Grand Cayman’s Famous Stingrays – Full Episode

In the shallow, turquoise clear waters of
Grand Cayman’s North Sound, dozens of wild Southern Stingrays glide effortlessly through
the sea. These southern rays are very, very important
to the Cayman Islands from an ecotourism perspective. Tourists from all over the world come to the
site to interact with the animals. You don’t get that experience anywhere else
in the world. It’s the number one water sports attraction
on the island. It’s a hundred foot vis, it’s generally
calm and the animals are very conditioned. Thousands of people each year visit the iconic
stingrays of Grand Cayman, and for more than a decade researchers have been studying the
animals. Among other things, they want to find out what impact human interaction might
have on the fish. From boat fuel, sunscreen, people eliminating
in the water, all of the different types of things that they’re exposed to at the sandbar
in really high concentrations could certainly be very detrimental to them long term. Because
the numbers of people that are visiting the sandbar just grow and grow every year.
The animals have a wretched time when there’s too many people there. They become very flighty,
they keep moving all the time, they stay on the perimeter of the sandbar and don’t interact.
So it’s a double edged sword – how much is too much?
This is our national treasure. Why not enjoy it, you know? But don’t abuse it.
Our concern is first and foremost the welfare of the rays. Secondarily, obviously very importantly
the experience of the visitors to our islands, and we probably have a million people a year
who visit the stingray. So, it’s clearly something that’s extremely important to us,
but it’s equally important that we get the balance right.
Major funding for this program was provided by the Batchelor Foundation, encouraging people
to preserve and protect America’s underwater resources. And by Divers Direct, Emocean Club,
inspiring the pursuit of tropical adventures and scuba diving. And by the Do Unto Others
Trust. The Cayman Islands are a popular travel destination
in the Western Caribbean. Grand Cayman, the largest of the country’s three islands,
is famous the world over as a major banking center, and for its beautiful beaches and
marine environment. And for the last thirty years or so, the island
has also become known for its tame stingrays that congregate in the shallow waters of the
North Sound. Fishermen would come inside to the area because
it was shallow, they could clean their catch. The stingray started to catch on and would
aggregate there to feed on the discarded fish parts that were thrown over the side and then
people decided that the rays were friendly and close enough so they could feed them and
it took off as a phenomenon. Normally, wild stingrays are solitary animals
that are very skittish of people and can rarely be approached closely. During the daytime
they are often found buried in the sand hiding from predators such as sharks. But at the
Stingray Sand Bar, also sometimes referred to as Stingray City after a nearby site where
scuba divers can interact with the animals, the fish actively engage with visitors, making
the area one of the most popular tourist attractions on Grand Cayman.
This is one of our main business right here on this island, especially for tourism. A
lot of the locals, the local guys does it and when it’s busy, the companies make money.
Long as my customers are happy, I’m happy. Renowned Marine life artist and scientist
Guy Harvey moved to Grand Cayman in 1999. I was interested in the turnover of animals,
the site fidelity, the sex ratio, what they do at nighttime, all these questions nobody
could answer. Nobody had any clue how many animals were there.
It’s really important to do this kind of research on the sand bar because human interaction
has changed the dynamics of the stingray so drastically.
In 2002, Guy began a research project in collaboration with the Cayman Islands Department of Environment
to learn more about the iconic rays. We started a two year population study using
two research students, along with a supervisor from the Guy Harvey Research Institute based
at Nova Southeastern University in Fort Lauderdale, and during that time they tagged 180 animals
from the sandbar and 20 others from around the island as control animals, so that was
our benchmark and the important thing was to get every animal tagged with a non- invasive
pit tag. These pit tags are similar to a pet’s micro-chip
and they allow the experts to identify individual animals when they are re-captured.
18261. We found that we had 100% retention of these
tags. Many of the large animals that are there at the sandbar today were tagged back in 2002
so that gives us a fantastic chronology of their life history.
During the first two years of the study, researchers monitored the animals monthly to gather detailed
information. We also did some sonic tracking at nighttime
to determine where they went because we realized that their behavior had changed completely.
They are typically nocturnal predators and will lay low in the daytime, but now they’re feeding in the daytime and they were laying low at night. Especially the large females, and
they would go and sit within a quarter of a mile of the sandbar.
The males, we found on the other hand, because they were out-competed because they are smaller,
would forage at night and actually cover two or three miles in a night before coming back
to the sandbar. We found that the two sexes had completely different behavior.
