Two leading Canadian biologists are raising concerns about a proposal to help the stalled recovery of the cod stocks in the Gulf of St. Lawrence. Ottawa is being pressed to consider a five-year study that would start with the slaughter of 73,000 grey seals in an area stretching from eastern New Brunswick to Cape Breton, N.S. The experiment is intended to determine whether significantly reducing the grey seal population in the Gulf would help cod stocks recover from a drastic decline. Hal Whitehead and Boris Worm — both professors at Dalhousie University in Halifax — say a proposed cull of 140,000 grey seals over five years is being driven by politics, not science. Worm says former fisheries minister Gail Shea recommended a cull two years ago and now federal scientists are being pushed to justify the decision.