Complex sentence: The Ottawa Delegation assigned Crummey to negotiate the Fisheries Portfolio with Canada and returned to the Newfoundland Legislature to report that the British North American Act dictated maritime affairs are a federal jurisdiction: that Newfoundland would lose sovereignty of its offshore resources if it joined Canada.
Split into simpler sentences: The Ottawa Delegation assigned Crummey to negotiate the Fisheries Portfolio with Canada. He returned to the Newfoundland Legislature to report that the British North American Act dictated maritime affairs are a federal jurisdiction and that Newfoundland would lose sovereignty of its offshore resources if it joined Canada.