NEW ORLEANS — Marcus Eriksen, a Metairie native and ecological adventurer who took a 2,000 mile trip down the Mississippi River on a homemade raft before founding the 5 Gyres Institute, was announced Tuesday as the 2013 commencement speaker for the University of New Orleans.

Traveling more than 35,000 miles through the world’s gyres, which are large systems of ocean currents, Eriksen’s organization works to locate and draw attention to patches of plastic garbage pollution.

The 5 Gyres Institute’s mission is to “conduct research and communicate about the global impact of plastic pollution in the world’s oceans and employ strategies to eliminate the accumulation of plastic pollution in the 5 subtropical gyres,” according to its website.

Eriksen earned his bachelor’s degree from UNO in 1993 and a master’s degree in education and curriculum in 1995.

In 2003, Eriksen completed his doctorate in science education from the University of Southern California before embarking on the five-month trip down the Mississippi River. The journey led to his career studying the ecological impacts of plastic marine pollution as executive director of the institute, which he cofounded with his wife, Anna Cummins.

Most recently, Eriksen traveled from California to Hawaii on a raft made out of 15,000 plastic bottles and a cabin made from a Cessna airplane fuselage.

The commencement ceremony will also feature New Orleans native John Larroquette, who will receive an honorary doctor of humane letters.

An actor in film, television and theater, Larroquette won four Emmy Awards for the role of Dan Fielding on “Night Court.”

He won a fifth Emmy for his role on “The Practice” and in 2011 won a Tony Award for his Broadway debut in “How to Succeed in Show Business Without Really Trying.”

The commencement will be held at 7 p.m. May 17 at the UNO Lakefront Arena. Tickets are not required. Seating is on a first-come, first-served basis.

Editor’s note: This article was corrected on Tuesday, April 23, 2013, to reflect that New Orleans native John Larroquette won a fifth Emmy for his role on “The Practice.”