Why the Hauraki Gulf needs us, and we need it

If you are ever lucky enough to witness the chaos of what marine biologists in New Zealand call a ‘workup’ I would recommend stopping in your tracks and sitting down to watch the spectacle, reflect on what you’re witnessing: interspecies relationships that have been forged long before humans arrived here.

High-activity workups happen when schools of smaller fish such as pilchards are herded into a tightly packed ball, sometimes called a ‘bait ball’, by larger predators like dolphins or larger fish. It’s not long before other large marine animals arrive, such as sharks, flocks of shearwaters, petrels and a ‘plunge’ of gannets.

It’s a remarkable display of oceanic synchronicity, in which everyone, from the 17cm storm petrel to a 15m Bryde’s whale gets a feed.

 Moana/Hauraki Gulf, which could easily cover more than a kilometre of area and last for an hour or more. In recent years, they’ve only lasted a minute or two and then move on to a new spot and start again.

I hope we’ll be seeing more of these astounding events now that New Zealand has taken a small but significant step toward protecting a little more of its marine environment. Specifically, the 1.2 million-hectare Hauraki Gulf Marine Park, one of the country’s most ecologically rich and culturally significant marine areas, which has had its protected zones increase from just 0.3 percent to 6 percent. The increased protection was officially enacted on Saturday, October 25. This increase is modest, but the benefits could ripple far beyond the boundaries of these new reserves.

We know from global research that removing fishing pressure allows marine life to recover – and not just within the protected zones. Fish populations often swim to adjacent areas, and the spores from kelp and eggs of many species such as crustaceans, shellfish and fish move via currents supplying ecosystems outside of the protected area in a spillover effect. In the Gulf, this could mean better outcomes for everything from tiny plankton to large predators like whales and sharks.

What recovery looks like was shown by my colleague Dr Kelsey Miller, whose recent PhD research involved a large team doing hundreds of dives to remove kina one by one from the barrens on shallow rocky reefs in the Gulf during the spring and summer of 2020 and 2021. This team’s work resulted in a remarkable and rapid restoration of forests of the brownish kelp Ecklonia radiata, on which myriad marine life depends on for food and shelter with lush forests often visited by large predators such as dolphins and sharks to feed on the fish.

A haven for marine life – and a warning sign

The Gulf is home to an extraordinary array of marine mammals, including the nationally critically endangered Bryde’s whales and orca, as well as bottlenose and common dolphins. The region is a global hotspot with rich biodiversity of seabirds, many of which are critically endangered, and a variety of sharks and rays in this internationally recognised Important Shark and Ray Area.

But this ecosystem is under enormous pressure. Climate change is not so much the elephant in the room, but the animal stampeding through it. Warming seas are pushing plankton – the base of the marine food web – deeper and further offshore. This shift is already affecting seabirds and cetaceans in the Gulf, which are being forced to adapt or move. We need urgent action to mitigate climate change and its cascading effects on ocean life. Marine protection alone won’t solve this, but it will help, and we need all the help and hope we can get. Even a small amount of protection can yield immediate benefits.

With 94 percent of the Gulf still open to fishing – the new reserves stand for a tiny sacrifice for potentially substantial ecological gains or at least some sanctuary – areas can serve as safe havens with more abundant prey for resident species and migratory visitors alike.

But protection on paper is not enough. The success of these marine reserves depends on people working collectively, for people to encourage others to understand how important the Gulf is, that their actions matter. Alongside robust monitoring and enforcement this would help ensure these spaces are given time to recover. We also need to invest in understanding whether these protections are working – and be prepared to adapt if they’re not.

A national responsibility

New Zealand is a maritime nation. With 94 percent of our territory made up of ocean, we have a responsibility to lead in ocean stewardship. The global ’30 by 30′ initiative – which aims to protect 30 precent of the world’s oceans by 2030 – is ambitious, but necessary. We must take it seriously especially at a time of rapid climate change wreaking havoc on marine ecosystems.

What economic cost or benefit will greater protection have? Assessing the economic value of the Gulf is extraordinarily complicated, as outlined in the NZIER report commissioned by the Hauraki Gulf Forum.

One of the main difficulties lies in the nature of marine ecosystems. Unlike terrestrial environments, marine ecosystems are three-dimensional, dynamic, and less understood, with interrelated processes occurring at the seabed, in the water column, and at the surface. For many megafauna they rely on all these ocean spaces. Moreover, several of the Gulf’s most valuable ecosystem services – such as recreation, cultural heritage, biodiversity, and water quality – are not traded in markets, which shifts the narrative of ‘value’ beyond money.

The report tries to pin down this complexity with the tools of economic analysis, applying a ‘total economic value’ framework to a marine environment that has long been under pressure. What emerges is a portrait of a place whose worth far exceeds its GDP footprint. The Gulf’s greatest contributions are not what we take from it, but what it gives freely: clean water, biodiversity, a sense of place, a connection that is often hard to explain.

We need to stop thinking of the Hauraki Gulf as a backdrop to economic activity, but as a living system whose health is inseparable from our own.

We need to value a thriving environment that supports all the other life that lives here year-round or visits on their way to somewhere else: the migratory whales, sea birds, sharks and manta rays. They find food here, on the seabed, in the open waters and for the seabirds, they nest and raise chicks on the many protected islands.

This latest move in the Hauraki Gulf must be the beginning of a broader, more coordinated effort in New Zealand and internationally. Government, mana whenua, scientists, divers, paddlers, sailors, fishers, and watchers from shore, everyone has a role to play. If we want a thriving ocean for future generations, we need to come together – for the ocean, not just for our own sake, but all other life who, like us, are utterly dependent on it.