The truth about sharks in Cayman

Q&A: Shark Project officer Johanna Kohler

Sharks are most commonly seen on East End reefs and along the north wall. Photo: Jon Barron, Ocean Frontiers

Recent sightings of sharks at Stingray sandbar and alongside Seven Mile Beach, as well as organised educational dives with East End operator Ocean Frontiers, have sparked new interest in the species in the Cayman Islands. We interviewed Cayman Islands Shark Project officer Johanna Kohler to get some of the facts about sharks in local waters.

Q: What are the most common shark species in Cayman and how many of each are believed to be in the islands’ waters?

A: We have confirmed reports of nine species that are frequently encountered in Cayman waters of which six are more coastal (i.e. reef-associated) and three are more oceanic (i.e. not likely to be encountered close to shore).

Coastal species (listed in descending order of relative abundance)
Nurse shark
Caribbean reef shark
Hammerhead species (e.g. great hammerhead, scalloped hammerhead)
Lemon shark/Bblacktip shark
Tiger shark

Oceanic species (listed in descending order of relative abundance)
Silky shark
Oceanic whitetip
Whale shark

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Currently, the low numbers of sharks in Cayman waters means that abundance estimates are inherently difficult to calculate at this time. As populations potentially recover with protection and longer data sets are established, we anticipate more in-depth analysis in the future that will allow better estimates of sharks populations resident in our waters.

Q: What is the work of the Shark Project focussing on? What are the goals going forward?

A: The Department of Environment and Marine Conservation International shark research aims to better understand our local shark populations in order to inform conservation, education and enforcement strategies.

The project relies heavily on a funding partnership, the Whitetip Conservation Fund, established with DoE and the Cayman Islands Brewery.

Multiple research approaches have been utilised to study and monitor the abundance and behaviour of sharks in Cayman including acoustic telemetry, utilising electronic tags to track movement around the islands; Baited Remote Underwater Video Surveys (BRUVS) to document and estimate the numbers and types of sharks present; photo identification of individual sharks as a method to estimate numbers of sharks; and the Sharklogger Network using volunteers and enthusiasts to submit shark sightings.

Researcher Johanna Kohler prepares a remote camera during a shark survey.

This way we are able to identify potential threats and improve shark conservation locally, which led to the full protection of all sharks and rays in Cayman waters under the National Conservation Law, 2013 (relevant section entering into force in 2015).

With the protection of all shark and ray species within national waters, the Cayman Islands have effectively established a shark sanctuary within the Caribbean and we must continue to monitor the shark population to gauge how effective these protection measures are.

Although it is early days, the protection measures have not yet yielded a major change in abundance which is most likely due to very slow reproductive and growth rates of most sharks.

Female Caribbean reef sharks, for example, can become pregnant every three years and give birth to three to six pups after a year of gestation.

Therefore, five years since the implementation is just not enough time to see any significant changes in shark abundance.

Furthermore, currently the network of marine protected areas around Cayman are not covering sufficient essential shark habitat to protect these animals from encounters with fishermen. The expected enhancement of the marine parks system will also increase reef fish biomass and diversity which will have a positive impact on sharks. It is essential to continue the monitoring of our local population in the future to further expand our knowledge of sharks in Cayman and reduce the risk of local extinctions.

Q: Do we have a healthy shark population or would it be better for the reefs if there were more?

A: Generally, sharks are at risk of extinction, with 90% declines in populations globally compared to pre-exploitation levels.

Sharks were actively fished in Cayman in the 1960s, given the intensity and locally small shark populations, caused the fishery to cease crash within 10 years.

Since then, sharks were occasionally caught and killed up until 2015 when the government implemented shark protection measures to make Cayman a shark sanctuary.

This aimed to aid the conservation of shark species in Cayman as these animals are needed for the health and balance of our marine ecosystem.

Although our shark population seems to be stable over the past few years, we do not have enough sharks in Cayman for a healthy ecosystem and compared to pre-exploitation levels.

Shark species present in Cayman are very slow growing, mature late (5-7 years old), have long gestation periods (about one year) and only have a few pups (three to six) per litter  which make them ecologically vulnerable to fishing pressure and it will take a long time for populations to increase.

Q: Is shark protection a concern in Cayman?

A: Cayman’s sharks are protected through the network of Marine Parks and the shark protection measures as part of the National Conservation Law.

This means it is prohibited to catch, take, kill or harass sharks in any form within national waters.

Despite this effort no fishing gear is 100% selective and accidental catch of sharks still occurs of which some end up dead either on the line (some species do not survive the pressure change when they get caught deep and get pulled up to the surface) or post release (due to stress and/or injuries).

We do get reports of dead sharks throughout the year and are constantly reminding the public to release sharks as fast as possible (remove the hook or cut the line) to increase the chances of the animal surviving accidental catch.

One concern is the evidence of sharks being killed or harassed on purpose; however, these are thankfully rare. Lastly, it is also illegal to feed sharks in Cayman waters to avoid the association between humans and food which reduces human-shark encounters and increases shark survival.

What advantages are there, do you think, to people diving with sharks and seeing them in their natural habitat?

Sharks are greatly misunderstood. They have an unfair reputation for being dangerous and aggressive.

They are wild animals and deserve our respect, but they are not the man-eating monsters that some media outlets portray them out to be.

Divers observe sharks off East End. – Photo: Jon Barron, Ocean Frontiers

This persistent public perception is the biggest challenge of shark conservation efforts worldwide and locally.

Diving with sharks and learning more about them can help to educate and change the public perception, which will undoubtedly help shark conservation generally.

Seeing a shark on a dive gives people the opportunity to experience and appreciate these animals firsthand within their natural surroundings.

In my experience, people are scared of the unknown; the picture that they have painted of sharks in their head is usually far from the reality.

Once people encounter a shark and see that they are not typically aggressive, as is often depicted in movies, but rather calm – some even shy mostly trying to avoid humans – people lose their fear and become admirers of these fascinating prehistoric animals.

However, it is important to note that the shark diving discussed above does not involve chumming for or deliberately attracting sharks to a particular location or, worse, having sharks associate people with food.

Sharks are encountered as a natural part of a dive on a healthy reef where sharks are not uncommon, precisely because the entire reef ecosystem is healthy; [in that way,] people can appreciate the true, passive, beauty of Cayman’s sharks.

  • Department of Environment Deputy Director Tim Austin also contributed to the answers for these questions.
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