Project Overview

Summary:

Overview

In January 2015, Dr. Martin Grosell at the University of Miami, Rosenstiel School of Marine and Atmospheric Science, was awarded an RFP-IV grant at $8,996,491 to lead the GoMRI Relationship of Effects of Cardiac Outcomes in Fish for Validation of Ecological Risk (RECOVER) Consortium which consisted of 3 collaborative institutions and 53 different research team members (including students) over the course of the four years of activities.  The ultimate goals of the RECOVER project are to:

• Provide a near complete mechanistic understanding of physiological effects of exposure to crude oil and PAHs. Such an understanding will provide a solid foundation for predicting effects on other species under other environmental conditions (UV penetration, temperature, salinity, oxygen tension, etc.)
• Provide insight into best practices for managing future spills involving other species and different physical-chemical environmental parameters.
• Furthermore, the proposed studies of potential reversal of induced effects seek to determine to what extent individual organisms are able to recover from damage induced by exposure to crude oil/PAHs.
• Finally, the proposed studies of predator-prey interactions, the first of their kind, examining oil/PAH impacts on fish, aim to inform population ecologists and thus assist with ecosystem effect predictions.

These goals were pursued by addressing the following:

• Cardiac Phenotype Questions
• Molecular and Genetic level questions
• Swimming performance questions
• Photo-Enhanced Toxicity Questions
• Predator-Prey Questions

Outreach

            Over its award period (3 years, plus a 12-month no-cost extension), RECOVER organized approximately 95 outreach activities or products, including:

1)    Sea Secrets at the University of Miami Rosenstiel School (1/23/2018) –

Dr. Grosell presented “In the Wake of an Environmental Disaster – Is there a silver lining?”. His presentation included the impacts of Deepwater Horizon oil spill throughout the Gulf of Mexico, focusing on the impact to the pelagic fish species, including impacts to their important spawning grounds and baseline information about mahi-mahi biology

2)      UNT College of Science S.M.A.R.T. Talk (9/26/2018) – Dr. Robert’s presented “Researching Disaster: Understanding the Effects of Oil Spills on Aquatic Life". This lecture series is formatted in a TED talk format, where UNT’s College of Science highlights the scholarly work of their faculty, as well as bring together the UNT community to speak about scientific advancements.

3)      Seafood Wars at Texas State Aquarium (1/31/2017) – Dr. Esbaugh presented “The Power of Performance: What Exercise Can Teach Us About Fish and the Environment” as the Guest Speaker for a seafood-based event where redfish was the primary fish used. 

4)    Smithsonian: Two articles on RECOVER’s research were published by the Smithsonian Ocean Portal. The first published in April 2017, from Larvae to Adults – Finding Impacts of an Oil Spill on Mahi – Mahi, features the research of Lela Schlenker, Ph.D. student at UM Rosenstiel School, on mahi-mahi spawning behavior, habitat utilization and migration patterns through the use of pop – up satellite archival tags (PSATs). The second published in June 2018, Fish Heart Out of Water, features the research of Dr. Rachael Heuer (UM Rosenstiel School) and Derek Nelson (Ph.D. student at UNT) which focuses on the impacts of crude oil from Deepwater Horizon on the cellular function of the heart, and to cardiac function through monitoring blood flow and pressure, respectively.

5)    Virtual lab – Since its launch in January 2017, the first virtual lab lesson - Swim Performance – has been used in 22 states, as well as in British Columbia, with an average quiz grade of 74% across all grade levels. The second virtual lab lesson – Visual Acuity – was launched in February 2018 and has been utilized in 20 states since the launch, as well as an average quiz grade of 86% across all grade levels. Lastly, both virtual labs have seen an increase in the number of users since their launch. Smithsonian

6)    Webpage Social media presence: RECOVER’s Facebook page was created in March 2015, with the Facebook page’s followers – number of people who have followed the page – growing from 846 to 1,144 (today) with progressive growth each quarter since data collection began in April 2017. The number of times people have engaged with posts through likes, comments, shares, etc (Post Engagement) has been fairly consistent throughout data collection, with significant increases seen in September 2017 (234) and February 2019 (138). Compared to Year Quarter 1 of RECOVER 2, Year 2 Quarter 1 showed increased post engagement of each month.

