Fast Moving Coral Disease Alert on Bonaire

[rmorgan]

Over 42,000 corals treated in SCTLD crisis - Cayman Islands Headline News

A diver applies the antibiotic paste to corals around Grand Cayman (CNS): Dr Croy McCoy, a senior marine biologist at the Department of Environment, has warned that coral reefs are in crisis and th…

caymannewsservice.com

 

[scubadada]

Hi @drrich2

My impression is that the antibiotic is applied in some form of epoxy to the advancing border of infection. It remains in place and is designed to arrest the continued spread to uninfected coral by leaching out antibiotic at the site. This would not last forever but hopefully long enough the active infection burns out, leaving some healthy coral.

Personally, I have not seen longer term results, but, have not really looked. If others know more about this, please share with us.

Effectiveness of topical antibiotics in treating corals affected by Stony Coral Tissue Loss Disease - PMC

Since 2014, Stony Coral Tissue Loss Disease (SCTLD) has led to mass mortality of the majority of hard coral species on the Florida Reef Tract. Following the successful treatment of SCTLD lesions on laboratory corals using water dosed with ...

www.ncbi.nlm.nih.gov

“Since 2014, Stony Coral Tissue Loss Disease (SCTLD) has led to mass mortality of the majority of hard coral species on the Florida Reef Tract. Following the successful treatment of SCTLD lesions on laboratory corals using water dosed with antibiotics, two topical pastes were developed as vehicles to directly apply antibiotic treatments to wild corals. These pastes were tested as placebos and with additions of amoxicillin on active SCTLD lesions on multiple coral species. The effectiveness of the pastes without antibiotics (placebo treatments) was 4% and 9%, no different from untreated controls. Adding amoxicillin to both pastes significantly increased effectiveness to 70% and 84%. Effectiveness with this method was seen across five different coral species, with success rates of the more effective paste ranging from 67% (Colpophyllia natans) to 90% (Orbicella faveolata and Montastraea cavernosa). Topical antibiotic application is a viable and effective tool for halting disease lesions on corals affected by SCTLD.”

Note: the amoxicillin paste in the study cited by @rmorgan did not use epoxy as stated in my post. They tested two different bases in their study.

 

[tarponchik]

So, to apply the paste they had to touch the corals?

 

[drrich2]

From the article @tursiops linked, under the Discussion section:

"Collectively, we suggest that the results indicate slight beneficial effects of the intervention program, primarily for rare, highly susceptible species."

"Although there was little statistical support for these responses individually, the eight responses display a collective pattern suggestive of a subtle beneficial effect of antibiotic applications at the colony- and population-level."

"With these caveats in mind, it was encouraging that we detected benefits while studying the entire community, rather than just those colonies that received treatment. There are two possible mechanisms for site-wide effects: (1) only treated corals benefited from antibiotic application, but treated corals were a sufficiently large fraction of the total to make benefits detectable using a community-wide sample, or (2) treating some infected corals indirectly benefits untreated corals at the site by slowing the spread of SCTLD."

And under Conclusions:

"We showed that intervention programs using antibiotics may be a viable part of management plans for SCTLD at the epidemic stage, which complements work in Florida showing their value once SCTLD is well-established (Neely et al., 2021)."

Interesting talking points.

 

[tursiops]

So, to apply the paste they had to touch the corals?

Your point is?

 

[rmorgan]

There appears to be no touching. (In the Dry Tortugas, anyway.)

 

[tarponchik]

There appears to be no touching. (In the Dry Tortugas, anyway.)View attachment 788124

Wow, quite a machine. But how do corals survive this isolation from sea water? Aren't they supposed to breath and feed?

 

[rmorgan]

Wow, quite a machine. But how do corals survive this isolation from sea water? Aren't they supposed to breath and feed?

My first thought too. But it’s a diver’s arm, and the coral is right where it’s always been.

 

[tursiops]

Wow, quite a machine. But how do corals survive this isolation from sea water? Aren't they supposed to breath and feed?

The paste is put on the border between infected and not-yet-infected, to mitigate spreading. The still-living corals are not "isolated from sea water."

