A First Nation in British Columbia lost its bid to gain widespread access to commercial fishing rights in a Supreme Court decision Thursday.

The aboriginal band, called Lax Kw'alaams, was seeking a declaration that it is entitled to a native right to harvest and sell all species of fish – including seaweed, shellfish and fish – in its traditional territory in the Prince Rupert region of the province.

The band currently has the right to fish for food, social and ceremonial purposes, but not to sell. The claim was denied in lower courts and the Supreme Court upheld those decisions, and their reasons, in its unanimous decision Thursday.

If the Lax Kw'alaams had been able to establish that trade was integral to their culture and sustenance prior to contact with the Europeans in the 1790s, the Constitution would have protected their aboriginal rights and they could have been granted access to sell products on a commercial scale.

The Supreme Court found that they were not primarily a trading people pre-contact and therefore their ancient customs and practices do not translate into a constitutionally-protected right to harvest and sell all kinds of fish in a modern commercial fishery.

A lower court previously found that while the band's predecessors, the Coast Tsimshian, did fish a variety of species including salmon and halibut, they only traded in a specific grease product called eulachon, derived from one species.

The Supreme Court agreed with the lower courts that the eulachon trade was sporadic and not central to their sustenance.

"It is not enough to show that some element of trade was part of the pre-contact way of life if it was not distinctive or integral to that way of life," Justice Ian Binnie wrote in the decision.

"Such sporadic trade as took place in other fish products was peripheral to the pre-contact society and did not define what made Coast Tsimshian society what it was."

Lax Kw'alaams appealed the ruling but the B.C. Court of Appeal upheld the decision in December 2009, citing the trial judge's conclusion that it would be stretching the idea of aboriginal fishing rights to rule that the ancient grease trade must lead to a modern right to fish all species.

They argued the trial judge was too strict in her interpretation and that the eulachon trade was part of their ancestral way of life and on that basis, they should be allowed to continue to trade in fish generally.

The band had argued that under the Marshall decision of 1999, they have the right to fish and sell their harvest to economically support their community.

The Marshall decision granted fishing rights to Canada's First Nations and was itself based on a treaty right to earn a moderate livelihood.

A similar case brought before the B.C. Supreme Court in November saw a Vancouver Island native group, known collectively as the Nuu-chah-nulth First Nation, granted the right to harvest and sell all species of fish found within its territories.

The judge in that case also dismissed a claim to aboriginal title over the fishery, upheld the federal government's control over all fisheries and urged the band and Ottawa to negotiate how to handle native fishing and fish sales.

The Lax Kw'alaams First Nation had also argued that the Crown has a fiduciary duty to ensure they have access to the commercial fishery because of promises, expressed or implied, made by government officials in the 1880s when they were allotted reserves and fishing stations on their territory.

The Supreme Court also rejected that claim, saying the "Crown had not made express or implied promises of any preferential access to the commercial fishery, and had made its intention to treat aboriginal fishers in the same manner as other fishers clear."

With files from CBC News