Fisheries New Zealand is seeking feedback on how to address kina barrens. Here is our submission: 

The Hauturu Supporters Trust is a charitable trust with a long history of working to protect the unique environment of Hauturu-o-Toi or Little Barrier Island.

Hauturu-o-Toi is one of the most highly prized and protected areas of the natural environment in New Zealand. Ironically this protection stops at the shoreline. Below the waterline, it is open slather for all kinds of fishing activities. This has resulted in massive adverse impacts on this unique and important natural environment. Despite the Nature Reserve Boundary running along the waterline, the ecology of the island does not stop at this artificial boundary. For example, native lizards which inhabit the shoreline of Hauturu-o-Toi feed on kelp flies which lay their eggs on beachcast kelp, but less kelp is arriving on this coast because of changes in the underwater environment.

“The last 50 years or more of heavy fishing pressure around the island has had a devastating effect on the health of its reefs, leaving a desolate wasteland of urchin or kina barrens, depleted fish and other kaimoana stocks, and the loss of previously productive kelp forests (Ecklonia radiata). What we now have is a mere shadow of the rich and diverse marine ecology of yesteryear” (Grace, 2019).

More recent research confirms that unrelenting fishing pressure is continuing to damage the underwater ecosystems surrounding Hauturu-o-Toi (Dartnall, 2022). This research has found that kina barrens did not occur on the reefs around Hauturu-o-Toi in the 1950s. By the 1970s, however, they were a major habitat on subtidal reefs, covering 11.6% of reef at Hauturu-o-Toi. By 2022 this has almost tripled to 32%. “This progression is consistent with industrial scale removal of predators, such as the spiny rock lobster and snapper, from the middle of last century” (Dartnall, 2022).

In addition to the widespread destruction of the underwater environment of this precious motu, vessel activity in the vicinity of Hauturu-o-Toi, especially commercial fishing vessels, greatly increases the risk of incursion from pest species on the island, especially rodents. Such an incursion would be of major significance to the extremely high conservation values of Hauturu-o-Toi. To achieve pest elimination, a very expensive response would be needed. Furthermore, the addition of kina harvesting around the island has the potential to increase the risk of transmission of the invasive Caulerpa species to the coastal margins of Hauturu-o-Toi.

The Hauraki Gulf Protection Bill, if enacted, will support marine protection measures for only parts of the degraded reef systems on Hauturu-o-Toi. We believe that these measures need to be more extensive to provide for more comprehensive protection of a highly valuable marine environment that is integral to sustaining the ecological integrity of the associated nature reserve at Hauturu-o-Toi.

There is overwhelming scientific evidence from northeastern New Zealand that spatial closures to fishing, especially the fishing of kina predators, is a very reliable method for removing kina barrens and restoring the full productivity and biodiversity of shallow water reefs. Spatial closures are urgently required for all shallow water reefs affected by urchin barrens around Hauturu-o-Toi to address this ecological crisis. In contrast, increasing the harvesting and/or culling of kina does not offer a practical long-term solution to the significant ecological problem of kina barrens. This approach fails to address the underlying causes of the issue, which affects one of our most valuable conservation assets. The reef margins around the island should be protected by closing fishing out to at least 45 m depth to provide for recovery of these reef ecosystems. Such a protection measure should be placed in conjunction with rahui by Ngāti Manuhiri and Ngāti Rehua, tangata whenua of the motu.

References:

Grace, R. 2019. Seas around Hauturu. In: Hauturu: The history, flora and fauna of Te Hauturu-o-Toi Little Barrier Island. Eds. Wade, L. & Veitch, D. Massey University Press, pp.250-265.

Dartnall, L. 2022. The extent of kina barrens over time at Hauturu-o-Toi and the Noises Islands. MSc Thesis, in Marine Science. University of Auckland.

 

Photo (c) Shaun Lee

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