“American alligators are not indigenous to Maryland.” So reported journalist Jacob Baumgart for Patch Media on June 22. Then why did a father and his 14-year-old son encounter one earlier that month in a marshy area in southern Maryland?

The two were kayaking near their hometown of Lusby when they nearly collided with a 7½-foot gator laying motionless in the shallows. Chances are that the reptile was a released pet. It’s highly unlikely that alligators could colonize Chesapeake Bay — at least with its current climate. But there are other unexpected creatures that have made the Bay their home. 

Some Bay fauna are so uncommon that it’s surprising to see them. Others have been here for eons, went through a period of decline, and are now reemerging. Several nonnative species have gained a foothold after being accidentally or deliberately introduced. Still others have recently expanded their range into the Bay, because of changing climate. 

We’d all be flabbergasted to see Jaws patrolling the Bay’s waters. But three years ago a Maryland waterman caught a 310-pound bull shark, nearly eight feet long, at the mouth of the Patuxent River. Sharks occasionally show up in Chesapeake Bay, but they tend to be smaller and are more likely to cruise the lower Bay. Swimmers wouldn’t want to cross paths with a bull shark. They’ve been responsible for many deaths, worldwide. But it’s safe to go back into the water here — no shark attacks have ever been recorded in the Bay.

It’s more fun to swim with dolphins and they’re surprisingly common. Although these marine mammals have been in the Bay for a long time — in 1844, Washington residents admired a pod swimming near the nation’s capital — their numbers wax and wane. In 2015 a virus outbreak caused a large die-off, but their populations are now surging. Seals may seem out of place in the Chesapeake, but they show up every winter. Though most are harbor seals, several other species are occasionally sighted. Populations have exploded since hunting seals was outlawed in 1960.

Over 160 aquatic invasive species now populate the Bay’s waters. Some have been purposefully introduced. The most notorious are snakeheads. These voracious, sharp-toothed predators were originally imported for home aquaria. In 2002 they showed up in a Crofton, Maryland pond. They’ve since made their way into the Bay where they seem to be breeding. Similarly, the muskrat-like rodent, nutria, was released in 1943 into the Blackwater National Wildlife Refuge in Dorchester County for fur farming. Despite subsequent eradication efforts, they’ve spread rapidly causing major damage to their salt marsh habitats. Other harmful invasive species, like zebra mussels, have entered the Bay on ships’ hulls and in ballast water.

More welcome are occasional visitors which don’t inhabit the Bay but show up from time to time. These include Florida manatees (“sea cows”), sometime summer visitors to the Chesapeake. Bay Bridge Bound? Tropical fish may also enter the Bay, borne from afar by meandering currents. 

Did you know that another Florida icon, the brown pelican, is now a common summer resident of the Bay? Scarce around the Chesapeake until the late 1980s they now make up over 2,500 breeding pairs. Warming climate is apparently responsible, allowing for an expanded breeding season. Could alligators be far behind?

Then there’s Chessie. For hundreds of years, awe-struck observers have insisted that they’ve seen this purported cousin of the Loch Ness monster undulating in the Chesapeake’s shallow waters. Were the sightings actually of manatees? Large sharks? Massive leatherback turtles? Escaped anacondas? Or even the eel-like oarfish, that can be up to forty feet long? Perhaps Mount Gay rum inspired some of the sightings.

Chessie or not, many Bay creatures strike us as unusual and, in some cases, just don’t belong here. We should celebrate scarce long-term residents now making a comeback, like dolphins and seals, but lament the invasive marine animals that threaten iconic Bay species. For more information, see these articles by the author from past issues of Outlook by the Bay:

Invaders in the Bay (Fall 2011)

Monsters in the Bay (Winter 2011)

Exotic Species Invade the Bay (Early Spring 2018)

Repel Boarders: Keeping the Invaders at Bay (Spring 2018)

Henry (“Hank”) Parker is a scientist and writer who previously lived in Annapolis but now lives in Vermont.

Please support OutLook by the Bay with a subscription.

OutLook by the Bay magazine and this website are made possible through the support of our advertisers and subscribers. We guarantee you’ll learn something new each issue. Please subscribe today.

Henry S. Parker

Henry S. Parker is an adjunct associate professor at Georgetown University. He can be contacted at hspshp@gmail.com