In Southern stingrays, as in many other fishes, the females are larger than the males.
Having larger females gives you a reproductive advantage over everybody else because the
bigger you are the more pups you can have. Guy and his research team continued the summer
counts of the animals over the years. The research is critical, there’s obviously
an ongoing need to monitor these populations. When there was a sudden decline in the number
of stingrays at the site, the researchers and tour operators became concerned.
We first realized the decline of the population late in 2010, through casual observation alone.
And by 2011, we got concerned and 2012, we took our first January census in response to everybody’s
requests. And found that compared to our 2002, 2003
and 2008 numbers, they had dropped significantly. And from over 100 to 61 in January 2012 and
57 in July 2012. Very drastic decrease, but we had no idea why that would be the case.
Could it be sharks that were taking them more often now? Was it something to do with their
health – has the diet that we’ve been giving them taken a toll finally? Any kind of stress or
disease? To find answers to these questions experts
from the Georgia Aquarium in Atlanta joined the research team from the Guy Harvey Ocean
Foundation and the Department of Environment in 2012. They’re conducting health assessments
on the stingrays to understand what may have led to the decline in numbers and what impact
the human interaction is having on the animals. Well, I’m the stingray catcher. So, my job
is to continually bring rays so that we keep the production line going as quickly and efficiently
as possible, and that took many years of practice. I’ve had various help from tour boat operators
to friends who were very skilled in the art of catching a ray.
Young ones are sometimes extremely difficult to catch because they are flighty, they escape
easily from your hand, and you don’t want to end up putting too much pressure on them.
The larger ones are easier to catch, but harder to hold, because they’re basically like a
massive pizza, and they’re very powerful animals so one flap and they could be out
of your hands. Once securely on board the boat, the venomous
barb on the stingray’s tail is covered as a safety precaution.
The barb, of course, is a very important defensive mechanism for these animals and you have to
respect that. Next, the animals are scanned to see if they
have been tagged in the past. 553.
After the animal is identified, basic measurements are taken to look at their growth. Then a
vet takes blood samples from the vein that runs along the bottom of the tail.
We look at many things, such as complete blood counts, looking at the red cells, looking at
the white blood cell count. We look at their proteins, then we’ll look at a general chemistry.
We look at their stress hormones, and then we’re also looking at vitamins, minerals,
other nutrients, fatty acids – so it’s very similar to whether we took our dog or our
cat to the doctor’s office, had a blood sample taken, and doing a complete health
panel. The animals that are on the sandbar definitely appear relatively healthy.
When we look at their blood parameters and compare that to the very little bit of data
that is out there on free-ranging southern rays along the Atlantic coast, and then
we look at that in comparison to aquarium animals, they are very comparable with
most things. In general, we feel like those animals are doing fairly well.
Experts also take a small tissue sample from one of the fins.
We take it from the same place every time and that helps us identify that particular
animal in terms of whether she has actually been looked at on this particular assessment.
The tissue will eventually grow back. Both tissue and blood samples are also used to
study the nutritional health of the stingrays. In the wild these animals would be solitary,
and they are bottom feeders. They’d be eating things like clams, bivalves, crustaceans.
They may come across dead carcasses. So they would have a varied diet in the wild. Here
at the site, they’re actually being hand fed a non-native food item – squid. And squid
is fairly nutritionally poor to begin with. So, that could be related to why we’re seeing
some of the population level changes here at the sandbar. Also, a free ranging stingray
can travel miles and miles a day to actually find food. These animals are relatively
stationary because they know they will get access to food relatively easily day after
day. We’re looking at vitamins and trace minerals in their blood, and that’s sort
of a gross indicator of their nutritional status. And then we’re looking at some more fine
scale markers. We’re looking at fatty acids, and we’re also looking at stable isotopes.
Both of those markers are based on the fact that you are what you eat. We can actually
look at those markers to track over time what these animals have been eating. Some of the
preliminary data that we’re seeing is that the fatty acid profile of these animals is
very similar to squid, which makes sense because that’s primarily what they’re being fed,
and that’s telling us that their dietary history is not ideal for them and could, potentially
down the road, present some problems for these animals. All the animals here are getting
enough food, but are they getting the right kinds of food? So if we liken it from a human
perspective we could ask, “Are these guys couch potatoes? Are they eating too many potato
chips?” Evidence shows the stingrays at the sandbar
do forage for food in addition to being fed by people, but just how much might differ
between the sexes. To get a more fine-scaled picture of these dietary differences, Lisa
examined ten males and ten females on a quarterly basis in 2014.
