The decision to build a nuclear power plant at Calvert Cliffs on the
western shore of the Chesapeake Bay in southern Maryland resulted in a
Iandmark legal decision (Calvert Cliffs Coordinating Committee vs Atomic
Energy Commission) and began one ofthe mostintensive long-term studies
ever carried out in an American estuarine system. In the pages that
follow we describe the major results and findings from studies conducted
over more than a decade by scientists from The Academy of Natural
Seiences of Philadelphia (ANSP). These studies were designed to assess
the potential effects that operation ofthe Calvert Cliffs Nuclear Power
Plant (CCNPP) might have on the mid-portion of Chesapeake Bay. The
approach taken was to study major biotic components of the system over
an area and a time period sufficient to allow comparison of conditions
between preoperational and operational periods within a sampling
locality, and comparisons of conditions at reference sites with those at
impact sites afterplant operations began. Elementschosen for detailed
study included: species composition and production rates of major
primary producers; water chemistry; zooplankton, benthos and finfish
abundance and species composition; the abundance and growth rates of
commercially important shellfish (clams, oysters and blue crabs); and
the colonization sequences of invertebrates on artificial substrates.