Summary:
Overview
Dr. Debra Murie at the University of Florida was awarded an RFP-II grant at $1,366,544 to lead the RFP-II project entitled “Spatial and Temporal Effects of the Deepwater Horizon Oil Spill on Growth and Productivity of Recreational and Commercial Fisheries in the Gulf of Mexico” which was carried out between January 1, 2013, and December 31, 2015, with a one year No Cost Extension that ended December 31, 2016. The project consisted of 1 institution and 6 research team members. Through this work, Dr. Murie and her team aimed to determine to what extent the spill impacted the growth and productivity of important recreational and commercial fisheries in the Gulf of Mexico.
Research Highlights
Dr. Murie’s research included 10 outreach products and activities, resulted in 13 conference presentations, and 3 datasets submitted to the GoMRI Information and Data Cooperative (GRIIDC), which will be made available to the public. Dr. Murie engaged 7 students over her award period. Significant outcomes of her research are highlighted below.
Theme 3: Environment Effects
- Spatial and temporal changes in growth of coastal fishes collected from both Louisiana (impacted area) and Florida (reference area) were assessed by measuring growth increments from sectioned otoliths for Red Drum, which is an estuarine-dependent species and the main focus of the study, collected during 2005-2015. Decreased growth would be expected if the oil spill affected the food consumption through collapse of their food webs or through sub-lethal physiological stressors.
- Comparing the time series of growth increments for Red Drum from Louisiana with those from the reference site on the west coast of Florida indicated that an observed decrease in growth in 2010 and 2011, which is especially evident in age-0 fish, occurred in both regions and therefore could not be attributed to the impact of the DWH oil spill in Louisiana alone.
- Red Drum growth increments were positively correlated with March/April sea surface temperature (SST) for each region, respectively, with increasing growth as SST increased. Temperatures during 2010, however, were the lowest in the time-series in both regions and were therefore correlated with slow growth in both regions. It was therefore not possible to completely unconfound any potential chronic growth effects of the oil spill from the effects of low March/April SST that also occurred in 2010.
- Otolith sclerochronology using growth increments of Red Drum >15 years of age from Louisiana indicated that spring SST was the only significant environmental forcing factor for Red Drum growth in Louisiana. Minor impacts were detected for the Atlantic Multidecadal Oscillation and the El Niño Southern Oscillation. Tropical storms and hurricanes did not appear to have an immediate impact on Red Drum growth but may have some delayed positive effects. Adding the DWH oil spill as a comparable (relative) major hurricane event increased the correlation with the tropical storm data, and appeared to have similar positive delayed effects on Red Drum growth, but still remain a nonsignificant forcing factor overall.
