Friday, July 15, 2016

Episode 325 (7-18-16): A Student Shout-out for Chesapeake Bay Submerged Aquatic Vegetation

CLICK HERE to listen to episode audio (4:20)

Transcript of audio, notes on the audio, images, and additional information follow below.

All Web addresses mentioned were functional as of 7-15-16.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of July 18, 2016.

SOUND - ~ 4 sec

That’s the sound of an underwater recording in a river in the Chesapeake Bay watershed.   If you were under a few feet of water in the Bay or one of its river tributaries, what aquatic vegetation might you find submerged there?  This week, 16 Virginia high school students give us a quick lesson on that subject.  Have a listen for about 25 seconds.

VOICES - ~25 sec
Males: American Pondweed! Curly Pondweed!
Females: Horned Pondweed! Sago Pondweed! Slender Pondweed!
Males: Eelgrass! Muskgrass! Redhead Grass!
Females: Water Stargrass! Widgeon Grass!
Males: Common Waterweed! Hornwort!
Females: Wild Celery! Southern Naiad!

You’ve been listening to the names of 14 kinds of submerged aquatic vegetation found in the Chesapeake Bay watershed.  The names were shouted out by students from Achievable Dream High School, located in Newport News, Virginia, during the students’ two-week visit in July 2016 to Virginia Tech in Blacksburg.  Submerged aquatic vegetation, or SAV, is the formal name for plants and plant-like organisms that grow underwater in areas shallow enough that light can penetrate to the bottom.  In the Chesapeake Bay region, between about 15 and 25 such organisms are common or are otherwise ecologically significant, and collectively they’re often called Bay grasses.  Despite that common name, none actually are grasses; that is, they’re not classified in the grass family of plants.  Some—like Muskgrass—aren’t even plants, but rather are algae, which are not classified as true plants.

Those confusing details aside, there’s no confusion about the ecological importance of Bay grasses.  They’re a major source of food for waterfowl, as seen in names like Redhead Grass and Widgeon Grass; they provide habitat for fish, crustaceans like Blue Crabs, and other organisms; their leaves and roots harbor food sources for many animals; and they improve water quality by stabilizing sediments, taking up nutrients, and producing oxygen.  For all of these reasons, the extent of Bay grasses is an annually measured indicator of the Chesapeake’s overall health. In 2015, the Virginia Institute of Marine Science’ annual aerial survey reported 91,000 acres [Editor’s note: actually, over 91,600 acres were measured in 2015], a significant improvement over the record low of about 39,000 acres in 1984.

One goal of Chesapeake Bay-restoration efforts is to have 185,000 acres of Bay grasses.  That, and other challenging Bay-restoration goals, will take a lot of work.  But it’s not hard to imagine some of that work being done a few years from now by one or more of the Achievable Dream High School students you heard this week, who are already working to achieve their own challenging goals.  Thanks to those students for lending their voices to this episode.


For more Virginia water sounds, music, and information, visit us online at, or call us at (540) 231-5463.  Virginia Water Radio is produced by the Virginia Water Resources Research Center, part of Virginia Tech’s College of Natural Resources and Environment.  Thanks to Stewart Scales for his banjo version of Cripple Creek to open and close the show.  In Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.


Thanks to students and teachers in Achievable Dream High School in Newport News, Va., for their participation in this episode. The students who called out names of Chesapeake Bay submerged aquatic plants were the following:
Kameren Bluiett
Cassie Broadhead
Richard Cotman III
Anastasia DavĂ­la
Arahs Dixon
Daja Goodrich
Burt Hatton IV
Alonda Johnson
Johnell Judkins
Trent Kinney
Elijah Lydell
Rashid Normal-Jones
Caleb Weekes
Shealtiel Weekes
Markel Wiggins
Destiny Williams.

More information about Achievable Dream schools in Newport News is available online at

Thanks to John Gray Williams, John Seiler, and Maggie Furrow, all in the Virginia Tech College of Natural Resources and Environment, for their help with this episode.

The underwater sounds in this episode were recorded by Raven Harris, of Newport News, Va., on the Appomattox River in Petersburg, Va., on April 18, 2014; used with permission.  Thanks to Mr. Harris for providing the sounds.  Paddling videos by Mr. Harris are available online at


Top: Eelgrass; middle: Widgeon Grass; bottom: Wild Celery. All photos courtesy of the Maryland Department of Natural Resources, from their “Bay Grass Identification Key,” online at


Following is a list of Chesapeake Bay submerged aquatic vegetation (SAV, or “Bay grasses”), compiled from several references.  The list is divided into species native to this area and those that are non-native.  The scientific name is given in parentheses and italics.  The format for common names and the scientific names are according to the 2012 Flora of Virginia, except as noted for three organism groups not included in the Flora of Virginia.  Notes on habitat, occurrence in Virginia, and ecological significance are from the Flora of Virginia (page numbers indicated).  The numbers, corresponding to the references given below the organism list, indicate the reference(s) that the organism.

