DOVER — “We found a bowling ball once, how does that even happen — who brings a bowling ball to the beach?” said DNREC spokeswoman and Delaware Coastal Cleanup coordinator Joanna Wilson.

Over its 30 year history, the annual DNREC-hosted Coastal Cleanup effort has found some unique items discarded in the state’s parkland, rivers, marshes, wetlands and coastal areas. In addition to the 6 tons of ordinary trash 1,572 volunteers collected last year, the haul included unusual things like: a Walkman cassette player, a television, a set of pornographic DVDs, an air horn, bowling pin, badminton shuttlecock, fake aquarium plants, peach basket, vampire teeth, respirator, pacifiers, teething ring, selfie stick, dog crate, mailbox, a U.S. Postal Service plastic bin, two file cabinet drawers, two full beer bottles and a volleyball-sized round metal weight with an unknown purpose.

On Saturday, the 2017 Coastal Cleanup volunteers rallied once again an picked up trash at 45 sites along Delaware’s 97-mile eastern coastline. Volunteers of all stripes were on hand to help pick up garbage — both unsightly and potentially hazardous to animals and water quality. It’s DNREC’s largest one-day volunteer event. Around 1,500 people registered for the event this year.

About 13 volunteers showed up at Port Mahon on Saturday — the weather was a comfortable, cloudless 70 degrees. The small group already had a dozen or so trash bags filled up by 10 a.m. and had found some strange things.

“We found 15 pairs of shoes, fishing poles and all sorts of plastic and aluminum containers,” said Newark resident Lindsey Treston.

Ms. Treston heard about the cleanup through her work at KCI Technologies and was drawn to it by her interest in keeping the state’s natural resources clean.

“I have strong opinions on environmental matters and rights,” she said. “Just being out here, I’ve seen that this port really needs some trash cans. It seems like people just chuck a lot of their trash as far as they can into the marsh.”

The captain of the site, Anthony Gonzon, said that Port Mahon has been used unofficially for years as a sort of illegal dumping ground.

“There used to be a lot of people would dump anything out here — like large scale dumping — luckily we’ve seen less of that over the past few years,” he said.

Working as DNREC’s Bayshore initiative coordinator and belonging to the Delmarva Ornithological Society gives Mr. Gonzon both a personal interest and a professional one in cleaning up the port.

“It’s an important site for bird watching, there are a lot of shorebirds here in May,” he said. “A lot of people come down and enjoy the scenic view or to fish too.”

Although down from a participation high in 2010 of 2,500 volunteers, Ms. Wilson said the level of interest in the cleanup is still right where DNREC wants to see it.

“The interest this year has been huge — we’ve gotten lots of calls,” said Ms. Wilson. “Even more groups signed up this year. A lot of organizations like scout troops, businesses, community groups and garden clubs make it into an event of their own.”

The cleanup effort celebrates its 30th anniversary this year. The first Coastal Cleanup – originally known as “Get the Drift and Bag It” – was organized by DNREC and held in October 1987. The agency said that over the event’s history, nearly 52,000 volunteers have collected more than 600,000 pounds of trash.

“We’ve grown a lot over the years, our first event had only 700 people that were able to pick up 3,000 pounds of trash,” added Ms. Wilson.

2011 was the single year the largest amount of trash was collected — the total was 10.7 tons. Ms. Wilson said the high amount was due to severe flooding that year in Pennsylvania that brought a lot of trash down stream.

“It was so bad that the day after the coastal cleanup, I got a call from Broadkill and Slaughter beaches saying that even more trash than they’d picked up the day before just washed in with the tide,” said Ms. Wilson. “We had to organize a follow-up the next weekend for those sites”

Data collection is a particularly important part of the effort and DNREC has been aggregating details since the beginning. Delaware’s Cleanup is a part of the Ocean Conservancy’s International Coastal Cleanup, the world’s largest annual clearing of trash from coastlines and lakes by volunteers. Hundreds of thousands of people all over the world help each year to rid the environment of marine debris and collect detailed information on the types and quantities of refuse. The types and quantities of trash collected are recorded on data cards and forwarded to the Center for Marine Conservation, which compiles the information for all of the cleanups held in the country and around the world. This information helps identify the source of the debris and focus efforts on eliminating or reducing it.

“Cigarette butts are a big thing, the amount being found is going down in some areas though going down in some areas,” she said. “Some of that data has been used to help make a case for not allowing smoking in certain areas so there are less butts end up on the beaches.”

A recent marine debris report released by the Ocean Conservancy found that general-source marine debris — trash that comes from both ocean and land-based activities — increased across the United States by more than five percent each year. However, DNREC says their statistics show that, over the years, both an overall downward trend in the amount of trash collected, as well as declines in specific items that taint Delaware’s waterways.

DNREC says the most common finds continue to be cigarette butts, plastic bags and food-related trash like beverage containers, wrappers, straws and bottle caps.

“Beverage containers are usually the most common thing we find,” said Ms. Wilson. “Although, in the last 12 years I’ve been doing this, we’ve seen a big shift toward plastic containers rather than glass ones because they aren’t used as often anymore.”

DNREC hopes to have all the data from this year’s cleanup in hand by the end of the month.

For the cleanup effort, the Ocean Conservancy supplies trash bags, data cards and brochures on marine debris. Delaware’s cleanup is co-sponsored by Edgewell Personal Care/Playtex Manufacturing, which provides gloves, and Waste Management, which hauls trash and recyclables. DNREC is responsible for organizing the event, recruiting volunteers, distributing supplies, ensuring trash removal and tabulating all the data collected. Additional sponsors this year were Dogfish Head Craft Brewery and Redners Markets.