EPA's New 316(b) Rule: Do Biologists Have a Role?

In March 2011 EPA published its latest, and possibly last, proposed rule on minimizing impingement of fish and entrainment of eggs and larvae by cooling water intake structures such as those at power generating stations.  Before this latest rule, EPA's preference, partly for ease of administration, was to measure "adverse environmental impact" by how many fish, eggs, and larvae are lost to the aquatic community. The new rule raises, once again, the question of how much EPA's requirements for cooling water withdrawals should take into account the knowledge fisheries biologists have accumulated about aquatic communities.  The fundamental question is whether there are situations in which the sacrifice of fish (or eggs or larvae) does essentially no harm to the "environment" and whether EPA’s regulations should recognize them.  Conceptually there are at least two ways to go beyond a simple fish-count approach and consider the loss of organisms in the context of “environment.”  One is to estimate the “value” of fish, eggs, and larvae and then compare that estimate to the cost of preventing losses (that is, some form of cost-benefit analysis).  Here EPA proposes to use a public opinion survey to measure how much value the public assigns to changes in fish populations; there is some role for biologists in designing the survey instrument, but the data gathered are the lay opinions of the public.  The second approach is to consider the overall health of the aquatic community in the waterbody and whether it will be materially harmed by entrainment and impingement.  This cannot be done without an informed use of fisheries science, bearing on the questions what constitutes a “healthy” aquatic community?; how do aquatic communities react to stresses such as entrainment and impingement?; and how much loss can a community sustain without serious harm in the long run?