PRINCIPLE 1 – Let’s rebuild the fishery

The situation

Nearly all of our inshore fish stocks are sitting below the international best practice standard for sustainability, which is defined as at least 40% of the original stock size that existed in the absence of fishing.

We want this to change but Ministry officials and the commercial sector refuse to commit to remedying this because of the short term economic pain that would hurt the profits of a few quota owners.

Historically, fisheries managers have targeted a much lower level, around 20 to 25%. Commercial fishers seem content to fish down stocks and then keep those fisheries depleted. As long as the quotas can be caught and a profit made within a reasonable time there’s no pressure to change.

For example, the snapper stock in the Bay of Plenty is estimated to be below 10% of its original size. Commercial scallopers in the Nelson/Marlborough area can only catch around 10% of their allowable limit because the fishery is so depleted. Something needs to be done.

Rebuilding fish stocks requires that less fish are killed each year, however once the target of 40% is reached more fish will be able to be taken without depleting the stock below 40%

The system is failing everyone, apart from those who make money from leasing quota and selling fish.

Why you

Managing our fisheries towards depletion is having drastic effects on our oceans ecosystem. We are only just starting to understand how we are affecting these fragile systems.

Low stock sizes are causing a great deal of friction between the commercial and non commercial fishing sectors as they compete for access to a publicly owned resource.

These conflicts were manifested during recent reviews of kahawai, snapper, paua, scallops, crayfish, blue moki, blue cod, marlin and other fisheries.

The public has made it abundantly clear they are not interested in continuing to conserve fish just to see the commercial fishery continue unaffected and using smaller minimum legal sizes to their advantage. The public have taken several cuts to their daily limits and many people voluntarily fish to a larger minimum size limit, now it’s time for the commercial users to play their part.

Undoubtedly the recreational fishing experience is being badly affected by poor management decisions. Little regard has been given to our current fishing interests or our future wellbeing.

LegaSea’s solution

Let’s aim for abundance of fisheries and commit to protecting that abundance so that it is truly sustainable. All sectors can benefit from having abundant fisheries.

Let’s change the way our fisheries managers use the words “sustainable”. Sustainable is often used to describe the minimum level required to maintain revenue. We can change that so “sustainable” describes a more modern biological definition, one that moves us in the direction of the abundance of fish that our oceans once provided. Let’s make “sustainable” meaningful for future generations.

LegaSea says it’s time to Tip the Scales. We need to move from depletion to managing for abundance and sustainability. We can do this by setting a default minimum target of 40% across all our inshore fish stocks. So when our fisheries managers make important decisions, they are targeting a minimum stock size of 40%. This will bring us into line with world best practice and lend some truth to the claims that our quota system is world-leading.

To achieve rebuilt fisheries we will need to adopt a modern “ecosystem wide” approach to management, one that takes into account the interdependence of different species. After all, fish don’t live in isolation and neither do we. Together, let’s Tip the Scales.


International best practice in setting management targets for fish stocks at a minimum biomass of 40% of the original unfished stock size. To achieve this the exploitation rate on the snapper stock should not exceed 8%. The 40% stock target may not apply to fast growing stocks, but remains the default starting point.

1. Adopt the default target of 40% or better of the unfished biomass and set Total Allowable Catches (TACs) accordingly.

2. When the target biomass is reached allocation decisions can be made after fully considering the obligations to future generations, and after the full intentions of Part 3 of the Fisheries Act are adopted.

3. Adopt an ecosystem approach to stock management which better accounts for interdependent and associated species.

4. Adopt a cautious approach to management when stock assessments do not match up with the reality of what is actually happening in the water.

Prior to modern fishing fisheries were assumed to be at around 100%, or virgin stock size. Industrial fishing reduced many inshore fish stocks to very low levels. A stock size of 40% of the unfished size (B40) is the contemporary estimate of the stock size that will produce the maximum sustainable yield (MSY). B40 is best considered as a minimum stock size, because below this level the stock loses the ability to provide ecosystem services.

B40 has been adopted by Australia, and recommended by the Chief Scientist (Pamela Mace) at Ministry for Primary Industries (MPI) as the most appropriate target for New Zealand. Despite this, MPI don’t adopt this target in the harvest strategies applied to inshore fish stocks.

The average size of the fish are larger, and they are more numerous. This will result in better fishing success for all users, and a healthier marine environment. Catching costs will be reduced for commercial users and the public will find catching legal sized fish much easier.
Ecosystem management considers more than just a single species when setting catch limits. It is widely understood that most species in the inshore ecosystem are more or less interdependent; if one species is depleted it will have an affect on many others.

Although many of the exact details of species interactions are not fully understood it is necessary to account for these in the best manner available. In most cases this will be by discounting the Total Allowable Catch (TAC) to account for ecosystem degradation.

The exploitation rate has to be reduced. The exploitation rate is the proportion of adult fish in each year class that is taken by fishing. For example, for snapper on the northeast coast of the North Island (SNA1) the current exploitation rate is estimated to be between 11 and 15% , and there is a the difference is between the three sub-management areas of East Northland, the Hauraki Gulf and Bay of Plenty.

A reduction in fishing mortality is required for about 12 years to fully rebuild the northern snapper stock. We suggest targeting juvenile mortality and small fish in the first instance as these will provide the most saving. Protecting the juveniles and catching the fish when they are older means we will still be able to take a reasonable yield while the stock rebuilds.

The same situation applies to many other inshore species that have been fished down, to varying degrees.

There is no exact estimate of virgin biomass, and the current estimates are constructs of the modeling used by scientists. All measurements of current biomass as a proportion of the unfished use these original estimates.These estimates are the best available and uncertain; another reason we should be cautious when setting TACs.
The B40 target drives the strategy. By agreeing to the B40 target we turn our minds to the best way of achieving it. All our strategies result from accepting the rebuild target and that determines the rebuild timeframe.
Shaun WilsonPrinciple 1 – Rebuild the fishery