Last week, the Flats Ecology and Conservation team downloaded data from a large-scale passive acoustic telemetry array designed to track bonefish to their pre-spawning aggregations. A total of 61 receivers were placed around Eleuthera to track the movements of 39 bonefish and 14 barracuda that were implanted with acoustic transmitters. The research team downloaded key receivers and found schools of bonefish moving over coral reef habitats at night near tidal creeks on the East coast of Eleuthera, indicating that these fish may move offshore to spawn on the windward side of the island. Stay tuned for more updates in June.

As a bonus, while collecting receivers the team got to swim by several Elkhorn coral (Acropora palmata) colonies, an IUCN-listed critically endangered species. Elkhorn coral grows rapidly, providing significant structure and habitat for reefs throughout the Caribbean, though it is in severe decline as a result of coral bleaching, predation, storm damage, disease, and human activity. Though it was heartening to see so many healthy colonies of this critically endangered species, they are small compared to the large stands of dead elkhorn that used to thrive in the area. Our reef restoration project has begun mapping these areas and will be monitoring its growth.

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The Reef Ecology team has already begun the process of analysis, and Jocelyn was able to present some of these preliminary findings at the Bahamas Natural History Conference in Nassau earlier in the month. By continuing to spread and enhance the local knowledge within Eleuthera and beyond, the management of the lionfish will hopefully continue to grow.

Of the 16 patches that have been surveyed throughout the study, 8 have been designated as removal sites, and with a highly experienced team we were able to continue our contribution to the culling effort around The Bahamas and wider Caribbean. Stay tuned to hear the full results of our study and a more detailed picture of how the lionfish is making its presence felt around Southern Eleuthera. In the mean time don’t forget, You Slay, We Pay!

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This January, the Shedd Aquarium research vessel, The Coral Reef II, travelled to Long Island, to historical spawning sites, with a representative of The Cape Eleuthera Institute on board, to assist Dr. Stump with her research. Throughout the week-long journey, the researchers on board performed dive surveys to quantify spawning stock size at one specific site.  Unfortunately, very few Nassau grouper were aggregating at the site during the times of the surveys; at most 20 were noted on one survey. Illegal fishing was occurring at the time the vessel reached the site, which could explain the decreased abundance of the grouper. Poor weather conditions prevented the researchers from performing surveys on the night of the full moon, so it is unclear if numbers increased during the spawning event. 

Throughout the trip, amidst the dive surveys, Nassau grouper were  implanted with transmitters. These transmitters track the movements of the Nassau grouper from the spawning sites back to their original habitat with strategically placed receivers, in efforts to understand where they come from and how far these fish travel to these spawning sites. At the spawning site, the five receivers were extracted and replaced with new receivers. The data from the receivers showed the movements of the Nassau grouper which will add to Dr. Stump’s dataset. Blood samples were also collected from these fish for Krista Sherman from Exeter University, who is using this blood to look at hormone levels and ways of determining sex of grouper non-invasively.

Although the weather failed to cooperate, four fish were implanted with transmitters which will help provide data for the upcoming spawning period, and the receivers have provided Shedd Aquarium with useful data.

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CEI’s Flats Ecology and Conservation Program is currently studying the spawning migrations of bonefish, which support a catch-and-release flyfishing industry worth over $141 million annually in The Bahamas. To view our most recent publications on this economically important species, please visit our website www.ceibahamas.org. 

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Previous research indicates that bonefish migrate up to 80 km from shallow flats and tidal creeks to deeper water to spawn during the full and new moons. At these locations, bonefish gather in schools of hundreds to thousands of fish, forming spawning aggregations. To date, migration corridors and spawning aggregations have been located in South Eleuthera, Abaco, Andros, and Grand Bahama, and this information was used to create national parks on Abaco and Grand Bahama. The purpose of this telemetry study is to identify bonefish spawning aggregations and migration corridors around the island of Eleuthera.  Information generated by this research can be used by the Department of Marine Resources and BNT to designate marine parks on Eleuthera, which will help The Bahamas meet the goal of protecting 20% of their marine environments by 2020.

