Aboard a 21-foot boat named “Genetic Drift” in the choppy
waters of Nassau Sound near the Florida-Georgia border, UNF biology graduate
students Mike McCallister and Ryan Ford are keeping an eye on the darkening
sky. A storm is brewing. Just as the duo begin to pull in the 1,000-foot
fishing line they baited 30 minutes earlier, a gush of cool wind and the sound
of heavy rains to the immediate west take their attention momentarily away from
the surface of the water, away from the eagerly anticipated first batch of
sharks they’d hoped to score.
Quickly switching gears, the two scramble in
synchronicity to raise the boat’s Bimini top and toss their research gear under
cover as the wall of hard rain overtakes the inlet. Fortunately, just as
quickly as the storm approaches, it moves on, typical weather for a late summer
morning in Northeast Florida.
McCallister and Ford know that just beneath the surface
of the water there’s an endless variety of sharks lurking, some up to eight
feet long. So when they return their attention to the awaiting line and briskly
pull it up into the boat, they’re not surprised to find one angrily squirming
shark after another: five, to be exact.
The sharks they bring up are actually quite stunning,
with their glossy, metallic-gray skin and amazingly calm and greenish cat-like
eyes. A close inspection of the sharks’ skin unveils unexpected texture and
mottling: what appears to be a solid color is actually a composite of tiny speckles
of blue, green, silver and black. But there’s no time to admire the beauty of
these fascinating and feared creatures. The clock is ticking and there’s work
to be done.
Part of a team of student researchers headed by UNF
biology professor Dr. Jim Gelsleichter, McCallister and Ford go about their
work with precision and familiarity. They carefully unhook the sharks one at a
time and begin conducting a series of tests to gather a plethora of data.
“When we have a shark on the line, we’ll remove the hook,
measure the length of the shark, tag it, identify the species and determine its
sex and stage of maturity,” McCallister said. “If it’s an immature juvenile, we
check the status of the umbilical scar, if it’s present, to find out when it
was born. We also weigh the animal and record its condition upon capture and
release.”
Depending upon the sex, age, weight and condition of the
animal, a number of other quick tests are performed, including blood samples,
fin clips, muscle biopsies, and removal of the animals’ stomach contents. All
of this takes place within a matter of minutes before the shark is released
back into the wild with their dorsal fins adorned with small identification
tags for future tracking purposes.
On a good day, the team is able to repeat the fishing
procedure up to four times, but conditions are no longer ideal for additional
shark fishing today. After another attempt to catch a few more sharks proves
unsuccessful, the team members pack up the fishing gear and head back to the
boat ramp, disappointed but eager to get back to the lab and turn in the day’s
data.
This is just one example of how both graduate and
undergraduate UNF students delve into fieldwork to gain hands-on experience
that teaches them more than any textbook possibly could. The particular shark
research conducted by Gelsleichter and his crew focuses on a study funded
through the National Oceanic and Atmospheric Administration (NOAA). It’s called
the Cooperative Atlantic States Shark Pupping and Nursery (COASTSPAN) Survey
Program and it’s run by the National Marine Fisheries Service.
“The purpose of this study is to examine the importance
of Northeast Florida waters as an essential fish habitat for sharks and their
relatives, skates and rays,” Gelsleichter said. “Essential fish habitat
represents locations critical for the survival of shark populations because
they provide shelter from predators and food resources for juvenile sharks
during the period in which they grow to become sexually mature, or because they
are where adult sharks congregate to mate or where females give birth to
newborn sharks, known as pups.”
Essential fish habitat locations are also referred to as
nursery grounds or breeding/pupping grounds. It’s necessary to identify and
protect these areas so overharvested fish/shark populations can be managed and
conserved.
“This study will determine if the waters surrounding
Jacksonville and St. Augustine, including Nassau Sound, Cumberland Sound, the
St. Johns River and local portions of the Intracoastal Waterway, are nursery
and/or pupping grounds for commercially and recreationally important shark
species,” Gelsleichter said. “We’re also examining trends in the abundance and
health of sharks and rays in these locations.”
Some Atlantic shark populations have declined in the last
several decades due to overfishing and the animals’ slow reproduction rates, so
long-term information on shark abundance and the identification and protection
of essential fish habitats in the region are critical for the management of these
populations. But until Gelsleichter and his team of researchers took to the
waters in the summer of 2009 to begin gathering shark data, there had been a
longtime gap in knowledge.
McCallister, who just completed his second summer
catching and collecting data on local sharks, said this is the first time
anyone in the Northeast Florida region has participated in a COASTSPAN-funded
survey, or anything like it. “All the prior COASTSPAN surveys had spanned just
about every major estuary along the eastern seaboard, from the New England
states and Massachusetts area all the way down to Georgia, and it jumped from
the Florida-Georgia border down to the Indian River Lagoon area, continued
south to the Bahamas and then picked up on the Gulf side of Florida,” he said.
