SARASOTA, Fla. (May 2, 2017) – In response to recent concerns about current tracking equipment for manatees, Sea to Shore Alliance would like to take this opportunity to answer any questions and dispel any misconceptions about the equipment.
Sea to Shore Alliance staff have extensive experience tagging and tracking manatees in Florida and around the world. Satellite tracking is a tool researchers use to answer an array of questions. We use tracking information to determine if manatees are adapting back into the wild after rehabilitation; how manatees react to the loss of warm water habitat at power plants; the status and importance of foraging habitat; how and where manatees disperse during migrations in the warmer months; site fidelity — in other words, do manatees return to the same locations year after year? We use the information to characterize manatee behavior; to assess health of animals under various conditions; and to answer other important questions that arise over time. The dataset developed via this method of research is vast and invaluable.
We track and monitor manatees with specially designed equipment that has been used, tested, and refined for decades. Manatee tracking equipment is designed specifically for manatees, so it will not look or function like tracking units for other marine mammals. This is because each species has a different morphology (or body plan) and lifestyle, requiring specifically designed tracking studies to answer pertinent questions. The current model consists of a variety of well thought out parts: a padded belt, a flexible tether, and a float.
We consider it very fortunate that our tracking gear does not have to be surgically implanted or hooked into the manatee’s skin like other aquatic tracking devices used on sharks, whales, dolphins or ocean pelagic fish.
Belts come in many sizes and feature padding, a buckle, and nylon webbing. The padding adds extra comfort to the belt and reduces abrasion. The buckle and nylon webbing allow our researchers to custom fit each manatee’s peduncle (where the main body meets the tail) with a belt that can break away according to each animal’s strength and size. Should the flexible tether and float detach and the belt remain on the manatee, an ultrasonic beacon is incorporated into each belt to facilitate field tracking (with a sonic receiver and hydrophone) relocation as a failsafe. Belts may also feature a programmable breakaway release unit to allow release of the gear from an animal automatically and facilitate tag retrieval without disrupting the manatee after a study has concluded. If all else fails, nuts and bolts used in the construction of the belt corrode, which allows the belt to detach from the manatee if it is not relocated.
The 4 to 5-foot-long flexible tether functions to attach the belt to the float. It is made of nylon and features a safeguard “weak link” that allows the tether and float to break loose in case of an entanglement on vegetation, debris, a dock, etc. The length allows radio transmission to occur when the animal is at depths up to six feet. During winter studies, a small temperature logger may be attached to the base[M1] of the tether to gather information on water temperatures.
The float houses the tracking device or tag. The three components of the device are a GPS unit, a satellite-linked UHF transmitter, and a VHF transmitter. The GPS unit works just like the one in your cell phone and it can be programmed to acquire location data anytime at any interval. The satellite transmitter sends the GPS positions and other tagging data (like temperature and diving behavior) via radio signals to orbiting satellites, which are part of the Argos satellite system. Argos is a Low Earth Orbit global satellite-based location and data collection system dedicated to studying and protecting our planet’s environment. Our scientists can access this data at any time. When in the field, the VHF transmitter helps us locate the manatee. Each tag has a unique VHF frequency that allows us to hone in on a particular manatee. A limiting factor of all aquatic tagging projects is that to receive data, the tag has to break the surface of the water for transmission. GPS, UHF and VHF (aka radio waves) cannot transmit through saltwater which is why to this day, submarines must surface for communications that are not sonar. Thus, floating tracking units decrease incidences of lost signal. Additionally, manatee tags are encompassed with a float ring to protect the tag from damage routinely received from boat impacts and gator bites, a situation many other aquatic animals do not have to encounter.
The tracking equipment design, utilized also by state and federal researchers, does not harm the manatee, affect its movement, or behavior. Manatees with tags behave just like untagged manatees; they migrate long distances, feed, socialize, mate, give birth and raise calves. They spend the same amount of time below the water’s surface as untagged manatees, and even small manatees are capable of easily pulling the tag under.
We at Sea to Shore Alliance understand the concerns and reservations of putting tagging gear on any animal. Due to our devotion to the complete recovery of this species, the last thing we, as caring researchers, would want is for a single animal to be harmed which is why such devotion and care goes into fitting each animal with the appropriate tracking gear.
Sea to Shore Alliance, through research, education, and conservation, works to improve the health and productivity of coastal environments for the threatened and endangered species and human livelihoods that depend on them. Sea to Shore Alliance is a Florida-based 501(c)(3) grassroots, field-based research, conservation, and education organization with projects in the U.S., Belize, and Cuba. Sea to Shore Alliance’s projects all focus on three key species: manatees, sea turtles, and right whales. Please visit www.Sea2Shore.org to learn more.