As we celebrate the 20th anniversary of Stellwagen Bank National Marine Sanctuary, some of the scientists and experts there are introducing us to the fascinating research and activities they are involved with. David Wiley, the Sanctuary’s Research Coordinator, talks about one of the most interesting – but difficult to study – residents of Stellwagen Bank. – Ed.
Is there such a thing as an animal that is 55 feet long, weighs 50 tons and is almost invisible? If such a creature did exist, how would you study it? That animal does exist and it’s called a humpback whale, one of the most famous citizens of the Stellwagen Bank National Marine Sanctuary. As the sanctuary research coordinator, one of my jobs is to figure out how to study these invisible giants that spend 90% of their time underwater and out of sight. When I first began studying humpback and other large whales more than 20 years ago, we took pictures of them at the surface, wrote down the timing of their breaths, recorded the other animals they were with, and dreamed of being able to follow them into the depths of the ocean and their lives.
Today, those dreams have become reality, made possible by two technological innovations: DTAGs (Digital Acoustic Recording Tags) and National Geographic Crittercams. The DTAG is a synchronous motion, acoustic recording tag invented by our friend Mark Johnson when he was at the Woods Hole Oceanographic Institution. DTAGs are small computers attached to the whales via suction-cups that hold onto the animals for about 24 hours (see above photo). They collect a suite of data including body pitch, roll, heading, and depth, while recording sounds that the whale makes and hears. To make use of the DTAG, we have a team of 14 scientists working on the project.
A 3D trackplot map shows a humpback whale using bubbles to corral fish. Data was recorded by a DTAG placed on the animal’s back. Credit: SBNMS and UNH Advanced Data Visualization Laboratory.
For the past 9 summers, these scientists have journeyed to the sanctuary to unlock the secrets of humpback whale behavior. Each scientist has a particular team function. For example, Colin Ware, who is the head of the University of New Hampshire’s Advanced Data Visualization Laboratory, takes the DTAG data and turns it into amazing 3D maps of the whale’s behavior and movements (see image above), Elliot Hazen, of the National Marine Fisheries Service’s Southwest Fisheries Science Center uses SIMRAD Echosounders to map schools of sand lance prey, and Allison Stimpert, a National Research Council post-doc, examines how the whales use sound. To date, our team has published 10 research papers in scientific journals unveiling humpback life in and around the sanctuary.
In 2011, we teamed up with the Remote Imaging Program at National Geographic to get an entirely different view of humpback life. This effort uses a Crittercam. The miniature camera also attaches to a whale’s back with a suction-cup and provides an animal-based video observation of the whale’s behavior and surroundings. The Crittercam’s wide angle lens often captures images of numerous other animals, letting us watch multiple whales at the same time.
These two technologies have allowed us to begin to see our invisible whales for the first time. We have learned how they blow bubbles to capture fast moving fish and how they feed along the seabed where the whales are vulnerable to commercial fishing gear. Sharing our unique views with fisherman and shippers has helped us come to a common understanding of how whales behave and, in some cases, how they can be protected.
Top photo: A Stellwagen Bank sanctuary humpback whale sports a DTAG and Crittercam.
Credit: SBNMS file photo by Ari Friedlaender. Photo taken under NOAA Fisheries Permit # 14245.