American Pondweed (Potamogeton nodosus) – “...ponds, lakes, streams, and rivers...infrequent.” (p. 1136)
Common Waterweed (Elodea canadensis) – “Slow...waters of rivers and streams; tidal freshwater aquatic beds in the Coastal Plain....  Frequent in the mountains; infrequent in Piedmont and Coastal Plain.” (p. 1132)
Eelgrass (Zostera marina)“...tidal aquatic beds of the Chesapeake Bay and its tributaries. ...Infrequent in the outer Coastal Plain but often abundant where found.” (p. 1360)
Horned Pondweed (Zanichellia palustris) “...tidal aquatic beds of the Chesapeake Bay and its tributaries; ...ponds and sluggish streams in the mountains. ...Infrequent to locally common in the Coastal Plain.” (p. 1340)
(Common) Hornwort (or Coontail) (Ceratophyllum demsersum) “Submerged in tidal aquatic beds,...tidal marshes, ponds, and sluggish streams; ....  Locally common in estuarine waters of the Coastal Plain; rare in the Piedmont and mountains.” (p. 500)
Muskgrass (a group of algae species: Chara spp.) – not included in Flora of Virginia.
Redhead Grass (Potamogeton pefoliatus)“Tidal aquatic beds; also nontidal waters.  Infrequent in the Coastal Plain.”  (p. 1337)
Ribbonleaf Pondweed (Potamogeton epihydrus) – “Ponds, lakes, streams, and rivers....  Infrequent and local throughout, except absent from southwestern Virginia.” (p. 1335)
Sago Pondweed (Stuckenia pectinata)“...ponds, lakes, and estuaries.  Infrequent; scattered throughout the state; locally common, especially in brackish maritime ponds and estuaries.” (p. 1339)
Sea Lettuce (a species of algae: Ulva lactuca)not included in Flora of Virginia.
Shoal Grass (Holodule wrightii) Not included in Flora of Virginia; for more information, see this link.
Slender Pondweed (Potamogeton pusillus)“Ponds, lakes, and streams...infrequent throughout.” (p. 1338)
Southern or Common Naiad (or Bushy Pondweed) (Najas guadalupensis)  – “Rivers, streams, and impoundments...Infrequent, scattered throughout.” (p. 1134)
Water Stargrass (Heteranthera dubia)Slow to medium-gradient rivers and large streams  Locally common in the Piedmont and mountains, especially along the Potomac, Shenandoah, James, New and Clinch rivers.  (p. 1332
(Large) Water-starwort (Callitriche heterophylla) – Swamps, floodplain pools and ponds, upland depression swamps and ponds, impoundments, ditches, and muddy ruts; typically in shallowly seasonally flooded habitats....  Frequent in the Coastal Plain and Piedmont; more local in the mountains.”  (p. 780)
Widgeon Grass (Ruppia maritima) – “...tidal aquatic beds of the Chesapeake Bay and its tributaries; pools in salt marshes and salt pannes.  Locally common in the lower estuarine and maritime zones of the Coastal Plain.” (p. 1340)
Wild Celery (Vallisneria americana)Slow or still waters of rivres, lakes, and...estuaries....  Infrequent but locally common throughout.” (p. 1135)

Alligator-weed (Alternanthera philoxeroides)“Alluvial and tidal swamps, canals, sloughs, ditches, and ponds.  ...In the past several decades, this weedy, introduced, semiaquatic species has spread and become rampantly invasive in parts of southeastern Virginia; its continued spread into new areas can be expected.” (p. 211)
Curly Pondweed (Potamogeton crispus) “Ponds, lakes, and streams....  Frequent and locally common throughout the mountains and in scattered areas of the Piedmont and Coastal Plan; a problematic, invasive exotic in favorable aquatic habitats.” (p. 1335)
Eurasian Water-milfoil (Myriophyllum spicatum)“Tidal swamps, ...tidal aquatic beds, ponds, disturbed tidal (or formerly tidal) habitats.  Mostly infrequent or rare, and scattered throughout; locally abundant in tidal reaches of the Potomac River and its major tributaries, in Back Bay, and possibly other estuaries.” – p. 636)
Hydrilla (Hydrilla verticillata)“Still or slow waters of ponds, lakes, streams, and rivers (nontidal or tidal).  Infrequent throughout but usually abundant where found; most current records are from the Piedmont, but the species is rapidly spreading and can be expected in new areas.  One of our most invasive aquatic weeds, often clogging waterways and boat motors and outcompeting native aquatics.” (p. 1132)  Additional note 10/19/16: For more on Hydrilla in the Potomac River, please What’s up with the green stuff invading the Potomac River?, Washington Post, 10/15/16.
Parrot Feather (or Brazilian Water-milfoil) (Myriophyllum brasiliense or aquaticum) – “Swamps, ponds, ditches, sluggish streams and rivers.  Infrequent to locally common in the coastal Plain and Piedmont; rare in the mountains.  This invasive exotic appears to be actively spreading and increasing in abundance.” (p. 635)
South American Elodea (or Brazilian Waterweed) (Egeria densa or Elodea densa in some sources)“Sluggish or still water in rivers (nontidal or tidal, streams, and impoundments.  Infrequent to rare throughout, but often locally common where found; most frequent in southwestern Virginia.” (p. 1131)
Spiny Naiad (or Spinyleaf Naiad, Brittle Naiad) (Najas minor)Ponds and lakes.  This introduced species is rapidly spreading in Virginia and is quite tolerant of polluted waters.” (p. 1134)