Research Highlights

            As of January 31, 2019, RECOVER research resulted in 31 peer-reviewed publications, more than 100 scientific presentations and 67 datasets being submitted to the GoMRI Information and Data Cooperative (GRIIDC), which are/will be available to the public. RECOVER engaged 15 Masters and Ph.D. students over its award period. Significant outcomes of RECOVER research according to GoMRI Research Theme are highlighted below.

            Theme Three:

Significant outcomes are listed below as they related to questions addressed in pursuit of RECOVERs ultimate goal (see above).

Cardiac Phenotype Questions

Further studies on young adult Mahi demonstrated that reduced swim performance was due to a reduction in stroke volume rather than heart rate and that cardiac output was reduced by >40% following only 24 hours of exposure to ~10 µg∑50PAH·l^-1.

Studies on early life stages of Mahi and red drum were the first to quantify stroke volume and cardiac output in larval fish to also show oil impacts. Importantly, effects on stroke volume occur at lower concentrations than effects on heart rate.

Cobia, which is more tolerant of experimental manipulation than Mahi, was used in two studies of cardiac function to reveal that maximal cardiac output was impaired in oil-exposed cobia when swimming at higher speeds and further, that adrenalin at physiological concentrations may rescue cardiac function in cobia exposed to oil.

Molecular and Genetic level questions

Extensive RNAseq studies on Mahi and red drum revealed that, in addition to cardiotoxicity, steroid biosynthesis, peripheral and central nervous systems and nitrogenous waste excretion were likely affected by oil exposure during early embryonic and larval development. These results lead to functional characterization of the development of vision and possible oil impacts on three species, the sheepshead minnow, the red drum and the Mahi. All three species showed impaired eye development and impaired vision after exposure to oil during embryonic development with the most sensitive being Mahi showing effects at concentrations as low as 0.69 µg∑50PAH·l^-1.

Swimming performance questions

Studies on young adult red drum showed reduced swim performance and aerobic scope similar to what was observed for Mahi. In addition, these important studies on red drum revealed that oil induced swimming impairment persisted for >6 weeks after transfer to clean water.

Photo-Enhanced Toxicity Questions

Studies on Mahi revealed that UV wavelengths in natural light enhance crude oil toxicity substantially by up to one order of magnitude. Further, it was revealed that the timing of UV radiation, relative to developmental stage, matters for potentiation of oil toxicity.

Predator-Prey Questions

Juvenile reef fish behavior in mesocosms was impacted by short term exposure to low levels of oil, resulting in altered habitat selection and boldness. These behavioral alterations resulted in increased predation in the face of a natural predator.

Other discoveries not directly related to stated goals and objectives

Experiments on the red drum and especially Mahi, in most cases, represented the first studies and measurements of its kind. Consequently, novel information about the basic biology and physiology has been revealed. One example of such novel information, not directly related to oil toxicity regards the impact of UV exposure on embryos of pelagic fish. During studies examining interactions between oil and UV radiation, we observed that UV exposed Mahi embryos altered buoyancy to sink rather than float at the surface. We later learned that this change in buoyancy was reversible and that embryos would return to positive buoyancy and the surface after UV radiation was terminated. Although we are still working to understand how Mahi embryos alter buoyancy, it is clear that they are capable of sensing UV radiation and of dynamically altering their specific gravity. The adaptive advantage of this response seems clear as embryos during UV radiation in the wild would sink deeper and thereby avoid or reduce further damaging UV radiation. Current studies under RECOVER II is addressing the specific gravity changes which allow for modeling of vertical and horizontal distribution of embryos in the wild under natural conditions including UV radiation.  

Another example of insight gained into basic biology comes from the work we have conducted with pop-up satellite archival tags on Mahi. This work was conducted to prepare for a larger cruise in the Gulf of Mexico where a large number of Mahi, both pristine and oil exposed will be fitted with PSATs and released in the Northern Gulf of Mexico. So far 19 fish have been tagged and the data show extensive migrations of up to 100 km/day by adult Mahi. Further, the tags have revealed a thermal preference for 28 ºC with thermal habitats ranging from 20 to 31 ºC. Mahi spends the majority of their time in the top 1 m of the water column but will make excursions to depths exceeding 100 m. The data has also revealed extensive predation on tagged Mahi, illustrating that these fish serve as an important link in the pelagic ecosystem by acting as top-level predators while serving as prey for larger pelagic predators.   

 Proposal Abstract - RECOVER-1