Tissue Samples to be Tested for Plastic Presence and Toxicity

Tissue Samples to be Tested for Plastic Presence and Toxicity

Stomach, liver and white muscle tissue samples collected by CEI’s Sustainable Fisheries research team were successfully received by the University of North Carolina Wilmington last week. This is part of a three-year project currently led by Dr. Travis Van Leeuwen, Danielle Orrell and Eric Schneider of the CEI Sustainable Fisheries Team in collaboration with Bonnie Monteleone (Plastic Oceans) at the University of North Carolina, Wilmington. The project aims to investigate the presence, toxicity and cycling of marine plastics across pelagic, reef and deep-sea organisms in the Exuma Sound.

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The study is important as the relationship between plastics in oceans, its cycling in ecosystems and its presence in our food remains poorly understood. Recent predictions made by the Ellen MacArthur Foundation and the World Economic Forum claim that by 2050 there will be more plastic than fish in the world’s oceans (The New Plastics Economy report, 2016). Understanding how the increasing presence of plastics in our oceans is affecting its inhabitants, and how plastics are cycling within different ecosystems (coral reefs, the pelagic ocean and the deep-sea) is key to raising awareness and identifying solutions. 

  Changes in the ratio (number of plastics to fish in the ocean by weight) between 2014 and 2050, and the relative contribution of these plastics to global oil production as provided in  The New Plastics Economy  report (2016).

Changes in the ratio (number of plastics to fish in the ocean by weight) between 2014 and 2050, and the relative contribution of these plastics to global oil production as provided in The New Plastics Economy report (2016).

The plastics project at CEI began in 2014, with liver, white muscle and stomach samples collected from pelagic fish such as mahi mahi, wahoo and tuna which were obtained from sport fishing tournaments hosted in The Bahamas. This was supplemented by fish caught during a Fall 2016 Island School class focused on investigating plastic accumulation in pelagic species. It is hoped that these samples will provide an insight into the plastic toxins present in fish which are often eaten by humans. Similarly, samples from reef fish including barracuda, mutton and yellowtail snapper were provided by local fishing boats and anglers, and deep-sea samples from animals such as isopods and eels were collected during deep sea research trawls carried out by CEI researchers in 2015-2017.

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These samples are now at the University of North Carolina Wilmington ready for examination by a team of biologists and toxicologists. Within the next few months it is hoped that these samples will help unlock some of the mysteries around plastic cycling within ecosystems, and quantify presence and associated toxicology associated with consuming these fish.

  CEI researchers Eric Schneider (left) and Danielle Orrell (right) waving off Mark M. Steinberg (middle, pilot) transporting the samples to the US for analysis.

CEI researchers Eric Schneider (left) and Danielle Orrell (right) waving off Mark M. Steinberg (middle, pilot) transporting the samples to the US for analysis.

A Year of Firsts: Successful Spawning of Bonefish in CEI’s Wet Lab

A Year of Firsts: Successful Spawning of Bonefish in CEI’s Wet Lab

For the last eight months, the Cape Eleuthera Institute’s (CEI) flats ecology research team, in collaboration with Florida Atlantic University’s Harbor Branch Oceanographic Institute (FAU-HBOI), the Florida Institute of Technology (FIT) and the Bonefish & Tarpon Trust (BTT), has been investigating spawning mechanisms in bonefish as part of the Bonefish Restoration Research Project (BRRP).

Work began just before the full-moon on the 31st of December 2017. Using a series of reproductive hormone injections the team was able to successfully induce the final stages of egg maturity in a female bonefish that had been captured from a pre-spawning aggregation site and held in captivity. Days later the female was successfully strip spawned and fertilized with sperm collected from a mature male from the pre-spawning aggregation site. Just over 24 hours later this resulted in live bonefish larvae.

  19 hours post-fertlization – the embryo is wrapped around a transparent yolk sac, with bubbles of oil on top of the embryo (oil for floatation and energy).

19 hours post-fertlization – the embryo is wrapped around a transparent yolk sac, with bubbles of oil on top of the embryo (oil for floatation and energy).

  25 hours post fertilization – the embryo has developed to the point that the tail is now free from the tight circle where it was initially attached.

25 hours post fertilization – the embryo has developed to the point that the tail is now free from the tight circle where it was initially attached.

  0 hours post-hatch (26 hours post fertilisation) the backbone and bands of muscle are evident along the body; the beginning of the eye is at the left. The oil droplets have coalesced into a single large droplet of oil by the belly of the larva. The transparent structure covering almost the entire bottom of the larva is filled with transparent yolk that will fuel growth until the larva develops its eyes, gut, mouth, etc. 

0 hours post-hatch (26 hours post fertilisation) the backbone and bands of muscle are evident along the body; the beginning of the eye is at the left. The oil droplets have coalesced into a single large droplet of oil by the belly of the larva. The transparent structure covering almost the entire bottom of the larva is filled with transparent yolk that will fuel growth until the larva develops its eyes, gut, mouth, etc. 

This is the first time ever that bonefish have been successfully strip spawned with viable fertilised eggs hatching into larvae. Very little is known about maturation, spawning and the early development of the leptocephalus, or “slender head” bonefish larvae. This successful spawn will provide essential information on future larval development, and the conditions required to successfully spawn and culture larvae in captivity. Work will continue over the upcoming full moons with the aim of continuing this success and gaining more knowledge to understand bonefish spawning and larval development.

CEI Attends Abaco Science Alliance Conference

CEI Attends Abaco Science Alliance Conference

  Candice Brittain presenting the parrotfish research, and showing an image of Deep Creek Middle School students preparing a skit to perform in their communities conveying the importance of parrotfish to the marine ecosystem.