Sources for This List
Chesapeake Bay Program, “Field Guide of Bay Grasses,” online at
Chesapeake Bay Foundation, “Guide to Underwater Grasses,” undated, online at
L.M. Hurley, Field Guide to the Submerged Aquatic Vegetation of the Chesapeake Bay, U.S. Fish and Wildlife Service (PB 90-187402), Annapolis, Md., 1990.
Alice Jane Lippson and Robert L. Lippson, Life in the Chesapeake Bay, 3rd Ed., Johns Hopkins University Press, Baltimore, Md., 2006.
Maryland Department of Natural Resources, “Bay Grass Identification Key,” online at
Alan S. Weakley et al., Flora of Virginia, BRIT Press/Botanical Research Institute of Texas, Fort Worth, 2012.


Peter W. Bergstrom et al., Underwater Grasses in Chesapeake Bay & Mid-Atlantic Coastal Waters: Guide to Identifying Submerged Aquatic Vegetation, University of Maryland Sea Grant Publications, College Park, Md., 2006. Information about this 76-page guide is available online at

Karl Blankenship, Bay grasses make a comeback but annual survey is in jeopardy, Bay Journal, 7/10/16.

Chesapeake Bay Foundation, “Guide to Underwater Grasses,” undated, online at

Chesapeake Bay Program, “Bay Grasses,” online at; “Underwater Bay Grass Abundance (Baywide),” online at; and online field guide Bay grasses, July 2016, at

L.M. Hurley, Field Guide to the Submerged Aquatic Vegetation of the Chesapeake Bay, U.S. Fish and Wildlife Service (PB 90-187402), Annapolis, Md., 1990.

Alice Jane Lippson and Robert L. Lippson, Life in the Chesapeake Bay, 3rd Ed., Johns Hopkins University Press, Baltimore, Md., 2006.

Maryland Department of Natural Resources, “Bay Grass Identification Key,” online at

Alan S. Weakley, et al., Flora of Virginia, BRIT Press/Botanical Research Institute of Texas, Fort Worth, 2012; information about the Flora of Virginia Project is available online at

University of Maryland Center for Environmental Science, “Chesapeake Bay Report Card,” online at

Virginia Institute of Marine Science, "SAV in Chesapeake Bay and Coastal Bays," online at


All Water Radio episodes are listed by category at the Index link above (

Previous episodes on the Chesapeake Bay include the following:
Episode 279 - 8/24/15
Episode 280 – 9/7/15
Episode 305 – 2/29/16

A previous episode on aquatic and wetland plants is the following:
Episode 146 – 1/28/13.


This episode may help with the following Virginia’s 2010 Science Standards of Learning (SOLs):

Grades K-6 Earth Resources Theme
4.9 - Va. natural resources, including watersheds, water resources, and organisms.

Grades K-6 Living Systems Theme
2.5 - living things as part of a system, including habitats.
3.5 - food webs.
4.5 - ecosystem interactions and human influences on ecosystem.
6.7 - natural processes and human interactions that affect watershed systems; Va. watersheds, water bodies, and wetlands; and water monitoring.

Life Science Course
LS. 4 - organisms’ classification based on features.
LS.6 - ecosystem interactions, including the water cycle, other cycles, and energy flow.
LS.8 - community and population interactions, including food webs, niches, symbiotic relationships.
LS. 10 - changes over time in ecosystems, communities, and populations, and factors affecting those changes.
LS.11 - relationships between ecosystem dynamics and human activity.

Earth Science Course
ES.8 - influences by geologic processes and the activities of humans on freshwater resources, including identification of groundwater and major watershed systems in Virginia.
ES.10 – ocean processes, interactions, and policies affecting coastal zones, including Chesapeake Bay.

Biology Course
BIO.8 - dynamic equilibria and interactions within populations, communities, and ecosystems; including nutrient cycling, succession, effects of natural events and human activities, and analysis of the flora, fauna, and microorganisms of Virginia ecosystems.

The episode may also help with the following Virginia 2008 Social Studies SOLs:

Civics and Economics Course
CE.9 – public policy at local, state, and national levels.

World Geography Course
WG.2 - how selected physical and ecological processes shape the Earth’s surface, including how humans influence their environment and are influenced by it.
WG.10 - cooperation among political jurisdictions to solve problems and settle disputes.

Government Course
GOVT.9 – public policy at local, state, and national levels.

Virginia’s SOLs are available from the Virginia Department of Education, online at