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coral

Coral and Hurricane Matthew

As Hurricane Matthew made contact with the Bahamas in early October, it brought with it many threats of damage and devastation. The Cape Eleuthera Institute (CEI) was extremely fortunate in the sense that Matthew did not hit as hard as expected, but still the storm left its fair share of destruction. Coral reefs offer numerous benefits to ecosystems; one of these being that they can dissipate the power of storm waves generated by hurricanes and therefore lessen the blow of terrestrial damage. However, this absorption of wave energy does not leave the reefs unimpaired. During large storm systems such as hurricanes, corals are susceptible to fragmentation. Fragmentation is a negative effect in the sense that it can cause some stress to the coral, but on the other hand it can be a positive event because some coral species, such as Elkhorn coral (Acropora palmata) and Staghorn coral (Acropora cervicornis) use fragmentation as a form of asexual reproduction. That is, a new colony can grow from a fragment of the parent colony. Scientists across the Caribbean, including here at CEI, are using this method of growth to create coral nurseries which grow fragments to be outplanted onto damaged reefs.

Island School students aid in the monitoring and upkeep of our coral nurseries. In the above photo, students are measuring Staghorn coral (Acropora cervicornis) in order to track its growth rate. (Photo_ Brittany Munson)

As CEI continues to focus its research on the endangered Elkhorn coral (Acropora palmata) in the wild, the Coral Team went out to assess the toll Hurricane Matthew had on our local reefs. As expected, there was a decent amount of fragmentation found at Bamboo Point, where there was a large colony of Elkhorn coral with evidence of recent storm damage. Some fragments seen nearby were due to Hurricane Matthew whereas others were older and likely produced by past events. It is CEI’s hope that the newly-formed fragments will proliferate to form new colonies.

This photo displays some recent fragmentation of Elkhorn coral (Acropora palmata) caused by Hurricane Matthew. This fragmentation occurred at Bamboo Point, a site near the CEI campus. (Photo_ Reilly Edgar)

In addition to fragmentation, hurricanes have been shown to relieve thermal stress. By mixing the water column and bringing water temperatures down, storms can once again restore favorable thermal conditions and allow coral the chance to recover from bleaching events. As climate change continues and sea surface temperatures rise, coral bleaching events have become more prevalent as the coral’s symbiotic zooxanthellae are expelled. Due to a number of stressors including climate change, overfishing and pollution, coral are increasingly vulnerable. Major storm events are beneficial only once in a while, but if there are too many large storms too often it not only makes the environment uninhabitable for corals, but also can permanently damage reefs that are already existing at the upper limits of their stress tolerance.

As the 2016 hurricane season comes to an end, CEI will continue its monitoring and restoration efforts of Eleuthera’s reefs in the hopes that we can continue to enjoy the many benefits they provide!

CEI and SECORE document critically endangered coral spawning

SECORE (SExual COral REproduction) International arrived at the Cape Eleuthera Institute last month for a week of research focused on coral spawning. SECORE is a non-profit organization dedicated to the restoration of coral reefs using wild coral spawn, lab-based fertilization and breeding techniques and outplanting methods. Led by Dr. Dirk Peterson (founder and CEO), Christoph Haacke (BioDivers, Germany), Mark Schick (Shedd Aquarium, USA), and Mitch Carl (Henry Doorly Zoo and Aquarium, USA), the SECORE team believes that in order to rehabilitate degraded reefs, increasing coral survival, diversity and abundance through lab-based breeding techniques is essential. Dr. Peterson began his innovative coral breeding techniques in 2002 by fertilizing coral spawn and raising larvae in a lab. The coral restoration community took notice of his successes, and SECORE has since led projects in locations such as Guam, Mexico, Curaçao, and The Philippines. With reversing the decline of coral reefs a national priority in The Bahamas, SECORE aims to bring its expertise here to Eleuthera, in partnership with CEI, to help with rehabilitation and restoration efforts. image1

The focus of SECORE’s work in Eleuthera is Elkhorn coral (Acropora palmata), a critically endangered species. Elkhorn coral spawning has rarely been documented in The Bahamas, but is known to occur elsewhere in the Caribbean after sunset, during the days following August full moons. As the week-long workshop began, SECORE aimed its efforts on diving after sunset in high-density areas of Elkhorn coral in hopes of not only documenting the exact timing of the annual spawning event, but also collecting egg and sperm for fertilization back in the lab. To the group’s delight, the timing was perfect. SECORE and CEI documented Elkhorn coral spawning in Eleuthera for the first time! In addition, SECORE collected approximately one to two hundred thousand eggs from four different coral colonies that spawned simultaneously.

