FIU

In search of scalloped hammerheads

Mission Overview

Thanks to the Moore Charitable Foundation and Paul G. Allen Philanthropies, we headed to San Salvador in the Bahamas in search of endangered scalloped hammerhead sharks. Although a shark sanctuary, there are few data showing the existence of scalloped hammerheads in Bahamian waters. On 840 baited remote underwater video surveys (BRUVs) previously completed in the Bahamas by our team, no scalloped hammerheads were documented. Anecdotal accounts of scalloped hammerheads from local dive shops and fishers sparked our interest to investigate further.  From our core research team were Florida International University’s Dr. Demian Chapman and Gina Clementi, as well as Dalhousie University’s Taylor Gorham. Joining them were FIU researchers Dr. Yannis Papastamatiou, Dr. Bautisse Postaire, and Megan Kelley as well as photographer Andy Mann, free-diver Trevor Bacon, Captain Scott Genereux, first mate Joey Salomone, journalist Amaro Pablo-Gómez, and Pew Charitable Trusts conservationist Maximiliano Bello. Using BRUVs, dive surveys, and environmental DNA (eDNA) collection, the team had their sight set on confirming the presence of scalloped hammerheads in San Salvador.

Day 1

With energies still high, we decided to start the trip off with BRUVs. After completing eight deployments, we headed in for the night to enjoy dinner together and test out our new eDNA sampling equipment. But, as luck would have it, the boat we were using to set BRUVs had a mechanical issue, taking away dinner while it was practically right under our noses. That feeling must be what it’s like to be a shark not able to get the bait in our cages! After a couple of hours waiting safely at sea for assistance, we finally returned to our home boat, the Lady G. With full stomachs, we headed to the deck to collect eDNA samples. After spotting lemon sharks and one southern stingray swimming around the boat, we decided to call it a day – a very successful one!

Dr. Postaire (left) carefully drops the Niskin bottle over the side of the boat to collect water that was later filtered for eDNA. Back in the laboratory he will use genetics to try to look for sharks and rays. He will likely find the lemon shark that was swimming around the boat, pictured on the right.

Day 2

Today, it happened! Yannis and Megan spotted a scalloped hammerhead immediately after a dive and right before a BRUV retrieval. Although not filmed by the BRUV, Yannis was able to capture a video of it pooping, seen below. We completed nine BRUVs today and sampled for eDNA at three sites.

Day 3

Diving and BRUVs continued, with our second scalloped hammerhead sighting.

Diver Megan Kelley seen with a Nassau grouper. Photo credit: Andy Mann

Day 4

Taylor and Bautisse sampled another four sites for eDNA while the rest of the team went to explore a seamount. Sighted were silky sharks, oceanic whitetip sharks, three whales, and a tiger shark on a drifting pelagic BRUV.

A curious silky shark investigates the team. Photo credit: Andy Mann

Day 5

Edd Brooks from the Cape Eleuthera Institute joined the team. We were slowed down by strong wind and rain today, but we didn’t let that dampen our spirits. Three BRUVs were completed and a pod of dolphins swam around us for 30 minutes, playing with corals, eating gobies in the sand, and chasing barracuda.

Day 6

The talented Andy Mann filmed a few staged BRUVs today (check out some of the resulting footage on our homepage), while the science team completed three BRUVs and sampled five sites for eDNA. Edd took some of the team to the mangroves where they successfully caught a juvenile lemon shark for a tissue sample.

A Caribbean reef shark swims past our staged BRUV, allowing photographer Andy Mann to capture this stunning moment on camera.

Day 7

Our trip has come to end. Due to prevailing winds and because both our Niskin bottle and pump for filtering water broke, we decided to end the trip early. After 26 coral reef BRUVs completed, one pelagic BRUV set, two deep BRUVs set, 21 eDNA samples collected, and sightings of scalloped hammerheads, we can call this a successful mission!

And we’re off! Photo credit: Bautisse Postaire 

Impacts of sharks on coral reef ecosystems

Do healthy reefs need sharks? This is one of the most misunderstood questions in coral reef ecology. Shark populations are declining due to habitat loss, overfishing, and other stressors. It is important to understand how these losses could affect the rest of the ecosystem.

Understanding the predator-prey interactions between herbivores and sharks is crucial for coral reef conservation. As top predators, sharks not only eat other fish, but they can also affect their behavior. In the presence of sharks, herbivorous fish may be concentrating their grazing to small, sheltered areas. Because these fish would likely be eating where they are safe from predators, there should be more space to allow young coral to settle, grow, and thrive. In the absence of sharks, herbivorous fish may spread out their grazing randomly across large patches of algae, leaving few well-defined or cleared areas for corals to settle.

