Every spring, the herring arrive in the cold Alaskan waters of Sitka Sound to spawn. But as those waters have warmed, their numbers have fallen drastically.

Tribal leaders in Sitka have long called for better protection of herring, a fish that holds cultural as well as economic significance for the people here. To demand protection of the sac roe herring fishery on which their way of life depends, they are taking the Alaskan government to court.

For the subsistence harvesters of sac roe herring in the sound, this decline has been accelerated by what they see as the failure of the government to manage the herring fishery properly. Since 2002, the Sitka Tribe of Alaska (STA) has been appealing to the board of fisheries with proposals to protect the herring population.

The scale of the decline was underlined in April, with the cancellation of an annual derby that usually sees hundreds of boats from the North Pacific gather in Sitka before setting sail for two to three days’ fishing. This year, not a single ship left the port and not a single herring was caught.

The Sitka tribe, of more than 4,000 people, welcomed cancellation of the derby by Alaska’s department of food and game. But the move doesn’t reverse a decade of decline. While in 2009 the derby had celebrated a record fishing season, by 2018 the Sitka sac roe herring fishery was forced to close early because the herring were too scarce and too small.

It was the fourth time in eight years that the herring fishery had shut down early without meeting the quota, following early closures in 2012, 2013 and 2016. In 2018 the department had expected a catch of more than 11,000 tonnes of sac roe herring, but not even 3,000 tonnes were produced, according to its own report.

While the commercial industry harvests the eggs from inside the fish once caught, subsistence harvesters set out hemlock branches after the fleet leaves, where herring spawn and lay their eggs. Native Alaskans have been harvesting herring in this way for centuries but, in recent years, they have been pulling up branches bare. They say herring spawn now only cover a fraction of the coastline, and fear is mounting within the Sitka tribe that local stocks are on the verge of collapse.

At the heart of the dispute with Alaska’s authorities is the question of whether the herring – which feeds on zooplankton and phytoplankton and is a key food for salmon, seabirds and marine mammals – is designated a forage fish. The STA wants the species to be included on a forage fish management plan, acknowledging its importance in the Alaskan food web.

The Sitka tribe also want Alaskan authorities to decrease the size of the herring that can be taken to market in order to protect the species, but say their requests have fallen on deaf ears. Herring return to spawn for up to seven years, each year growing larger depending on conditions in the ocean. It takes a fish at least five years to reach the size and roe maturity that processors want.

In 2018, the fisheries board turned down a proposal to reduce the level of the commercial catch, and last December STA launched legal action in the superior court to demand a new management plan for the fishery. The Sitka tribe also want the court to find the actions of the fisheries board department of food and game illegal.

I love the life of a fisherman, my father was a fisherman and the decision to follow him was an easy one Zamor Saline, Sitka

A spokesperson for the STA explained the action, saying: “The time is now to ensure that our people have the chance to fulfil their cultural responsibilities, which have been interwoven with the herring since time immemorial, and to fill their freezers. We cannot sit by while the state of Alaska shirks its statutory and constitutional duties to citizens. We demand action by the state.”

The trial – the culmination of more than two decades of concern over declining herring for the Sitka tribe – has been set for January.