Transcript of audio, notes on the audio, photos, and additional information follow below.
All Web addresses mentioned were functional as of 9-4-15.
TRANSCRIPT OF AUDIO
From the Cumberland Gap to the Atlantic Ocean, this is
Virginia Water Radio for the week of September 7, 2015.
SOUNDS – 5 sec
That underwater sound from a Chesapeake Bay tributary sets
the stage for our second episode on the importance of the Eastern Oyster—this
week, on the oyster’s role in the Bay’s nitrogen
cycle. To start, have a listen for about
15 seconds to these mystery sounds,
and see if you can guess what particle-removing process the famous Bay bivalve
uses to make its living. And here’s a
hint: without this process, coffee’s grounded and car oil’s gunky.
SOUNDS - 15 sec – pouring muddy water, then motor of
vacuum-pump filter apparatus, then release of vacuum
If you guessed filtering, you’re right! You
heard muddy water being pumped and filtered in a water-chemistry lab. Lab equipment, coffee-makers, cars, and other
machines use filters to separate solid particles from liquids. And so do oysters, which pump water over gills
to filter out floating algae. By
consuming algae, oysters also consume the nitrogen that the algae previously absorbed from the water. Nitrogen’s a component in many biological molecules, and excess nitrogen
can stimulate an excess of
algae. Too much algae can
result eventually in low dissolved oxygen levels and shading out of ecologically
important underwater plants.
Oysters’
filter-feeding on algae is one reason why these shellfish are a focus of efforts
to restore the Chesapeake Bay ecosystem. Of particular interest currently are oysters
raised in aquaculture operations,
and just how much nitrogen those oysters can remove from Bay
waters. Oysters use some of the nitrogen they consume to build
shell and tissue, but much of the nitrogen gets excreted or deposited onto bottom
sediments. Measuring the fate of nitrogen
in those sediments is the challenge being undertaken by various scientists,
including University of Virginia master’s student Abby Lunstrum, one of four students
receiving research grants in 2014 from the Virginia Water Resources Research Center. Ms.
Lunstrum’s work, based on sampling
at an oyster farm in Northampton County, Va., seeks to quantify how much
sediment nitrogen gets buried, how much gets converted back to forms that algae
can absorb, and how much gets converted into nitrogen gas and returns to the atmosphere.
Putting those nitrogen-cycle pieces together
is necessary for determining what role oyster aquaculture may play in the
nitrogen-reduction goals of the Chesapeake Bay TMDL, the pollution-reduction
plan published by the U.S. EPA in 2010. In that context,
Ms. Lunstrum’s work is part of another kind of filtering process:
filtering scientific observations into repeatable measurements, practical
technologies, and effective public policies. Just right for the
Chesapeake’s most legendary filter-feeder.
We
close our two-episode oyster encounter with part of “The Oystermen's Ball,” by
Bob Michel.
MUSIC – ~ 16 sec
For more Virginia water sounds, music, and information, visit
us online at virginiawaterradio.org,
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.
AUDIO NOTES AND
ACKNOWLEDGEMENTS
"The Oystermen’s Ball," from the 2004 album of the
same name, is copyright by Bob Michel, used with permission. This music was featured in Episode
279 (8-24-15), “Oysters, Nitrogen, and the Chesapeake Bay – Part 1.” This song was inspired by the oysters of Delaware Bay, where—as in the Chesapeake
Bay—oysters and their filter-feeding remain a focal point for human and aquatic
communities. More information on
Mr. Michel's music is available online at http://www.bobmichel.com/.
Abby
Lunstrum’s research on nitrogen processing by oysters was supported in part by
a grant in 2014 from the Virginia Water Resources Research Center. Ms. Lunstrum’s grant is one of four grants
for 2014-15 (awarded in 2014) under the Water Center’s “Competitive Grants
Program” to assist student research projects.
More information on the program is available online at http://www.vwrrc.vt.edu/grant-opportunities/competitive-grants/. Future Water Radio episodes will focus on
other student research projects supported by this Water Center grant program.
Thanks to Tony Timpano for his assistance in recording the
pump and filter sounds, recorded July 30, 2015, on the Virginia Tech campus.PHOTOS
 |
| Scenes in summer 2014 from Ruby Salts Oyster Farm in Northampton County, Va., the site of University of Virginia student Abby Lunstrum's field work on nitrogen processing by aquacultured oysters. Photos courtesy of Abby Lunstrum. |
EXTRA FACTS ABOUT OYSTERS,
NITROGEN, AND COASTAL WATERS
On Aquaculture
Oyster aquaculture
has been practiced in Asia for centuries and since the 1800s in parts of the
United States. In the Chesapeake Bay
region, aquaculture has traditionally meant adding oyster shells to natural
oyster beds in order to provide more attachment points for wild-produced oyster
larvae. But newer developments include
use of hatchery-raised oyster larvae and of various kinds of constructed floats
or cages to house developing oysters.
