Dr. Mark Hixon’s PhD students from Oregon State University returned to CEI for a fourth summer of invasive lionfish research.
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!
Deep-water sharks are slow growing, slow to mature, and have a relatively small number of young, and as a result are extremely vulnerable to human-based disturbances. This, coupled with the migration of commercial fisheries from coastal to deeper waters, has resulted in large population declines in a number of deep-water shark species. Similar to their coastal counterparts, deep-water sharks are assumed to exert important top-down control on deep-sea communities, and, as a result, their behavior plays a particularly important role in influencing healthy ecosystem dynamics.
In order to further understand their ecological role and inform constructive management and policy, it is critical to assess the unique behavioral characteristics of these poorly understood elasmobranchs.
This semester members of the Shark Research and Conservation Program have been working diligently in collaboration with Microwave Telemetry to explore and uncover some of the mysteries behind the behavior of deep-water sharks. This particular study, led by Research Assistant and recent MSc graduate Oliver Shipley, aims to assess the daily vertical behavior of common deep-water sharks in the Exuma Sound via satellite telemetry.
In order to assess movement patterns over a 24-hour cycle, animals are captured via demersal longlines (lines that sit on the ocean floor) and hauled to the surface using an electronic pot-hauler. These movements are assessed by attaching X-satellite tags (Figure 1), (measuring time, temperature, depth, and light) to the dorsal fin of animals deemed large enough to carry the tag without impairing movement. X-tags measure high resolution (every two minutes) data over a 14-day period.
Once tagged, animals are then placed into a newly designed release cage (Figure 2), in order to prevent predation by larger sharks during descent. Once the cage reaches the sea floor, a weighted door opens, enabling the shark to safely swim out. After the two week tracking period, a release mechanism causes the tags to pop off and rise to the surface, transmitting the data to an Argos satellite prior to analysis. Continue reading →
Three months ago, the Cape Eleuthera Institute (CEI) welcomed back Simon Fraser University (SFU), and their 2015 field team of seven researchers. Based in British Columbia on the west coast of Canada (with two more collaborators joining them from the University of Bristol, UK), they made the trip down to Eleuthera to continue their research on various aspects of the lionfish invasion in The Bahamas. From acoustics to nutrient dynamics projects, the summerwas a dynamic one for SFU, filled to the brim with scientific escapades. And the most important thing they’ve learned? Every problem can be solved with cinder blocks and cable ties.
May kicked off with an exciting collaboration between the SFU team and Brendan and Sophie Nedelec from the University of Bristol that delved into the effects of lionfish on the acoustics of a coral reef – are reefs with lots of lionfish perhaps quieter than those with fewer or no lionfish? To tackle this question, the team needed more than keen eyes, and their ears certainly weren’t sharp enough to pick up on any differences. Sophie and Brendan came down equipped with a hydrophone, accelerometer, DJ-like switchboard, and a lot of cords that were loaded onto the boat and brought out to patch reefs to take sound recordings during the day and at night (when lionfish are typically hunting). Continue reading →
Congratulations to CEI Director Aaron Shultz! He successfully defended his doctoral dissertation on “Responses of Subtropical Nearshore Fishes to Climate Change” at the University of Illinois, Urbana-Champaign, with Dr. Cory Suski as his lead advisor.
Aaron’s research focused on how climate change stressors affect fish in nearshore ecosystems. These ecosystems are important nursery and foraging grounds, but there was insufficient knowledge on how fish in these areas will react to the predicted increases in temperature and carbon dioxide.
The Slayer Campaign has been a huge success at the Cape Eleuthera Institute this year, and we’re well on our way to setting a new record for the total catch this season. The initiative provides the perfect opportunity for local fishermen, while also removing invasive lionfish from the reefs. Here at CEI we always make sure the fillets are passed on to our kitchen staff so that the taste can be shared throughout the community.
