Questioning Maximum Sustainable Yield at low biomass
Inconvenient Questions for the Minister of Fisheries
June 2009; www.seafriends.org.nz/issues/fishing/bmsy.htm


Fisheries in New Zealand are managed by a so-called Quota Management System (QMS) by which fish catches are allocated according to individually transferable quotas (ITFs), set by a Total Allowable Catch (TAC). At the basis of it dominates the hypothesis that maximum sustainable yield is achieved at a mere 20% of the original biomass. Fisheries management elsewhere has shown that this is a very risky strategy, most likely the cause of fisheries collapses worldwide. Having researched the issues extensively, we have severe misgivings, reason for this letter to the Minister of Fisheries in New Zealand. Is maximum sustainable yield at low biomass a fraud? Does it give maximum yield, and is this sustainable?

21 June 2009

Hon. Phil Heatley
Minister of Fisheries
Parliament Buildings
Wellington

Dear Minister,

congratulations with your renewed effort to bring New Zealand's fisheries into a sustainable regime by 2015. We at Seafriends work hard to achieve the same; to save the sea for future generations. Sadly we've had to debunk myths and fallacies about our presumed 'knowledge' of the sea (seafriends.org.nz). Likewise we have misgivings about the very basis on which fisheries management is founded, that of Maximum Sustainable Yield at 20% of original Biomass (the '20% BMSY hypothesis').

On behalf of present and future generations of New Zealanders, we invite you to answer the following three questions that lie at the heart of our concerns:

1) Show us the calculations that led to the 20% BMSY hypothesis.

2) Show us the ecological principles on which these calculations are based.

3) Show us the scientific research that has tested the hypothesis and proved its correctness beyond doubt.

I hope you will understand the gravity of our concerns and that we expect a well-founded answer within a reasonable amount of time of say 4 weeks.

This correspondence is closely monitored by the fishing community at large and the press, both local and international. An answer in the spirit of reassurance, public relations or propaganda is therefore entirely inadequate.

Thank you for your earliest attention.

Yours sincerely,
Dr J Floor Anthoni,
Director Seafriends Conservation and Education Centre.



5 October 2009

Dear Minister,

On 21 June we wrote a letter asking you to explain three questions about the very basis of fisheries management. We thought a reply period of one month would suffice. In the meantime over two months have lapsed.

Must we assume therefore that the Ministry of Fisheries is unable to answer the three questions, and that indeed an ecological foundation for present fisheries management is lacking, and scientific proof of the assumptions on which it is based, is also missing? Must we therefore conclude that fisheries management is merely a bean-counting exercise with unproven models that have no proven basis in the reality of the marine environment?

The New Zealand public has reasons to be concerned, particularly since New Zealand's shellfish fisheries have recently collapsed.
 
 

Sincerely yours,
 

Dr J Floor Anthoni,
Director Seafriends Conservation and Education Centre.