Mallows Bay Eco Tour - Final

<p>Ospreys, or "fish hawks," are mid-sized raptors that live near water, mate for life, and often reuse and enlarge the same nest each year. In the Mid-Atlantic, they breed from March to August, then winter in Central and South America. A pair once nested in the shoreline tree here, but a storm destroyed the nest; ospreys are resilient and may rebuild nearby.</p>

Paddlers passing the pilings often see double-crested cormorants drying their wings. With less oil in their feathers than other waterbirds, cormorants absorb water, gaining weight that helps them dive deeper and faster for fish. Wooden platforms atop the pilings were built by Mallows Bay Park staff to support osprey nests after storms and high tides washed away earlier nests.

The <i>Accomac</i> is home to two osprey nests. Ospreys build nests in open areas high off the ground, safe from predators, often atop trees or man-made structures like nest platforms, telephone poles, or shipwrecks such as the <i>Accomac</i>.<br><br><a href="https://sketchfab.com/3d-models/accomac-b37b10a438ac47b58aad669a54c460c1">View a 3D model</a>

A real-time water quality buoy in the river channel, managed by the Maryland Department of Natural Resources' Eyes on the Bay program, collects data every 15 minutes on temperature, salinity, pH, dissolved oxygen, clarity, and chlorophyll. This data supports decisions and tracks trends over time. <a href="https://sanctuaries.noaa.gov/mallows-potomac/visit/water.html">Current Conditions</a>

<p>The water quality buoy also carries an acoustic telemetry receiver that collects data on fish tagged with transmitters for research. Sanctuary staff review the data in partnership with the Smithsonian Environmental Research Center and the Mid-Atlantic Acoustic Telemetry Observation System, helping them understand what fish species are present, including rare, endangered, or threatened species. Since 2019, the receiver has recorded 26,715 detections from 44 tagged fish.</p>

<span><i>Benzonia</i> rests on top of the <i>Caribou</i>, another U.S. Shipping Board wreck. Half of the <i>Benzonia</i> rises out of the water and is covered in plant growth that supports a variety of species, including an osprey's nest on the back of the ship. <a href="https://skfb.ly/oNvTQ">3D model of these vessels</a></span>

At Mallows Bay's northern edge, sunken ship remains trapped sediment to form Grady's Spit, a landmass where wetland plants took root. It provides paddlers a small beach to rest. Volunteers sample water weekly here and at the boat ramp, with results posted on <a href="https://www.theswimguide.org/">SwimGuide</a> through a program run by the Potomac Riverkeeper Network.

<p>The wreck sites of Moosabee, Dertona, and an unidentified vessel are known as the "Three Sisters," sitting near shore against a bluff, the farthest inland of the Ghost Fleet sites. Covered in plants like marsh tickseed and cardinal flower, the ships now support wildlife, including an active beaver lodge on the unidentified vessel.</p>

These unidentified "flowerpot" wrecks are named for the plants growing inside them, as in a flowerpot. Rocks placed in their hulls weighed them down, and over time sediment and seeds collected, forming man-made islands that stabilize Mallows Bay's shoreline and extend its wetlands. Marsh tickseed, cardinal flower, and interior sandbar willow now grow here, supporting wildlife such as red-winged blackbirds and zebra swallowtail butterflies.

<span>Bald eagle nests can sometimes be seen high in the pine trees here. Bald eagles build nests near water, often in older trees strong enough to hold nests weighing over 1,000 pounds. Bald eagles and ospreys are both common in the area and feed on the plentiful fish in Mallows Bay.</span>

Shallow water near shore supports underwater grasses that provide food and shelter for fish, crabs, and other animals; abundant grasses indicate healthy water. About a dozen types grow here, most commonly water stargrass, coontail, and naiads. Hydrilla, a non-native grass introduced in the 1970s-1980s, now dominates Mallows Bay, offering some benefits but crowding out native grasses.