According to the Virginia Institute of Marine Science, Virginia’s number
of “aquacultured market oysters” sold increased from fewer than 1 million in
2003 to 39.8 million in 2014.
On Nitrogen
Nitrogen and
phosphorus are two key nutrients in photosynthesis and growth of plants and
algae. Many bodies of water, however,
including the Chesapeake Bay, Gulf of Mexico, and other estuaries, receive more
nutrients—particularly nitrogen—that is healthy for ecological balance in those
ecosystems. While most of the atmosphere
consists of gaseous nitrogen, that form of nitrogen is not usable by plants and
algae. It must first be converted into
“reactive” nitrogen compounds—nitrate, ammonia, and ammonium. Reactive nitrogen forms reach water bodies
like the Chesapeake in runoff from streams, through the air, and by
nitrogen-fixation (the conversion of atmospheric nitrogen into reactive forms)
by certain bacteria. Human activities
that lead to excessive reactive nitrogen in U.S. estuaries are fossil fuel
combustion, fertilizer use, and waste production by humans and livestock.
Too much algae in the Chesapeake or other aquatic systems leads to two
big problems: shading out ecologically important submerged aquatic plants; and
reduced levels of dissolved oxygen, both at night when algae use more oxygen
that they produce through photosynthesis, and after the algae die, when
bacteria use oxygen while decomposing the algae.
On the “Coastal Filter” Concept
Oysters are only one or many coastal organisms—animals and
plants—whose collective activities to remove suspended or dissolved materials
from water have been called the “coastal
filter.” That term typically refers
to the capacity of coastal plants to
absorb nitrogen or other plant nutrients, and retain those materials in their
tissues for some period of time, reducing the impact of such materials on
coastal and ocean waters. But the
coastal areas capacity to filter out materials arriving in watershed
tributaries also includes oysters and other animals—such as clams, mussels, and
some fish—that feed on algae which (like aquatic plants) absorb nitrogen and
other nutrients from the water.
On Denitrification
The audio referred
to some sediment nitrogen in oyster areas being converted back to nitrogen gas
and returning to the atmosphere. That
part of the nitrogen cycle, accomplished by bacteria, is called denitrification. Denitrification represents removal of
nitrogen from an aquatic system, so it’s a main focus of Abby Lunstrum’s research
on the fate of nitrogen in oyster aquaculture operations. Denitrification is also of interest to
scientists studying the nitrogen cycle in other aquatic areas, too. For example, the associate director of the
Virginia Water Resources Research Center, Dr. Kevin McGuire, is part of
collaborative research efforts in at the Hubbard Brook Long Term Ecological
Research site in New Hampshire to measure the amount of denitrification in
small forested streams, part of the tributary network whose waters eventually
feed coastal estuaries like the Chesapeake Bay.
For more on that work, please see Virginia Tech College of
Natural Resources and Environment, “Patches of groundwater responsible for
nitrogen loss from forests,” CNRE News, Summer
2015, Virginia Tech, Blacksburg, Va., available online (as PDF) at http://cnre.vt.edu/magazine/toc/201508/index.html.
SOURCES
Used in Audio and Extra Facts Section Above
Chesapeake Bay Program, “Eastern Oyster,” online at
http://www.chesapeakebay.net/fieldguide/critter/eastern_oyster.
C. T. Driscoll, et al., Nitrogen Pollution: From the Sources to the Sea, Science Links
Publication Vol. 1/No. 2 , Hubbard Brook Research Foundation, Hanover, N.H.,
2003.
Encyclopedia Britannica, “Nitrogen-fixing Bacteria,”
online at http://www.britannica.com/science/nitrogen-fixing-bacteria.
Rona Kobell, “Oyster aquaculture in MD, VA hit some snags in 2014,”
Bay Journal, 11/6/14, online at http://www.bayjournal.com/article/oyster_aquaculture_in_md_va_hit_some_snags_in_2014.
Alice Jane Lippson
and Robert L. Lippson, Life in the
Chesapeake Bay, Johns Hopkins University Press, Baltimore, 2006.
Abby Lunstrum,
“Nitrogen Cycling in Oyster Aquaculture,” online at http://www.abbylunstrum.com/research.html.
University of Maryland Extension, “Oyster Aquaculture and
Education Program, online at https://extension.umd.edu/aquaculture/oysters.
