Sustainable Shark Fisheries and Trade Act of 20 21 This bill addresses the conservation and management of sharks. The bill prohibits the importation into the United States of shark products from a nation that does not have measures to provide for the conservation and management of sharks and measures to prohibit shark finning (the removal of a shark's fins, including the tail, and discarding the remainder of the shark at sea) that are comparable to those of the United States. The bill includes exceptions to this prohibition for law enforcement, subsistence purposes, education, conservation, or scientific research. The Department of Commerce must certify nations with protections for sharks that are comparable to those of the United States. Commerce must revise its regulations to include rays and skates as species that are subject to the Seafood Import Monitoring Program. (The Seafood Import Monitoring Program has data reporting and recordkeeping requirements for imported fish or fish products entering U.S. commerce.)