Lw. Hall et Rw. Alden, A REVIEW OF CONCURRENT AMBIENT WATER COLUMN AND SEDIMENT TOXICITY TESTING IN THE CHESAPEAKE BAY WATERSHED - 1990-1994, Environmental toxicology and chemistry, 16(8), 1997, pp. 1606-1617
The objectives of this study were to identify toxic ambient areas in t
he Chesapeake Bay watershed by using a battery of water column and sed
iment toxicity tests. Twenty-five ambient stations in nine river/harbo
rs were tested during 1990 through 1994. Seasonal and annual compariso
ns were conducted at selected stations. Inorganic and organic contamin
ants were evaluated in ambient water and sediment concurrently with wa
ter column and sediment tests to assess possible causes of toxicity, a
lthough absolute causality cannot be established. Multivariate statist
ical analysis was used to develop a TOX-INDEX at each station for both
water column and sediment toxicity data. Water column tests from the
5-year testing period showed that 43% of the time, some degree of toxi
city was reported. The most toxic sites based on water column results
were located in urbanized areas such as the Elizabeth River, Baltimore
Harbor, and the Middle River. Water quality criteria for copper, lead
, mercury, nickel, and zinc were exceeded at one or more of these site
s. Some degree of sediment toxicity was reported from 70% of the tests
conducted during the 5-year period. The Elizabeth River and Baltimore
Harbor stations were reported as the most toxic areas based on sedime
nt results. Sediment toxicity guidelines (Long and Morgan effects rang
e median [ER-M] values) were exceeded for one or more of the following
metals at these two locations: arsenic, cadmium, chromium, copper, le
ad, nickel, and zinc. At the Elizabeth River stations 9 of 16 semivola
tile organics and 2 of 7 pesticides measured exceeded the ER-M values.
Various semivolatile organics exceeded the ER-M values at a number of
Baltimore Harbor sites; pyrene and dibenzo (a,h) anthracene were part
icularly high at one of the stations (Northwest Harbor).