Healthy Reefs

Long Term Records to Strengthen Our Understanding of Coral Resilience

Coral reefs are the largest mass of construction workers on the face of the earth. They are natural architects in the shallow sea but only remain productive when juvenile corals are able to survive after recruitment onto the reef. At every dive location on the reef around Little Cayman, we see evidence of recruitment. This is a good sign for the future.

Using the AGRRA, Atlantic Gulf Rapid Reef Assessment protocol and collecting additional recruitment data, this project investigates the potential for juvenile corals to survive and replenish the local reefs. Results from this work will help generate an understanding of the mechanisms that are driving reef resilience.

AGRRA data on the benthic habitat and fish populations surrounding Little Cayman has been collected regularly since 1999. As CCMI researchers continue to collect this data annually, notes, reports, and peer reviewed journal articles are available online to scientists, policy-makers, and the general public. These surveys document patterns of local change over the last two decades and enable regional comparisons through the Healthy Reef Framework developed for evaluating the Mesoamerican Barrier Reef.

Key Results from the latest Little Cayman Reef Report Card (released 6 June 2021):

• In August 2020, the surveyed reefs were in a period of recovery, with their health status improving overall compared to 2019.
• Of the reefs surveyed, 27% were in “very good” health in 2020, versus only 16% in 1999 and 17% in 2010.
• At the bottom end of the health spectrum, we had no surveyed reefs listed as in “poor” health, and only 18% of the reef classified as “fair”, compared to 36% the year before.
• Composition of the coral community on the reef has shifted over time, from reefs dominated by massive boulder corals, such as Orbicella spp., to smaller corals such as Agaricia spp. and Porites spp.
• The size of corals surveyed has decreased overall, which may indicate that the reefs are less structurally robust and capable of providing some of the important services we depend upon them for, such as storm protection and complex habitats for a variety of marine life.
• There is a cyclical pattern of decreasing and increasing coral cover from 1999 to 2020, which may represent periods of disturbance, recovery, and recruitment. However, the current trend is towards increasing abundance, which suggests the reefs of Little Cayman are in a period of recovery.
• There was a gradual, significant decline in the percent cover of algae on the reefs in Little Cayman from 1999 to 2020.
• Fish abundance has increased overall since 1999, indicating a rebounding fish population.
• Little Cayman’s coral reefs show positive traits of resiliency, with continued high coral and fish abundances.
• Shifts in species contributions and colony size indicate that while coral cover remains high, Little Cayman is not immune to human impacts and global climate change.

Full report card available below.

2021- Little Cayman Reef Report Card

2020- Coral Reef Resilience Over Two Decades at Little Cayman Island | Reef Report Card

2019- 20 Year Report on the Status and Trends of the Coral Reefs in the Cayman Islands 1999 – 2018

2015 – Project Overview

2013 – A Positive Trajectory for Corals at Little Cayman Island

2007 – Coral community decline at a remote Caribbean island: Marine no-take reserves are not enough

2003 – Status of coral reefs of Little Cayman, Grand Cayman and Cayman Brac

The CREWS provides CCMI with the opportunity to be at the forefront of coral reef science because it offers near real time information on the ocean environment around the robust reefs of Little Cayman. The project is led by the United States National Oceanographic and Atmospheric Administration (NOAA). CREWS gets its name from its success in modelling and alerting impacts on coral reefs from climate-related events such as, coral bleaching, seasonal upwelling, or approaching storms. This system is considered part of a NOAA Integrated Coral Observing Network (ICON) and is thus named ICON/CREWS.

The CREWS buoy system uses local information about weather and marine conditions that is continually gathered by a series of monitoring stations and buoys located across the Caribbean Sea as well as worldwide. The data is transmitted in real-time to NOAA for integration and analysis, while also being made available online to researchers, policy-makers, and to the public. ICON uses the data collected by CREWS in conjunction with satellite data and radar technologies to analyse and forecast regional oceanographic and atmospheric trends. The CREWS system has been successfully used in modeling and alerts of coral bleaching conditions both locally in the Cayman Islands and the Caribbean Sea. Over time, it is NOAA’s intent to expand the CREWS system by installing stations in more geographic regions and to further refine the systems capability to better predict the impact of climate patterns on coral reefs.

Originally installed in 2009, this monitoring location gave CCMI, the Cayman Islands, and the general public access to real-time weather information and records of local climate patterns over time. In October 2012, Hurricane Sandy unfortunately damaged CCMI’s monitoring system beyond repair. Almost one year later, a more rugged and robust monitoring buoy was installed in its place and remained in place until 2017, when recurring communications issues required it to be replaced.