The females are a little bit pushier animals so the males tend to be on the fringes. Based
on some of the tracking data that has been done by our colleagues, we know that the females
tend to stay put. The males tend to range a little bit more. So, I suspect the reason
that they’re ranging is because they might be feeding on other things, because they cannot
get access due to the competition by the females out at the sandbar. So, if that is true, we
should be able to see that in the stable isotope and in the fatty acid data.
The scientists also hope that 2014’s quarterly survey will give them a better understanding
of the animals’ reproductive cycle. This, of course, has particular relevance to
the sustainability of the whole experience. Dr. Alexa McDermott conducts an ultrasound
on each female that comes onboard. Unlike most fish, stingrays give birth to live pups.
First I look at the uterus, usually because it’s the easiest, most prominent thing to
find, especially if the animal is pregnant, and with the ultrasound you can see the uterine
wall and you can see little finger-like projections inside the uterus on some of the animals if they’re pregnant, and those secrete nutrients for the developing pups. So, this is an image of a pup inside
the uterus. So, the uterus will be here and then the pup is here. This is the body of
the pup and here’s the wing and a wing. So it’s as if the pup is swimming at you
on the screen, and you can even see the individual little cartilage rays in the wings. And then,
I also look at the ovaries, so I look to see how many they have, if they’re all the same
color, if they’re all the same size, if there are cysts present or not present. And
so, I’m looking to see if that changes with pregnancy, seeing if that changes over time
for individuals, and just kind of documenting it because it hasn’t really been done before
in this species. At each of the quarterly health assessments
in 2014, a little more than one-third of the females were pregnant, leading the scientists
to believe that there is no specific breeding season for this population of stingrays. As the sandbar
grew in popularity over the years, the increasing number of tourists at the site became a source
of concern. The animals, on a heavy cruise ship day, are
harassed, you can see that they are uncomfortable because they fly around the place, they’re
moving very quickly and they’re not stopping. In 2007, rules were introduced to better regulate
the interactions between rays and people. There’s three types of limits: A – a limit
to the amount of people you can have on the boat – and that’s restricted to 100 people.
Then there’s a limit to the amount of boats that can be in there at any one time. So,
the limit is 20 commercial boats for an hour or so, and obviously if you got 20 boats with
100 people on, that gives the theoretical limit of 2000 people, but there’s an actual
person limit of 1500 commercial passengers. So, that just accounts for the fact that most
of the boats can’t carry 100 people. The sandbar became what is known as a wildlife
interaction zone, or W.I.Z., and stingrays were protected inside this area.
You are allowed to hold them, you’re allowed to feed them, but you are not allowed to lift
them out of the water. There was also an issue with what people were feeding them. So we
introduced conditions that restricted the feeding to ballyhoo and squid. And you’re
not allowed to wear shoes in the water, you’re not allowed to fish or take any wildlife out
of the W.I.Z. zone, you aren’t allowed to harm the rays in any way. It’s a very difficult
job to balance the private interest versus the commercial versus the tourism product,
and above all that the environmental concerns. So yeah, we worked for close to five years
consulting with the stakeholders. I think it’s the best compromise that could be expected
under the situation. I do think that it does work well. There are definitely still days
when the timing is off and you get the full quota, the 20 boats with a lot of people and
the sense that it is very crowded and I don’t think people enjoy that, but on a typical
day with one to two ships it’s not so stressful at the sandbar. Yeah, there are things we
would like to change, but respecting all of the stakeholders and the compromise that we
are at, I think, yeah, the balance is pretty good.
