At 7am on an overcast morning in the north east of Scotland, Peterhead Fish Market is buzzing with buyers who have arrived for the morning sale.

Inside Europe’s largest white-fish port, dozens of men crowd round boxes of fish that are laid out in orderly rows running half the length of the building.

David Leiper, a sea fish processor, steps outside fromm the hustle and bustle for a cigarette on the harbour side to discuss the forthcoming EU referendum. A director of Seafood Ecosse, Leiper, is committed to leaving the EU.

“Personally, I don't see huge risks going forward. I think economically we may have one, two years of tough times outwith the fishing industry but I think we’ll manage to cope with that and grow stronger after it.”

Like many in the industry, the 40 year old’s frustrations stem from the level of quotas allocated to British fishermen.

“Just how the whole fisheries policy was developed, I think Britain was stitched up a long time ago and we didn’t get what we genuinely deserved. I know the Irish feel the same. Their waters are fertile, great waters as well and they haven’t got anything like the quotas that the Spanish and French to fish in their own waters. It’s a crazy situation.”

The quota system is implemented by the EU as part of the Common Fisheries Policy (CFP). The aim of the CFP is to ensure that fishing is environmentally, economically and socially sustainable whilst also ensuring that EU citizens receive a healthy supply of food.

As fish move across territorial waters, the EU considers them to be a common resource. Historically, British waters would have extended 200 nautical miles from the coastline but this exclusive economic zone is now restricted to 12 miles. The rest of the British waters are now part of the European economic zone which can be fished by any European nation subject to quotas and licenses.

The quota system is complex and renegotiated each year according to scientific advice. Introduced as a result of overfishing and declining fish stocks, the system has succeeded in arresting the decline of many stocks and ensuring a return to sustainable fishing.

Much of the controversy around the policy stems from the fact that British fleets are allocated quotas far lower than other nations for fish that migrate through former British territorial waters.

In the North Sea in 2015 for example, British fishermen were only allocated 5% of mackerel and 4% of sprat quotas. However, they were also allocated 84% of haddock and 81% of monkfish quotas. All in, the UK received 30% of the EU’s total quota in 2015.

Whilst this means that 70% of the quota is allocated to other member states it is arguably mitigated by the fact that the UK has only 13% of the EU’s total sea area yet receives 30% of the quota.

Scotland, however, has some of the richest seas in Europe. According to a Scottish government publication released in the lead up to the independence referendum, around four tonnes of fish are taken from each square nautical mile of Scottish waters compared to around 1 tonne on average for EU waters. Therefore, greater access to Scottish waters is more beneficial for fishermen from other EU states.

Leiper, who is also a representative of the Association of Processors, believes that British fishermen should have greater allocation of quotas and does not believe that membership of the European Union is necessary to ensure sustainability.

“I think [sustainability] would be far more maintained in Britain than it is in Europe. You’ve seen the Spanish and the French fishing in the west coast in enormous vessels with nets, gill nets stretching [across] huge parts of the west coast - and that doesn’t happen in Scotland. We have now got a very small fleet, sustainable. No one can come into the industry because it’s too expensive to buy quota, it’s too expensive to buy the boat, it’s too expensive to buy the license so I think you’ve got a very sustainable fishery going forward with the Scottish fleet as it is.”

Andrew Charles, a fish processor based in Aberdeen, however, disagrees. “Going forward now we’re part of the European Union, we have a very well managed fishery out there now, we have a fleet that is expanding, we have a very modern fleet. We’ve come from a position where every single commercial stock in the North Sea was under pressure, we’re now in a position where every single species that is commercially fished out in the North Sea and British waters is now sustainable and in good health. So although it’s taken about three decades the European fisheries management systems are working now.”

Charles, the third generation of his family in the business, has worked in the industry for 36 years and is concerned about the potential ramifications of leaving the EU.

“Now if we have a Brexit and we leave the European Union what is that plan going forward? Do we risk a European free-for-all? We’re going to be very unique. A lot of people say ‘well we should adopt the Norwegian plan or the Icelandic plan or the Faroes plan, look how successful they are’. We are not Norway or Iceland and we’ll be completely different. We will be the first nation to leave the European Union and stab it in the back. Now how are our other European trading partners going to adjust to that mindset in a UK fishery that they have no interest in? That could set the European fisheries plan of the European Union back decades if we had a free-for-all. So that’s a concern.”

