In their 1965 survey of dugongs on the north-east Australian coast, Dr. Colin and Dr. Kate Bertram made the welcome discovery that these aquatic mammals, whose numbers were seriously reduced throughout their range in the last century and the early decades of this, are now holding their own here and may even in a few places be increasing. Dugong meat and oil are highly valued by some Australian native people, and the animals fill an important ecological niche as consumers of aquatic plants in shallow water.