EPD does not monitor Total PAH levels in biota in the routine monitoring programmes. Total PAHs were not recorded in any tissue biota analysed during the baseline Study. As Total PAHs were not recorded above detection limits in biota analysed they will not be discussed further.

Naphthalene was recorded at high values in the tissues of Gizzard Shad (Clupanodon thrissa) , Croaker (Nibea diacantha) and Mantis Shrimp (Harpiosquilla harpax) trawled in January 1999 from Deep Bay, Mirs Bay and Southern Waters, respectively. Squid (Loligo sp.) trawled in September 1999 from Port Shelter also contained high Naphthalene levels. Based on the data obtained in this Survey, there would appear, therefore, to be no consistent pattern for Naphthalene contamination of biota in local waters indicating diffuse (ie non-point) source inputs.

The major uses of Naphthalene are in the production of phthalic anhydride (an intermediate for polyvinyl chloride plasticizers) and as an insecticide particularly in moth repellents(75). Naphthalene is not particularly toxic to aquatic organisms (eg 8d LC50 to Hemigrapsus nudus 2800 ug L-1) and is considered to be one of the least toxic PAHs(76).