The search for a humpback whale last seen yesterday in the Bay of Islands with rope tangled around its head has been called off for the day.
The search will continue tomorrow, weather permitting.
A rescue team is on hand to try to cut what is thought to a crayfish rope around the sub-adult whale first seen yesterday.
It was last seen at nightfall but a search in rough conditions this morning failed to find the marine animal that had been showing signs of distress yesterday.
The Department of Conservation in a helicopter and specialist whale rescue teams in boats searched a wide area, with no luck.
Marine mammal expert Floppy Halliday said the whale appeared to be having difficulty holding its head properly when first sighted.
Yesterday afternoon a whale entanglement response team was able to assess the situation. The team was unable to free the whale but took photos and collected information.
Bay of Islands marine weather conditions were expected to worsen by midday, DoC spokeswoman Abi Monteith said.
''Therefore, a call will be made at this time on whether it is safe to continue the response. If the weather makes it unsafe to proceed today, the weather conditions are due to ease tomorrow morning and another plan will be put in place for a response tomorrow,'' Monteith said.
''The Department has received offers of help, however at this stage we have enough resources on the water including a spotter plane and vessels to assist and support the main response team. Any further resources may hamper the rescue effort.''
She said the team needs to focus its attention on the whale and minimise any further disturbance to the whale, and would appreciate vessels staying well clear of the area.
•Humpback whales can weigh up to 50 tonnes, and will not be happy with being interfered with, so extreme caution is required.
•The public are requested to stay clear of the area to prevent further stress on the animal and allow the response team to focus their efforts on the animal.
•Marine Mammal Regulations 1992 state: No boats allowed within 50 m of whales; no person shall make any loud or disturbing noise near whales.
New Zealand's winter and early spring was the whale's peak migration time and in the past month there have been a number of humpback whale sightings in the region.
Early last month an adult female humpback and a calf died after stranding on Baylys Beach, south of Dargaville, and a week later another humpback was spotted in Whangārei Harbour.