Attempts to move the boat to deeper waters to protect its structural integrity were stopped on Monday because the hull had settled firmly on a large rock.
The regional council’s on-scene commander, Emma Parr, said staff had made every effort to retrieve hazardous and loose material from the wreck, while monitoring its stability.
“We continue to work with the salvage team to oversee and guide alternative options for the most effective and timely recovery of Black Cat,” she said.
“Our focus remains on reducing environmental impacts and ensuring the safety of everyone involved.”
The boat was carrying 2240 litres of marine diesel fuel and around 120 litres of other oils in sealed containers and engines combined.
Retired Otago University professor and biologist Liz Slooten said nearby Hector’s dolphins could be exposed to diesel pollution if it was not cleaned up quickly.
“Diesel will get into their eyes, diesel and other oils that come out of the vessel,” she said.
“It will get into their lungs by inhaling the fumes, which tend to accumulate close to the water surface because it’s heavier than normal air. That’s exactly where these dolphins are breathing.
“When they eat contaminated fish, it will get into their digestive system.”
Parr said the council was monitoring any immediate effects on the environment or wildlife and that fuel had rapidly dispersed.
“We have not observed any immediate impacts on the environment or wildlife,” he said.
Research had been done on the effects of oil and diesel spills on dolphins and showed they led to a range of serious health effects, including lung disease and adrenal gland problems, Slooten said.
She called on authorities to be more proactive when responding to emergencies.
“It seems that each time something like this happens, basically everybody stands around going, ‘oh my goodness, what are we going to do now’. We need a plan up front, rather than waiting for a disaster to happen and then trying to figure out what to do about it. That is obviously not effective,” she said.
It is the second diesel spill near Banks Peninsula in just over two years after the Austro Carina fishing boat ran aground at Shell Bay in September 2023.
Slooten said the boat would cause further environmental problems if it broke up.
“Then you’ll get plastic and metal and goodness knows what other pollutants into the environment. The longer it’s left and the more it breaks up, the harder it’s going to be to clean up the mess,” she said.
In a statement posted to social media on Saturday, Black Cat Cruises said while some of the 38 passengers were shaken by the grounding, they commended the crew for their calm, efficient and reassuring manner during evacuation.
“This is the first incident to occur in over 40 years of this nature and naturally safety is our No 1 priority and we are deeply saddened that this has occurred. We are very grateful for the support of local operators and boaties that assisted us during this incident.
“We are commencing an investigation into the incident and working with authorities on the matter.”
-RNZ