Field research institutions provide a window into a deeper understanding of trends and changes across multiple spatial and temporal scales of an ecosystem. The Little Cayman facility has provided a resource for hundreds of visiting scientists and is a location where a long-term record of oceanographic and ecological data is available. Over the years, through an affiliation with NOAA, we have maintained a Coral Reef Early Warning System and we have continued to study the reef each year collecting ecological data to establish trends across the area.
CORAL REEF EARLY WARNING SYSTEM (CREWS) INTEGRATED CORAL OBSERVATION NETWORK (ICON)
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.
CREWS Buoy Technical Specifications
200WX-IPX7 Ultrasonic WeatherStation, 3-axis compass, rate gyro, 10 Hz GPS, tilt, temperature, pressure & wind
WXT536 air temperature, humidity, pressure, rainfall & wind sensor
LI-COR terrestrial light sensor mount for CB-Series data buoys
LI-193 underwater spherical PAR sensor with microamp output, requires underwater cable
EXO3 multi-parameter water quality sonde with 4 sensor ports & 1 wiper port, 10m depth sensor
EXO central wiper
EXO wiped conductivity & temperature sensor
EXO unguarded pH sensor
EXO optical dissolved oxygen sensor
Aquadopp Z-Cell 600kHz (+2MHz this provides water movement data through 13 depth ranges between 0-50ft (approx. 4 ft per cel)
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In June 2018, CCMI installed a new, modern, state-of-the-art oceanographic buoy on the north side of Little Cayman, thanks to funding provided by the Dart Foundation and the Edmund F. and Virginia B. Ball Foundation. Near real-time weather and ocean state information will be easily accessible from a mobile phone or computer. It contains a weather system and instruments to measure light (photosynthetically active radiation- PAR) and 5 instruments underwater measuring light (PAR), dissolved oxygen, conductivity (salinity), temperature, and pH. This is the first time that we are able to test for changes in the acidification of the seas surrounding Little Cayman. Ocean acidification is a major threat to biodiversity and has been linked to lower calcification rates in skeletal organisms and poor larval development. The new CREWS includes an Acoustic Doppler Current Profiler (ADCP) which will measure the movement of water traveling across the reef system. Understanding currents will help direct future work to understand the replenishment of fish and corals as they spawn near our marine protected areas.
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.
Twenty years after the first three-island surveys conducted by the team of scientists led by CCMI, researchers revisited the same sites around Grand Cayman, Little Cayman and Cayman Brac to again to capture a snapshot of the reefs and to record the trends for coral cover, coral size, fish density, fish size and macroalgal cover across the region. This 20 Year Report on the Status and Trends of the Coral Reefs in the Cayman Islands 1999 – 2018 is a brief summary prepared for our stakeholders as a profile of how the reef has evolved.
This document reports that by 2018:
- Corals have declined on average going from a ‘good’ rating with 21% cover to ‘fair’ with 17% cover in 2018.
- Total fish density (of all fish species combined) has not changed on any island and fish sizes have increased. The recent proposed increase of MPAs to 46% across the Cayman Islands should support this trend.
- Fleshy algal cover, a negative factor for coral recruitment, has increased significantly on Grand Cayman (34%-57%) and Cayman Brac (50%-64%). This can indicate nutrient pollution and that key herbivores require special protection.
- Average coral size has decreased across all three islands. Larger species are not fulfilling their growth potential. Smaller coral growth indicates the reefs are persisting, however.
- Coral which is critical to providing complexity for fish and invertebrates has declined from 21% to 15% on Grand Cayman, from 28% to 22% on Little Cayman and from 15% to 13% on Cayman Brac.
Full report available below.
2015 – Project Overview
BUILDING RESILIENCE AND PROTECTING BIODIVERSITY
Herbivorous Fish: Key to Coral Reef Health in the Caribbean
Coral reef health relies on dynamic interactions among key functional groups of organisms. Disruptions to the roles these taxa play (fish, coral and algae) can lead to changes in community structure with negative implications for coral reef biodiversity. Algae is an important food source in reef systems, but it is an excellent competitor to corals and can compromise coral larval recruitment. It has overtaken corals on many reefs, and this phase-shift from coral to algal dominated systems is problematic for the functioning of the reef system and for the people who rely on it.
Herbivorous fish keep algae in check so that corals can grow and reproduce, and this helps to keep the system in balance. This project will identify functionally important herbivores that maintain the balance between algae and corals. The outcomes will help us to understand which herbivorous species make the biggest contribution to the reefs of the Cayman Islands and how we can protect them.
This project is investigating the characteristics of herbivorous fish across all three of the Cayman Islands. This includes understanding their abundance, distribution, their diet preferences and their population connectivity in the local reef ecosystem. We are also seeking to understand the pressures these populations face, so that we can create a comprehensive biodiversity action plan that can be of use to the national government in managing these critical species.
This project has been integral in the development of education modules which are shared with education groups visiting CCMI’s Little Cayman Research Centre, with classrooms throughout the Cayman Islands and with an international audience. Relevant teacher resources including videos, fact sheets, activity sheets, lesson plans and lesson slide decks are available freely on our website.
The project is supported by Darwin Plus Initiative, which provides grants for UK overseas territories that are rich in biodiversity, Alexandra Bancorp Limited, the Smithsonian, the Cayman Islands Department of Environment and private donors that support CCMI.