They’re the Pav and Heidi of Neil Perry’s flagship Margaret restaurant, which has the Pav and Heidi’s bigeye tuna on its menu. But the Walkers are also among the biggest tuna suppliers in the country and, they say, are being taken advantage of by a Sydney investment firm trying to squeeze commercial fishing families to maximise returns.

It might be one of the most alternative of alternative asset classes but fishing licences and quotas – the right to catch specific species every year – is becoming a serious business. Walker Seafoods leases theirs from Longreach Maris, part of the $3.1 billion asset manager Longreach Alternatives. The two parties are at an impasse about how much the lease of those quotas are worth.