A new report exposes nine fisheries that throw away half of what they catch every year, unnecessarily killing a number of endangered and protected species.

The research shows that "non-target" marine life, or "bycatch," is a significant problem, an Oceana news release reported.

"Anything can be bycatch," Dominique Cano-Stocco, campaign director at Oceana, said in the news release. "Whether it's the thousands of sea turtles that are caught to bring you shrimp or the millions of pounds of cod and halibut that are thrown overboard after fishermen have reached their quota, bycatch is a waste of our ocean's resources. Bycatch also represents a real economic loss when one fisherman trashes another fisherman's catch."

Bycatch is believed to be most prevalent in "open ocean trawl, longline and gillnet fisheries," the news release reported.

"Hundreds of thousands of dolphins, whales, sharks, sea birds, sea turtles and fish needlessly die each year as a result of indiscriminate fishing gear," Amanda Keledjian, report author and marine scientist at Oceana, said in the news release. "It's no wonder that bycatch is such a significant problem, with trawls as wide as football fields, longlines extending up to 50 miles with thousands of baited hooks and gillnets up to two miles long. The good news is that there are solutions - bycatch is avoidable."

Most fisheries are not monitored and do not document how much bycatch they dispose of.

To see the list of top nine "dirtiest" fisheries click here.

"Reducing bycatch is a win/win for fishermen and conservationists," Cano-Stocco said. "By eliminating wasteful and harmful fishing practices we can restore and maintain fish populations that are essential to renewed abundance and healthy oceans, while also preventing the deaths of whales, dolphins, seals and sea turtles."

"The solution can be as simple as banning the use of drift gillnets, transitioning to proven cleaner fishing gears, requiring Turtle Excluder Devices in trawls, or avoiding bycatch hotspots," Doctor Geoff Shester, California program director at Oceana, said in the news release. "Proven solutions and innovative management strategies can significantly reduce the unnecessary deaths of sharks, sea turtles, dolphins and other marine life, while maintaining vibrant fisheries."