It connects the notions of sovereignty and fairness.

It connects to fierce passion on both sides and the U.

K's trade negotiators.

No, there are clear expectations have the best fishing grounds on Europe has taken advantage of about 40 years on.

We want to take our grounds back.

Focus on fishing is constant in the Brexit process, on the idea that a country should decide who fishes in its waters has a persuasive logic.

As this English fishermen puts it, We're an island nation that's profit from their seats.

The UK government is in sync with that, saying it will decide who fishes in our waters and on what terms.

But what sounds simple is proving far from it, not least because the UK helped create the situation it now wants to change.

Let's start with deals done in the seventies by the UK and its neighbors.

They're the basis of the quota system that the U uses.

This is how it works.

Here's the U.

K s exclusive economic zone marked in red, but if you're in the U, it's not exclusive everyone zones are treated as a single shared resource.

Each country gets a quota based on their fishing catches in the seventies, and individual fishermen and companies can then own a part of that national quota, and that allows them to fish a certain amount.

So that's the system.

Then, in the nineties, some fishing rights change, some quotas lost value, and some English fishermen sold their quotas to foreign businesses.

They voluntarily gave up their right to fish their own waters on.

In that time, those quotas gain value.

The BBC found that by 2019 over half of the value of England's fishing quota was controlled by vessels in foreign ownership.

The same was true in Wales, though in Scotland the figure is much lower.

So because of the EU quota system because of foreign ownership, both of which the UK agreed to.

Europe's boats have been operating in UK waters for years on from a European perspective, there are good arguments for this to continue.

The first is that a way of life is a steak.

If we content her British waters, it's practically the end of our professional.

Emmanuel Macron is clear.

He says he won't let that happen, and no circumstances will our fishermen be sacrificed to Brexit.

The second argument is that the UK doesn't have a domestic market for some of its fish.

Take herring, for example.

European fish companies argue Either they catch it and sell it or English people have to learn to eat herring a lot of it.

But for all the European arguments, of course, Brexit is a reality.

The UK is opting out of the EU's quota system on.

We're heading for an inevitable reset on fishing.

Some argue that you has yet to accept this.

The analyst, Mujtaba Rahman, says the EU position on fish is absurd.

Essentially, it's everything changes because of Brexit, but on fish it stays the same.

Perhaps the point is that fishing, despite being a relatively small industry, is in fact about everything.

It's about the UK sense of sovereignty.

It's about brexiteers keeping promises.

It's about the U demonstrating its collective strength and one last thing on that here the use core principles for Brexit negotiations.

Look closely and you'll read.

Nothing is agreed until everything is agreed, and that's where fishing finds itself part of a far larger conversation about how the U.

K and the U interact compromises are inevitable, resources will still be shared, and that includes, to some degree the U.

K's fish.