Effects of the Razor Clam Tagelus plebeius on the Fate of Petroleum Hydrocarbons: A Mesocosm Experiment
The relationship between organisms and contaminants may be a two-way interaction: contaminants affecting the biota and the biota affecting the environmental fate and distribution of the contaminants. This may be especially so for sediment-dwelling organisms, because their burrowing and feeding can drastically influence sediment characteristics. The present study looked at the influence of the suspension-feeding stout razor clam Tagelus plebeius on the distribution of crude oil and pyrene in greenhouse mesocosm experiments. Water column turbidity and sediment redox also were monitored during the 15- to 30-day exposures to provide information on the influence of hydrocarbons and the razor clams on environmental conditions. For the experiment with crude oil, sediment was taken from the mesocosms at the end of the experiment, and the hydrocarbon-degradation potential was assessed in incubations with 14C-naphthalene. The experiments used four treatments: hydrocarbons present/absent and razor clams present/absent. Hydrocarbon dosing levels were relatively low (1 mL of oil or 30 mg of pyrene per mesocosm with 22 L of natural sediment and 11 L of seawater). The presence of the razor clams resulted in hydrocarbon concentrations at the sediment surface being 25% lower than in mesocosms without clams. No consistent effects were noted for polycyclic aromatic hydrocarbon (PAH) concentrations in the water column or in subsurface sediment. The naphthalene-degradation potential was elevated for sediment from mesocosms dosed with oil, but the presence of the clams did not affect this potential. The presence of the razor clams resulted in a lowering of water column turbidity, but no effect on sediment redox. The hydrocarbon addition had no effect on turbidity, but sediment redox was lowered. While results show that the presence of the razor clams resulted in a loss of hydrocarbons from the surface sediment, the other results do not provide a clear picture of the underlying mechanisms and the fate of the PAHs lost from the sediment surface. We hypothesize that the loss of surface sediment PAHs was due to burial of surface sediment and possibly bioaccumulation by the clams. While additional research is needed for further insights into underlying mechanisms, the present work demonstrates that the presence of sediment-burrowing suspension feeders decreases hydrocarbon levels in surface sediment. This means that assessments of the impact of an oil spill should pay attention to effects on these organisms and to their influence on the fate and distribution of the spilled oil.
The authors greatly appreciate the assistance provided by William Anderson, Emmanuel Blankson, Jessica Ector, Fatima Fazal-ur-Rehman, Marco Franco, Marie Hoag, Frank Higgins, Simon Pecknik, Mohammed Gazzaz, and Taylor Terracina. This research was made possible by Grant GoMRI-025 from The Gulf of Mexico Research Initiative. Data are publicly available through the Gulf of Mexico Research Initiative Information & Data Cooperative (GRIIDC) at https://data.gulfresearchinitiative.org (DOIs https://doi.org/10.7266/n7w093ws, https://doi.org/10.7266/N7MK69WH, https://doi.org/10.7266/N7GT5K6N and https://doi.org/10.7266/N7DV1H8X).
- Castagna M, Chanley P (1973) Salinity tolerance of some bivalves from inshore and estuarine environments in Virginia waters on the western mid-Atlantic coast. Malacologia 12:47–96Google Scholar
- Chung WK, King GM (2001) Isolation, characterization, and polyaromatic hydrocarbon degradation potential of aerobic bacteria from marine macrofaunal burrow sediments and description of Lutibacterium anuloederans gen. nov., sp. nov., and Cycloclasticus spirillensus sp. nov. Appl Environ Microbiol 67:5585–5592CrossRefGoogle Scholar
- Colin PL, Suchanek TH, McMurtry GM (1986) Water pumping and particulate resuspension by callianassids (Crustacea: Thalassinidea) at Enewetak and Bikini Atolls, Marshall Islands. Bull Mar Sci 38:19–24Google Scholar
- McMurtry GM, Schneider RC, Colin PL, Buddemeier RW, Suchanek TH (1986) Vertical distribution of fallout radionuclides in Enewetak lagoon sediments: effects of burial and bioturbation on the radionuclide inventory. Bull Mar Sci 38:35–55Google Scholar
- Qin X, Sun H, Wang C, Yu Y, Sun T (2010) Impacts of crab bioturbation on the fate of polycyclic aromatic hydrocarbons in sediment from the Beitang estuary of Tianjin, China. Environ Toxicol Chem 29:1248–1255Google Scholar
- Remaili TM, Simpson SL, Amato ED, Spadaro DA, Jarolimek CV, Jolley DF (2016) The impact of sediment bioturbation by secondary organisms on metal bioavailability, bioaccumulation and toxicity to target organisms in benthic bioassays: implications for sediment quality assessment. Environ Pollut 208:590–599CrossRefGoogle Scholar
- Yang T, Speare K, McKay L, MacGregor BJ, Joye SB, Teske A (2016) Distinct bacterial communities in surficial seafloor sediments following the 2010 Deepwater Horizon blowout. Front Microbiol 7:1384Google Scholar