Maryland Sea Grant, “Oysters,” online at http://www.mdsg.umd.edu/topics/oysters/oysters
(page has links to several key publications and other information sources); “Oyster
Aquaculture and Restoration,” online at http://www.mdsg.umd.edu/topics/oysters/oyster-aquaculture-and-restoration.
Clyde L. McKenzie, Jr., “History of
Oystering in the United States and Canada, Featuring the Eight Greatest Oyster
Estuaries,” Marine Fisheries Review,
Vol. 58, No. 4, 1996, available online at http://spo.nwr.noaa.gov/mfr584/mfr5841.pdf.
Karen J. McGlathery, Kristina Sundbäck, and Iris C. Anderson,
“Eutrophication in shallow coastal bays and lagoons: the role of plants in the
coastal filter,” Marine Ecology Progress
Series, Vol. 348, pp. 1-18, 2007; available online (as PDF) at http://www.faculty.virginia.edu/mcglathery/McG_Lab/Publications_files/McGlathery%20et%20al_MEPS07_Eutrophication_Lagoons_Review.pdf.
NOAA/National Sea
Grant College Program/Virginia Sea Grant/Maryland Sea Grant, “Oyster Research
and Restoration in U.S. Coastal Waters: Research Priorities and Strategies,”
2004, Publication VSG-04-01, available online (as PDF) at http://www.mdsg.umd.edu/sites/default/files/files/store/oysterrestoration_summary.pdf.
National Oceanic and Atmospheric Administration
(NOAA), “Oyster Denitrification Research Overview,” online at [have printout],
online at http://www.chesapeakebay.noaa.gov/habitats-hot-topics/oyster-denitrification-research-overview.
Roger I. E. Newell and Roger Mann, “Shellfish
Aquaculture: Ecosystem Effects, Benthic-Pelagic Coupling and Potential for Nutrient
Trading” (report prepared for the Virginia secretary of natural resources),
June 21, 2012, available online from the Chesapeake Bay Program at http://www.chesapeakebay.net/channel_files/18087/attachment_v_-_oyster_aquaculture_report_2.pdf.
Robert R. Stickney, Estuarine Ecology of the
Southeastern United States and Gulf of Mexico, Texas A&M University
Press, College Station, Tex., 1984.
U.S. Environmental Protection Agency (EPA), “Accounting
for the Benefits of Filter Feeder Restoration Technical Documentation—Strategies
for Allocating Filter Feeder Nutrient Assimilation into the Chesapeake Bay TMDL,”
Appendix U of the Chesapeake Bay Total Maximum Daily Load (TMDL), December
2010, available online (as PDF) as http://www.epa.gov/reg3wapd/pdf/pdf_chesbay/FinalBayTMDL/AppendixUFilterFeeders_final.pdf.
Neil M. Dubrovsky, et al., “Nutrients in the Nation's
Streams and Groundwater 1992-2004,” U.S. Geological Survey Circular 1350, Reston,
Va., 2010, online at http://water.usgs.gov/nawqa/nutrients/pubs/circ1350/.
Virginia Institute of Marine Science (VIMS),
“Oysters @ VIMS,” online at http://www.vims.edu/research/topics/oysters/; and
“Virginia
Shellfish Aquaculture—Situation and Outlook Report (Results of 2014 Virginia
Shellfish Aquaculture Crop Reporting Survey)” VSG-15-01/VIMS Marine
Resource Report No. 2015-3, March 2015; online at http://www.vims.edu/research/units/centerspartners/map/aquaculture/index.php.
Virginia Marine Resources Commission/Conservation and
Replenishment Department, online at http://mrc.virginia.gov/replenishment.shtm;
see particularly “Virginia’s Oyster Management and
Industry Today,” 2001, online (as PDF) at http://mrc.virginia.gov/VIRGINIAS_OYSTER_MANAGEMENT_AND%20_INDUSTRY_TODAY.pdf.
Don Webster,
University of Maryland, “Oyster Aquaculture Production,” November 2007,
online (as PDF), at https://extension.umd.edu/sites/default/files/_docs/programs/aquaculture/2_Production%20Methods.pdf.
John Page Williams, Jr., Chesapeake Almanac,
Tidewater Publishers, Centreville, Md., 1993.
For More Information about Oysters, Oyster Aquaculture, or Nitrogen in
the Chesapeake Bay or Other Estuaries
Artisans Center of Virginia, “Virginia Oyster Trail,” online
at http://www.virginiaoystertrail.com/.
Nigel Moore, “The
Oyster’s My World—History of Oysters and Oyster Cultivation,” online at http://theoystersmyworld.com/.
