SACRAMENTO, Calif. – Several members of Congress representing coastal states are voicing concern about a proposed federal regulation that could pre-empt state bans on buying or selling shark fins.

Democratic Rep. Jared Huffman of California is being joined by representatives of New York, Florida and Guam in seeking changes to a proposal they say would take away a state tool to protect shark populations.

California, Hawaii, New York and several other states have passed regulations on the sale and trade of shark fins, which are used in a soup considered an Asian delicacy. California’s ban on the sale, trade and possession of shark fins will go into effect Monday after a compromise allowed time for restaurants and businesses to use up their existing supplies.

A letter from the representatives and the delegate says that a proposed rule by the National Oceanic and Atmospheric Administration’s fisheries management division, the National Marine Fisheries Services, would undermine those laws. California state lawmakers also were circulating an opposition letter.

“If we are to address the problem of shark-finning head on, we must allow state and territorial statutes to complement the federal regulations and further the U.S. leadership in global shark conservation,” states the letter, which has not yet been sent to the fisheries service.

In addition to Huffman, it is to be signed by Democratic Reps. Sam Farr of California and Grace Meng of New York, Florida Republican Rep. Vern Buchanan and Democratic Delegate Madeleine Bordallo of Guam. Their letter is dated July 8, which is when the public comment period on the proposed rule is scheduled to end.

The proposal under consideration says state and territory shark fin laws are pre-empted if they are found to be inconsistent with federal fishery management plans or regulations.

Conservation and animal welfare groups are circulating petitions against the proposal, but representatives of the fishing industry have argued that federal pre-emption is necessary to maintain fishing of commercially viable shark species.

Congress passed and President Obama signed the Shark Conservation Act of 2010 in an effort to strengthen federal laws against shark finning.