Nearly 1000 fur seals have died along the Kaikōura coastline in the past five months, and scientists say it is a result of warmer sea temperatures and depleted fish stocks.

Post-mortem tests showed many were baby seals that had starved to death, and further research was being done to work out what exactly was going on.

Department of Conservation marine science adviser Dr Jody Weir said an increase in fur seal deaths at the end of winter was not uncommon, but this was an unusual mortality event at the Ōhau Point seal colony, north of Kaikōura.

“It began in the dozens, then the hundreds and we are seeing lots of pups less than one year old and many foetuses and pups born too early that haven’t survived.”

“That is an indication that there is probably nutritional stress happening with the adult females, they need to get enough food and energy to not only feed themselves but supply milk to a growing pup and they are generally pregnant at the same time, so they need energy for that too.”