OpenStax Biology 2e
The Chesapeake Bay has long been valued as one of the most scenic areas on Earth; it is now in distress and is recognized as a declining ecosystem. In the 1970s, the Chesapeake Bay was one of the first ecosystems to have identified dead zones, which continue to kill many fish and bottom-dwelling species, such as clams, oysters, and worms. Several species have declined in the Chesapeake Bay due to surface water runoff containing excess nutrients from artificial fertilizer used on land. The source of the fertilizers (with high nitrogen and phosphate content) is not limited to agricultural practices. There are many nearby urban areas and more than 150 rivers and streams empty into the bay that are carrying fertilizer runoff from lawns and gardens. Thus, the decline of the Chesapeake Bay is a complex issue and requires the cooperation of industry, agriculture, and everyday homeowners.
Of particular interest to conservationists is the oyster population; it is estimated that more than 200,000 acres of oyster reefs existed in the bay in the 1700s, but that number has now declined to only 36,000 acres. Oyster harvesting was once a major industry for Chesapeake Bay, but it declined 88 percent between 1982 and 2007. This decline was due not only to fertilizer runoff and dead zones but also to overharvesting. Oysters require a certain minimum population density because they must be in close proximity to reproduce. Human activity has altered the oyster population and locations, greatly disrupting the ecosystem.
The restoration of the oyster population in the Chesapeake Bay has been ongoing for several years with mixed success. Not only do many people find oysters good to eat, but they also clean up the bay. Oysters are filter feeders, and as they eat, they clean the water around them. In the 1700s, it was estimated that it took only a few days for the oyster population to filter the entire volume of the bay. Today, with changed water conditions, it is estimated that the present population would take nearly a year to do the same job.
Restoration efforts have been ongoing for several years by nonprofit organizations, such as the Chesapeake Bay Foundation. The restoration goal is to find a way to increase population density so the oysters can reproduce more efficiently. Many disease-resistant varieties (developed at the Virginia Institute of Marine Science for the College of William and Mary) are now available and have been used in the construction of experimental oyster reefs. Efforts to clean and restore the bay by Virginia and Delaware have been hampered because much of the pollution entering the bay comes from other states, which stresses the need for interstate cooperation to gain successful restoration.
The new, hearty oyster strains have also spawned a new and economically viable industry—oyster aquaculture—which not only supplies oysters for food and profit, but also has the added benefit of cleaning the bay.
Clark, M., Douglas, M., Choi, J. Biology 2e. Houston, Texas: OpenStax. Access for free at: https://openstax.org/details/books/biology-2e
Research Article: Uncertainty in Model Predictions of Vibrio vulnificus Response to Climate Variability and Change: A Chesapeake Bay Case Study
Date Published: May 29, 2014 Publisher: Public Library of Science Author(s): Erin A. Urquhart, Benjamin F. Zaitchik, Darryn W. Waugh, Seth D. Guikema, Carlos E. Del Castillo, Ben Bond-Lamberty. http://doi.org/10.1371/journal.pone.0098256 Abstract: The effect that climate change and variability will have on waterborne bacteria is a topic of increasing concern for coastal ecosystems, including the Chesapeake … Continue reading
Date Published: October 5, 2018 Publisher: Public Library of Science Author(s): Cassandra N. Glaspie, Rochelle D. Seitz, Judi Hewitt. http://doi.org/10.1371/journal.pone.0205162 Abstract: In Chesapeake Bay, the soft-shell clam Mya arenaria (thin-shelled, deep-burrowing) exhibits population declines when predators are active, and it persists at low densities. In contrast, the hard clam Mercenaria mercenaria (thick-shelled, shallow-burrowing) has a … Continue reading
