Sea beckons dolphins

Five bottlenose dolphins who spent three days up a Far North river have swum back to sea.

The pod swam down the Oruaiti River and back into Mangonui Harbour either on Saturday night or yesterday morning, Department of Conservation spokeswoman Carolyn Smith said.

The dolphins are thought to have entered the river to escape killer whales.

One dolphin died on Thursday after stranding itself on the riverbank, and DoC staff went to the river every day thereafter, monitoring their behaviour for signs of stress.

Ms Smith said the dolphins appeared to be acting normally, so DoC staff, on advice from national marine mammal experts, decided not to interfere, in the hopes that the mammals would head back out to sea of their own accord.

She said it was not uncommon for bottlenose dolphins to head up rivers, but extended periods in the freshwater environment increased their risk of disease and parasites and provided only a limited food source.

- NZPA