 

[tursiops]

Today in the Bonaire Reporter, June 7-June 21, 2023 year 30, Issue 12

STINAPA talks SCTLD with the public

On May 30, STINAPA biologist Roxanne Liana-Francisca led two information sessions on SCTLD (Stony Coral Tissue Loss Disease), one in Papiamentu and one in English to a total of 46 local individuals concerned about Bonaire’s coral.

What the coral is and does

Francisca began by explaining that coral is what builds the mass of the reef and can be identified as a rock, animal and plant. The coral is made up of individual coral polyps with transparent tentacles that obtain their color from algae.

Bonaire’s entire coast from the shore to 60m deep has reefs made up of hard coral, soft coral and sponges. Bonaire has 40% high coral cover while the rest of the Caribbean has less than 20%.

Coral reefs are important as they provide coastline protection from storms, homes for marine life, jobs, tourism, recreations like diving and snorkeling and food. Without the ocean’s reefs, 75% of all marine species are endangered. And the reefs are a part of Bonaire’s rich heritage.

The reefs help control carbon dioxide which has increased as a result of climate change. The coral absorbs and stores carbon dioxide turning it into food and energy through photosynthesis to grow.

SCTLD

In the past 30 years, Bonaire’s reefs have proved resilient against the massive loss of the algae controlling sea urchins, white band coral disease, black band disease, hurricanes and several massive coral bleaching events from overly warm water.

Francisca said, “As of this year, our coral had completely recovered. The first place in the world for this type of coral recovery event.”

But SCTLD is a new and major challenge. It is an unknown pathogen thought to be a bacteria and it is unclear how to test for it. One lesion can expand by 3-4 cm. (1.24 – 1.75 in) per day.

SCTLD was discovered in Florida in 2014 at the port of Miami. Currents spread the disease both north and south overtime infecting all Caribbean waters. The disease is spread through direct contact by animals, divers or the bilge water from boats.

SCTLD comes to Bonaire

In Bonaire the disease was first noticed in July 2022 on maze coral but a diagnosis was incomplete. In March 2023, SCTLD was diagnosed at Calabas Reef, 18th Palm and the Town Pier; April 2023, Bachelor Beach to Cliff and May 23, Punt Vierkant and Small Wall. Six coral species have been infected.

Francisca explained, “STINAPA is trying to flatten the curve because it [SCTLD] can’t be stopped. Our strategy is to slow it down to give us more time to try other things including some guidelines from other islands.”

STINAPA has closed dive sites north of Karpata to all motorized boats as ballast water from boats could be carriers. And there is a partial closure on Klein Bonaire.

“We have been watching the currents and how they move – convergence and divergence from Vierkant to Wekua. We are watching how water circulates. Currents between Klein and Bonaire are mostly on the surface.,, We are trying to slow this down as much as possible”, said Francisca.

The harbour is the starting point and has the most impacted areas. The disease moves much slower further away from that point.

Francisca said, “Cruise ships might play a role but they have strict ballast water regulations. Other ships are possible too.”

One guest questioned why large tankers and tugs were allowed at Bopec even though the north area is currently closed to boats.

Francisca answered saying, “Certain things are not in our control, but we keep communicating with the government.”

STINAPA’s strategies

STINAPA has treatment trials with antibiotics ongoing but are still determining which are the best coral species to treat. To date they have treated four colonies taking 10 minutes to treat one lesion or four-five in a dive.

Another guest questioned the funding for the expensive cost of antibiotic treatment. Francisca replied that STINAPA is working closely with the local government on the budget for treatment of the disease.

In July, STINAPA will begin working with Reef Renewal on genetic banking and spawning monitoring trials. Colonies with some resistance will be kept in a nursery. Spawning monitoring can help the corals have more successful reproduction.

Several participants expressed their desire to help with coral treatments or in other capacities to stop the spread. Francisca replied that STINAPA would be training people once they knew they were treating the right corals.

“This is going to take some time even if we do our part and everyone else does their part. Some corals have some level of immunity. Other islands have said they have seen some recovery in two years,” said Francisca.

What you can do now: decontaminate your gear before and after every dive, enjoy recommended dive areas, plan your dives and enjoy the green dive areas. For up-to-date information follow STINAPA Bonaire on Facebook.

Julie Morgan