Jellyfish are flourishing in the world's oceans, washing up on beaches, causing a major problem for fisheries.
"It happens as a consequence of the vagaries of tides, winds, currents, season plankton blooms and all of that so it's somewhat unpredictable," said NIWA jellyfish specialist, Dr Dennis Gordon.
The plankton blooms are the result of pollution, as well as warmer waters from climate change.
Most fish will struggle in the conditions, but jellyfish thrive.
"It effects the environment in terms of there being too many jellyfish, they're then competing with fisheries because the jellyfish consume the eggs and the larvae and the baby fish that other fisheries rely on, so they are directly competing," said Dr Gordon.
Few species eat jellyfish.
Turtles do, but they get them confused with plastic bags and can die.
While the likes of tuna are being over-fished and can't keep up with the jellyfish bloom.
So The Larder owner, Jacob Brown has decided to do some pest control.
"I think it's almost a sin that we've got tuna on our menus, unsustainable and being over fished and we don't have jellyfish which is abundant," he said.
The Wellington chef first started serving jellyfish three years ago.
"If you can imagine a cucumber that's been soaked in the sea so it's crunchy and briney and pretty unflavoursome, so it takes on whatever flavour you want to throw at it really," he said describing the taste of jellyfish.
It's full of protein, low in fat, and possibly the new superfood needed to deal with this growing problem.
Island nations are pushing to crack down on industrial emissions in a bid to reduce levels of mercury found in fish.
A recent study found Pacific Islanders in the Cook Island, Kiribati, Tuvalu and the Marshall Islands have particularly high levels of mercury mainly because of their rich fish diet.
Of those tested, 97 percent had three times what the body can safely deal with.
Mercury can harm the brain, heart, kidneys, lungs and immune system, particularly those of unborn children and infants.
Researchers say it's about giving people guidance on which fish are less likely to be damaging.
"It's not very practical to tell people on small pacific islands not to eat fish more than once a month," Pacific study researcher Imogen Ingram said
"My next task is to sort out which fish are safer to eat, perhaps skipjack, not to eat swordfish and marlon.
The issue is being raised at the first UN Convention of mercury held in Geneva this week.