What do plastic grocery bags, fishing nets and plastic milk containers have in common?

They are all items you can find littering Pacific beaches and waters and, according to the Marine Conservation Alliance Foundation, they are harming fisheries.

At Thursday’s opening of ComFish, Steven Campbell, Kodiak area training coordinator for the Alaska Marine Safety Education Association, was on hand to talk trash and its potential to harm Alaska fisheries.

According to studies, the oceans are so littered that for every pound of plankton, there are 6 pounds of trash. Campbell said as proof, all you need to do is travel to the circular current south of Kodiak.

“I’ve talked to some fishermen that have gone through there and they say, ‘All of a sudden you hit a spot and you can’t believe how much garbage is out there.’ It just sits and spins in these areas.”

Campbell said the vast majority of trash originates from shore, but 20 to 40 percent of the trash is thrown from vessels at sea, which includes nets and lines, buoys, plastic bottles, fishing gear, packaging bands, gloves, clothing, strapping bands and cigarette butts.

Don’t expect this trash to go anywhere anytime soon, as plastic bottles have a lifespan of 450 years, plastic bags 20 years and monofilament line 600 years. Members of the audience said that some of the new fishing line has a lifespan of forever.

Campbell said in his presentation that ocean trash has several adverse effects on the fishing industry. It can affect a fisherman’s wallet by curtailing a fishery due to species endangerment.

According to studies, 267 different species of marine life are harmed by ocean trash worldwide because they either eat it or get caught in it.

“Trash can mimic food,” Campbell said.

In a dissection of one sea bird, researchers found hundreds of small bits of plastic in the bird’s stomach, including a small plastic Bic lighter.

In addition, trash can destroy fish habitat.

Campbell said another adverse effect of trash in the ocean is the perception by consumers that fish are contaminated. Trash also causes expensive repairs and lost fishing time because of boat damage.

Campbell said it may seem a grim picture, but there are things fishermen can do to help protect their fisheries.

The easiest is just to create less trash and never discard anything overboard.

Consider reusing plastic bags or, better yet, carry supplies on board in boxes and leave the plastic bags at home.

A lot of gear is lost in heavy weather, so the best solution is to make sure that everything is secured. Finally, take a lesson from backpackers — if you carry it in, carry it out.

Leave nothing at sea but your wake.

Mirror writer Ralph Gibbs can be reached by e-mail at rgibbs@kodiakdailymirror.com.