Status of Dutch Caribbean Reefs

Following the Royal Palace Symposium in the Netherlands

in December 2016, and the harsh call to action by Professor

Jeremy Jackson (Scripps Institution for Oceanography) that,

if drastic action is not taken to protect them, our coral reefs

could disappear within the next 15 years, DCNA has spent the

past year collecting and collating all the available information

on the status of coral reefs in the Dutch Caribbean. This Special

Edition of BioNews, containing reviews of the status of coral

reefs on Bonaire, Curaçao, Saba, Saba Bank, St. Eustatius and

St. Maarten, is the result of that work.

 

Coral reefs in the Wider Caribbean Region have suffered considerable

declines in health and abundance in recent decades with

serious declines in benthic coral communities and shifts from

coral to macroalgae dominated reefs. Coral reefs in the Dutch

Caribbean are not immune to regional trends and the effects of

global climate change and are also showing signs of distress.

 

Bonaire and Curaçao’s coral reefs have long been considered

some of the healthiest and most diverse in the Caribbean.

However, research spanning the past several decades reveals

an alarming trend with reduction in coral cover and species

composition and increases in macroalgae, turf algae and

cyanobacterial mats.

 

Recent work providing the first evidence of coral reef resilience

in the Caribbean showed that, thanks to conservation measures

taken to protect Bonaire’s reefs, there have been signs of

recovery from the last severe bleaching event of 2010.

Indications of reef resilience, such as relative abundance in

juvenile reef-building coral species, have also been found on the

reefs of the Saba Bank.

 

Overfishing of reef grazers, particularly parrotfish, has been

singled out as the most damaging fisheries activity to threaten

the health of reefs. While parrotfish biomass has declined

around some Caribbean islands, Bonaire’s ban on parrotfish

catch in 2010 is proving to be a success. The average parrotfish

biomass of Bonaire’s leeward coast rank amongst the three

highest in the Caribbean, just above Curaçao which ranks fifth,

and may have helped Bonaire’s reefs recover more quickly from

the 2010 bleaching event.

 

In the Windward Islands of Saba and St. Eustatius, findings

show that the reefs are also under pressures from local, regional

and global stressors. First assessments of the status of St.

Maarten’s reef since Hurricane Irma show that the damage

from the category 5+ hurricane is significant.

 

The devastation caused by Hurricanes Irma and Maria in

September 2017 should serve as a wake up call to all of us concerned

about the future of our coral reefs and a reminder about

the potential for more and more severe weather events in the

future. Thermal stress has also become a considerable cause

for concern, with two severe bleaching events (2005 and 2010),

which caused extensive coral mortality amongst Caribbean

reefs and mounting concern in the scientific community about

the long-term impacts of ocean acidification.

 

Above all, the importance of reducing local stressors in order to

increase coral reef resilience cannot be underestimated. Local

stressors have been identified as the most significant drivers of

reef degradation throughout the Wider Caribbean, particularly

overfishing, introduced species, coastal development and

pollution associated with increases in tourism visitation and

local populations. The resulting increases in eutrophication and

sedimentation are highly detrimental to coral reef health.

 

The need to increase the resilience of our coral reefs has

never been more pressing. Coral reefs are marine biodiversity

hotspots that are not only invaluable for coastal protection but

also have a high economic value through associated tourism

and fisheries. Our islands are particularly dependent on the

health of the coral reefs due to our economic dependence on

nature-based tourism.