Candice Brittain presenting the parrotfish research, and showing an image of Deep Creek Middle School students preparing a skit to perform in their communities conveying the importance of parrotfish to the marine ecosystem.

Last week, Candice Brittain (Director of Outreach and Partnerships), Meagan Gary (CEI Scientist) and Eric Schneider (CEI Scientist) attended the 8 th Biennial Abaco Science Alliance Conference in Marsh Harbour, Abaco.  Hosted by Friends of the Environment, the conference attracted researchers, government officials, local stakeholders and a range of other conservation-minded participants from across The Bahamas and abroad.  The conference hosted great scientific presentations as well as important networking opportunities for collaborative work. Candice presented on the ongoing parrotfish project in partnership with ISER-Caribe.

The first year of the project focused on fisher and consumer perceptions of parrotfish with the goal of developing long-term education and management strategies in The Bahamas. This year a communication campaign will be launched sharing the important ecological role adult parrotfish play in the marine ecosystem as the most dominant algae grazers on the coral reefs, maintaining healthy habitat for other important animals like grouper and crawfish (spiny lobster).

  Meagan Gary, CEI Scientist

Meagan Gary, CEI Scientist

Meagan spoke about the spatial variation in green sea turtle diet. This is a part of a larger study that is monitoring seasonal and spatial fluctuations in seagrass growth and distribution and its influence on green sea turtle diet. The inception of this project was due to social survey results showing that a large percentage of people living in Eleuthera believe that green sea turtles eat fish and conch. Understanding green sea turtle diet is integral as ecosystem management continues to develop in The Bahamas.

  Eric Schneider, CEI Scientist

Eric Schneider, CEI Scientist

Eric presented the early findings of several projects looking into the sustainability of the emerging stone crab fishery in The Bahamas. As this new export fishery develops, it will be increasingly important to ensure the science and regulations behind it are adequate. The presentation lead to conversations with a local fisher/exporter and several fisheries officers and managers that all showed interest in the research and eagerness to support the work moving forward.

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Understanding Bonefish Spawning

Understanding Bonefish Spawning

Not much is known about bonefish spawning or their juvenile stages. As a $141 million-dollar industry in The Bahamas alone, understanding these crucial phases of the bonefish lifecycle is important to ensure the population is kept healthy and the fishery sustainable. In the past few months, Dr Travis Van Leuween and the Flats Ecology team focused on identifying and understanding bonefish spawning behavior.

 Bonefish in one of the wet-lab tanks at CEI

Bonefish in one of the wet-lab tanks at CEI

 Bonefish eggs collected in the wet-lab this week

Bonefish eggs collected in the wet-lab this week

In partnership with the Bonefish and Tarpon Trust, the team has been tracking the hormone levels of 43 individual fish using blood samples to create hormone profiles during both spawning and non-spawning time periods for the last eight months. By matching hormone levels to potential spawning events, we can identify hormones which may promote reproductive cues including egg and sperm production. We have also collected data on environmental cues including lunar phase and water temperature.

 

Prior to the last full moon, we collected bonefish from what is believed to be a spawning aggregation in order to attempt to spawn individuals in the lab. Performing cannulations on all fish captured, we identified which individuals were fertile. We then injected our lab-reared fertile female along with the newly captured egg-bearing females with hormones to accelerate egg development and promote egg release, but unfortunately our attempts were as of now unsuccessful. We are hoping to have more luck with the next full moon when we will be joined by researchers from Florida Institute of Technology and Florida State University. This is the first parallel study to record hormone profiles and bonefish spawning in a lab environment, and we are hopeful that future attempts will be a success.

    The Flats Team includes (from left to right) Olivia Eisenbach, Dr Travis Van Leeuwen, Cynthia Hsia, Danielle Orrell, Greg Sayles

 

The Flats Team includes (from left to right) Olivia Eisenbach, Dr Travis Van Leeuwen, Cynthia Hsia, Danielle Orrell, Greg Sayles

CEI research teams present at Fall 2017 Parents Weekend

Collaborating with Island School students is always a rewarding experience for CEI researchers, and it was no different for the class of Fall ‘17. This semester, CEI research classes both built upon previously established projects and pioneered new ones.

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Senior Research Assistant Meagan Gary and Research Technician Chelsea Begnaud worked with six students to determine the optimal time to collect diet samples from green turtles (Chelonia mydas). This methods study fits within the wider, ongoing turtle research at CEI looking at seasonal and spatial variations in their diet. Having performed esophageal lavage at different times of the day and different tidal states, the team presented preliminary results regarding the optimal conditions at which to collect diet sample to maximize their size.


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Research Associate Dr Nathan Robinson and Research Technician Giulia Cardoso co-advised seven students on the very first drone-based research project at CEI. The team conducted paired drone and snorkel surveys in two mangrove creeks, and compared results to assess the advantages and limitations of using drones to monitor megafauna in shallow-water environments. The results are highly encouraging, showing that some species, such as lemon sharks (Negaprion brevirostris) and bonefish (Albula vulpes), are preferentially spotted on drone surveys.


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The third research class was led by Senior Research Assistant Eric Schneider and Research Technician Reid Webb. The two advisors and their six students worked on a new project focusing on the ecological significance of fish aggregation devices (FADs) and their role as conservation tools. In collaboration with some CSD staff members, the team successfully assembled and deployed sub-surface FADs and began monitoring their early colonization by pelagic species.

All three teams delivered excellent presentations, leaving the 150-strong crowd of parents, siblings and community members incredibly impressed by their grasp of the science conducted and their confidence in communicating it. The class advisors and the rest of CEI are extremely proud of the Fall ’17 research teams and wish them all the best for the rest of the semester!