A recent video on Facebook has sparked fears that mollusk populations in New Zealand could be under threat. Rising sea temperatures are thought to be the main culprit.
High temperatures and mid-day low tides are being held responsible for a recent discovery of hundreds of thousands of dead "cooked" muscles on a beach in New Zealand. A local resident, Brandon Ferguson, recently posted a video on Facebook showing the devastation on Maunganui Bluff Beach.
Located in New Zealand's North Island, the resident was horrified to find many dead mussels littering the beach. In an interview with Business Insider, Ferguson spoke of his horror at the discovery.
"I'm local to the area so I'm always out on 'the coast' gathering food for the family," he told them. "That day I was out with friends and family while they were fishing. We waited for the tide to turn so we could gather mussels."
This time, however, what he found was very upsetting to him.
Here is the video below. Please note the video contains some colorful language.
"It smelled like dead rotting seafood," Ferguson said. "Some of the mussels were empty, some of them were dead … Some were just floating around in the tide."
"There were well over 500,000 mussels and shells littering the coastline."
This isn't the first time the phenomenon has been seen
Ferguson also told Business Insider that this event isn't unprecedented. He had seen similar things in the past, but with different shellfish washing up dead.
"It has happened in the past due to warm water temperatures, low mid-day tides, and high pressures," Ferguson explained.
According to a New Zealand government report from 2019, Ferguson's theory appears to hold some water. The report reviewed data from between 1981 and 2018 and found that overall sea-surface temperatures across New Zealand's four oceanic regions have increased by around 0.1 to 0.2 degrees Celsius a decade.
This might not sound like a lot, but the effect on the local biota is telling.
"New Zealand's oceans act like a giant sponge against the effects of climate change," wrote New Zealand's Secretary for the Environment Vicky Robertson in the report.
"It's likely our seas take up more carbon dioxide than our forests, but there is only so much they and the life in them can take - and the limits aren't yet known," she explained.
Rising sea temperatures are also affecting other forms of ocean life around the planet.
Warmer water holds less C02
The report expands on the issue at hand by explaining that the warmer water gets the less likely it can absorb. and hold, gases like C02. This, the report explains, acts like a kind of negative feedback making the situation worse.
A marine scientist at the University of Auckland, Andrew Jeffs, told the New Zealand Herald that the mussels most likely perished from "heat stress" brought on by hot weather and mid-day low tides.
"The mussels die of heat stress. You imagine lying in the midday sun every day for four hours for the best part of a week. You'd be pretty sunburnt at the end of that," Jeffs told The Herald.
Jeffs went further and made a prediction that mollusks, like mussels, might disappear entirely from New Zealand's coastal regions.
"In many other countries, we are seeing [the] poleward movement of the distribution of the species as they adjust to temperature increases associated with climate change," he added.
New Zealand is no exception in Jeffs' view.
Whether such stark predictions will come true is yet to be seen, but such mass-deaths of shellfish indicate that something is perversely affected the local ecosystems. Whether local mollusk species can adapt fast enough to oceanic changes of this magnitude is yet to be seen.