Observed behaviors and post-mortem levels of pollutants found in one of two bottlenose dolphins (Tursiops truncatus) that Inhabited Upper Newport Bay Ecological Reserve, Newport Beach, California, From July to November 2004.

In July 2004, two bottlenose dolphins (Tursiops truncatus) took up residence in Upper Newport Bay Ecological Reserve (UNBER) in Newport Beach, California. Currently there is no scientific documentation of this event occurring in the history of coastal bottlenose dolphin research along the coast of Orange County, California. The Coastal Dolphin Survey Project (CDSP) observed the dolphins and recorded data biweekly for a period of five months, using photographs, videotape, and field notes. The dolphins were primarily found to exhibit feeding, playing, and resting behavior during the observation period. On September 18, 2004, we believe that the larger of the two dolphins was found dead far up into Upper Newport Bay Ecological Reserve; however the dolphin’s advanced state of decomposition ruled out the possibility of a necropsy and positive identification.  Subsequently the larger of the two dolphins was no longer observed during our study.   This animal was buried in a location that was recorded with GPS coordinates for eventual recovery of the skeleton. Observations continued on the surviving dolphin until November 23, 2004. One week later, the smaller of the two dolphins was found dead washed up on the shores of Lido Island in Newport Harbor. Our representative recovered the corpse and a necropsy was performed on this dolphin on December 10, 2004.  The necropsy revealed signs of starvation accompanied with severe reduction of the blubber layer but the cause of death could not be positively determined. Tissue samples of blubber, liver, kidney, muscle and brain were collected and sent to CRG Marine Laboratories in Torrance, California, for chemical analysis. The results showed considerable levels of the pesticide DDT and its constituents (82.5 µg/wet g), PCBs (18.2 µg/ wet g), Tributaltyn (0.098 µg/ wet g) and Mercury (9.4 µg/wet g) in all tissues sampled. Recent (2002) reports on the pollutants found in the sediment and fishes in Newport Bay, lead us to believe that the polluted food web in the bay played a key role in the total burden of contaminants found in the dolphin’s tissues through bioaccumulation.