While the rays now had protection inside the wildlife interaction zone, no laws prohibited
the taking of rays elsewhere around the island. The W.I.Z. zone isn’t large enough for the
typical ray territory of a stingray. So, once a stingray traveled outside the W.I.Z. zone,
it was theoretically possible that you could capture that ray and there was no law saying
what you did with it – you could eat the ray, you could put it in a tank – which
is actually what happened. We had a local establishment that had about
ten rays they had put into a tank and had them on display with other creatures that
it had there. They said they came from fishermen, they were caught by hook and line and would
have died anyway. But one thing that was very noticeable about the rays that were in the
tank is that they were not freaked out by humans and that you could hand feed them,
which everybody immediately assumed these rays had come from the sand bar. So there
was a hue and cry about the fact that people were taking rays from the sand bar. So, we
investigated the situation and found that out of the ten rays that they had, a couple
of them had been tagged from our research efforts. And from our research, we know that
stingrays around the sandbar show a strong site fidelity to the area and so the likelihood
that they would have come from Stingray City was quite high, but you can’t prove that
because some will forage elsewhere if they haven’t been fed enough for the day, and
they’re not protected outside the W.I.Z. zone. And that actually heightened the awareness
of, “Wow! We think the numbers of the animals on the sandbar have been declining and might
this be another reason why they’re declining. Are people actually fishing for them, are
they being taken to other locations?” I think that was definitely an eye-opener,
if you will, for the Department of Environment, for the ecotourism industry down here that
more protection was needed. In the press it became quite a heated item because the owner
and operator of the Dolphin Discovery didn’t want to let go of the animals and the D.O.E.
made them put back the tagged ones but they held onto the six untagged ones and we were
pushing to get them protected because theoretically anybody can take a stingray and fling it on
their barbeque, because people do eat them, or put them in their own pool or put them
in their bathtub and do whatever they want and there was nothing to protect the stingray. Why would you want this to happen if these animals are worth so much money? So, I took
a back of an envelope calculation and said, you know 60 rays, at the time there were only
60 rays, 500,000 people paying 40 dollars a head, each animal generates half a million
dollars a year, they’re long lived slow growing animals, so in 20 years an animal
theoretically can generate 10 million dollars for this country. Why wouldn’t you protect
them? Until we put it into dollars and cents finally the penny dropped for the politicians
and something got done about it. And the next Minister of Environment, he gets it, said,
“You put those stingrays back in the ocean where they belong.” And there was a big
palaver about that and they got released, and I’m glad to say many of those same animals
are still at the sandbar so they’ve become acclimatized to their new location and are
doing fine. In May 2013, a law was put in place that protected
Southern Stingrays and two other species in the Cayman Islands.
You could no longer have a ray in captivity, you could no longer take one from the wild,
so that was the reason that that was introduced. Again, not really to protect rays because
they were threatened as a species, but the sandbar rays were threatened by entrepreneurs
that wanted to kind of exploit the fact that these rays were already conditioned to being
hand-fed. So, the majority of the rays in captivity were male, and subsequently there
was a very big fall off in the number of males at the sandbar, and this was actually quite
a serious issue because there was already a very large imbalance between male and female.
There are currently 7 females to 1 male and so removing animals, especially males, from
the population could have a drastic effect. But since the return of the captive animals
to the sandbar, the population has rebounded. The population has definitely rebounded for
reasons we still don’t fully understand and this is why the blood work coming in from
the Georgia Aquarium folks is so valuable. You can get a better handle on their reproductive
rate, body analysis and all that. We’re not seeing the numbers necessarily that we would
have seen in 2008, but they have certainly increased from 2012, which is very
positive. But despite the rules and new protections,
some in the community still feel there are too many boats at the site.
You cannot give the people what they are paying for when there’s 800 or 1,000 people out
here. I want them to have good memories of what
this is all about, it’s not just to enjoy themselves, but to be educational and to respect
the environment. I’m very emotional when I see a stingray get hurt, I literally want
to cry because they’re a part of my life. This is a big earner for Cayman and this is
one of our national gifts and we should respect it and not abuse it. Put less boats out here.
Lot of the boats, I feel, is overloaded. On the major cruise ship days you can get up
to 5 or 6 ships in dock, so it does become very busy indeed. Those animals may see 5,000
people in a day during the busy season. That’s an awful lot of human interaction. My recommendation
is that there be no more than three or four hundred people on the sandbar at any given
time and how you control that from a government perspective is up to them. Our job
is to provide the data, the science, on what is happening out there and give it to the
policy makers to make a decision. It can be a difficult balance to strike, but I think
we should nonetheless make every effort to get the balance right. It has high economic
value for us. But if we aren’t good stewards, and if the welfare of the rays are not our
primary focus and somehow we do something to lose that, then we have lost the battle
and we have lost everything. So, we need to really err on the side of caution and try
to make sure from a conservation perspective that we get things right.
Major funding for this program was provided by the Batchelor Foundation, encouraging people
to preserve and protect America’s underwater resources. And by Divers Direct, Emocean Club,
inspiring the pursuit of tropical adventures and scuba diving. And by the Do Unto Others

Leave a Reply

Your email address will not be published. Required fields are marked *