Coastal Napier sea-life mystery ‘indicates marine ecosystem is struggling’

Perished sea-life stricken on the beach off Hardinge Rd, Ahuriri, on Thursday. Photo / Warren Buckland

Warnings advising against touching or consuming perished sea life washed ashore at Ahuriri remained in place on Friday as experts awaited answers in the mystery of how the “heart-breaking” event happened.

Hawke’s Bay Regional Council science manager Anna Madarasz-Smith said the science team on Thursday observed crayfish, kina, starfish and sea cucumbers and collected samples for analysis.

Hundreds, and possibly thousands, of the species were reported on the northeast-facing Hardinge Rd foreshore from early afternoon on Thursday, but almost 24 hours later the council reported in a media release: “At this stage the situation is unexplained and isolated in nature.”

“This event is heart-breaking, and shocking for our community, and indicates the marine ecosystem is struggling,” Madarasz-Smith said.

“We have had heavy rain and warm seas, and this may have contributed to this event,” she said. “Our team are out on the water today taking samples. We need to undertake scientific analysis to determine the cause, and it may be some days before we have any answers.”

The council is taking the lead on this situation as this is possibly a wider environmental issue – with support from Mana Ahuriri, Te Whatu Ora, Ministry for Primary Industries, National Aquarium of New Zealand, Department of Conservation, and the Port of Napier.

Yesterday the regional council’s marine science team investigated the dead sea life and took samples, but by the time they arrived about 1.30pm, most of the dead animals had been removed by people in the area.

“We do urge people to not gather or consume the dead sea life,” Madarasz-Smith said.

The council’s pollution response team was also investigating for any spills in the known high-risk areas in the vicinity.

Some coast and seafood watchers suggested the event could be caused by such factors as the algal bloom that has predominated on the Hawke’s Bay coastline for the last month, deoxygenation amid the warming of the waters off the coast, and repeated impacts from swollen rivers flowing into the Bay, including high levels of freshwater into the environments of shallower-water sea life, and possibly bombardment from logs and other debris in the waves.

In Auckland, beaches are off-limits to the public because of waste contamination following the extreme conditions of more than 250mm of rain in 24 hours a week ago.