Subject: Harbor Porpoise: Plastic ingestion and diet of harbour porpoise (fwd)

Mike Williamson (pita@www1.wheelock.edu)
Fri, 16 Oct 1998 13:18:18 -0400 (EDT)

---------- Forwarded message ----------
Date: Thu, 15 Oct 1998 14:29:30 -0400
From: "Robin W. Baird" <rwbaird@IS.Dal.Ca>
To: MARMAM@UVVM.UVIC.CA
Subject: Plastic ingestion and diet of harbour porpoise

We recently necropsied a 95 cm harbour porpoise which was found dead
on the Northumberland Strait (Gulf of St. Lawrence) coast of Nova
Scotia, Canada. Two things were particularly of interest. The porpoise
had ingested a 5 cm x 7 cm piece of plastic, which was lodged in the
posterior end of the esophagus. Immediately anterior to this were the
remains of 18 recently ingested juvenile threespined sticklebacks
(Gasterosteus aculeatus).

I have found a number of references on harbour porpoise diet
(citations below), none of which appear to mention feeding on
threespined stickleback. Presumably at 95 cm, the animal was only
recently weaned, and it was also visibly emaciated, thus it seems
likely that it was feeding on fish not normally in the diet of the
species. This might also explain the ingestion of plastic. Such
plastic ingestion appear to be rare, not only in harbour porpoise, but
in cetaceans in general (some citations below). I'm wondering whether
any researchers have records of harbour porpoise ingestion of
plastic, or feeding on threespined sticklebacks, or any references
(published or unpublished) to plastic ingestion in other cetaceans
other than those noted below.

I'm also interested in the size of weaning for North Atlantic harbour
porpoise, if anyone has any information on this.

Thanks very much,

Robin



Harbour porpoise diet references

Fontaine, P.-M., M.O. Hammill, C. Barrette, and M.C. Kingsley. 1994.
Summer diet of the harbour porpoise (Phocoena phocoena) in the estuary
and the northern Gulf of St. Lawrence. Can. J. Fish. Aquat. Sci.
51:172-178.

Gannon, D.P., J.E. Craddock, and A.J. Read. 1998. Autumn food habits
of harbor porpoises, Phocoena phocoena, in the Gulf of Maine. Fish.
Bull., U.S. 96:428-437.

Rae, B.B. 1965. The food of the common porpoise (Phocaena phocaena).
J. Zool., Lond. 146:114-122.

Rae, B.B. 1973. Additional notes on the food of the common porpoise
(Phocoena phocoena). J. Zool., Lond. 169:127-131.

Recchia, C.A., and A.J. Read. 1989. Stomach contents of harbour
porpoises, Phocoena phocoena (L.), from the Bay of Fundy. Can. J.
Zool. 67:2140-2146. Smith, G.J.D., and D.E. Gaskin. 1974. The diet of
harbor porpoise (Phocoena phocoena (L.)) in coastal waters of Eastern
Canada, with special reference to the Bay of Fundy. Can. J. Zool.
52:777-782.

Smith, R.J., and A.J. Read. 1992. Consumption of euphausiids by
harbour porpoise (Phocoena phocoena) calves in the Bay of Fundy. Can.
J. Zool. 70:1629-1632.

Plastic ingestion references

Barros, N.B., D.K. Odell, and G.W. Patton. 1990. Ingestion of plastic
debris by stranded marine mammals from Florida. Page 746 in Proc. 2nd
Int. Conf. Marine Debris, Honolulu, HI. NOAA Tech. Mem. NMFS 154.

Kastelein, R.A., and M.S.S. Lavaleije. 1992. Foreign bodies in the
stomach of a female harbour porpoise (Phocoena phocoena) from the
North Sea. Aquat. Mammals 18:40-46.

Tarpley, R.J., and S. Marwitz. 1993. Plastic debris ingestion by
cetaceans along the Texas coast: two case reports. Aquat. Mammals
19:93-98.

Whitaker, B.R., J.R. Geraci, and A. Stamper. 1994. The near-fatal
ingestion of plastic by a pygmy sperm whale, Kogia breviceps. Proc.
Int. Assoc. Aquat. Anim. Med. 25:108.





==========================================================
Robin W. Baird, Ph.D.
Biology Department, Dalhousie University, 1355 Oxford St.,
Halifax, Nova Scotia B3H 4J1 Canada
Phone (902) 494-3723
Fax (902) 494-3736
e-mail: rwbaird@is.dal.ca
http://is.dal.ca/~whitelab/index.htm