This time on Jonathan Bird’s Blue World, Jonathan travels to the Turks and Caicos to
learn how marine biologists conduct underwater research!
Hi, I’m Jonathan Bird and welcome to my world!
It’s the middle of the night on the tropical island of South Caicos.
A group of marine biology students are wading into a mangrove, helping to tag baby sharks.
How I got here is an interesting story.
I get a lot of emails asking about how to become a marine biologist.
You might be surprised to discover that I’m not a marine biologist!
So I think it would be fun to check out some of the ways that marine biology students learn
what it takes to do field work.
I’m off to the sunny but remote island of South Caicos, in the Turks and Caicos Islands,
just southeast of the Bahamas.
Here, the School for Field Studies operates a field research facility where college students
from all over the United States come for some hands-on marine biology field work.
Faculty at the School for Field Studies have ongoing research projects investigating fisheries
management, reef health, shark populations and even human impact.
My goal?
To spend some time tagging along with the students to see what they do every day in
their pursuit of a degree in marine biology.
My day begins with the shark research team led by Professor Aaron Henderson.
Henderson and his students are investigating how the marine protected areas around South
Caicos are affecting the shark population.
Their first task for the day is to deploy some baited camera rigs.
These rigs will hopefully attract and film several species of sharks.
The goal: to learn how many and what species of sharks are here in the marine protected
area.
Many different species visit the cameras including Nurse sharks, Caribbean Reef sharks, Tiger
sharks, Lemon sharks and even Great Hammerheads!
Next the team deploys what are known as “drum lines.”
These are baited hooks attached to a float and a weight.
They are designed so that sharks can swim around when they are caught, so they won’t
drown.
The goal is to catch sharks so they can be tagged and released.
With five drum lines set, the team goes back to the first one and checks for a shark.
The goal is to check each line at least every 10-15 minutes, so a shark doesn’t stay hooked
too long.
It doesn’t take long before they have their first shark.
Dr. Henderson places a tag on its dorsal fin, while the students take a small tissue sample
from is tail for an isotope analysis of the shark’s diet.
While the shark team is out tagging sharks, another team of students is heading out to
sea as well.
This group is studying the fish population of the island, again trying to determine the
effectiveness of marine protected areas.
Instead of working from the boat, these students will be doing their research with scuba gear.
Underwater, the team heads to a nice section of coral reef and begins a transect.
Essentially they reel out a very long tape measure over the reef, which defines a specific
path of a specific length.
Of course swimming over the reef causes all the fish to swim away and hide.
So they wait a few minutes for the fish to go back to their normal routine, then they
slowly swim along the transect taking notes on what species of fish they see and keeping
count.
Of course they don’t see every fish.
This lionfish hiding in a hole escaped detection.
But this technique yields a pretty good estimate of fish numbers on this section of reef.
By comparing the transect results inside and outside of the marine protected areas, the
students can learn not only how well the marine protected areas are working but on which species.
Of course, fishing pressure is what affects fish populations, so it makes sense to also
try to get a handle on what species of fish are being caught.
The students work with the local fishermen who volunteer to allow the students to come
down to the docks at the end of the day and see what kind of fish they are catching and
how big they are.
The fishermen know that research like this and marine protected areas will help to insure
that there are always enough fish to catch.
Another team of students, another research project.
This team is working in snorkel depths without scuba--studying a big snail called a conch.
The conch is one of the most popular seafoods in the Caribbean, and a whopping 10% of the
world’s supply comes from the tiny island of South Caicos, so it’s an important resource.
The conch population seems to be dropping, so the conch research team urgently needs
data.
This transect in the seagrass bed is being used to count conch.
But their work doesn’t end there.
They also collect a few conch for additional research on land.
Back at the shore, alongside a representative from the Turks & Caicos Department of Environment
and Maritime Affairs, the students crack the conch open in the traditional way.
Student Daniel Liu is trying to come up with a way to determine the size of the shell…when
the shell is gone.
Fishermen often take the meat out of the shell at sea and return with only the meat and no
shell.
How can the government recommend or enforce size regulations if there is no shell to measure?
So Daniel’s research is looking at other ways to gauge the maturity of a conch, without
a shell.
As the sun sets and the air cools down, my day following the students isn’t over.
I have re-joined with the shark team to follow along on their night work.
Baby sharks live in the mangroves, where they are safe from a lot of larger predators.
A couple of nights a week, Dr. Henderson and his students head over to the mangrove areas
to catch baby sharks.
They start by setting a net in the chest-deep water, hoping to snare small sharks as they
cruise by.
Every 15 minutes they check the net, and when they have a shark, they bring it back to a
makeshift lab on shore where they will weigh it, tag it with a electronic tag, take a small
tissue sample, some ID photos, and then quickly get it back into the water.
One of the students will swim the baby shark around for a few minutes to re-oxygenate its
gills, and then they send it on its way.
From sharks, to fish to conch and more sharks, my day with the marine biology students at
the School for Field Studies in South Caicos was exhausting but exciting.
I saw how marine biology can be conducted from shore, from a boat, and underwater using
scuba or snorkeling.
Sometimes we imagine marine biologists as having glamorous jobs working with marine
mammals, or exciting jobs diving with sharks.
But marine biology is a broad spectrum of ocean-related studies with specialists in
everything from plankton growth to whale rescues, and everything in between.
Sometimes it is pretty exciting.
Sometimes, it’s not very glamorous.
But if you love the ocean and the life in the ocean, marine biology is a job that will
never be boring!