Ingestion of Plastic and Unusual Prey by a Juvenile Harbour Porpoise

Abstract

Considerable quantities of plastic debris are found throughout the world’s oceans (e.g., Dufault and Whitehead, 1994), and may impact a diversity of species, including marine turtles, birds and mammals (Laist, 1997). Since many species of whales and dolphins live in waters far from shore, and may sink upon death, opportunities to record instances of ingestion of marine debris by cetaceans are infrequent. Despite this, there are several cases where ingestion of plastic or other marine debris has been documented for cetaceans, with published reports existing for 21 species of odontocetes (Laist, 1997). We know of an additional five species of odontocetes for which marine debris ingestion has been documented: the killer whale (Orcinus orca; K. Evans, pers. comm.), northern bottlenose whale (Hyperoodon ampullatus; R. Michaud, pers. comm..), finless porpoise (Neophocoena phocoenoides; C. Parsons, pers. comm.), white-beaked dolphin (Lagenorhynchus albirostris; R. Kastelein, pers. comm.), and pantropical spotted dolphin (Stenella attenuata; K. Robertson, pers. comm.). For most species of odontocetes, only one or a few records have been reported. Here we document the third reported case of plastic ingestion by a harbour porpoise (Phocoena phocoena), and discuss factors that might have contributed to its ingestion.