Mysterious vegetation on Castlecliff Beach baffles residents

Castlecliff residents are baffled about piles of plant matter that appeared on the beach last week. Photo/Lynne Douglas

Massive piles of plant matter that appeared on Castlecliff Beach has residents mystified.

Longtime Castlecliff resident Lynne Douglas said the vegetation began washing ashore last Friday and it appeared to be "a mix of grass cuttings, leaves and some seaweed".

"It was banked up 2m high and spread all the way along the beach from Morgan St almost to Rangiora St," she said.

"The only other time I have seen some of this was near a stormwater outlet on the river mudflats, but never on the beach, or in this sort of quantity."

One person Douglas spoke to said it was sea grass and a natural thing that occurs often in other places.

"Everyone else I know is completely baffled as to the massive quantity and why it is only on the beach and not along the river bank."

Another Castlecliff resident, Potanga Neilson, said he thought the piles looked like "mature compost" and thought someone may have dumped it from a truck but Douglas said she was fairly certain it had washed ashore because she had seen it building up during the weekend.

It has since washed away.

Both agree that the appearance of the vegetation was highly unusual and as beach regulars over many years, they have never seen anything like it before.

Graham Pearson of Castlecliff Coast Care said it sounds like it may have come from the river mouth.

Whanganui Department of Conservation spokesman Peter Lock changing weather patterns mean there are larger amounts of plant matter being washed up.