“Wild kelp harvest is native forest logging of the sea”? Or just like “mowing the lawn”? It had marine science and conservationists in an uproar today, so what’s it all about?

Phil Heatley likes picking seaweed. So do I.

In a whipping wind, against a rising tide, I choose the nicest pieces, the prettiest colours, as many shapes as I can find. In my mind, I am composing a sea vegetable salad; actually, I’m making liquid fertiliser.

Fertiliser is but one among the many things industry wants to harvest wild seaweed for, and Minister of Fisheries Phil Heatley is happy to oblige them.

Yesterday, he riled conservation and marine science advocates, by announcing he would open wild bladder kelp fisheries to a larger commercial harvest than expected. There will be two new fisheries, one south of Kaikoura, the other round the Chathams. For simplicity, this post just gives figures for one, the larger one, down the South Island’s east coast.

He's gambling with high stakes, because of the kelp’s ecosystem importance. Worse, he knows all about the size of the stakes, and the paucity of his information, and he’s proceeding anyway, seemingly hoping that if he says “cautious” and “conservative” enough times, someone will believe him.

There are two parts to it: quota management for kelp, and what the quotas should be. People were, it seems, prepared to wear quota management, given the unregulated alternative. But whereas most submissions urged caution, in setting the 'total allowable catch' or quota, and a number of them wanted it set at zero for the time being, Heatley in his final decision has multiplied the proposed quota three times, from what was consulted on.

We want it for food and body products, stock food and, yes, fertiliser. But, at sea, kelp is a nursery and refuge for all sorts of marine species; the start of their food chain, and therefore, our food chain; and, by modifying wave and tidal action, helps slow coastal erosion.

Its critical marine ecosystem role is recognised and, on the face of it, pretty fully addressed in the Ministry of Fisheries’ advice to Heatley, and in his final decision. He notes that “little information is available on the adverse effects, if any, of harvesting bladder kelp in New Zealand. However, given the role of this species in the ecosystem I believe a cautious approach to management is required ...”.

Really, the dispute is about what “cautious” ought to mean in this context; how should “conservative” look, in practice? Heatley thinks he has been both of these things; others disagree.

For example, he did not choose the worst among the range of options developed by his officials post-consultation; nor were officials in developing those options prepared to go as far as some submitters. But in contrast to the three options consulted on -- 375.8, 41.2, or 18.2 tonnes -- the ’total allowable catch’ (TAC) he has set, that will come into effect next week on October 1, is 1,238 tonnes.

Was this in line with submissions? Well, yes and no. His Ministry received 32 submissions, from the whole range of interest groups: conservation (DOC, Forest & Bird), fisheries' industry, iwi, marine scientists. And true: 24 of these did not support any of the options put forward. Of those 24, there were 8 submissions that “strongly oppose any commercial harvest of attached bladder kelp, and a number of them request that a TAC … of zero tonnes be implemented” and another eight that considered “that all of the TAC options presented were exceptionally, and unnecessarily, conservative”. [Update: see footnote, on the comments thread.]

“I consider the TAC’s strike an appropriate balance between providing incentive for development of the fishery while ensuring sustainability of the stocks” writes Heatley. And, “I believe these TACCS will provide real opportunity for development of this important resource within sustainable limits”. And, “The recommended TACCs would provide industry with greater harvest opportunities from the resource to derive greater economic return, while reflecting the developing nature of the fishery”.

Officials’ advice notes that even the 375.8T option (supported by only two submitters) would have created “a moderate incentive for quota-holders to invest and develop the fishery based on the guaranteed harvest level”. In the end though, they recommended, and Heatley chose, the 1,238T option, with a “high level of risk associated with adverse effects of harvesting” which, with harvest management tools, could be mitigated to a “moderate” risk [p 59 of final advice].

“The level of risk increases with higher TAC levels. In order to manage this risk MFish has consulted on a range of additional harvest management measures … that would complement the TAC”. They propose a maximum cutting depth of 1.2 metres from sea surface, to protect the base of the kelp where it reproduces, prevent removal of whole plants, and allow young fronds to continue to grow.

A decent compromise? It’s worth bearing in mind how much weight has been placed on the importance of this: the whole weight of the proposal really, because in its absence, officials would only have recommended a TAC of either 41.2T or 18.2T, which would not have been out of line with what some, eg DOC, would have supported.

One can only speculate at how the conversation might have gone: presumably, the options laid out were not economically viable according to industry, so that faced with the alternative of no viable fishery at all, Heatley was ultimately persuaded the resulting risk could be managed by a cutting restriction.

And maybe it can. Officials also consider their approach to have been “conservative”, because they did the numbers based on actual kelp growth data, "rather than assumptions about what the kelp may be able to sustain". They had also looked at overseas (Californian) examples.

Some doubt, though, whether Californian kelp and New Zealand kelp are the same, and whether the Californian outcomes are proof of sustainability. This risk was noted by the officials: “Research overseas has shown that harvest of bladder kelp canopies does not appear to have significant effects on the bladder kelp beds themselves … MFish acknowledges that the majority of available research has been conducted off the California coast where the scale and size of bladder kelp beds are much larger and the physical environment different than in New Zealand”.

Responding to concerns of submitters (because the 1.2 m idea was put to them, and not considered an adequate response to the risk): “MFish acknowledges there may be situations or areas where this measure is less effective, particularly if the majority of a plant is exposed to harvest at low tide … However, MFish considers this measure would be effective in reducing the overall impact of harvesting on most bladder kelp beds. MFish considers harvesting is most likely to occur where the beds are deep enough for this measure to be effective. MFish also considers there is sufficient industry incentive to encourage rapid post-harvest recovery to ensure maximum canopy development over a shorter timeframe. MFish would review this measure if new information suggested changes were necessary to preserve plant structure and productivity.”

And, “new information on the potential ecological impacts of bladder kelp harvesting in New Zealand will likely be available in the next three years to support future decision-making”. Of course it will, because we’ll be trying out some harvesting for ourselves in the meantime.

This is, in other words, a three-year experiment. And, even cloaked in the language of caution, it doesn’t look wholly cautious to me, by my definition of that concept, in the context of a very large risk. It looks like 'harvest first, and ask the questions later'.

I’d rather ask the questions now; of course, meantime, they will go ahead and harvest anyway.