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.
2015 – Project Overview