Gelsleichter made it his mission to fill that gap upon
coming to UNF in August of 2008. One reason he was drawn to UNF was because of
its Coastal Biology Department’s Flagship status, which the department achieved
in 2006 because of its excellence in faculty scholarly accomplishments, the
potential of faculty to produce exceptional educational outcomes for students
and its power to link quality education to a range of civic needs in the
community. He also looked forward to working with students who share his
passion for marine life.
With 10 years of experience as a marine scientist at the
Center for Shark Research at the Mote Marine Laboratory in Sarasota,
Gelsleichter was already a seasoned veteran when it came to securing necessary
funding for this type of research. He immediately applied for funding to
investigate and gather data on local shark habitats — and successfully secured
the initial grant from COASTSPAN to begin the multi-faceted project just a few
months into his tenure at UNF. Since then, numerous other grants have been
received, supplementing the annually renewable COASTSPAN grant.
Fieldwork for the project is conducted primarily in the
summer months, during which student researchers head to one of several specific
waterways — from Nassau Sound near the Florida-Georgia border to the Tolomato
River just north of St. Augustine — to collect the information needed. Equipped
with ropes, buoys, hooks, fishing line, bait, NOAA identification tags and an
array of research tools, the team’s mission is to find and catch as many sharks
as they can.
So far, they’ve caught 14 of about 18 local shark
species, including blacknose, blacktip, spinner, sandbar, lemon, nurse and
bonnethead sharks, as well as several species of rays and skates. The sharks
range in size from 12 inches to more than eight feet, but because this research
is focused on nursery habitats, sharks caught are usually very young, measuring
only two to four feet long. Data collected is used not only for the COASTSPAN
survey, but also for various concurrent projects, including grad students’
theses.
While McCallister’s thesis directly relates to the
COASTSPAN sampling program, grad student Ryan Ford is narrowing in on a
specific small coastal species, the blacknose shark, for his thesis. “I’m
looking at the diet and reproduction of this species. The reproductive part
will be coupled with the diet aspect to look at the differences in diet between
males and females and between pregnant females and non-pregnant females, to see
what the trends are.”
Gelsleichter’s newest grad student, Brenda Anderson,
focuses on the use of hormones in the blood as a non-lethal way to examine
reproduction in sharks and rays. And grad student Christina Walker is using the
data collected to focus on pollutant exposures and their effects, not only for
sharks in this area, but also for sharks in the Gulf exposed to oil as a result
of the Deep Water Horizon catastrophe.
“We have collaborators in Alabama who have already
provided us with samples from hundreds of animals, half from before the oil
spill and half from after the spill, and Christina has analyzed a large number
of these so far,” said Gelsleichter, who conducts his own research on
environmental contaminants and the resulting alterations in exposed animals’
reproductive biology. “We’re trying to find out if animals exposed to oil have
been physiologically altered as a result. The research is very comprehensive
and systematic.”
When summer is over each year, the fieldwork ends, except
for the occasional excursion to south Florida where sharks don’t flee for the
winter season. And samples continue to come in from various colleagues around
the country. During the cooler months, Gelsleichter and his research team spend
time in the lab analyzing the collected data and trying to identify important
correlations and trends.
Although it’s too soon to come to any jaw-dropping
conclusions, Gelsleichter said they’re already starting to form a few
hypotheses regarding local shark populations, but that it’s just the beginning
of many years of work to come.
“With the work we’ve done so far, we’ve already greatly
expanded knowledge on shark populations in this area, but what we’ve done is
really just scratching the surface,” he said. “What we need to do is expand on
our techniques and keep doing what we’re doing right now. There’s really no
reason to go in any other direction, because everything we’re doing right now
is already so new and exciting.”
The future looks like clear sailing for Gelsleichter and
his UNF research crew. Ongoing projects like the COASTSPAN survey include
various components that offer grad students multiple options for thesis work
and undergrads unmatched hands-on experience, and there’s no shortage of
research that needs to be done in the area.
The team is also establishing and strengthening bonds
with numerous colleagues in the field — and is becoming quite well known in the
region as local shark experts. Last summer, when sharks made headlines
following four shark attacks in the Jacksonville area (including one UNF
student featured on page 24), Gelsleichter was there to take countless calls
from the media and the public. It’s just a part of the job.
But while public fascination in sharks escalates when
news spreads about local attacks, Gelsleichter and his team of researchers
maintain a constant state of fascination in these marine animals. To this
tight-knit group of biologists, sharks are far from the scary predators
portrayed in movies like “Jaws” and sensationalized in the news; they’re simply
the subjects of important research that will help scientists better understand
the feeding, reproduction and migratory patterns of these fascinating fish.
