Parrotfish: important coral reef keepers

Parrotfish are especially important to reef health, given the current increase in major stressors such as coral bleaching events and Stony Coral Tissue Loss Disease. Increased protection in the Caribbean region will be considered in the next Conference of parties for the Cartagena Convention (COP) meeting later this year on Aruba. 

Coral reefs provide a valuable habitat for fish and other animals. People also benefit from the many ecosystem services coral reefs provide including coastal protection, food and income from tourism and fisheries. In fact, coral reefs are one of the most important sources of income for the Dutch Caribbean islands.  

Important grazers 

Besides removing macroalgae and promoting coral settlement and growth, parrotfish are also natural bio-eroders. They produce sediment by grazing on rocks, calcareous algae and corals (less than 10 percent of their food). In this way they help recycle nutrients and produce 'sand' for (eroded) coastal areas.   

The 2014 Global Coral Reef Monitoring Network (GCRMN) report 'Status and Trends of Caribbean Coral Reefs: 1970-2012' documented quantitative trends on coral reef health over 43 years in the wider Caribbean. The report identifies that one of the major drivers of coral reef decline in the Caribbean is the overfishing of herbivores, particularly parrotfish. 

Threats 

Parrotfish thrive best in healthy coral reefs ecosystems. Therefore, these fish are subjected to the same threats as corals. This includes the negative effects of climate change, ocean acidification, pollution and diseases such as Stony Coral Tissue Loss Disease. In addition, overfishing can quickly wipe out local parrotfish populations. Studies show that reefs are healthier and have a higher recovery resilience capability in locations where parrotfish are protected. This highlights the importance of parrotfish for reefs to be able recover and regrow from these threats. 

Protecting Parrotfish 

In the Dutch Caribbean - on Aruba and Bonaire - there are local rules and regulations to protect all parrotfish. On these islands it is prohibited to catch, kill, wound, or disturb them. Luckily for the other islands in the (Dutch) Caribbean, the Kingdom of Netherlands and the Republic of France have formally submitted a proposal to include all parrotfish in Annex III of the Specially Protected Areas and Wildlife (SPAW) Protocol, a regional agreement for the protection and sustainable use of coastal and marine biodiversity in the Wider Caribbean Region. If approved during the next COP for the Cartagena Convention later this year on Aruba, this measure will provide a legal framework for the conservation of the parrotfish to ensure and maintain population at an optimal level in the Wider Caribbean. 

More information

Do you want to learn more about local parrotfish populations? Check out the following related articles: 

• Fish poop: an underappreciated food source for coral reef fishes?
• Recovery of Orbicella annularis corals from parrotfish predation
• Parrotfish key to reef survival
• The proposal to include parrotfish in the SPAW protocol can be downloaded here  (pdf: 1,8 MB) 

The Dutch Caribbean Nature Alliance (DCNA) supports science communication and outreach in the Dutch Caribbean region by making nature related scientific information more widely available through amongst others the Dutch Caribbean Biodiversity Database, DCNA’s news platform BioNews and the press. This article contains the results from several scientific studies but the studies themselves are not DCNA studies. No rights can be derived from the content. DCNA is not liable for the content and the in(direct) impacts resulting from publishing this article. 

Text: DCNA
Photos: Marion Haarsma (lead photo: Redband Parrotfish (Sparisoma aurofrenatum); Steph Wear