“Attacks like this are not uncommon - the sharks seem to be attracted to the streamers because of the electrical impulses emitted,” project manager Tim Allan told EnergyReview.Net from Wellington this morning.

"However, the fact that the streamer was completely severed is indicative of a very aggressive shark."

The Norwegian Multiwave Pacific Titan vessel started the 100,000 sqkm survey off the East Coast Basin for Crown Minerals last week and was about 100km east of Gisborne when the attack occurred last Sunday.

Bad weather prevented the retrieval of the severed 2.5km section of the 12km-long streamer at first, until a chase boat was able to hook it and tow it to calmer waters in Hawke’s Bay where it was reattached to the appropriate Pacific Titan streamer.

The survey resumed yesterday and Hall said he expected the survey to be completed by mid-April.

The survey is Crown Minerals’ first major foray into seismic acquisition and the results of that, and subsequent geotechnical studies, will be released to the industry free of charge to support future block offers and encourage further exploration in those areas.