Report of a cetacean survey in the Western Approaches of the ...

Dolphin 6SPECIES: Common dolphin (Delphinus delphis)SEX: femaleDATE FOUND: Found floating at sea by Greenpeace vessel Esperanza on 15/03/05LOCATION FOUND: English ChannelNATIONAL GRID NUMBER:DATE OF POSTMORTEM: 18/05/05PATHOLOGIST: P Jepson/R Deaville1. BASIC MEASUREMENTSFROZEN: Yes.CARCASS CONDITION: Slight decompositionBODY WEIGHT: 77.2kgLENGTH, GIRTH AND BLUBBER THICKNESS:-blubber thickness in front of dorsal fin:-tip upper jaw to tail notch: 186.0cm-girth in front of dorsal fin: 105.0cm-dorsal mid-line: 16.0mm-lateral: 15.0mm-ventral mid-line: 17.0mm2. GROSS POSTMORTEMExternal examinationNutritional state: Good.Body orifices: The eyes were present. The left dorsal eyelid appeared to have been pecked by scavengers.There was a (approx. 1metre) long longitudinal slit in the ventral body wall (knife injury?) extending fromthe genital slit to just caudal to the ribs. The abdominal cavity was exposed and some of the abdominalviscera were missing. A section of approximately 7-8 adjacent teeth in the right lower dental arcade werebroken off at the level of the gingiva. Several additional teeth were missing from the right caudal upperand lower arcades.Ectoparasites: None.Fins and flukes: Three parallel and short linear cuts were located on the anterior insertion of the leftpectoral fin. These lesions were consistent with monofilament gillnet (tested by applying a section ofgillnet to the lesions). There were two fresh and slightly jagged tears on the trailing edge of the left tailfluke (one was still bleeding). A similar tear was noted on the trailing edge of the dorsal fin. A section ofthe trailing edge of the right pectoral fin was also missing, possibly having been cut away.Comments:This adult female common dolphin was in good nutritive condition at death. A number of findingsconsistent with entanglement in fishing gear (by-catch) were found on postmortem examination. Theseincluded a long and deep incision within the ventral body wall, submandibular and thoracic retialcontusions and recently ingested prey. No evidence to support an alternative cause of death was found. Anumber of external lesions were consistent with entanglement on monofilament gillnet-type fishing gear,including suspected net marks on the left pectoral fin and left body wall, and fresh jagged tears in thetrailing edge of the dorsal fin and left tail fluke.This report is based on gross findings and may be modified after the laboratory findings are known.Laboratory results pending: none.Paul JepsonLondon, 19/05/05.40