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By Greg Bartlett

Since the early 1990’s, the Virginia Aquarium has organized an annual dolphin count along Cape Henry and even into Chesapeake Bay. With 17 year’s worth of statistics pooled, the Virginia Aquarium is a good source from which to draw data on the numbers of dolphins that traffic north and south along the eastern coast of the United States. On August 1, 2009, volunteers met along these beaches in Virginia for this annual dolphin count – with lawn chairs and sun protection in tow. This year was unusual, however, for several reasons, but particularly because the Virginia Aquarium had set as a goal the calculating of the speed of dolphins. How could this be done? Could a volunteer do this even from land? With GPS tracking, the answer to both these questions is: yes!

GPS, which stands for the Global Positioning System, is the United States’ global navigational satellite system (GNSS) – the only system of its kind in full operation. GPS dates back to World War II and is operated by the United States Air Force. Since being released to public use in the 1980’s, GPS has become common-place for many people of the twenty-first century. The number of and variety of uses of GPS seem to only be as limited as the human imagination. GPS navigation and GPS tracking are both products of the U.S. Air Force’s Global Positioning System. Communications between satellites in GPS and GPS receivers allow the navigational coordinates of the GPS receivers to be calculated and logged 24/7. GPS tracking, in particular, monitors the “trail” made by any person, animal, or object – to which a GPS device is attached – to be tracked at any given period of time. How could such a system help in calculating the speed at which dolphins travel along the coast?

Volunteers were asked to help monitor the speed at which dolphins travel along the eastern coast of the United States by using GPS tracking units. A GPS tracking device was given to each volunteer involved with this aspect of the Virginia Aquarium’s 2009 annual dolphin count. Each volunteer was asked to then spot dolphins and choose one to follow by walking, in pace with the swimming dolphin, from the shoreline. Each time a volunteer witnessed the dolphin’s leaping from the water, the volunteers were to shoot a GPS position, while walking parallel with the dolphin on shore. Thus the longitudinal coordinates of the dolphin’s position could be accurately recorded over a brief period of time. The distance traveled could then be figured, and the speed could be calculated. Thanks to GPS tracking a difficult task was made simple!