The Federal Court of Appeal on Wednesday reserved judgment on a legal challenge by Ottawa of an earlier ruling regarding measures required to protect endangered killer whales.

In December 2010, the Federal Court ruled that Ottawa had not done enough to protect the critical habitat of killer whales related to issues of salmon availability, environmental contamination and noise pollution from marine traffic.

A coalition of conservation groups, represented by Ecojustice, had launched the lawsuit in 2008.

At the heart of the issue was whether federal fisheries officials had a legal obligation to protect the biological features of critical habitat.

The court in 2010 ruled that Ottawa must use binding federal laws as outlined in the Species At Risk Act, rather than relying on provincial policies or guidelines, which do not legally protect habitat.

Margot Venton, a lawyer for Ecojustice, said Wednesday in Vancouver that Ottawa has suggested it can protect the whales through federal legislation such as Section 35 of the Fisheries Act, which prohibits the harmful alteration, disruption or destruction of fish habitat.

But Venton argued that the same section allows for destruction of habitat provided it is authorized, which does not amount to enduring protection for the whales.

The court has asked for further written submissions from legal counsel, she said, estimating it could be six months before the three justices render a decision.