Various brooding corals collected to obtain coral larvae. The species are Undaria humilis and U. agaricites.

To ensure ample genetic diversity among corals fertilized in the lab, SECORE collects eggs and sperm from multiple Elkhorn coral  colonies. This diversity is  essential for the survival of this endangered species, which can be threatened by a genetic bottleneck as populations decline. Once SECORE induced fertilization, larvae were placed in a breeding chamber for development. Live rock similar to that upon which wild coral larvae attach on natural reefs was introduced to the tanks, allowing lab-reared corals to become established as would their wild counterparts. CEI’s and SECORE’s collaborative goal is to give juvenile corals a head-start by providing a predator-free, controlled environment where survival is enhanced during critical early growth stages. Once juveniles have survived in the lab beyond those critical early stages, they will be strategically out-planted onto local reefs in an effort to rehabilitate areas where Elkhorn corals are in decline.

Coral reproduction workshop led by Dr. Dirk Peterson from SECORE International. Here, various scientists and conservationists are collecting brooding coral larvae from individual tanks to be observed under the microscope!

Many thanks to SECORE International for educating scientists, students and conservationists on site during the visit, and for its continued work to rehabilitate populations of essential, reef-building corals not only in Eleuthera, but throughout the Caribbean.

Coral reef survey techniques workshop help at CEI

On August 20th, Dr. Craig Dahlgren from The Perry Institute for Marine Science Laboratory arrived at CEI along with more than 20 scientists and conservationists from around the Bahamas and United States to  learn how to conduct reef surveys.  The protocols focused on those developed for Atlantic and Gulf Rapid Reef Assessment (AGRRA). Formed in 1998, AGRRA assesses key attributes of coral reefs in the Caribbean using a standardized protocol leading to valuable regional surveys of coral reef health in an online database. AGRRA surveys incorporate coral, benthic and fish species. For this workshop participants were trained in either coral or benthic surveying, in order for each surveyor to be properly specialized, resulting in the highest quality data. Surveys were conducted at the few Eleutheran reefs left with Staghorn coral, an endangered species in the Caribbean (Photo C. Dahlgren).

Data collected during AGRRA surveys is used to create Coral Reef Report Cards. Eleutheran reefs have never been surveyed using AGRRA protocols and therefore there has been a knowledge gap for this area.  Some of the workshop participants were already AGRRA certified and conducted official surveys around South Eleuthera right away, while others began the training needed to conduct the surveys, led by Dr. Dahlgren.

Elhorn coral colony (Photo C. Dahlgren)

The week-long training included diving and practicing survey methods out on the reefs as well as classroom time learning and identifying species of coral and algae. Members of CEI were also included in the training in order for AGRRA surveys to be carried out all around Eleuthera in the future to fill knowledge gaps and help advise marine resource management decision-making.

A coral survey is conducted, identifying, measuring, and assessing health of species found along the reef (Photo C. Dahlgren).

Participants involved in the surveying and training included members from The Bahamas National Trust, Bahamas Reef Environment Educational Foundation (BREEF), The Nature Conservancy, The Bahamas Environment, Science and Technology Commission, Disney Conservation Fund, , Stuart Cove’s Dive Bahamas, Perry Institute for Marine Science, Atlantis, Ocean Crest Alliance, , Greenforce, Forfar Field Station, and Young Marine Explorers. After a busy week everyone was an official AGRRA surveyor and many surveys had already been conducted on the nearby reefs!

Participants from organizations all over the Bahamas joined us.

Stay tuned to hear more about the workshop conducted by SECORE International involving these participants that combined with their AGRRA training during the week.

