Q&A: Mackerel wars explained
An often bitter wrangle over mackerel quotas between Scotland, the European Union, Iceland and the Faroes has been capturing headlines for several months, and now the EU is deciding on what steps to take.
Here are answers to some of the main questions surrounding the issue.
When did the mackerel wrangle begin?
In August last year, Fisheries Secretary Richard Lochhead warned "short-sighted and selfish" mackerel quotas set by the Icelandic and Faroe Islands governments could be "disastrous" for the Scottish fleet.
Iceland, which landed very little mackerel before 2006, had allocated itself a 130,000-tonne quota for the year.
This was said to be up from 36,000 tonnes in 2007, 112,000 tonnes in 2008 and 116,000 in 2009.
The Faroes, a set of islands about 250 miles north of Scotland, tripled its usual entitlement to 85,000 tonnes.
The Scottish Fishermen's Federation said the decisions were "astonishing".
And the Scottish Pelagic Fishermen's Association said fishermen were "very angry".
Why the high level of concern?
Mackerel is the most valuable stock to the Scottish industry.
In 2009, it was estimated to be worth £135m at a 'first-sale' value, which represented about a third of the value of landings by the Scottish fleet.
The Scottish industry said the raised quotas were at odds with efforts to promote sustainable fishing practices across the EU.
What justification was offered for the increased quotas?
Iceland and the Faroes said they saw the situation differently.
The countries argued that the mackerel stock has gravitated north in recent years - thought to be due to climate change - so they were now fishing in their own zones.
And a recent fall in the herring catch meant the mackerel was even more welcome.
What are the qualities of mackerel?
It once had an image problem with shoppers.
But mackerel has grown in popularity and is regarded as an excellent source of omega-3 fatty acids and vitamin B12.
It is perhaps best known as a smoked and vacuum-packed fillet.
What direct action has been taken over the quotas?
A week after concern was first raised, fishermen in Peterhead preveted a Faroese fishing boat offloading its cargo of mackerel.
The Jupiter was met by dozens of protesters at the harbour in the early hours of the morning.
What was the result?
The Jupiter's skipper, Emil Pedersen, had to leave port and return home - and claimed the blockade cost him more than £400,000.
Mr Pedersen said the catch had been good for human consumption, but would instead go into areas such as oil production.
Of the blockading fishermen, he claimed: "This is not their job, this is a political matter."
What happened next politically?
First Minister Alex Salmond called for political action to end the ongoing dispute.
And a Scottish MEP called for an EU-wide blockade of Icelandic and Faroese boats.
Conservative Struan Stevenson said Iceland and the Faroes were "acting just like their Viking ancestors" by "plundering" stocks.
What were ecologists saying?
Governments, not scientists, had to tackle the row over mackerel quotas, according to a leading adviser on the Common Fisheries Policy.
Poul Degnbol, head of the advisory programme at the International Council for the Exploration of the Sea (Ices), said: "It is all about getting a working arrangement to share the access to the resource between different fleets, or countries, so that the fisheries overall is sustainable.
"Obviously, when the total of the quotas set by different parties exceeds what is considered sustainable, the overall mackerel fishery cannot be sustainable, but this is independent of who is taking the fish."
Did talks work?
No. A series of talks last year aimed at resolving the issue failed to do so.
What happened next?
Last month, Iceland announced it was setting a 2011 quota of 146,818 tonnes, up from the 130,000 in 2010.
Scottish fishing leaders condemned the decision.
However, Tomas Heidar, chief negotiator of Iceland on mackerel fisheries, said they had legitimate rights to a fairer share of the EU's total allowable mackerel catch.
Ahead of the impending EU decision, Mr Heidar told the BBC Scotland news website this week: "Mackerel fisheries by Icelandic vessels have in recent years almost exclusively taken place within the 200-mile exclusive economic zone of Iceland and all catches have been landed in Icelandic ports and processed in Iceland.
"Mackerel has been migrating in growing quantities into the Icelandic exclusive economic zone.
"We remain committed to finding a fair solution on the allocation of mackerel that takes into account the legitimate interests of all the parties."
What has the EU now done?
On Friday, the European Union signalled an intention to block Icelandic boats from landing mackerel at EU ports, ahead of more talks.