 With the assistance of Dr. Karen Murchie (COB), Christopher Haak (University of Massachusetts Amherst), Dr. Liz Wallace (FWC), and Dr. David Philipp (FCF), 61 VEMCO acoustic receivers and 25 transmitters have been deployed around Eleuthera. Transmitters were implanted surgically into 25 anesthetized bonefish that were released at their capture location after fully recovering from the procedure. The receivers act as underwater listening stations, recording the date and time of any transmitter-implanted fish that swim past them, allowing researchers to locate migration corridors and spawning aggregations. This research would not have been possible without the support of local guides and businesses. Specifically, Zev Waserman of Rainbow Inn hosted the team for several days of fieldwork in North Eleuthera, and Manex Newton (Coco Loba Tours) and Denny Rankine (Eleuthera Island Fishing) provided boats and guided the team around Bottom Harbour and Savannah Sound, resulting in the successful tagging of 6 bonefish. The team plans to deploy 15 more transmitters by the end of January.

This study will track bonefish spawning movements around Eleuthera for the next three years. Contact georgianaburruss@islandschool.org and aaron.dean.shultz@gmail.comfor more information or to support our research efforts. Stay tuned for another update this spring!

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On the seashores of The Bahamas, it is common to see conch middens, or large piles of discarded conch shells. When fishermen return from their fishing trips, they take the fleshy meat from inside the shell and then throw that shell away. Recent conch shell midden data shows a significant increase in the harvest of juveniles. In South Eleuthera, 49.2% of the conch shells in one local midden are characterized as juveniles (lack of a flared lip).There has also been a significant decline in the number of adult conch mating aggregations in South Eleuthera.

Understanding if there is still an important juvenile conch nursery in South Eleuthera will help determine the current status of this economically and ecologically important species. Using methods created by researchers at the Shedd Aquarium, snorkelers are towed behind a boat on a manta-tow board with a Gopro attached. Images are taken continuously to document the number of conch, life stage and habitat type throughout the tow. The images are then pieced together to create a visual map of the tow. This methodology allows a rapid, accurate assessment of conch, and also documents the habitat types conch are being found in. The depths and temperature are also recorded for each tow.

During many of the surveys,  only a small number of queen conch were observed, and in some tows no conch were found. But, recently, a high density of juvenile queen conch was discovered. These findings could help inform future sustainable harvesting strategies and conservation management for queen conch.

Our partner, the Shedd Aquarium, have a research team that is currently conducting further research to investigate the dispersal of conch eggs throughout the oceans currents. This further research is vital for understanding the full life cycle of queen conch and the locations of important habitats for this species.

We recommend that you only harvest conch with a fully flared lip with at least a 15mm thickness. This is when conch is considered sexually mature and can reproduce. It is important that species are able to reproduce before they are harvested, otherwise populations will most likely crash and possibly become endangered or even extinct.

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To keep the coral as healthy as possible, the team carried out a deep clean, which involves brushing off any smothering algae that can cause coral mortality. Unfortunately, bleaching was seen in several fragments; bleaching is characterised by the coral turning white. This occurs when the algae that lives within corals are expelled due to stress.

One of the main reasons for this increase in stress is a rise in water temperature. We could be seeing a large increase in bleaching because this is an El Niño year. NOAA has declared this year a major bleaching event, only the third major bleaching event on record.  The first global bleaching event was in 1998, during a strong El Niño that was followed by an equally strong La Niña. A second one occurred in 2010.  El Niño years are characterized by changes in upwelling. Upwelling of cold currents is replaced by warmer waters and increases sea surface temperatures. With this in mind, we will keep closely monitor the nursery, and we hope to see continual growth during the next check, despite the El Niño warm waters.

Here is a link to a time-lapse video of the team cleaning the coral nursery!

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As part of a long-term project, PhD student Alex Davis, and her field assistant, Kristian Dzilenski (from the University of Rhode Island), observed the home ranges of lionfish on large reefs in order to understand whether different types of habitat affect whether lionfish frequent certain areas of a reef and/or leave a reef altogether.  In addition to this continued monitoring, she added an observational and experimental study on the bicolor damselfish (Stegastes partitus) and their interaction with lionfish.

This study was comprised of three components. First, she mapped the location of and tracked growth and abundance of bicolor damselfish on the same large reefs where she monitored lionfish movement. Second, she placed small PVC tubes with tracing paper inside of them called “Tunnels of Love” (TOLs) on the reefs, which allowed her to monitor egg production of the damselfish and determine if proximity to lionfish influences egg production. Third, she conducted a “model bottle” study to see if lionfish affect damselfish behavior.  Each damselfish was exposed to an invasive lionfish in a clear plastic bottle, an empty bottle (for control), and a native predator, egg predator, and food competitor, each also in a bottle. The behavior of the damselfish was recorded, and a comparison of how the damselfish react to the lionfish versus the native fish and empty bottle will help us understand if damselfish see lionfish as a potential threat.

