SOS FOR REEFS: NAVIGATING THE CARIBBEAN’S CORAL BLEACHING EMERGENCY
A tale of resilience and distress
Marine guardians fight to save coral reefs amid climate challenges
Published:Wednesday | January 31, 2024 | 12:07 AMAsha Wilks/Gleaner Writer
At the same time when the vibrant hues of the coral reefs beneath Jamaican waters were rapidly disappearing, the small island of Tobago was experiencing the same fate.
But despite this, experts are even more grateful that an outbreak of coral reef diseases, such as the stony coral tissue loss disease (SCTLD), is not another issue that Tobago must contend with.
Since 2014, the Caribbean has been beset with SCTLD, which originated in Florida and entered the region soon after.
Dr Anjani Ganase, a coral reef ecologist at the Institute of Marine Affairs (IMA) in Trinidad and Tobago, told The Gleaner last week that she was pleased to report that there has not been any evidence of SCTLD in Tobago to date.
The National Oceanic and Atmospheric Administration (NOAA) reported in 2023 that there was “an unprecedented outbreak” of SCTLD that affected coral reefs in the Atlantic Caribbean, causing damage throughout Florida, as well as at least 22 Caribbean nations and territories, including the US Virgin Islands, Puerto Rico, and the Flower Garden Banks in the Gulf of Mexico, due to its rapid spread, and high rates of tissue loss and mortality.
The most recent data available on the outbreak of this lethal disease is dated October 2023, indicate that 34 coral species were impacted by SCTLD, which was reported to be present in 30 countries and territories.
Located in the Caribbean, southern Gulf of Mexico, Florida, and The Bahamas, the pillar coral ( Dendrogyra cylindrus) experienced the highest disease rate among the types of coral affected.
According to the dashboard that tracks SCTLD in the Caribbean – which was created by the NOAA and other partners – of the 34 countries and territories affected, only 12 possess the necessary treatments to tackle the disease. It also reported that 10 nations and territories have been involved in the rescue operations.
Jamaica was last impacted by SCTLD in December 2017. There has been no further report since.
CHANGING PATTERN
According to international reports, coral bleaching occurred across the Caribbean region, Mexico’s east and west coasts, Kiribati, Fiji, and eastern New Guinea.
Ganase stated that several reports of coral bleaching during September and October were received.
As early as May, NOAA, she said, began issuing bleaching watch warnings, one month earlier than when it would typically do so.
Ganase further noted that temperatures of 31 degrees Celsius were recorded at the surface of the sea, with shallow waters reaching up to 34 degrees Celsius, according to data loggers in Tobago last year.
Minor bleaching was noticed in August, but as time progressed, multiple species such as the brain coral ( Diploria labyrinthiformis), which is the largest species of coral in Tobago’s reefs and is highly susceptible to the disease; the mountainous star coral ( Orbicella faveolata), which is thought to be one of the main reef-building corals in Tobago; and the boulder star coral ( Orbicella annularis) were later discovered to be impacted in five of 11 sites surveyed in Tobago. This represented approximately 15 to 23 per cent bleaching.
Ganase said further that 42 per cent of corals within the western part of the Buccoo Reef – which falls within the marine protected area – were either bleached or impacted by disease.
“This site was the hardest hit, and it was mainly our brain and massive corals that were bleached,” she said.
The reef-building coral species of Elkhorn and Staghorn, which are more abundant in Jamaican waters, have not fully recovered in Tobago since the 1980s, the coral reef ecologist told The Gleaner. However, after a survey conducted on one site in October, the Elkhorn was found to have grown back and were relatively healthy.
SIGNIFICANT BLOW
Drawing comparisons with 2010 – when Tobago saw a major ocean-warming event that severely stressed the coral reefs, causing extensive coral bleaching – Ganase stated that the heatwave experienced in 2023 was more severe.
“Say we had about 30 per cent hard coral cover, we lost 50 per cent of that in the years after [2010] ... and between that die-off and now, we’re basically stuck at that level. We have not had significant recovery of the hard corals, ... which means that the facilities that assist recovery are not there ... . You would expect the reefs to naturally increase, but the chronic conditions are preventing that,” Ganase explained.
One way in which the IMA is treating with this issue is through its marine resilience initiative, which is essentially a project of intense care focused on improving coral recovery after the bleaching event. This would be accomplished by managing environmental conditions, such as restricting land clearing, fishing, and other human activities that can slow or worsen recovery; and active coral restoration.
Ganase stated that a lot of chronic local issues contributed to limiting the natural recovery of the reef, in addition to disturbances such as hurricanes and marine heatwaves.
Ganase stated that the IMA is stepping up its management practices related to bleaching and climate change events as part of this initiative as well.
Additionally, the IMA is ramping up its restoration strategies to give the corals a boost in their reproductive cycles, given that the survival rate of larvae is naturally very low, especially in Trinidad and Tobago.
“The restoration that we’re trying to do is to improve the survival of the larvae species – it’s called larval propagation restoration – instead of doing the coral farming. We are focused on the brain corals because we want to build genetic diversity of common species for the future of unknowns, thus we focus on that sexual reproduction where you have a mixing of genotypes … ,” Ganase explained.
The IMA conducts an annual monitoring of the health of Tobago’s coral reef, which is typically done in the calmer summer months.
Ganase stated that although the institute was still in the process of assessing the extent of the bleaching damage to Tobago’s reefs, she would not be able to do a determination of mortality for another couple of months.
She told The Gleaner that there is a great fear that Tobago would be playing “catch-up”, because while the island has skilled experts, it has been a challenge to get people “on board” with the management of the reef.
“[A part] of the issue is that willingness of the wider community to sort of understand the value and connect the dots on how it affects our lives and livelihoods as Caribbean islands, and have that ... political will for us to [see it] as a real issue. It’s not prioritised on a national agenda, especially with climate change. Nature is one of our best defences as it can naturally adapt, so we can learn together and reap the benefits significantly from it, but we need to take care of it,” Ganase said.
THE NEGRIL PICTURE
Over in Negril, Westmoreland, one of Jamaica’s popular tourist destinations, Reanne McKenzie, executive director of the Negril Environmental Protection Trust (NEPT), is advocating for greater collaboration to address this regional issue.
In an interview with The Gleaner, she urged the National Environment and Planning Agency, other sanctuaries, and major stakeholders to help restore Jamaica’s reefs, preserve the corals that are still alive, and develop a plan that will guarantee the sustainability of the interventions put in place.
“We’re really at a point where we’re kind of frantic about what to do, because it would make no sense to continue doing exactly what we’re doing when 2023 has proven that it can be lost so quickly,” she said.
Jamaica has been battling with coral bleaching and coral diseases, such as the black-band disease, white-band disease and the SCTLD, simultaneously with the bleaching for several years now, McKenzie said.
She pointed out that there is still evidence of significant bleaching occurring at the Negril Marine Park and the corals have not recovered.
McKenzie said that typically by January, the corals would have shown an indication of regaining colour, but this has not been the case this year.
“We in Negril, we have a pretty hard road ahead of us in terms of restarting our coral nursery,” she said, noting a 100 per cent loss due to bleaching.
She said that the fishermen noticed the changes and are worried about the potential effects on their livelihood. Also concerned were the tourists, who participate in water sports and have seen that “something is wrong”.