The organotin research at NBS is solely conducted on a reimbursable basis 

 with funding from four agencies, including (1) Transportation— Coast 

 Guard, (2) Interior — Minerals Management Service, (3) Defense — Navy, and 

 (4) Commerce — NCAA. An automated sampling methodology is currently being 

 developed for the continuous analysis of organotin compounds with a 

 detection limit of 5 ng/1 with continuous measurement capability over 

 complete tidal cycles. 



2.4.2 National r>rv=>ani c and Atmospheric AJministration 



The principal office within NCAA having the responsibility for monitoring 

 of organotin concentrations in the aquatic environment is the Ocean 

 Assessments Division (CAD) within the National Ocean Service. The CAD is 

 responsible for the NCAA Status and Trends Program (S&T) which is col- 

 lecting water, sediment and tissue samples from a series of 150 coastal 

 stations to establish the status and trends of specific contaminants over 

 time. This program has added TBT and DBT to its sampling program in 

 specific areas beginning in 1987. 



The NCAA National Sea Grant College Program has sponsored a research study 

 with organotins, testing for toxicity and sublethal effects with the 

 Fiddler Crab ( Uca Puailator ) and Killifish (Fungulus heterclitus) at 

 Rutgers University (Weis et al., 1987a, b) . 



2.4.3 U.S. Environmental Protection Aaency 



The Environmental Protection Agency (EPA) Chesapeake Bay Program (CEP) 

 initiated a small scale (500) sample monitoring program during the Summer 

 of 1986. These samples were analyzed by EPA's Gulf Breeze Laboratory, 

 which has a lower detection limit of 20 ng/1. The study was coordinated 

 by the EPA Chesapeake Bay Liaison Office with the assistance of Dr. 

 Lenwood Hall of Johns Hopkins University as a twenty week, small-scale 

 sampling program to measure concentrations of tributyltin and dibutyltin 

 at four selected harbor sites in Northern Chesapeake Bay: Annapolis, 

 Solomons, Oxford and Plaindealing Creek. The survey concluded that 

 sources of TBT measured in the harbor areas are directly linked to local 

 boating and marina activity and specifically to TBT leachate from 

 antifouling paints, and that the sampled harbors are a source to TBT to 

 the estuarine environment beyond the boundaries of the harbors." The 

 highest average concentrations of TBT by site were found at Annapolis 

 (70.6 ng/1) followed by Solomons (34.7 ng/1) Oxford (27.7 ng/1) and 

 Plaindealing Creek (20.1 ng.l). It was concluded that these 

 concentrations were high and sufficiently constant enough to pose a threat 

 to organisms living in the harbor areas (EPA Chesapeake Bay Program, 

 1987) . Improvements in instrumentation are underway to enable a larger 

 monitoring program to be conducted in Chesapeake Bay. 



In the near future, EPA will issue a Data Call In Notice requiring TBT 

 registrants to conduct a three to four year study of U.S. waters. This 

 study will provide baseline information on the extent and levels of TBT 

 found around representative docks, marinas and other sensitive areas. 



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