Sea creatures that roam Trinidad and Tobago waters

While it may seem like new and strange creatures have been making their way into our waters over the past few years, this is not the case.

According to Dr Rahanna Juman, deputy director of Research at the Institute of Marine Affairs (IMA), though some sightings may be rare, there have not been any marine life that should not be in our waters.

This includes the whale shark which was seen in Peake Yacht Services marina on July 5, the bull shark that attacked a British national in Tobago in April of last year, or the pod of orcas, killer whales, spotted off Bayshore in the Gulf of Paria in October 2023.

Addressing the most recent incident at Peake’s she said the whale shark, the world’s largest fish, is commonly seen in TT as it moves between Brazil and the US state, Florida.

She said on July 9 the IMA received a report from staff at a hotel in Chaguaramas. They said the whale shark was under its jetty.

“By the time I sent out my officers and they went out, it was already dead. But people have been saying they saw it there since Sunday. When we went it was already starting to decompose, so I think it's because it started to smell that the hotel called.”

She said, because of the decomposition, the IMA could not say conclusively what caused the death but it was suspected that the whale shark was hit by a boat.

There are over 900 species of fish in TT waters but only a few are harvested commercially. These include carite, king fish, snapper, dolphin fish, grunt, jacks, and salmon. Most of these have been recorded as overexploited or fully exploited, forcing fishermen to go further out to sea to make their catch.

“It's about fisheries management. It's also about us trying to see if the other species that we have in our water could become more commercially viable. And the other thing the IMA is attempting to do is to start up a mariculture system to farm the fish.”

She explained that the idea was to have the fish spawn and grow to a certain size at the IMA before putting them in cages in the ocean to grow. This would decrease the pressure on the natural stock while providing a secondary food source.

There are also over 25 species of shark in local waters. IMA senior research officer Farahnaz Solomon said the most common were the smooth hound, sharpnose, and bigger sharks like the black tip, Caribbean reef, tiger and bull sharks.

Solomon said, “The majority of them are coastal, they are not offshore, and so they are caught by gill nets. We eat most of them.”

Apart from sharks, dolphins are often seen down the islands, and there are also pilot whales. Juman said with pilot whales, if the leader is unwell it tends to beach itself and the others follow. TT has a Marine Mammal Stranding Network comprising people from various industries, including the School of Veterinary Medicine at UWI, who look for the next leader and guide it out so the rest will follow it back into open waters or generally assist marine animals.

Sea turtles are another common marine creature found locally. These include leatherback, green and hawksbill turtles. Juman noted that while the latter two used to be common in Chaguaramas, they are now mostly found on the reefs in Tobago.

“Green turtles in particular, they feed on sea grasses, something we call Thalassia testudinum or turtle grass, because the turtles feed on it. We used to have turtle grass here in Chaguaramas, but we've lost most of it due to build development, pollution, reclamation, boats anchoring and destroying the grass if it hits the bottom, all those kind of things.”

Now there is but a sparse population of Thalassia in Williams Bay. There used to be extensive sea grass beds in the area, and in the past, she would see a lot of seahorses. It may still have them, but she has not seen them in a few years.

The only extensive sea grass beds remaining in TT is in the Bon Accord Lagoon and Buccoo Reef in Tobago. Many species live within these grass beds and in the soil.

“When you have these sea grasses, they provide a nursery for juvenile species – fish, lobster, shrimp. So you used to get all the different species of grunts and snappers, different types of shrimp and crabs. We used to get the fighting conch and murex and different types of bivalves (a type of mollusc).

“And because you have all these invertebrates in the grass bed, fish would come in to feed. So you would get things like the stingrays coming in to feed on the sea grass beds.”

She stressed the need to protect these marine habitats because if they are degraded or destroyed, the marine life there will be lost.

Coral reefs also support many marine animals, including manta rays, sea urchins and starfish. However, last November TT had one of its worst coral bleaching events as sea surface temperatures were above 29 degrees Celsius, which negatively impacted the reefs.

Corals, which are also animals, have microscopic plants in their tissues which help nourish them and give them their colour. When it gets too hot, which is part of the impacts of climate change, they expel the plants.

“We in Trinidad, there's certain things that we have no control over, like certain elements of climate change. But there are things that we have control over, like pollution.

“So when we talk about building resilience of our ecosystems, we remove the impacts that we have control over. So we put in management, we remove those impacts, we make our systems more resilient so when they have impacts from climate change, they're more likely to survive or bounce back after an event.”

Juman said the influx of sargassum seaweed was also linked to climate change, and when it comes in, it impacts local ecosystems.

She recalled that in 2015, when sargassum covered several areas in Tobago, the seagrass beds were destroyed when the sargassum blocked out the light.

Recently there was a lot of sargassum beaching in Matura. Members of Nature Seekers had to remove it so the leatherbacks could come onto the sand to nest.

“The other thing too, we haven't done much research on it but it is an issue, is that, when sargassum is out in the ocean, it's a habitat, it's a nursery, it's functioning there.

“But sometimes it becomes problematic when it comes onshore or near shore. When it comes on land, you don't know what other organisms could be coming with it.”

Another impact of climate change is ocean acidification, which will impact various sponges, corals and mollusks. Although the IMA has not done the local research on this as yet, it is monitoring the issue.

The IMA has, however, done research on alien invasive species such as the lionfish. Juman said before the lion fish, the green mussel was an invasive species. However, people started to eat it, which controlled the population, and it was eventually considered naturalised.

The IMA has been encouraging people to eat the lionfish for years and is in the process of developing a fish pot to more easily catch it. They are currently working with fishermen to test them.

The institute is also on the lookout for a coral disease called stony coral tissue loss disease, which is currently in Grenada and has decimated much of the hard coral species in the region. She said it is just a matter of time until it arrives here.

In the mangroves, there are manatees, crabs, mussels and oysters. Juman added that mangroves provide many ecological services, such as protecting the coastlines and providing nurseries for fish and shellfish. Recent information indicates they capture and store two to five times more carbon dioxide than other ecosystems in their trunks and in the sediment. If they are disturbed, the carbon dioxide is released back into the atmosphere.

With climate change, pollution and human activities continuing to impact TT’s marine environments, experts at the IMA stress that the protection and management of these ecosystems is no longer optional. It is mandatory.

From conserving seagrass beds and coral reefs to responsibly harvesting marine species and controlling invasive ones, the choices made today will determine whether these rich and diverse waters continue to sustain the country’s food security, economy and natural heritage for generations to come.