Fortunately,Untitled Florida International University has just the place to explore these dynamic questions, a lab under the sea – Aquarius Reef Base. From September 7th to 14th, a mission at Aquarius Reef Base will combine sonar with baited remote underwater video surveys (BRUVs), an experiment the first of its kind to bring these technologies together. Researchers on this mission strive to understand the direct impact of shark presence on herbivorous fish behavior as well as the indirect impact of sharks on algae communities. Combining these technologies:

 

  • Provides a new way to study reef fish behavior
  • Carves the path forward for future ecological research
  • Offers insights that may lead to critical marine conservation outcomes

Below are data produced from last year’s shark mission: a shark swims by the remote camera and shows up on the multi-beam imaging sonar.

© FIU, Dr. Kevin Boswell

Mission Overview

Dr. Kevin Boswell

Dr. Kevin Boswell, an assistant professor of biology, is leading this mission. His lab will use low frequency sound to attract sharks around Aquarius. HD remote video combined with multi-beam imaging sonar will be used to quantify how fish behavior changes in the presence and absence of sharks. At the same time, grazing intensity by herbivores will be measured to understand the impacts on the benthic community.

 

 

 

Dr. Michael HeithausDr. Michael Heithaus, Dean of the College of Arts, Sciences & Education & Global FinPrint’s co-lead principal investigator, is co-leading this mission. His lab will set BRUVs to provide data on fish behavior in the presence & absence of sharks. Setting the BRUVs is also part of Global FinPrint, which attempts to assess the presence of sharks & rays on coral reefs all over the world, understand the factors affecting their distribution, and inform conservation actions for threatened species.

 

 

 

TUS

 

In an effort to inspire the next generation of ocean enthusiasts and engage the public using innovative research technologies, a FIU student teacher, Carlos Calle, will take part of this mission via the Teacher-Under-the -Sea program. This work would not be possible without the help of our amazing Aquarius Reef Base staff and the support of the Paul M. Angell Family Foundation.

 

 

Join the adventure live online

Aquarius Reef Base Twitter #Angellsharks

SEAS Twitter #sharksFIU

Global FinPrint Twitter #count2save

Meet the Team

Alain Duran – Science Team Lead

  • Ph.D. candidate at FIU.
  • Studies the effect of biotic and abiotic drivers of herbivorous fish-algae interactions and their impacts on coral reef dynamics and conservation.
  • Works on the dynamics of coral reef fish, particularly herbivores.

Benjamin Binder - Scientist

  • Graduate student at FIU.
  • Focuses on the community wide effect of fish spawning aggregations (FSA) in the South Florida region and the spatiotemporal patterns of FSA formation.
  • Tools of his trade include various fisheries sonars, which will be used extensively during the mission. 

Frances Farabaugh - Scientist

  • Ph.D. student in the Heithaus Lab at FIU and is involved with the Global FinPrint project.
  • Focuses on behavioral ecology of marine predators.
  • Hopes to elucidate the role sharks play in structuring reef communities by investigating predation risk effects and the functional redundancy of top predators. 

Roy Bartnick - Science Translation Specialist, Teacher-Under-the-Sea Program

  • Currently working on his Ph.D. dissertation in Educational Leadership at Capella University, Minneapolis, MN.
  • Goal is to seamlessly blend STEM across the curriculum at the elementary school levels in hopes of fostering a love of learning while providing students the ability and opportunity to apply their knowledge to real world applications on a global community level.
  • Will mentor the FIU student teacher, Carlos Calle, and lead many of the educational programs conducted aboard Aquarius through collaboration with Skype in the Classroom.

 

Carlos Calle – Science Translation Specialist, Teacher-Under-the-Sea Program

  • Studies elementary education at FIU and is completing his internship at Norman S. Edelcup K-8 Center in Sunny Isles, Florida.
  • Has a special interest in conducting experimental research in natural sciences and will work hand-in-hand with the science team.
  • Will lead many of the educational programs conducted aboard Aquarius through collaboration with Skype in the Classroom. 

Cathy Guinovart – Aquarius Reef Base Education and Outreach Coordinator

  • Senior pursuing a Bachelor’s degree in Sustainability and the Environment.
  • Started a student-run organization at FIU called “Age of Aquarius”, which is dedicated to teaching the community about the value of Aquarius and the oceans as a whole. 
  • Schedules all virtual field trips for this mission and facilitates shore base live links with Carlos Calle.