More than half of the $491 billion the US restaurant industry rakes in annually comes from the 500 highest-grossing restaurants, according to Restaurant Business Online -- and there are quite a few seafood chains in that mix.

Market research firm Technomic released its Top 500 Chain Restaurants of 2015 recently, and the highest-ranking seafood chain is Red Lobster, which brought in just over than $2.4  billion last year from its 662 units.

Rounding out the eight seafood chains that made the list are Bonefish Grill, Joe's Crab Shack, Pappadeaux Seafood Kitchen, McCormick & Schmick's, Legal Sea Foods, Bubba Gump Shrimp and Chart House.

2016 Rank

Chain Name

2015 U.S.