Lillian Tuttle is another PhD student from OSU, who visited CEI for 5 weeks this summer.  Last summer she discovered that invasive lionfish will eat cleaner gobies, small but ecologically important reef fish that pick parasites off of other fishes.  But when lionfish eat cleaners, the lionfish hyperventilates as if it ate something super spicy!  She conducted a lab experiment that discovered that lionfish quickly learn to avoid the cleaner goby, meaning that this goby is one of remarkably few native fish that lionfish WON’T eat!  But what about native predators?  Must they also learn not to eat the cleaner goby, or are they born with an innate understanding that cleaners are friends, not food?  Lillian returned to the lab and found that native graysby grouper will eat the cleaner goby and hyperventilate, just like the lionfish.  But graysby are slower learners than lionfish, continuing to strike during subsequent exposures to the goby.  With these kinds of friends, who needs enemies?  It’s no wonder the goby has evolved a defense to makes them distasteful!  Now Lillian is collaborating with chemical ecologists to identify the toxin that makes her gobies “spicy,” and she plans to defend her PhD in June 2016.

We wish the both Alex and Lillian a fond farewell and the best of luck with their Ph.D. write ups!

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Located 90 feet deep near the wall of the Exuma Sound, the Cage serves as an aggregation spot for large marine creatures. Many fishermen frequent the area to catch large jacks, snappers, and groupers attracted to the cage.

Within minutes, a well-known large black grouper, affectionately named Bradley, approached the divers. Bradley came quite close to the group, turning and showing multiple hooks, wire leaders, and weights hanging from his jaw and gills. He moved in closer as Kelly Hannan, a University of Illinois graduate student, took out a pair of scissors.

Bradley investigated the scissors and seemed to decide that Kelly was not a threat. He let her cut off two feet of tangled wire leader and three fishing weights that were hanging from the right side of his mouth. Unfortunately, the scissors were not strong enough to cut the hooks out, but the team hopes to return to the Cage with wire cutters to remove them from Bradley’s jaw in the near future.

Bradley seemed to understand that no harm would come to him from these divers and was very calm throughout the procedure. He continued to follow the divers throughout the rest of the dive.

Later that week, at the same dive site, the Flats team removed over 50 feet of fishing line from a nearby reef. Another wire trace with lead weights was picked up near the base of the Cage.

Although these dives had positive outcomes, they serve as a reminder of the impacts of fishing pressure and pollution on the marine environment. Thanks to Bradley, we had a very personal reminder of our relationship with the ocean and how our actions can affect the lives of the creatures that live in it.

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During March 2014, CEI installed a coral reef nursery at Tunnel Rock in collaboration with the University of Miami RSMAS and NOAA’s Atlantic Oceanographic and Metrological Laboratories and CEI Research Manager Annabelle Brooks. In the face of rapid coral population declines, growing coral through nurseries has been an initiative to replenish wild coral. The team measured the growth progress and refragmented the coral that has been steadily amassing at CEI’s nursery.

Fragmentation of coral refers to splitting of coral to help increase coral colonies and therefore increase reproduction. Half of the fragments were re-attached to the coral nursery at Tunnel Rock, and the other half were set up at a new nursery site closer to The Island School.  This summer, the team will compare the growth and survival rates of the coral at these two different sites. The long-term goal is to transplant the coral frags out on the reef.

This summer the team is also being kept busy with the success of the Slayer campaign and has filleted over 150 pounds of lionfish- and has over 200 lbs to do! Over the past couple of weeks, a few local fishermen have delivered hundreds of pounds of lionfish for CEI’s “You Slay, We Pay Campaign.” These lionfish are also dissected to examine gonad development and stomach content, which can offer important insight on the invasion impacts.

Additionally, the team prepared for parrotfish behavioral research this summer. This prep has involved dive teams using a herding technique to catch the juvenile parrotfish, as well as setting up raceways in the lab to conduct a feeding behavior experiment.

A few other exciting events include three of the reef interns completing their Advanced Diving Certification and starting on their Rescue, as well visit of a teenager Earthwatch group who assisted with research for a week.  Additionally, working with The Island School students to sample inland ponds and dissection lionfish was great fun.  The whole team is pumped for the rest of the summer and getting much more achieved.

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