“Oyster Noises,” 10/16/13 post (http://theoystersmyworld.com/2013/10/16/oyster-noises/) lists many songs with an oyster theme.
National Oceanic and Atmospheric Administration
(NOAA)/National Estuarine Research Reserve System, “Estuary Education,” online
at http://estuaries.noaa.gov/Default.aspx.
NOAA/National Marine Fisheries Service, “Status
Review of the Eastern Oyster (Crassostrea
virginica), Report to the National Marine Fisheries Service,” February 16,
2007, online (as PDF) as http://www.nmfs.noaa.gov/pr/species/Status%20Reviews/eastern_oyster_sr_2007.pdf.
Partnership
for the Delaware Estuary, “Delaware Bay Oysters,” online at http://delawareestuary.org/oysters.
Patricia Samford, Jefferson Patterson Park and
Museum/Maryland State Museum of Archeology, “Oyster Wars,” 7/9/13, online at https://jeffersonpatterson.wordpress.com/2013/07/09/oyster-wars/.
Smithsonian Marine Station at Fort Pierce, “Crassostrea
virginica/Eastern Oyster,” online at http://www.sms.si.edu/irlspec/Crassostrea_virginica.htm.
World Oyster Society, online at http://www.worldoyster.org/index_e.html.
RELATED VIRGINIA WATER RADIO EPISODES
For another episode on research by a Virginia graduate
student, please see Episode
259, 3-30-15, “Red-winged Blackbird Research Follows Connections among
Hormones, Avian Malaria, Aquatic Habitats, and Mercury.”
Listed below are some other episodes on subjects related to the
Chesapeake Bay.
Atlantic Menhaden: EP128 – 9/17/12
Chesapeake Bay Restoration Efforts: EP115 – 6/18/12
Estuaries: EP120 – 7/23/12
Estuaries: EP120 – 7/23/12
Exploration of the Chesapeake Bay: EP140 – 12/10/12
Oysters, Nitrogen, and the Chesapeake Bay, Part 1: EP279 –
8/24/15
Plankton: EP171 – 7/22/13
Virginia Water Radio episodes are listed by category at the
Index tab above (http://www.virginiawaterradio.org/p/index.html).
SOLS INFORMATION FOR
VIRGINIA TEACHERS
This episode, in conjunction with Episode 279 (8/24/15), may
help with the following Virginia’s 2010 Science and 2008 Social
Studies Standards of Learning (SOLs):
SCIENCE
Grades K-6 Earth
Resources Theme
3.10 - impacts on survival of species.
4.9 - Va. natural resources, including watersheds, water
resources, and organisms.
Grades K-6 Life
Processes Theme
3.4 - behavioral and physiological adaptations.
Grades K-6 Living Systems
Theme
2.5 - living things as part of a system, including habitats.
3.5 - food webs.
3.6 - ecosystems, communities, populations, shared
resources.
4.5 - ecosystem interactions and human influences on
ecosystem.
5.5 - organism features and classification.
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’ features and classification.
LS.6 - ecosystem interactions, including cycles and energy
flow.
LS.8 - community and population interactions, including food
webs, niches, symbiotic relationships.
LS.9 - adaptations for particular ecosystems’ biotic and
abiotic factors.
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.3 – characteristics of Earth and the solar system (including
sun-Earth-moon relationships, tides, and history of space exploration).
ES.8 - freshwater resources, including groundwater, and
influences by geologic processes and the activities of humans.
ES.10 – ocean processes, interactions, and policies affecting coastal
zones, including Chesapeake Bay.
Biology Course
BIO.2 – water chemistry and its impact on life processes.
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.
Physics
Course
PH.3 – nature and practice of science.
SOCIAL STUDIES
Virginia Studies Course
VS.2 – physical geography of native peoples, including how
American Indians related to their environment to secure food, clothing, and
shelter.
VS.4 – life in the Virginia colony.
United States History to 1865 Course
USI.2 – water features important to the early history of the
United States.
USI.5 – factors that shaped colonial America.
Civics and Economics Course
Civics and Economics Course
CE.9 – public policy at local, state, and national levels.
World Geography Course
WG.2 - how humans influence the environment and are
influenced by it.
WG.3 - how regional landscapes reflect the physical
environment and the cultural characteristics of their inhabitants.
WG.6 - past and present trends in human migration and
cultural interaction as influenced by social, economic, political, and
environmental factors.
WG.7 - types and significance of natural, human, and capital
resources.
WG.10 - cooperation among political jurisdictions to solve
problems and settle disputes.
Government Course
GOVT.9 – public policy at local, state, and national levels.
GOVT.16 – role of government in Va. and U.S. economies,
including examining environmental issues and property rights.