The true spearing skills of our local fishermen were recently highlighted by the size of one lionfish in particular, whose total length reached a rather impressive 44 cm. You may remember we recently set an official record here at the Cape Eleuthera Institute with a 42 cm fish. So, when this new record breaker was laid before us on the dissection table, we decided to submit the numbers (and photo to prove it!) to the wider international community of fellow lionfish slayers. We can now proudly announce that our own 44 cm lionfish is the new official record for the whole Bahamas. Great work Dennis Johnson and Leonardo Butler for slaying this fish!
If you’re curious, the world record is currently held at 47.7 cm, so we’re not too far behind! Check out the Lionfish.co website for more details.
On Friday 18th September, Dr. Owen O’Shea of the Shark Research and Conservation Program along with Shark Program intern Amanda Billotti and Educational Program leaders, Anna Zuke and Lydia Geschiere made the trip to Spanish Wells’ All Ages School to deliver a workshop to 36 students from 11th and 12th grade as well as their teachers. This was the first time that CEI scientists have visited this tiny fishing community off the north coast of Eleuthera to share the exciting work we do here. During the workshop students were given presentations about the evolution ecology and importance of rays and sharks, particularly in Bahamian waters lead by both Dr. Owen O’Shea and Amanda Billotti. One of the main themes touched upon was the importance of these ancient animals as economic resources in The Bahamas; discussing how a living shark or ray is of greater value as a tourism tool, then a dead one at market.
The students then participated in group discussions where they were able to collaborate amongst themselves to demonstrate and share what they had learned. Four key concepts were randomly assigned to each of four groups, and the CEI team mentored a group each, before a student from each team presented their groups responses to the class – these topics included discussing the ecological role of these animals in marine ecosystems and global challenges to the conservation of these animals.
CEI research teams in collaboration with the Educational Program team are striving to increase outreach to other communities on Eleuthera. Each month will see representatives of the Shark Research and Conservation Program travel to a different school to deliver interactive workshops and discussion with students about these most valuable of marine resources.
CEI and team EP aims to continue to promote internship opportunities to Bahamian students, and this was warmly received by all of the students we interacted with last week.
While all visiting groups are special to us here at CEI, certain ones touch our hearts in unique and unexpected ways. Akhepran International Academy, visiting us for the first time from Nassau, was one group that made a big impact in their short time with us.
On Monday August 24, 10 students along with 2 teachers arrived from New Providence and jumped straight into the island school life. They had a jam packed day to orient them to our campus, complete with a sustainable systems tour and awesome day one snorkeling.
The rest of the week had a large emphasis on working with our research teams and discussing the implications of their work on our world. Lloyd Allen, head chaperone and a teacher at Akhepran, has a big vision for his scholars and hoped that in their time here they would see the plethora of career options in sciences and engineering and be inspired to pursue their passions.
Some students have dreams of being engineers. These students really enjoyed learning about our aquaponics system with Michael Bowleg and spoke excitedly about going home and engineering their own aquaponics system at home. Others dream of being marine biologists and, after a morning learning about and dissecting lionfish, want to go back to Nassau and tell everyone they know about this invasive species and get them to eat lionfish instead of more commonly overfished species.
These examples are just the beginning of this group’s studies.
Their curiosity, questions, and positive approach to life made them a joy to spend the week with. By the end of the week many spoke about how their perspectives on the ocean had shifted and they had learned to love the ocean they grew up around even more. One student said, “every time a wave hits against me it’s like a kiss from mother nature” and another admitted that she had fears about the ocean, but that swimming in it and “being one with the fish” showed her she didn’t need to be so afraid.
This was truly a week of growth and inspiration, and even though their trip was cut short by threats of a hurricane, we look forward to this relationship and have hopes to visit their school in Nassau in the future.
