Eelgrass (Zostera marina L.) in the Chesapeake Bay Region of Mid-Atlantic Coast of the USA: Challenges in Conservation and Restoration

Abstract

Decreases in seagrass abundance reported from numerous locations around the world suggest that seagrass are facing a global crisis. Declining water quality has been identified as the leading cause for most losses. Increased public awareness is leading to expanded efforts for conservation and restoration. Here, we report on abundance patterns and environmental issues facing eelgrass (Zostera marina), the dominant seagrass species in the Chesapeake Bay region in the mid-Atlantic coast of the USA, and describe efforts to promote its protection and restoration. Eelgrass beds in Chesapeake Bay and Chincoteague Bay, which had started to recover from earlier diebacks, have shown a downward trend in the last 5-10 years, while eelgrass beds in the Virginia coastal bays have substantially increased in abundance during this same time period.Declining water quality appears to be the primary reason for the decreased abundance, but a recent baywide dieback in 2005 was associated with higher than usual summer water temperatures along with poor water clarity. The success of eelgrass in the Virginia coastal bays has been attributed, in part, to slightly cooler water due to their proximity to the Atlantic Ocean. A number of policies and regulations have been adopted in this region since 1983 aimed at protecting and restoring both habitat and water quality. Eelgrass abundance is now one of the criteria for assessing attainment of water clarity goals in this region. Numerous transplant projects have been aimed at restoring eelgrass but most have not succeeded beyond 1 to 2 years. A notable exception is the large-scale restoration effort in the Virginia coastal bays, where seeds distributed beginning in 2001 has initiated an expanding recovery process. Our research on eelgrass abundance patterns in the Chesapeake Bay region and the processes contributing to these patterns have provided a scientific background for management strategies for the protection and restoration of eelgrass and insights into the causes of success and failure of restoration efforts that may have applications to other seagrass systems.

Twenty-first century climate change and submerged aquatic vegetation in a temperate estuary: the case of Chesapeake Bay

“…The resiliency of natural versus restored eelgrass meadows is an unanswered question. However, it is clear that cooler temperatures and adequate water transparency often favor successful SAV restoration efforts (Orth et al 2010aMoore et al 2012;Zimmerman et al 2015).…”

“…Recently, encouraging recoveries of native aquatic vegetation in certain areas, for example, wild celery in the Susquehanna Flats (Figure 1(a)), have been documented. Also, reseeding efforts have been successful in establishing local populations of eelgrass in the Virginia coastal bays, areas characterized by good water quality (Figure 1(b)) (Orth et al 2010a;Moore et al 2012). However, eelgrass populations have not recovered in the larger polyhaline portion of Chesapeake Bay, where water quality remains poor.…”

Macrofaunistic Diversity in Vallisneria americana Michx. in a Tropical Wetland, Southern Gulf of Mexico

“…At present, its vulnerability in face of the eutrophication of coastal aquatic ecosystems and the declination or disappearance of populations with the resulting loss of biodiversity are a matter of concern (Wigand et al, 2000;Ni, 2001;Bayley et al, 2007;Duarte et al, 2008;Orth et al, 2010). SAV populations, including those of the American Wildcelery Vallisneria americana Michx., have however decreased drastically or disappeared in coastal ecosystems throughout the world (Short et al, 2006;Best et al, 2008).…”

Sustainable Seagrass Restoration in the Virginia Coastal Bays

“…Eelgrass (Zostera marina L.) is found in coastal areas along the North Atlantic and North Pacific basins (Orth et al 2010). Historically, eelgrass was found in the Chesapeake Bay and in the coastal bays of the Delmarva Peninsula (Orth et al 2010).…”

“…Historically, eelgrass was found in the Chesapeake Bay and in the coastal bays of the Delmarva Peninsula (Orth et al 2010). However, in the Virginia Coastal bays the wasting disease Labyrinthula zosterae followed by a hurricane extirpated the eelgrass population in 1933 (Orth et al 2006a).…”