Mass Stranding Of Whales And Dolphins

Mass strandings

• Groups of marine mammals come ashore and die.

• They are frequent where the 1.  may alter rapidly.

Possible explanations

Parasites

• Parasites can damage an animal's 2. , which is essential for navigation.

Toxins

• Whales commonly consume poisons originating in 3. .

• In 1988, saxitoxin killed whales at Cape Cod.

Accidental strandings

• Animals may chase prey onto shore, as observed by Thurston in 1995.

• This is doubtful because most animals were not 4.  when they stranded.

Human activity

• 5.  produced by military tests have been associated with recent cases.

• The Bahamas event in 2000 was unusual because the whales:

• were all 6. 
• were not together in a 7. .

Group behaviour

• Strandings occur more often among the most 8.  whale species.
• In the 1994 dolphin case, only the 9.  was sick.

Further reading

• Connor's Marine Mammals Ashore provides information about stranding 10. .