This report documents the progress of the third year of research (fiscal year 2012) to investigate environmental issues associated with marine and hydrokinetic energy (MHK) generation. This work was conducted by Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy’s (DOE’s) Office of Energy Efficiency and Renewable Energy (EERE) Wind and Water Technologies Office. The report addresses the effects of electromagnetic fields (EMFs) on selected marine species where significant knowledge gaps exist. The species studied this fiscal year included one fish and two crustacean species: the Atlantic halibut (Hippoglossus hippoglossus), Dungeness crab (Metacarcinus magister), and American lobster (Homarus americanus).
The research reported here was supported by the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy, Wind and Water Power Technologies Office, under Contract DE-AC05-76RL01830 with the Pacific Northwest National Laboratory (PNNL).
Controlled laboratory testing
The goal of the experimental work conducted during FY12 was to conduct laboratory screening level assessments of behavioral responses to EMFs by selected marine organisms considered to be high priority by regulators and stakeholders, and for which scientific data are currently lacking. Hence further work was conducted with Atlantic halibut and Dungeness crab. Preliminary investigations with small adult American lobster were also conducted. These species were selected because of their conservation and management status and their ecological and economic importance in the United States.
- Atlantic halibut exhibited a single significant response to the EMF exposure in terms of spatial distribution (less time spent in the upstream low zone; p = 0.03). Halibut did not exhibit a significant change in behavioral activity as measured by the frequency of change in behavior as a result of EMF exposure. Although not quite reaching the level of statistical significance, the frequency of change in behavior for the EMF-exposed fish during the night and day-night combined was greater in the upstream low zone (p = 0.06 and p = .05 respectively). This observation is consistent with the observation regarding spatial distribution in the upstream-low zone. The observed differences between Control and Exposure in this zone could be due to orientation related to the upstream current, responses to changes in the vector field orientation produced by the EMF coil, or other tank effects. The activity level of the halibut was higher during the night, but overall their activity level was very low. This could be partially explained by their foraging habits. Atlantic halibut are considered to be a “sit and wait” predator (Nilsson et al. 2010); they remain undetected until prey is within a lunging range. In these experiments, prey availability was intentionally excluded as part of the study design.
- There were no statistically significant responses due to EMF strength alone with respect to spatial distribution or activity levels of Dungeness crabs. However, there were several significant responses when the data was examined with respect to the combined effects of EMF strength and vector orientation, water flow direction and other tank effects (p < 0.05 for Trial 2 flow-specific zone data). Although suggestive, these results are confounded by the fact that crab exhibited relatively large differences in behavior among days and between the two trial periods. In general, the crabs spent more time buried in areas closer to the ends of the tanks than in the center of the tanks. This general pattern of burial and location has also been noted in holding tanks of similar size and shape at MSL prior to the experimental trials. Activity levels also showed mixed results. During Trial 1, the first 2 d showed marginally higher levels of activity in the EMF Exposure Tank relative to the Control Tank (p < 0.10); however, this pattern was not repeated during Trial 2.
- Individual lobster exhibited a high level of variability in both space use and behavior within the experimental tanks independent of the EMF treatment. Within the 15 trials conducted, the lobsters did not exhibit a statistically significant response to the EMF, indicated by their use of space or a change in activity. They spent a majority of time either in the shelters (40%) or burrowed (a form of sheltering, 36%), and considerably less time (24%) out in the open (e.g., walking, digging, climbing, resting). A greater level of activity was noted during the nighttime compared to daytime hours for both control and EMF-exposed lobsters.
Woodruff, D.; Cullinan, V.; Copping, A.; Marshall, K. (2013). Effects of Electromagnetic Fields on Fish and Invertebrates - FY2012 Progress Report. Report by Pacific Northwest National Laboratory (PNNL). pp 62.