Deep-Sea Coral Systems on Lord Howe Rise: Groundbreaking Proof Fuels Bottom Trawling Debate in New Zealand

Groundbreaking Evidence Emerges from Lord Howe Rise Expeditions

New footage and analysis from recent expeditions have provided what environmental advocates call irrefutable proof of vast deep-sea coral systems on the Lord Howe Rise, a submerged plateau in the South Pacific high seas between New Zealand and Australia. 40 62 Greenpeace's 2024 seamount expedition documented over 350 species of corals and sponges, highlighting ancient ecosystems that could take centuries to recover from disturbances. This revelation coincides with New Zealand's push for increased orange roughy quotas in the region, intensifying the national conversation on sustainable fishing practices.

The Lord Howe Rise, managed under the South Pacific Regional Fisheries Management Organisation (SPRFMO), features chains of seamounts teeming with vulnerable marine ecosystems (VMEs). These findings underscore the urgency of balancing commercial interests with conservation, drawing attention from scientists at New Zealand institutions like the National Institute of Water and Atmospheric Research (NIWA), which collaborates closely with universities.

Understanding Deep-Sea Coral Systems: Slow-Growing Ancient Forests

Deep-sea corals, unlike their shallow-water counterparts, thrive in cold, dark waters below 200 meters, forming complex structures known as coral gardens or reefs. Species like Solenosmilia variabilis (stony coral) and black corals can live for hundreds to thousands of years, growing at rates of just millimeters per year. These frameworks support diverse biodiversity, providing habitat for fish like orange roughy (Hoplostethus atlanticus), sponges, and other invertebrates. 61

In the Lord Howe Rise area, these corals create three-dimensional habitats on seamount slopes and plateaus, acting as hotspots for pelagic species and migratory pathways for whales and sharks. NIWA's comprehensive reports detail over 1,300 deep-sea coral records in New Zealand waters, emphasizing their vulnerability to physical disruption.

The Geological Marvel of Lord Howe Rise

The Lord Howe Rise is a vast underwater ridge spanning 1,400 km, remnant of ancient Gondwana separation, featuring volcanic seamounts and abyssal plains at depths of 400-2,000 meters. Its isolation fosters unique biodiversity, including long-lived corals that rival ancient redwood forests in longevity. A 2025 research symposium in Sydney gathered nearly 70 experts, including New Zealand scientists, to discuss its geological and biological significance. 55

This region's seamounts serve as fish aggregation devices and navigation beacons for marine migrants, making it ecologically vital yet under threat from human activities.

Bottom Trawling Mechanics and Direct Impacts

Bottom trawling involves dragging heavy nets weighted with rollers across the seafloor to harvest species like orange roughy. While effective for commercial fishing, it plows up everything in its path, crushing corals, sponges, and sediments. Recovery times for affected areas can exceed 1,000 years, leading to biodiversity loss and habitat homogenization. 61

• Physical destruction: Nets break coral frameworks, burying survivors in sediment.
• Bycatch: Exceeding 15kg limits triggers closures under SPRFMO rules.
• Indirect effects: Disrupts food webs and carbon sequestration in seafloor communities.

New Zealand is one of the last nations permitting bottom trawling in high seas, prompting global scrutiny.

High-Profile Trawling Incidents Ignite Controversy

In October 2024, the NZ-flagged trawler Tasman Viking scooped 37kg of gorgonian sea fans, black, and stony corals from Central Lord Howe Rise, surpassing SPRFMO's 15kg threshold. This prompted a two-year closure of the affected patch. 62 The vessel had a prior conviction in 2023 for unreported 20kg bamboo coral bycatch, fined NZ$52,000. Greenpeace obtained coordinates via Official Information Act, revealing government reluctance to disclose locations. 51

These events highlight enforcement challenges in international waters.

Environmental Advocates Demand Immediate Bans

Groups like Greenpeace and WWF Aotearoa decry bottom trawling as 'industrial-scale destruction,' citing 78% public support for a South Pacific ban per recent polling. They urge SPRFMO to designate the area as a marine protected area (MPA) and accelerate High Seas Treaty ratification. Expert Dr. Riley Elliott notes, "Deep-sea corals are ancient ecosystems we can't afford to lose."

Calls include incorporating First Nations knowledge for stewardship.

Government and Industry Push Back on Restrictions

Oceans Minister Shane Jones advocates reviewing bycatch limits, arguing NZ needs sustainable orange roughy access amid global protein demands. Fishing industry representatives emphasize accidental bycatch and compliance with SPRFMO, contributing research jobs in fisheries science. However, proposals to weaken protections have drawn criticism amid COP16 coral pledges.

Balancing economic value (orange roughy worth millions) with conservation remains contentious.

New Zealand Universities and NIWA Lead Coral Research

NIWA, partnering with universities like Victoria University of Wellington and University of Auckland, has mapped deep-sea corals via voyages and genetic studies. The 2019 NIWA report catalogs species distributions, while 2025 symposium abstracts feature NZ researchers on connectivity and climate impacts. 47 42

• Genetic connectivity projects assess population resilience.
• Habitat modeling predicts climate change effects.
• Training programs foster next-gen marine biologists.

These efforts position NZ higher ed as a hub for ocean science. View research assistant jobs in marine biology.

SPRFMO Regulations and Global High Seas Treaty

SPRFMO mandates move-on rules for VME indicators and data sharing. The 2024 incident review led to closures, but NZ seeks quota expansions. The UN High Seas Treaty (BBNJ) promises stronger protections, yet ratification lags. SPRFMO site details ongoing measures.

Ecological and Economic Implications

Coral loss disrupts orange roughy spawning, threatening NZ's $50M+ fishery. Broader impacts include reduced carbon storage and biodiversity collapse. Conservation could boost eco-tourism and sustainable aquaculture.

Pathways Forward: Solutions and Innovations

Alternatives include mid-water trawling, cameras for real-time monitoring, and MPAs. University-led AI modeling and ROV surveys offer non-destructive assessment. Public support (78%) pressures policy shifts.

Photo by Heidi Bruce on Unsplash

Careers in Marine Science: Join the Debate

NZ universities offer degrees in marine biology, with demand for experts in conservation tech. From PhDs at Otago to postdocs, opportunities abound. Engage via Rate My Professor or higher-ed jobs. Career advice available.