European fish stocks will continue to serve as a joint bank account after Brexit - but the UK and EU have yet to agree on a budget. With each passing month, the comparison of Brexit to a painful divorce proceeding seems increasingly accurate. The process is messy, conflict-ridden, and frustratingly drawn-out.

Nowhere are these frustrations more strongly felt than in the fishing industry, where despite concerns over tariff and non-tariff barriers to the hugely important EU market, many fishers are eager for the UK to gain the power to set its own fishing limits.

But there’s a catch – a messy separation that leaves the UK and EU setting their own fishing limits is almost guaranteed to deliver rampant overfishing.

Shared resource

European fish stocks are by their very nature a shared resource. Fish swim around with no respect for borders and no sense of patriotism.

In the context of the Brexit divorce, it is helpful to think of fish stocks as a joint bank account, and the reality is that both the UK and the EU will continue to have access to the joint account under every possible Brexit scenario – even without access to each other’s waters.

The danger, then, is that both parties are also able to deplete the account, should they choose. Would either party seek to damage fish stocks? Not intentionally, but the risk remains regardless.

Maximum sustainable yield

Fortunately, we are in a good starting position. The principle of conserving fish stocks by only fishing as much as can be replaced each year - termed “maximum sustainable yield” - is enshrined in the EU’s Common Fisheries Policy and the UK Government has committed to upholding this principle post-Brexit.

Here, too, there is a similarity with a bank account, where sustainable management means leaving the capital and only taking out the interest that is generated each year.

Great that the EU and UK agree on how much can be taken out - but the problem that arises is how that budget is shared.

Currently, Ministers from EU member states meet at the end of each year to agree on how much fish can be caught the following year.

Sharing the seas

At these council meetings, official scientific advice on sustainable catch limits is translated into a total quota limit on fishing (e.g. 6,000 tonnes of plaice), which is then distributed through fixed shares to the UK and other EU countries.

For Channel plaice: 28 percent of the quota goes to the UK and 72 percent goes to other EU countries including Belgium, the Netherlands and France.

These relative shares - based on historical fishing patterns - were agreed when EU fishing quotas began in the early 1980s and have remained in place ever since.

These shares represent one way to split the available budget, but post-Brexit the UK would like to claim a greater share of that budget based on proportion of the fish stock that is located in UK waters over the course of a year, whereas the EU would like to keep the division based on the proportion of historical catches.

Messy divorce

The UK position would reverse the 70/30 split for Channel plaice, and other species. This is the messy part of the divorce settlement on fisheries and will not be an easy conflict to resolve.

And yet March 2019 draws nearer. The UK’s position on a potential implementation period recently confirmed in the Prime Minister’s ‘Road to Brexit’ speech, is that the UK should first determine its ‘fair share’ of the available budget and let EU countries settle on the rest.

But what if the EU’s concept of a ‘fair share’ and the UK’s concept of a ‘fair share’ exceed the available budget?

It is possible that neither party is overfishing from their own perspective - but adding 70 percent and 70 percent equals systematic overfishing.

Fish wars

Norway, Iceland, and other countries with a share of European fish stocks provide a helpful illustration. Their management of shared stocks are not a model to replicate.

As Norway, Iceland, the EU, and other parties have the power to set their own ‘fair share’, northern fish stocks are frequently overfished when negotiations break down, as seen more recently in the so-called cod, mackerel and herrings wars.

In terms of following scientific advice, Norway, Iceland and other countries have a worse record than the EU. The UK and the EU are on course to replicate this model unless fixed shares are agreed by both parties.

Collective vs individual interest

Independent countries overexploiting a shared resource is one of the oldest lessons in managing natural resources, from grazing pastures to greenhouse gas emissions in the atmosphere.

While the EU structure is not without faults, collective agreement did solve the fundamental lesson of shared resources: individual interest is to overexploit a resource as the cost of doing so are shared by everyone.

As the Brexit negotiations carry on, one of the main considerations is whether the UK or the EU has a stronger voice in the negotiations. This remains unclear, but it is obvious that when it comes to fisheries, the weakest voice is that of the fish themselves.

Ignoring the need for an agreement on how the UK and the EU will share the available budget post-Brexit will deplete fish stocks at the industry’s and society’s peril. This must be part of a transition deal with independent fisheries policy.

This blog was originally published by The Ecologist here.