Manatee Captures for Health Assessment
By Michael Mock
On November 9th and 10th
2011, Dr. Tucker selected five students from the conservation biology class to participate in manatee
captures for health assessment in Crystal River, Florida. Students from the College of Coastal Georgia,
as well as, veterinary students attending the University of Florida and other Universities
and agencies worked alongside scientists from the United States Geological
Survey and the Florida Fish and Wildlife Conservation Commission.
The Florida manatee is a large
aquatic mammal that migrates to the warmer waters of Florida in the winter
months of the year to thermoregulate.
Manatees live in a wide variety of environments and can be found in
areas as diverse as large urban waterways to freshwater artesian spring
habitats with little human interaction and even salt marsh habitats. Manatees face a number of factors that make
them vulnerable to population decline, making their well-being of particular interest
to conservation groups. One of these
factors is the manatee’s low reproductive rate, only having one calf every
three years and having an 11-13 month gestation period. Along with the reproductive rate, the calf is
usually dependent on the mother for two years which requires significant
parental investment. Florida manatees
are also thought to have low genetic diversity which could be the result of the
founder effect, suggesting the population was started by only a few individuals
or was dropped to a low number at some point in the past.
The purpose of the captures was to
gain knowledge of the health, sex ratio, genetic diversity, and migratory
patterns (through telemetry) of the manatees that were present in this area of
Crystal River. With regular assessments,
the data that is gathered can be used to show patterns and assess the health of
the manatees in the area. It can be
treated as a baseline for future studies as well. Is the population declining? Staying the same? Or is it improving?
Manatees were initially spotted by a
team using a bridge as a good vantage point.
Once spotted, a team on an adjacent beach was alerted and prepared to
encircle the passing manatee with a large net being trailed from the capture
boat. Once confined in the net, a team
standing on the beach pulled the net in and landed the manatee on the
shore. Lone manatees were targeted as to
not separate a cow and calf pair in most cases, yet some pairs with older
calves were captured. Once on the shore,
the manatee was moved in a stretcher apparatus carried by 10-12 individuals to
a transport boat to taxi the animal around the bend to the data collection
beach. This small beach was outfitted
with several tents which held different stations to gather various kinds of
data. Being removed from an aquatic
habitat and surrounded by strange people in the terrestrial environment caused
the manatees to struggle in some cases, but for the most part were calm and
kept as comfortable as possible. Blood
was drawn, all vitals were checked first thing and small tissue samples were
taken for genetic and contaminant analyses.
The animals were also weighed and morphometric data was collected by
measuring the length and girth of the animal at several points. The sex was also recorded. The manatees were scanned
to see if it had any pit tags indicating it as being an individual that had
already been previously captured. These
pit tags are similar to the microchips that they put in your household pets
nowadays. If no pit tag was found, one
was implanted in each shoulder area and recorded in a log so the individual could
be documented. One of the more
interesting aspects of the captures was the photo identification of each
manatee to include in the database of manatees using external features such as
scars from boat strikes or any other distinguishing features. These photos are compiled to have a list of
members of a population so identification can be done to recognize manatees if observed
or captured at a later point. The
manatees were kept on land for an average of an hour with regular application
of water to the body and oxygen supplied to ensure their comfort and their
health status.
This experience allowed me to get an
idea of the kind of work and man hours required for the conservation efforts
that go into the preservation of one species.
The amount of data recorded in just two days will take a great deal of
time to evaluate and used to make management efforts more efficient. The attention paid to detail, as well as the
requirement of consistency were paramount while working with animals that are
so important and fragile in an area. The
care for the animal was also of high importance, making sure that conservation
efforts do not cause more harm than good.
Respect for the animal while gathering data was balanced well, so I
believe that this particular event was successful and will go far in the
protection and promotion of this important species.
No comments:
Post a Comment