Mallows Bay-Potomac River National Marine Sanctuary

08/20/2026

08/04/2026

August is National Water Quality Month!💦 Did you know that you can check the bacteria levels in the sanctuary all summer long? From May through September, volunteers with the Potomac Riverkeeper Network take weekly water quality samples at three locations in the sanctuary—at the Mallows Bay Park boat launch, Grady’s Spit, and Liverpool Point. The monitoring results are posted to the Swim Guide website and app every Friday, allowing all visitors who plan to enjoy the water to be aware of any potential health concerns.

Learn more about the monitoring effort here:
https://sanctuaries.noaa.gov/mallows-potomac/science/community/bacterial-monitoring.html

📸: Courtesy of Stephen Badger/Maryland DNR

08/02/2026

Today is National Coloring Book Day!🎨Have you checked out the Mallows Bay Activity Book yet? It's filled with coloring pages, crossword puzzles, word searches, and other fun games about the history and nature of Mallows Bay! Available for download at the link below ⬇️

https://sanctuaries.noaa.gov/mallows-potomac/education/resources/students.html

07/29/2026

Happy International Tiger Day...or here at Mallows Bay-Potomac River National Marine Sanctuary, tiger swallowtail butterfly day! 🦋 Eastern tiger swallowtails are a native butterfly species, named for their vibrant yellow wings with four black "tiger" stripes. They are one of the most common butterflies in the sanctuary, often flying amongst the wetland plants on the flowerpot wrecks of the Ghost Fleet.

📸: Matt McIntosh/NOAA

07/22/2026

📣JOIN OUR TEAM: Mallows Bay-Potomac River National Marine Sanctuary is officially searching for a Sanctuary Superintendent!

As a Supervisory Sanctuary Superintendent, you will perform key duties:
🌅 Drive sanctuary programs and build key stakeholder partnerships.
💼 Oversee daily admin and strategic multi-year planning.
🌊 Spearhead development of plans and programs to conserve, protect, enhance, restore, investigate, and manage sanctuary resources through research and outreach.
🤝 Lead, mentor, and strategically plan for sanctuary staff.

We're looking for a strategic, community-minded professional ready to navigate policy, manage federal resources, and protect the sanctuary for generations to come. If you are ready to combine your love for special marine places with top-tier public service, we want you on our team.

👉 Apply now on USAJOBS: https://www.usajobs.gov/job/877472000. Applications close at 11:59 p.m. ET on July 28, 2026.

07/16/2026

Happy World Snake Day! Snakes are an important part of the ecosystem, maintaining balance in the food web and serving as a natural pest control. Several species of snakes have been documented at Mallows Bay Park, the gateway to Mallows Bay-Potomac River National Marine Sanctuary. Swipe through to learn more about some of the snakes you may spot at the sssssanctuary! 🐍

NOAA Office of National Marine Sanctuaries

📸: Taylor Schneider/NOAA, Jeffrey Goldstein/Maryland DNR, Brian Seymour/Maryland DNR, John White/Maryland DNR, James Rode/Maryland DNR, Kim Norris/Maryland DNR, Andrew Godsen/Maryland DNR, Stephen Hayes/Maryland DNR

07/15/2026

This past weekend, sanctuary staff joined Heroes on the Water and the National Park Trust to support a veteran's fishing event at Mallows Bay-Potomac River National Marine Sanctuary! Veterans brought their families to the sanctuary for a fun-filled day of kayaking around the Ghost Fleet and fishing for blue catfish, which each family took home for dinner at the end of the day!🎣

Thank you to Atlantic Kayak and the Maryland chapter of the Coastal Conservation Association, who guided participants on the water, and to Heroes on the Water and National Park Trust for organizing the event and choosing Mallows Bay for such a special day.

📸: Megan McCabe/NOAA

07/14/2026

It's Shark and Ray Awareness Day!🦈You likely won't see sharks or rays in the waters of Mallows Bay-Potomac River National Marine Sanctuary due to its tidal freshwater environment, but they can be found further south near the mouth of the Potomac River.

You may spot a cownose ray, a migratory species along the Atlantic Coast that visits the shallow waters of the Chesapeake Bay each summer to give birth and mate. Bull sharks are another summertime visitor to the Chesapeake Bay, and can sometimes be found in its freshwater tributaries. They are known predators of cownose rays, with both species playing a vital role in the Bay's ecosystem.

Graphics courtesy of University of Maryland Center for Environmental Science Integration and Application Network.

07/13/2026

On this day in 1918, Benzonia was launched! Benzonia was built by the G.M. Standifer Construction Corporation of Vancouver, Washington. Benzonia was built at the wooden shipbuilding shipyard, styled as a Ferris-type cargo steamship for the United States Shipping Board as part of the large war effort of World War I. Named after a town in Michigan, Benzonia launched on July 13, 1918, to great fanfare. Sold to Western Marine and Salvage Company in 1922, Benzonia ended up in Mallows Bay, Maryland in 1929.

Swipe to see how Benzonia looks today in Mallows Bay-Potomac River National Marine Sanctuary!

📸: Slide 1: Photograph of the bow of Benzonia, just before launching into the water on July 13, 1918. (Source: Washington State Archives). Slide 2: The remains of Benzonia (Tyler Smith/NOAA).

07/07/2026

On this day in 1949, Holiday carried a load of passengers on board. After its service as Virginia Lee, this vessel was refitted for service and renamed Holiday. Holiday entered service in 1949 and operated as a ferry running between Boston, Plymouth, and Provincetown, Massachusetts. After changing hands again, it was renamed Accomac, and was intended for service between Cape Charles and Norfolk, Virginia. A 1964 fire took it permanently out of commission, and in 1973, it was abandoned at Mallows Bay.

Now one of the most recognizable vessels at Mallows Bay-Potomac River National Marine Sanctuary, swipe to see how it looks today!

📸: First slide: Starboard view of the Holiday with passengers on board, dated July 7, 1949. (Source: The Mariners' Museum and Park, Newport News, Virginia). Second slide: Accomac in the sanctuary today (Will Sassorossi/NOAA).