By Kathryn Skelton,Staff Writer

Dead man’s fingers. Purple loosestrife. Hydrilla. Northern pike.

They’re here, they’re hungry, they’re prolific and they’re having their way with Maine nature.

Maine has at least 45 invasive species – foreign plants, animals, fish and marine life with traits like high fertility, mobility and adaptability – most often brought here by ship, human hand or accident. (Setting your goldfish and its leafy habitat free in your local pond? Not such a good idea.)

Some invasives displace other species. Some are a pain, like the biting Asian lady beetle. Others can be catastrophic, like the zebra mussel in the Great Lakes that could cost $5 billion to deal with over a decade – one U.S. Fish and Wildlife Service estimate. It was spotted in New Hampshire last month.

While lake-choking variable-leaf watermilfoil grabs the most ink – it’s the Tom Cruise of invasive species – there are plenty of others Maine biologists worry about that are also here, and plenty more they’re keeping an eye on in other states.

Prickly water chestnuts have been found as close as Massachusetts. Asian gypsy moths that can wreak havoc on hardwoods are still a coast away. There’s a pair of aggressive, huge mute swans being held at bay at the Maine border. (See related story.)

Already here: Voracious and fertile fish have been a particular problem over the last decade, infiltrating lakes and ponds.

Peter Bourque blames satellite TV.

Specifically, he blames those popular shows that feature guys just reeling ’em in, inspiring big fish envy. Anglers get selfish. They want to catch that same specimen in their closest watering hole, so they let a couple loose and the new fish take over, said Bourque, director of fisheries management at the Department of Inland Fisheries and Wildlife. “White perch is a classic example.”

White perch are native to Maine along the coast. But they’ve been brought inland, become invasive and kicked brook trouts’ tails.

One reason: A 1-pound native brook trout female can lay 500 to 1,000 eggs a year. A white perch, same size, can lay 150,000 eggs.

Tough to compete against those odds.

Pretty but pushy purple loosestrife is even more fertile than perch.

A problem here going on 20 years, a mature plant can produce 2 million to 3 million seeds annually. It’s illegal to sell in some states, but not Maine.

“It’s kind of become the poster child of invasives,” said Lois Berg Stack, an ornamental horticulture specialist with the University of Maine Cooperative Extension. “It’s actually out-competing (native) cattails.” Left alone it can run wild in wetlands, crowding out other plants that provide food and shelter for wildlife and offering neither in return.

Two new invasives – the lily leaf beetle and viburnum leaf beetle – likely rode in on plant material, said Jim Dill, a pest management specialist at the cooperative extension. As the names suggest, both attack plant leaves.

Asian lady beetles were let loose in the mid-Atlantic on purpose, as aphid-killers. In recent falls, they’ve been everywhere in Maine, begging to cozy up indoors for the winter. (Native ladies aren’t as wussy.)

The invasive European green crab caused an uproar on the Maine coast back in the 1940s and ’50s. “They were definitely a very significant if not huge component of the soft shell clam industry declining,” said Pete Thayer, scientist with the Department of Marine Resources.

The issue: They eat clams, too. Lots of them.

So back then the state tried everything to get rid of green crabs: trapping, netting, cages, pesticides. Didn’t work.

“The marine environment is kind of a whole different ballgame. It’s such a vast and open system, for the most part, there’s not a lot you can do,” Thayer said.

In a twist of invader irony, the green crab’s now getting bullied by the Asian shore crab, another newcomer.

A special count a year ago showed 33 types of marine life from away that like the water here just fine, thank you. The majority are benign, but some – like didemnum, which grows in mats and coats piers and fishing gear – cause problems, Thayer said.

The U.S. spends $130 billion annually to deal with all types of invasives, according to Thayer’s department.

Maine’s budget is a smidge of that.

A mandatory boat sticker program raised almost $1.2 million in 2004, money that was split between combating invasive fish and combating invasive aquatic plants.

Maine’s got a list of “11 Most Unwanted” aquatic plants, only four of which have been found here so far. Paul Gregory, an environmental specialist at the Department of Environmental Protection, said 1,200 people have been trained as “invasive plant patrollers” to keep their eyes peeled for those 11 on local lakes and ponds. Other volunteers conducted 30,000 inspections last year, checking boats and tow carriages for weeds and debris that can spread invasives.

Three times, they stopped a confirmed undesirable from coming in.

Left unchecked, Gregory said, plants like Eurasian watermilfoil (in one Scarborough pond) and variable watermilfoil (in 22 ponds and lakes) degrade water quality by pushing out native plants, blocking sunlight and replacing fish food. (They’re not good eating.)

The issue is both environmental and economic, he added, since there’s potential to hurt both tourism and shoreland real estate values.

Maine marine groups that collaborate on the investigation of invasives have offered tips for slowing their spread, like:

• Never toss bait or seafood waste in the water. Compost or trash it only.

• Clean boats before and after use.

• Worried a plant from a pet store fish tank might be invasive? Ask. Either way, don’t release it, or your pet, in a waterway, storm drain or sewer.

It’s difficult to compare Maine’s invasive experience with other states, but Maine appears to be doing relatively well. The catch, Gregory said: “If we stand out as being the most pristine, if that draws more people, we’re inviting more risk.”

More people means more temptation to move or introduce invaders, and no one wants a Tom Cruise to grab their ankle while they’re swimming.