Calls to Ban Bottom Trawling Grow Louder as Massive Coral Destruction Exposed
- Natalie Jessup
- Jun 15
- 3 min read
Updated: Jun 16
The Endangered Species Foundation is supporting calls for urgent government action to ban bottom trawling in Aotearoa and the wider South Pacific following the worst reported case of coral destruction in New Zealand waters in over a decade.
In late 2024, a New Zealand bottom trawling vessel hauled up six tonnes of bycatch from the Chatham Rise (pictured above). Much of that was stony coral - a legally protected, slow-growing reef-building species. The incident, revealed through an official information request by the Deep Sea Conservation Coalition, highlights the indiscriminate destruction caused by trawl nets dragging across fragile seafloor habitats.
NZ trawlers destroy huge amounts of coral every year, with the fleet reporting tonnes of coral bycatch annually. In 2022 - 2023 the observer-reported amount of coral bycatch from trawlers was over six tonnes - and that's just from the 22% of trawls that were overseen by observers onboard.
Pictured above: Bycatch, mountains of stony coral and gorgonian coral weighing 80 kilograms, around 300 years old, all destroyed by the NZ fishing fleet.
Karli Thomas, ESF Oceans Advisor and campaigner with the Deep Sea Conservation Coalition, described the coral bycatch as “a disaster for deep sea corals” and “truly heartbreaking.”
“If this incident had happened in the international waters of the South Pacific, the area would have been immediately closed to trawling. Coral must be protected if we want healthy and thriving ocean ecosystems and this latest coral bycatch is a reminder of how destructive bottom trawling is - and why it must be banned from ancient and fragile deep sea habitats” says Thomas.
Bottom trawling destroys ocean habitats and puts endangered species like Māui and Hector’s dolphins at even greater risk.
“These destructive fishing practices bulldoze entire ecosystems, including critical feeding and breeding habitats for marine life,." says Natalie Jessup, General Manager of the Endangered Species Foundation. "We cannot afford to let this continue.”
Māui dolphins are already teetering on the edge of extinction, with fewer than 50 individuals left. Their cousins, Hector’s dolphins, are also in serious decline. Once the most common dolphin in Aotearoa’s waters, their population has plummeted from an estimated 50,000 in 1975 to just 10,000–15,000 today.
There is no mystery about what’s driving the decline:
“The fishing industry has killed more Māui and Hector’s dolphins than any other known cause. Entanglement in nets remains the biggest human-related threat to these animals. These images of nets bursting with coral and massive bycatch are the result of destructive practices that destroy habitats for all sea life,” says Jessup.
In the latest MPI bycatch data, covering the first three months of this year, two Hector's dolphins were killed in trawl nets and one in a set net over that period.
Map of bottom-trawled areas around Aotearoa
This map shows spatial variation in the level of bottom trawl seafloor contact across the New Zealand region. The level of contact is presented as the Swept Area Ratio (SAR), the total accumulated swept area (km2 per 1 km2 grid cell) of all recorded bottom trawls between 1990 and 2020, shown on a log scale.
“The government cannot continue to promote reef conservation internationally while allowing massive ocean destruction at home,” said Jessup. “If we are serious about protecting our ocean and preventing the extinction of the Māui dolphin, then we need to end destructive fishing practices.”
The Endangered Species Foundation is calling on the NZ Government to urgently:
Expand marine protected areas to include the full range of Māui Dolphin habitats out to 20 nautical miles or 100 metres depth. This would include banning set nets and trawling in these areas to eliminate the most lethal threats to these species.
Ban all bottom trawling around Aotearoa
Stop issuing permits to New Zealand vessels to bottom trawl on seamounts in international waters - New Zealand is the only country still bottom trawling the South Pacific high seas.
References:
NIWA Report "Identification of protected coral hotspots using species distribution
modelling". Report prepared for Project POP2021-02, Conservation Services
Programme, Department of Conservation August 2023
