Fears dumpsite could harm dolphins

• Published date: 28 October 2021
• Publication title: Southland Express

However, the council responsible for protecting an old dump site next to the tranquil bay says the area in question is low risk, and it has no immediate plans to protect it.

In the past four months, Colac Bay/Oraka residents have come out in force, lobbying the Southland District Council (SDC) to take action over a retired landfill in the coastal town.

The site is located behind an ever-crumbling coastal road, and residents claim it contains car bodies, batteries, plastics, oil, herbicides and paint.

Dolphin researcher Gemma McGrath, who has lived at Colac Bay/Oraka since 2018, said the strip between the beach and wetland — which covered the old dumpsite — was getting narrower with every tide cycle.

‘‘A worst-case scenario would be nasty toxins like DDT and 2,4,5-T leaching out into our marine environment, going through the food chain,’’ McGrath said.

‘‘Our ecosystem will be toxic, and our kai moana won’t be safe.’’

Just what is contained within the ground was yet to be confirmed, but statements provided by 10 past and present residents painted a grim picture.

Some locals believe old herbicides are buried at the 50- to 60-year-old site.

In a written statement presented to SDC, ex-resident Pete McKay pointed out agricultural chemicals in the 1980s were rife with ‘‘typically horrific chemicals like DDT, ‘2,4,5-T’’’, indicating some could be contained in the wetland.

If that was the case, Ms McGrath believed the bay was in trouble, because the now-banned DDT and 2,4,5-T had a half-life of 150 years.

She said Colac Bay/Oraka was not just home to the eight or so Hector’s Dolphins, which frequented the area, but also orca, bottlenose and common dolphins.

‘‘Colac was the first bay around mainland New Zealand to have a southern right whale give birth again, since the whaling days, when this species was targeted to near extinction,’’ Ms McGrath said at a Community Board meeting last week.

‘‘Hector’s Dolphins have sharply declined over the past 70 years, due to accidental bycatch in fishing nets.’’

Recovery was a slow process because female Hector’s only had one calf every three to four years — and that was when conditions were good, she said.

‘‘They are true locals, having a small alongshore range of 30km-50km.’’

Because Hector’s along the southern coast depended on each other for breeding, if the situation turned south for the Colac/Oraka regulars, it would also spell bad news for the Riverton/Aparima pod and those further down at Oreti.

‘‘I’ve seen Hector’s...