Atlantic swordfish are in trouble, no thanks to fishing nations that this week refused to lower the allowable catch to a level scientists believe is sustainable. Delegates to an international negotiating meeting in Rio de Janeiro, which concluded on Monday, lowered the swordfish catch to 11,660 tons for next year, down from 12,980 this year, but scientists recently concluded that the catch would need to drop below 11,000 tons to give stocks a 50-percent chance of recovering within 10 years. The U.S. and Canada, which take about 40 percent of the catch, pushed for lower limits, while Japan and the European Union, led by Spain, the single largest catcher of swordfish, fought against them. More than one-third of the North Atlantic swordfish and 83 percent of the Mediterranean bluefin tuna caught by Spain were smaller than the legal limits, according to a recent report by the World Wildlife Fund.