Contributors | Affiliation | Role |
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Walther, Benjamin | Texas A&M, Corpus Christi (TAMU-CC) | Principal Investigator |
Oster, Jacob | Texas A&M, Corpus Christi (TAMU-CC) | Student |
Rauch, Shannon | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
Fish collection locations and associated information are found in an accompanying dataset for this project: https://www.bco-dmo.org/dataset/916418.
Muscle samples from individual fish were dissected, dried, and pulverized to a fine powder. Powdered muscle samples were analyzed at the SUNY College of Environmental Science and Forestry. Samples are weighed into boats and placed in an autosampler. The autosampler places the boat into a furnace to undergo thermal decomposition under oxygen. A catalyst furnace then removes interferences and reduces all mercury species. The mercury is subsequently trapped on a gold amalgamator, then desorbed and swept into an atomic absorbance spectrophotometer equipped with a 254-nanometer (nm) mercury lamp.
- Imported fish collection location data (file "916418_v2_fish_collection_locations.csv")
- Imported original file "Hg data upload_v2.xlsx" into the BCO-DMO system.
- Flagged "NAN" as a missing data value (missing data are empty/blank in the final CSV file).
- Added the following columns from the fish collection location data file to this dataset by joining on Fish_ID: Station_Latitude, Station_Longitude, Date_Collected, Species.
- Saved the final file as "961606_v1_fish_muscle_mercury.csv".
Parameter | Description | Units |
FishID | Unique identifier number for each individual fish included in the project. IDs include a prefix of "MB" (Matagorda Bay) or "PB" (Project Breathless) followed by a unique sequence of digits. | unitless |
Species_Code | Code indicating whether fish was a Red Drum ("RD"), Atlantic Croaker ("CR") or Southern Flounder ("FL"). | unitless |
Species | Latin binomial (Genus species) of each individual collected | unitless |
Hg | Muscle tissue mercury concentration | micrograms/gram (ug/g) |
Station_Latitude | Collection location latitude in decimal degrees; positive values = North | decimal degrees |
Station_Longitude | Collection location longitude in decimal degrees; negative values = West | decimal degrees |
Date_Collected | Date of fish collection | unitless |
Dataset-specific Instrument Name | Milestone DMA-80 Tricell |
Generic Instrument Name | Milestone Direct Mercury Analyzer |
Generic Instrument Description | The Milestone DMA-80 is a mercury analyzer used to determine mercury concentrations in liquid and solid samples. The DMA-80 is based on the principles of sample thermal decomposition, mercury amalgamation, and atomic absorption detection. See more: https://milestonesci.com/direct-mercury-analyzer/ |
NSF Award Abstract:
Ocean oxygen loss (deoxygenation) is increasing due to climate warming. This warming, together with nutrient loading, is causing many marine and freshwater systems to experience increasing episodes of hypoxia (low oxygen) of greater duration and intensity. Impacts on fish and fisheries have been difficult to quantify; direct observation has been challenged by a lack of long-term exposure indicators. This team has successfully refined the use of fish chemical biomarkers in fish otoliths (earstones) to directly assess lifetime hypoxia exposure in fishes. This project will those findings to look for additional biomarkers and models, to expand our understanding of how hypoxia affects fish and their food webs, contaminant transfers, and ecosystem services including economic impacts. The project includes a unique way of training students in science communication, posing the question: What forms of media and "messaging strategies" about deoxygenation are most effective at raising public awareness and understanding? Students are developing entries for PlanetForward's Storyfest, which is a contest to tell compelling stories to foster environmental understanding and solutions. Students from historically underrepresented, economically disadvantaged backgrounds are particularly sought out to participate. The investigators will engage with regional, national, and international management agencies and other relevant stakeholder groups to share information.
This project encompasses a novel, linked set of interdisciplinary studies of food webs, and ecosystem services assessment. The thematic questions explored in this project are: 1. How does hypoxia alter habitat use for fishes? 2. How does hypoxia-altered habitat use and habitat productivity change food webs? 3. How does hypoxia affect/enhance trophic transfer of methylmercury? 4. How do hypoxia-induced changes in food webs affect aquatic ecosystem services? The set of linked studies will employ chemical analyses of otoliths and eye lenses, combined with chemical analyses of muscle tissues (Questions 1 and 3), physiologically-structured food web modeling informed by monitoring time-series (Questions 2 and 4), and a scoping workshop to address ecosystem services (Question 4). The investigators are using a "trans-basin" comparative approach to system-specific responses, studying fishes in Lake Erie, the Baltic Sea, and a Gulf of Mexico estuary. They study three species from each system that represent different degrees of benthic reliance, to discern differential responses to the increasingly hypoxic environment. This research provides novel insight about variable biotic responses to oxygen loss and the impacts on ecosystem functioning.
Funding Source | Award |
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NSF Division of Ocean Sciences (NSF OCE) |