C. Boyd Pfeiffer: The good, the bad and the ugly reality

They are the “bad” guys, although some exotics are considered “good”. From an environmental/ecological standpoint, any introduced species is bad. But we selfishly like some anyway.

How they get here is also subject to question, usually based on our own human interests despite objections from Mother Nature. Mute swans were brought here for lawn/pond ornaments. Five escaped in 1962 from an Eastern Shore property. We hit a 1999 peak of about 4,000 of them tearing up Chesapeake Bay grasses faster than Department of Natural Resources staff and volunteers could plant them.

The bad guys are things such as kudzu, phragmites, zebra mussels, nutria, snakeheads, purple loosestrife and those mute swans. They — the bad ones — should all be destroyed. Protests of killing mute swans occur because they are cute. On that basis, we can introduce zebra mussels to Loch Raven (just kidding!). They’re cute also — never mind that they clog water pipes.

The “good” guys are rainbow trout, sika deer, brown trout, smallmouth bass and pheasant, all of which we hunt/fish during established seasons. The jury is still out on carp, perhaps first introduced to the U.S. in Baltimore's Druid Hill Lake in 1887.

Ring-necked pheasant debuted in Oregon in 1892 before moving east, rainbow trout moved from the West Coast in the 1800s, sika deer came from southern Japan in the early 1900s, while brown trout emigrated from Germany with some first taking a short visit to Scotland.

Smallmouth bass from the Ohio River drainage were stocked in the C&O Canal in 1854 courtesy of a General Shriver and a B&O Railroad water tender. They escaped to the Potomac that year and in 1869 were introduced in the Susquehanna. The rest is history and great smallmouth fishing. There I go! See what I mean about our selfish interests?

These “good” species — smallmouth bass, rainbow and brown trout, sika deer and pheasant — are accepted. Others, such as mute swans, literally and figuratively stir up things so much that we lose aquatic grasses necessary to nurture juvenile crabs, striped bass, white perch and other native species.

Fortunately, as a result of continued DNR efforts, mute swans are down from that nearly 4,000 peak. That’s good. Fewer mute swans equal less grass-planting expense, more restorative bay grasses and more native wildlife. That’s good also.

Oh, and no more piranha/pacu from fish tanks, please. Sure, they die in the winter, but in the meantime, a few piranha can still be rough on other game fish populations — native and exotic — along with swimming kids.