A tray at the Virginia Institute of Marine Science (VIMS) holds the remnants of some of the unique organisms found in the stomach contents of fish. Depending on the species, a fish’s diet may include smaller fish like bay anchovy and menhaden, or underwater invertebrates like mysid shrimp, worms and bivalves.
Fisheries in the Chesapeake Bay are an important part of the region’s culture, economy and ecosystem. As key species in the food web, larger fish like striped bass and bluefish rely on “forage”—the smaller fish, shellfish and invertebrates that underwater predators feed on. But despite their importance, uncertainty remains about the species that make up the forage base and how they interact with their environment.
Programs like the Chesapeake Bay Multispecies Monitoring and Assessment Program (ChesMMAP) and the Northeast Area Monitoring and Assessment Program (NEAMAP), which collected the samples above, help scientists understand which forage species predators rely on by looking directly at the source: the fishes’ stomachs.
"The main objectives of the survey are primarily to get a handle on the abundances of all the different fishes and invertebrates that are inhabiting the Bay," said Jim Gartland, an Assistant Research Scientist at VIMS, one of the many organizations who partner to conduct the surveys. With a better understanding of the interactions between predators and forage species, experts can work to better support both predator species and the Bay ecosystem as a whole.
Learn more about forage in the Chesapeake Bay by watching our Bay 101: Fish Food video.
Image by Will Parson
For many of us, cold weather means digging your coat out of the closet and turning up the thermostat. But for the animals that call the Bay home, it means adapting to spending winter outdoors: by hiding in hibernation, by growing their own warm winter coat or by traveling south to warmer weather. Below, learn how a few of these native critters spend their winters.
Many animals stay in the Chesapeake Bay region year-round—but others are quick to leave once temperatures cool. While some striped bass remain in the Bay throughout the winter months, many head south to the warmer waters of the Virginia and North Carolina capes. In spring and early summer, they’ll return to the Bay’s tidal tributaries to spawn.
As water temperatures in the Bay start to cool, blue crabs retreat from the shallow areas where they spend the summer into deeper waters. After burrowing into the mud or sand at the water bottom, the crustaceans lie dormant for the winter months. While not technically considered hibernation, dormant crabs remain inactive until water temperatures rise above around 50 degrees Fahrenheit. Because the cold crabs are slow and sluggish, they’re easier to track down—which is why experts in Maryland and Virginia conduct their annual survey of blue crab population between December and March.
Blue crabs aren’t the only critters that spend winter in the mud. Typical residents of saltwater marshes and mudflats, diamondback terrapins bury themselves into river banks and at the bottom of creeks and rivers to hibernate. There, they remain completely submerged and inactive until temperatures begin to warm.
The wood frog can be found in forests throughout the Bay watershed, particularly in the northern reaches of Pennsylvania and New York. These tiny amphibians have garnered attention for their winter survival method: they freeze. Many frogs are known to survive winter by freezing a portion of the water that makes up their body and are able withstand being frozen for a couple of weeks at temperatures a little below freezing. But wood frogs are remarkable in the length of time—and extreme temperatures—they can tolerate. In the most frigid areas of their range, like Alaska, wood frogs have been known to stay frozen for up to seven months at zero degrees Fahrenheit.
Delmarva Fox Squirrel
While many critters go dormant to endure the winter, others remain just as active as ever. With the help of its soft, fluffy coat, the Delmarva fox squirrel is able to keep warm nesting in tree hollows. Like other squirrels, the Delmarva fox squirrel buries nuts and acorns in the ground to feed on throughout the winter.
The Chesapeake Bay region may be too cold in the winter for some animals, but for the tundra swan and other waterfowl, it’s a warmer destination. As their name implies, tundra swans live for part of the year in the Arctic tundra. As temperatures drop, they migrate to the wetlands and marshes of Bay region in late October and early November, where they stay until returning to the Arctic in early spring to breed. The Bay’s underwater grasses provide much-needed food for tundra swans and other migrating waterfowl.
Curious about how other Bay critters spend the winter? Learn more in our Field Guide!
For 117 years, the National Audubon Society’s Christmas Bird Count has seen thousands of birders organize for what is the oldest citizen science project in the country. It began in 1900 as a proposed alternative to winter hunting traditions. Today, the data helps Audubon and other organizations monitor the health of bird populations and inform conservation work.
