Hundreds of fish are believed to have died in a suspicious fire which gutted an iconic Mapua aquarium this morning, one of three fires in the Nelson Bays town overnight.
Emergency services were called to the blaze at the Touch the Sea Aquarium on Aranui Street around 3am.
Fire Service Southern Communications shift manager Karl Patterson said seven engines and two tankers were called to the fire, which was "well involved" on arrival.
Mapua chief fire officer Ian Reade told Radio New Zealand 37 crew were at the scene at the height of the blaze, and were assisted by a helicopter dousing the flames.
Crews were not able to go inside the building to combat the blaze, he said, but had been able to stop the blaze spreading to other buildings.