where basic abundance estimates are still unknown; it makes you truly appreciate all of the research that has taken place in Sarasota Bay.