The Sea Turtle Research and Conservation team here at CEI welcomes three new members to the team for the fall semester! They arrived last Saturday and, after a few days of orientation, they got to finally jump on a boat and head into the field. Despite the early finish due to unpredictable weather conditions, all the interns had an amazing time getting hands-on experience in working with Meagan Gary on her Masters study by monitoring for sea turtles carrying her acoustic tags. Brittany Bradshaw (left), who had the task of listening for sea turtles, is a 21 year old college graduate from the University of the West Indies St. Augustine campus (Trinidad and Tobago), where she did her BSc. in Biology and Environmental Resource Management. Although she came from a Caribbean island, she honestly believes without a doubt that Eleuthera is the hottest place in the world! Brittany is excited to learn and will be spending her free time scuba diving and participating in projects with the other staff members at CEI.
Anna Safryghin (middle), manning the hydrophone, is a 21 year old half Italian and half Russian placement year student from Plymouth University, UK. Anna studies Marine Biology and Coastal Ecology and also plays soccer for the University team. She left the freezing Russian cold behind her to come and enjoy the hot and stunning Eleuthera. In her free time, Anna can usually be found engaging in some kind of physical activity, from water polo Wednesday to volley ball Tuesdays. During her 6 months at CEI Anna is looking forward to gaining experience in the field in all ways possible.
Last but not least, there is Jorell Pageot (right), who did a great job recording the positions of the turtles during her first field day. She is an 18 year-old, recent highschool graduate, from the not-so-far Nassau, New Providence. Jorell has been so enthusiastic about everything since her arrival. It is actually her first time on any of the family islands and so far she is “loving it”! Jorell looks forward to working with the turtle team and learning new things, she plans to become a marine biologist and is already looking at colleges to begin her studies to achieve that goal. Jorell loves meeting new people, soccer, and she wants to become a certified scuba diver. We look forward to working with this team for the rest of Fall 2015!
On Friday, August 21st, the Shark Research and Conservation Program at the Cape Eleuthera Institute was once again honored to host and be involved with 22 young Bahamian students from the Bahamas Reef Environment Educational Foundation (BREEF) Eleuthera Sea Camp for a full day of research-related activities. Friday capped off a week-long summer camp focused on the Eleuthera’s marine environment, and the relationships that residents of the Bahamas have with that environment.
Firstly, students were introduced to our systems and facilities via a 60-minute walking tour of campus including a visit to our permaculture farm, aquaponics system, wet lab, and biodiesel facility. At each stop, members of the community informed students about sustainable farming practices, biodiesel production, and how we grow fish to not only eat, but that help us grow our lettuce and herbs. Following the campus tour, the students ate a picnic lunch at the Boathouse with members of the Shark Team.
The afternoon was full-on, filled with the CEI shark research team, shark handling demonstrations, and a stingray tagging experience. Research Technician Cameron Raguse kicked things off with a short presentation on shark ecology, explaining their role as a top-predator in the Bahamas and how integral they are to maintaining a stable ecosystem. The students then split into groups alternating between two activities: one with Dr. Owen O’Shea and his team for stingray tagging; and one with University of Illinois graduate student, Ian Bouyoucos demonstrating shark handling and physiology. In each case, the students got an in-depth look at research here at CEI, as well as getting up-close with some often misunderstood animals.
At the end of the day, the group left with a better understanding of elasmobranchs as a whole, and a deeper appreciation for the wildlife right at their doorstep.
On August 7th at three o’clock in the afternoon, while conducting benthic surveys on Ike’s reef, some of our summer interns came across the annual spawning event for the Brown Encrusting Octopus sponge (Ectyoplasia ferox). These common bright orange tubular sponges immediately caught their attention because they appeared to be smoking. When the interns took a closer look the smoke appeared to be stringy neon orange mucus attached to the sponges.
The mucus filaments contain fertilized eggs that hatch into larvae and settle down on the reef to form new sponges. The Brown Encrusting Octopus Sponge, like most sponges, is a hermaphrodite; meaning they function as both sexes simultaneously. Fertilization takes place within the sponge once sperm makes its way through the water column to an individual of the same species. August is the usual time for the spawning of this species and a number of variables make it hard to predict the exact date to witness this unique event. These sponges are generally found on coral reefs and other nearby areas at depths from 40 to 75 feet, so keep an eye out this month!