Assessing Coastwide Effects of Power Plant Entrainment and Impingement on Fish Populations: Atlantic Menhaden Example

Abstract

A method was developed for assessing coastwide effects of power plant impingement and entrainment on managed fish stocks. The method imbeds an assessment of anthropogenic effects that occur during the first year of life of fish (the period when most entrainment and impingement occur) into a standard age-structured stock assessment that addresses age-1 and older fish. The method thereby provides a straightforward means for comparing the effects of entrainment and impingement mortality to other forms of anthropogenic mortality affecting coastwide fish stocks. The method uses standard equations from fishery science that represent the relationships among independent competing forces of mortality, stock abundance, and landings. Power plant mortality is treated like fishing mortality, and power plant losses are treated like fishery landings. The total age-0 natural mortality rate is allocated to the individual age-0 life stages based on a power function relating daily natural mortality rates to age-specific dry weights of fish. An illustrative example of the use of the method is presented for the Atlantic coast stock of Atlantic menhaden Brevoortia [Article]tyrannus, which was chosen because it is a coastwide stock, has a coastwide fishery, and is described by highquality fisheries-dependent data. However, because available entrainment and impingement data were not adequate to support defensible coastwide estimates of the annual numbers killed by entrainment and impingement, actual estimates of the effects of entrainment and impingement on the coastwide Atlantic menhaden stock could not be computed. The method could be used to address the effects of any form of anthropogenic mortality affecting age-0 fish, including loss of habitat, effects of toxic substances, fishing mortality, and fishery bycatch, provided that valid coastwide estimates of the annual numbers of fish killed by the source of mortality are available. 570 HEIMBUCH ET AL.

Potential Environmental Impacts of Coastal Desalination Intake Structures: Urgent Data Gaps and Policy Needs

“…The influence of environmental factors on impingement, entrapment and entrainment (IE&E) underscores the importance of conducting site-specific EIAs to inform siting decisions for proposed SWRO facilities. This assertion is further supported by the Atlantic States Marine Fisheries Commission’s determination that IE&E data collected at existing coastal facilities cannot reliably be used for purposes of assessing potential risks at other facilities or for the development of coastwide assessments (even for species with high-quality fisheries-dependent data) . This finding is relatively unsurprising, given the list of factors that exert considerable influence over IE&E risks at a given site.…”

“…In addition, there is a dearth of quantitative data available that definitively describe the impacts of desalination intakes at the population and community levels of biological organization, particularly at coastal sites with restricted water exchange with the open ocean. 4,22,27,29 ■ IMPACTS OF IMPINGEMENT ON MARINE BIOTA Studies that have endeavored to provide conclusive quantitative measures of IE&E impacts on aquatic systems also face additional challenges beyond those previously discussed. For example, a multiyear study conducted near a power plant cooling water intake on the Hudson River (New York, USA) estimated that IE&E reduced juvenile and adult populations of seven fish species by 10−20%; however, the data used to derive those estimates were collected over a 3-year time frame just after the power plant became operational.…”

“…This finding is relatively unsurprising, given the list of factors that exert considerable influence over IE&E risks at a given site. In addition, there is a dearth of quantitative data available that definitively describe the impacts of desalination intakes at the population and community levels of biological organization, particularly at coastal sites with restricted water exchange with the open ocean. ,,, …”

“…This assertion is further supported by the Atlantic States Marine Fisheries Commission's determination that IE&E data collected at existing coastal facilities cannot reliably be used for purposes of assessing potential risks at other facilities or for the development of coastwide assessments (even for species with high-quality fisheries-dependent data). 29 This finding is relatively unsurprising, given the list of factors that exert considerable influence over IE&E risks at a given site. In addition, there is a dearth of quantitative data available that definitively describe the impacts of desalination intakes at the population and community levels of biological organization, particularly at coastal sites with restricted water exchange with the open ocean.…”

Effect of Intermittent Traveling Water Screen Operation on Fish Survival

“…A literature review by Barnthouse (2013) found that impacts from impingement and entrainment on fish populations are small compared with those caused by overfishing, habitat destruction, pollution, and invasive species. However, there are methods for incorporating these losses into stock assessments either to quantify the effects of impingement and entrainment to the total stock (e.g., Heimbuch et al 2007) or to determine restoration offsets associated with losses from a particular power plant (Barnthouse et al 2019). Adverse environmental impacts at a population level have been more difficult to quantity (e.g., Lohner et al 2000;Lewis and Seegert 2002).…”