On Friday during a break between rain showers, Lisa Randlette stepped out of a small boat and onto an enormous wooden structure floating in Quartermaster Harbor.

“Be careful, it’s really slippery,”  said Randlette, a rain gear-clad planner with the state Department of Natural Resources’ Aquatic Resources Division. She and Rolin Christopherson, another DNR official, were at Dockton that day to put a third and final bright-pink notice on an old net pen — a 120-foot-long dock-like structure crisscrossed with walkways. Both Randlette and Christopherson said itis the largest abandoned structure they’ve ever dealt with.

Two earlier notices on the net pen produced no response, and as early as next month, the state will remove the net pen, part of its wide-ranging effort to clean up Quartermaster Harbor and bring order to the many boats and buoys moored there. It has already removed two abandoned boats and one sunken vessel through a similar process.

“This is one piece of the puzzle to clean up the harbor,” Randlette said.

The large net pen was put in the harbor about 20 years ago, and some Dockton residents say they think an old Island family once used it to rear salmon in large nets strung between the walkways. Those who put it there, they say, are likely long gone.

In recent years, boaters who used the aging net pen as an makeshift dock to tie their vessels to have taken steps to maintain the structure. Cables have been strung to hold the pieces together, lights have been added in spots, and a large plastic box full of tools now sits in the middle.

Still, the net pen, which no one has stepped up to claim, has to go, Randlette said. Not only is it illegally moored on state-owned land — something Randlette equated to abandoning a car at a state park — but it’s a safety hazard and is harming the marine environment.

Pieces of the net pen, which Randlette called “held together by a lick and prayer,” have broken off over time. Old anchors, chains and creosote pilings holding it in place have likely damaged the underwater habitat, and the pressure-treated wood is surely leeching chemicals, Christopherson said.

One area of the net pen is full of styrofoam floats, and officials think the tires lining the bottom are also full of styrofoam, Randlette said.

“Styrofoam breaks down over time,” she said, looking down at the floats. “Animals have probably eaten it thinking it is food.”

What’s more, the net pen sits in the area DNR has designated for a new buoy mooring field at Dockton. Standing on the net pen, Randlette pointed to the boats clustered around the marina at Dockton Park.

“None of these boats are legally moored, but most of them have submitted applications now,” she said.

Come this summer, the state will begin granting buoy licenses to boat owners who prove they have safe and environmentally sound anchor systems. Those buoys will then be spaced in rows both at Dockton and Burton, leaving ample space for waterfront homeowners and day-use mooring. At the same time, around 100 unclaimed buoys and anchor systems will be pulled up.

The net pen, visible from Dockton Park, sits right where some of the new buoy spaces will be.

“You can see it’s in a pretty prime location,” Randlette said.

At a recent public meeting on Vashon, Randlette and other state officials presented a draft of the plan, which was finalized last month. While some Islanders thanked the visitors for attempting to bring some order to the harbor, several boat owners complained that it didn’t seem like the state planned for an adequate number of buoys at the two locations.

After tagging the net pen, Randlette explained that the state, per request, was trying to incorporate more buoys into its final plan.

“That’s why we do this draft and the public process,” she said.

“The challenge is figuring out where and how many we can fit,” she added. “We’re already starting to look at that.”

As for the net pen, the state is planning to hire a crew to break the structure into pieces that it will then tow to shore for disposal. It will also work to address a sunken boat that lies directly beneath it.

Greg Rabourne, Vashon’s basin steward for King County, said he’ll be pleased to see the state haul the old net pen away. Rabourne is currently planning a shoreline restoration project at Dockton not far from to the net pen and said any unnecessary structure in the water can harm the environment simply by blocking sunlight and scouring the sea bed. As part of the state’s plan, docks at Dockton Park will eventually be replaced with more environmentally friendly ones. On the other side of the harbor, the Quartermaster Marina has already made environmental improvements to its dock, and the Quartermaster Yacht Club plans to do the same.

“It’s another step in the right direction, and hopefully we’ll continue along with restoring the harbor to get it going back in the right direction,” Rabourne said.