Research Article: Environmental DNA analysis of river herring in Chesapeake Bay: A powerful tool for monitoring threatened keystone species
Date Published: November 1, 2018 Publisher: Public Library of Science Author(s): Louis V. Plough, Matthew B. Ogburn, Catherine L. Fitzgerald, Rose Geranio, Gabriella A. Marafino, Kimberly D. Richie, Hideyuki Doi. http://doi.org/10.1371/journal.pone.0205578 Abstract: Environmental DNA (eDNA) sampling has emerged as a powerful tool to detect and quantify species abundance in aquatic environments. However, relatively few studies … Continue reading
Research Article: Antimicrobial Susceptibility of Vibrio vulnificus and Vibrio parahaemolyticus Recovered from Recreational and Commercial Areas of Chesapeake Bay and Maryland Coastal Bays
Date Published: February 25, 2014 Publisher: Public Library of Science Author(s): Kristi S. Shaw, Rachel E. Rosenberg Goldstein, Xin He, John M. Jacobs, Byron C. Crump, Amy R. Sapkota, Raymond Schuch. http://doi.org/10.1371/journal.pone.0089616 Abstract: Vibrio vulnificus and V. parahaemolyticus in the estuarine-marine environment are of human health significance and may be increasing in pathogenicity and abundance. … Continue reading
Research Article: Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region
Date Published: June 28, 2016 Publisher: Public Library of Science Author(s): Sangchul Lee, In-Young Yeo, Ali M. Sadeghi, Gregory W. McCarty, W. Dean Hively, Megan W. Lang, Upendra M. Sainju. http://doi.org/10.1371/journal.pone.0157637 Abstract: The adoption rate of winter cover crops (WCCs) as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake … Continue reading
Research Article: Modeling the Effect of Hypoxia on Macrobenthos Production in the Lower Rappahannock River, Chesapeake Bay, USA
Date Published: December 31, 2013 Publisher: Public Library of Science Author(s): Samuel Kersey Sturdivant, Mark J. Brush, Robert J. Diaz, Ruth H. Carmichael. http://doi.org/10.1371/journal.pone.0084140 Abstract: Hypoxia in Chesapeake Bay has substantially increased in recent decades, with detrimental effects on macrobenthic production; the production of these fauna link energy transfer from primary consumers to epibenthic and … Continue reading
Research Article: Tidal Marshes across a Chesapeake Bay Subestuary Are Not Keeping up with Sea-Level Rise
Date Published: July 28, 2016 Publisher: Public Library of Science Author(s): Leah H. Beckett, Andrew H. Baldwin, Michael S. Kearney, Just Cebrian. http://doi.org/10.1371/journal.pone.0159753 Abstract: Sea-level rise is a major factor in wetland loss worldwide, and in much of Chesapeake Bay (USA) the rate of sea-level rise is higher than the current global rate of 3.2 … Continue reading
Research Article: Successful recruitment, survival and long-term persistence of eastern oyster and hooked mussel on a subtidal, artificial restoration reef system in Chesapeake Bay
Date Published: October 15, 2018 Publisher: Public Library of Science Author(s): Romuald N. Lipcius, Russell P. Burke, José A. Fernández Robledo. http://doi.org/10.1371/journal.pone.0204329 Abstract: Restoration efforts with native eastern oyster, Crassostrea virginica, in Chesapeake Bay and elsewhere have been limited by shell availability, necessitating the use of alternative structures as subtidal reefs, yet these have rarely … Continue reading
Research Article: Evidence of Eelgrass (Zostera marina) Seed Dispersal by Northern Diamondback Terrapin (Malaclemys terrapin terrapin) in Lower Chesapeake Bay
Date Published: July 29, 2014 Publisher: Public Library of Science Author(s): Diane C. Tulipani, Romuald N. Lipcius, Silvia Mazzuca. http://doi.org/10.1371/journal.pone.0103346 Abstract: The initial discovery in May 2009 of eelgrass (Zostera marina) seeds in fecal samples of wild-caught northern diamondback terrapins (Malaclemys terrapin terrapin) was the first field evidence of eelgrass seed ingestion in this species. … Continue reading