At the ground level, it involves small groups of volunteers undertaking count circles that are 15 miles in diameter and making a note of every single bird they see or hear. Often starting in the pre-dawn hours, participants are out almost all day, with tallies compiled in the afternoon. This winter, the count was conducted from December 14th through January 5th. The tally is still moving upward, but last year’s total for the United States was about 54 million birds.
Along the shore of the Chesapeake Bay near Deale, Maryland, Marcia Watson and Gene Scarpulla began counting gulls and other shorebirds at a private harbor where they had secured permission ahead of time.
“This area is a little tough because it's mostly private property; there's very little public access,” said Watson, a retired professor and college administrator.
While scanning the water, Watson described how she and other birders have observed pelicans farther up the Bay this year, possibly because of below-average rainfall letting saltwater come farther north.
Watson said she has observed another change in the various counts she and Scarpulla have participated in—fewer birds in general. For example, she said the Chesapeake Bay region used to host huge mixed flocks including common grackles, red-winged blackbirds, European starlings, and brown-headed cowbirds.
“I remember counting twenty-some years ago in Cecil County, standing in one spot from about 4 p.m. to 5 p.m., and counting continuous streams of blackbirds coming in to roost,” Watson said. “They numbered in the hundreds of thousands. Now, you might see one or two flocks numbering in the hundreds.”
At another count circle in Baltimore County, Kevin Graff left his vehicle near the bank of the Back River and started making sound by forcing air through his teeth, spotting a chickadee and a few song sparrows while scanning some trees.
“It’s a trick that bird watchers use when they want to bring some more of them in, so they can see them,” said Peter Webb, a member, along with Graff, of the Baltimore Bird Club.
Webb said the pishing sound resembles the noise that Carolina wrens make when scolding, which attracts a lot of small birds.
Graff and Webb, like Watson and Scarpulla, have also had issues with public access during the count.
“We actually used to do it including the harbor in downtown Baltimore, but most of the places we had access to we lost access to,” Webb said. “Gradually more and more places got industrialized and ‘no trespassing’ signs came up on fences all over the place.”
Webb said it got to the point where it wasn’t worth doing the count there anymore, and they moved to the new circle about five years ago.
But on this count, which happened to fall on New Year’s Eve, Graff and Webb came away with a satisfying list of birds. Among the species they spotted or heard calling were bald eagles, red shouldered hawks, American black ducks, winter wrens, several kinds of woodpecker, greater and lesser scaup, red breasted mergansers, vultures, a kingfisher, a kestrel and a rusty blackbird.
Not much further into the new year, Audubon returns with the Great Backyard Bird Count (GBBC), happening from February 17th through the 20th. While the Christmas Bird Count is an all-day affair, the GBBC makes it even easier for everyday folks to participate. People of any age can count birds for as little as 15 minutes and report their findings using an app called eBird. And, as you might guess, they don’t have to leave their backyard.
Photos and text by Will Parson
To view more photos, visit the Chesapeake Bay Program Flickr page
A lion's mane jellyfish visits Spa Creek in Annapolis, Maryland, on January 18, 2017. Sometimes called the “winter jellyfish,” the lion’s mane jellyfish (Cyanea capillata) visits the Chesapeake Bay region from late November through March. Their preference for frigid, Arctic temperatures means they only venture down from northern latitudes when waters are sufficiently cold.
The type of lion’s mane jellyfish that visits the Bay is planktonic, meaning it floats where the currents take it—so while the lion’s mane is not an uncommon sight in the Chesapeake Bay, its presence can be unpredictable. When water currents and chilly temperatures align to bring them to the area, though, they’re easy to spot, because they prefer to float near the water’s surface.
Like the sea nettles that are prevalent in summer months, lion’s mane jellyfish have stinging tentacles. But since fewer people are out swimming in the chilly waters of January—except, perhaps, those participating in a Polar Bear Plunge—swimmers are less likely to suffer the lion’s mane’s sting.
Lion’s mane jellyfish that visit the Bay average about four to six inches in diameter, similar in size to the sea nettle. Travel further north, however, and you may encounter a much larger specimen. In 1870, the largest recorded lion’s mane jellyfish washed up along a beach in Massachusetts: its body measured more than seven feet in diameter, and its tentacles were 120 feet long.
Learn more about jellyfish that can be found in the Chesapeake Bay.
Image by Will Parson