Alexandre Zerbini

NOAA Fisheries Affiliate, Alaska Fisheries Science Center

Marine Mammal Laboratory & Cascadia Research Collective

Seattle, WA & Olympia, WA

Authored by Thomas Gray, CLS America

(Note: A full list on contributors can be found at the end of the article)

 

In order to get critically needed information to conserve whales, dolphins, seals and other marine life, academic and government scientists around the world use satellite tags to collect data on animal migrations, diving and feeding behavior and their most important habitats.

 

Alex and the team of scientists he works with are involved in a number of on-going whale tagging studies throughout the world, acting as science liaisons in some and as the primary investigator on others. This story is about a collaborative study off Cape Cod, Massachusetts involving humpback whales and advancements in satellite tag development.

 

Tagging a whale is not easy. They cannot be captured and held alongside a boat or obviously brought on deck like fish (tuna, some shark, salmon, etc.) or smaller marine mammals. This limits the types of tags that can be deployed on whales and the methods used to deploy them. Marine biologists have two options to deploy the tag from a nearby boat: either with a long pole or an air compressed gun.

 

The tags that stay attached the longest with either method are those that have an opportunity to anchor through the skin, blubber, and into the connective tissue layer above the muscle (the fascia).

​

Tagging whales with Argos implantable tags is a widely accepted method of tracking; however, the scientific community is committed to identifying ways to address potential physiological issues (infection, swelling, or illness) that might be associated with these tags. Alex’s group, in collaboration with colleagues in the US and in Australia (full list at the end of the article), have been looking for better ways to tag humpback whales that further reduce the potential for harm.

 

Humpback whales in the Gulf of Maine have been studied for the last 40 years. The Center for Coastal Studies (Provincetown, MA) collects photos and other data on individually identified whales. As a result, the majority of the individuals are well known, as is their family, age, sex, health and life history. “It is a unique scenario…you usually don’t have this amount of data (30-40 year data sets) for an entire population,” noted Alex.

​

The project, spanning from 2011 through 2017, allows the team to tag animals previously photo identified so baseline information, by individual, including presence or absence, and behavioral data exists.

 

As part of their research, the research team tags a whale and follows it for the entire season, monitoring the tag and tag site to study the healing process and whether any severe physiological reactions, such as infections, occur. Key research questions include:  does swelling occur, does it go away, and does the whale’s behavior change?

 

Because the sighting history of these whales is well known, scientists can better understand how, if at all, the tags affect the animal’s life history. For example, do satellite tags increase the likelihood of mortality or reduce reproductive rates?

 

The project is also generating new information about humpback whale movements and habitat use in the region.

 

In the first two years of the project, the team identified some improvements to Argos satellite tags, which have been the industry standard for the last 10-15 years. A major focus was on modifying the anchoring system (i.e., the portion of the tag used to attach the tag itself to the whale’s body).

 

With funding from the US Office of Naval Research, in 2015, they developed a new tag design with Wildlife Computers (Redmond, WA). You can review the report published by ONR here.

 

In 2016, they combined data from all previous survey years (2011-2015) to assess how well the new tag design worked. They demonstrated that, with this new design, properly implanted tags lasted 20% longer than before with minimized physiological effects.

 

In addition, the team noted that tags attached higher on the body, close to the dorsal fin, showed less tissue reaction than those attached lower on the flank.

 

In the future, the tag developed through this study will likely have a multitude of sensory functions when it is made commercially available.  The tag used in this study is equipped with an Argos transmitter and light sensor. Light sensors help scientists estimate the tag’s rate of rejection (the time it takes for the animal’s body to reject the foreign body).

 

One of the biggest design changes from the previous version of the tag was combining the tag and anchor into a single unit rather than two separate pieces fused together. This new design eliminates the likelihood that parts of the anchor can remain in the body after the tag itself is ejected. Like previous designs, the new tags are manufactured from surgical quality stainless steel, which is inert in biological tissues.

 

The ultimate goal of this project is to make the design of the tag (how to build it) available to the community so that improvements can be made by all manufacturers. The project is expected to wrap up in December of 2017 with the last deployment of tags in the summer of 2017.

 

Project partners include:

Center for Coastal Studies (Provincetown, MA)

Marine Mammal Center (Sausalito, CA)

Cascadia Research Collective (Olympia, WA)

Woods Hole Oceanographic Institute (Woods Hole, MA)

Texas A&M University (Corpus Christi, TX)

Alaska Sea Life Center (Seward, AK)

Australian Antarctic Division (Australia)

Marine Ecology and Telemetry Research (Seabeck, WA)

Wildlife Computers (Redmond, WA)

 

“I think it is important to highlight that partners from different parts of the world are working together to find better, safer ways to tag whales so we can continue to collect important data and information for species conservation,” Alexandre Zerbini.