 

Operation Wallacea student investigates growth rates at the CEI coral nursery

Over the course of six weeks, Natasha Webbe of the University of Leeds, a student representing Operation Wallacea, has been working with the Cape Eleuthera Institute to study the success of the coral nursery set up in Cape Eleuthera. This will be determined by studying staghorn (Acropora cervicornis) and fused staghorn coral (Acropora prolifera) growth rates in relation to the environmental conditions surrounding the coral restoration nursery installed near CEI in March 2014 in collaboration with the University of Miami. University of Leeds undergraduate student Natasha Webbe by the coral nursery at Tunnel Rock

Coral reefs are extremely important worldwide as the most biologically diverse ecosystem, providing essential goods and services. The Bahamas, in particular, are dependant upon coral reefs to support their fishing industry through the habitats they provide. Acropora cervicornis is a major coral reef building species however have been classified as critically endangered by IUCN’s red list, therefore, conservation efforts are crucial to re-establishing healthy coral reefs around Eleuthera, The Bahamas, and the Wider Caribbean.

Healthy coral fragment (A. cervicornis) on the coral nursery

This project consists of measuring each coral fragment growing in the nursery and conducting data analysis on three years’ worth of data to assess growth rates at different depths of the tree and during different seasons of the year. Complexity will also be studied as fragments with higher complexity may be more beneficial for transplantation, aiding the outplanting success in the long term. Fragments are vulnerable to thermal stress due to climate change causing bleaching and the overgrowth of algae. Therefore, using an index, bleaching and algae have been recorded and can be compared with previous data to establish any significant correlations with the time of year or environmental conditions. Additional observations are recorded, such as,  Domecia acanthophora crabs which are known as the ‘Elkhorn crab’ and are good for coral nurseries. Water samples have also been taken to analyse pH and salinity as well as having recorded temperature on site to see whether any of these variables are affecting growth rates.

Domecia acanthophora on one of the coral fragments on the nursery

This research will form the basis of Natasha’s undergraduate dissertation aiming to determine any relationships between A. cervicornis and A. prolifera growth rates and their environment in the nursery. This can establish their optimum growth conditions to further improve the coral nursery as a restoration method.

Summer research focusing on critically endangered coral reef species

Elkhorn (Acropora palmata) and staghorn (Acropora cervicornis) corals are major reef-building corals found off the shores of Florida and throughout the Caribbean. In recent decades there has been a widespread decline in distribution and abundance of elkhorn and staghorn corals. Their decline is the product of compounding effects from local stressors and global factors linked to climate change including ocean acidification, sea level rise, coral bleaching, disease, and the increased severity of hurricanes. The loss of the Acropora species negatively affects the reef function and structure. This summer, McMaster University student, Heather Summers, in collaboration with Operation Wallacea and the Cape Eleuthera Institute, has been investigating the abundance and distribution of the Acroporid coral populations in South Eleuthera, Bahamas. Undergraduate dissertation student, Heather Summers, recording the habitat assessment score at one point along the transect.

The purpose of this study is to collect qualitative and quantitative observations of coral reefs for use in the development of a mathematical model that will help describe these complex marine ecosystems. The data collected includes benthic assessment, species abundance, bleaching status, and environmental conditions of temperature, pH, and salinity. At each site transects are laid out and benthic communities are assessed using habitat assessment scores (HAS) and the line-point-intercept method in order to quantify the coverage of live scleractinian coral and macroalgae. This research project also investigates the impact of predation and herbivory on coral health by recording the abundance of key fish families and invertebrates including Diadema antillarum, Scaridae, Acanthuridae, Pomacentridae, and Pterois. The information amassed by this research project can help inform decisions on coral nursery site selection and identify potential donor colonies for regeneration in the nursery.

Staghorn coral colony

Coral reefs are complex, dynamic marine biomes and their health is reliant upon many factors. This complexity makes coral reefs ideal platforms for the development, testing, and validation of mathematical models that can be used to help explain and predict the impacts of adverse conditions on Acropora health.

Elkhorn coral colony

If you spot any elkhorn or staghorn on Eleuthera or elsewhere throughout the Bahamas please report it to us! info@ceibahamas.org