Evaluating the Assessment End Point, Health, and Maintenance of Local Flounder Populations

observations: demersal eggs, nondispersive larvae, juvenile phases, and complete

lack of adult mixing with other stocks.

Winter flounder spawn in most estuaries from Chesapeake Bay through the

Gulf of Maine from midwinter to early spring (Azarovitz 1982). It is believed

that winter flounder return to the same spawning location year after year National

Marine Fisheries Service (NMFS) (1986). Winter flounder eggs are demersal and

adhesive, and therefore the spawning and nursery areas for the species should

coincide.

In areas north of Cape Cod, winter flounder remain in bays and harbors year-

round, moving into deeper holes and channels during the warmest weather

(Azarovitz 1982).

Winter flounder feed by sight near the bottom. For example, Pearcy (1962)

showed that fish fed in a dark room did not eat until zooplankton died and sank to

the bottom. Field observations confirmed that feeding occurs during the day.

These organisms are clearly bottom dwellers who spend significant portions of

their lives in close contact with sediments.

It is also significant that winter flounder eat bottom-dwelling organisms

because the consumption of these organisms provides another potential exposure

pathway. Several investigators (Pearcy 1962; MacPhee 1969; Frame 1972) noted

that they are omnivorous, opportunistic feeders, and prey upon polychaete

worms, amphipod and isopod crustaceans, pelecypods, and plant material.

Note that this example continues with assessing risk to winter flounder. The

risk assessment should similarly address other selected receptors such as a

representative benthic organism(e.g., softshell clams) or water-column organisms

which may concentrate COCs from suspended sediments.

Evaluating the Assessment End Point, Health, and

Maintenance of Local Flounder Populations

Consultation with the State Division of Marine Fisheries and the Save The

Embayment Association (a citizen's action group) indicates that the area around

the planned dredged material management site is a commercial flounder fishery.

These groups are concerned that the disposal of dredged sediments from the

marina slips may adversely affect flounder populations.

The assessment end point "health and maintenance of local flounder

populations" is a reasonable assessment endpoint and it meets the evaluation

criteria.

a. Ecological relevance. Flounder are major bottom feeders in this section

of the Bay. Flounder populations generally play a major role in such

marine ecosystem level properties as maintenance of invertebrate

diversity and nutrient cycling.

Appendix F Hypothetical Example