One man who has no concerns about leaving the EU is John Buchan. Buchan, a semi-retired skipper of the Atlantic Challenge, is a member of the Fishing for Leave campaign. As you walk round the harbour several boats proudly fly the Fishing for Leave flag. “We can’t get the flags made quick enough. We’ve put them all round the country,” he says.

Buchan, talking over a coffee in the Dolphin Cafe at the Merchants Quay, believes the power exerted by the European Union is not what the UK signed up for.

“The very first vote I ever got was the referendum [in 1975] and I was told it would be a market. Nothing was ever mentioned about a European superstate. Nothing was mentioned about all our fishing quotas and all our rules regulated from Brussels and as time has gone on it’s become more and more a massive European superstate, just a dictatorship.”

Buchan, whose son now skippers the boat and is the fifth generation of his family to do so, has no objection to other Northern European nations fishing in British waters and is not naive enough to assume that a ‘Brexit’ would result in British seas being exclusively fished by British fleets.

“There’s always going to be the Dutch, the French, the Germans, the Danes, they are always going to have a share, they’re always going to be fishing in UK waters, they’ve always done it.”

However, he strongly objects to the presence of the Spanish and believes their access to British quotas is part of the reason fishermen want to leave the EU.

“They are one of the biggest problems. In [1986] when they joined they had no quota and access was made available to them. They’ve got massive grants from the EU and they ended up buying British quota with the grants and moving boats into the UK. You’ll be very hard pushed to get any fishermen in the UK to be wanting to stay.”

Buchan’s enthusiasm for ‘Brexit' is palpable and his motivations are not financial.

“Of course economics is important but to me it’s really not important if I’m a few pounds richer or a few pounds poorer, it’s my country’s freedom I want. I’ve waited 40 years for this. The emotions in my throat are just speaking to you.”

For most people in the industry, however, economics will likely play a greater role than issues of sovereignty. The UK fishing industry has seen a significant decline in the number of vessels over recent years. In 2014 there were 6,383 fishing vessels registered in the UK compared with 7,022 in 2004, a reduction of 9 per cent.

Additionally, the number of fishermen working in the UK in 2014 was 11,845, a decline of 12 per cent since 2004. Of these fishermen, 4,796 are based in Scotland.

Since 1970, employment on Scottish based fishing vessels has fallen 49 per cent.

Despite these gloomy statistics, the port of Peterhead is thriving. In 2014 Peterhead was the port with the highest landings in the whole of the UK with a total value of £145 million. It has been estimated that roughly 40% of the 18,000 population in Peterhead is reliant on the fishing industry.

In spite of this, Alan Pirie, a fish merchant and director of the harbour based Sustainable Seafoods Peterhead, is another committed to leaving the EU.

“From our business point of view, regarding the fishing community, it would be an out. The quota is the main issue, it’s a burning issue whether you’re in the catching sector or whether you’re in the processing sector. Quotas are a massive problem.”

Sitting in his office above the fish processing plant and alongside his business partner Norman Davidson, Pirie acknowledges that, despite his desire to leave the EU, there will be risks to his business and the wider industry.

“There’ll be downsides. Migrant workers - this is an industry that’s became reliant on them, so what happens to all them if we come out of Europe? The legality of staying here and being able to work here?

“It would be a concern, I’m sure it would be a concern for a lot of processors and not just in this sector but obviously outside the fishing industry. It’ll be a big concern for a lot of people but I’m sure that there must be ways round it by just immigration control. You know they can still come here and work and obviously they’ll have to work some sort of visa system and ensure it works.”

Whilst Pirie worries that by leaving the EU he may not have access to the large migrant pool of workers, for Lorraine Greig the ability to prevent EU nationals freely entering the UK is one of the main advantages of leaving.

“I think housing could possibly get better because of the people coming over from [Europe]. There’s a new council housing estate and nearly every one of them is from Poland, from other EU countries.”

Greig, who runs the cafe in the Fishermen’s Mission, an organisation that supports fishermen and their families, claims she does not object to foreign nationals coming to work but like many people in the country appears to resent the perceived dilution of British culture caused by immigration.

“I went into Morrison’s last week and I never heard an English voice until I went to the check out and that was the self service bit. Everybody that was in there, I don’t think there was anybody Scottish or English.”