Seagrass

Seagrasses are flowering plants that grow in shallow waters and are found along the coasts of every continent except for Antarctica. Seagrasses not only provide critical ecosystem services as the nurseries of the sea, but also serve as a reliable source for carbon sequestration. Seagrasses occupy 0.1% of the seafloor, yet are responsible for 11% of the organic carbon buried in the ocean. Between 2–7% of the earth’s seagrass meadows, mangroves and other coastal wetlands are lost annually.

Through our SeaGrass Grow Blue Carbon Calculator you can calculate your carbon footprint, offset through seagrass restoration and learn about our coastal restoration projects.
Here, we have compiled some of the best resources on seagrass.

Fact Sheets and Flyers

Pidgeon, E., Herr, D., Fonseca, L. (2011). Minimizing Carbon Emissions and Maximizing Carbon Sequestration and Storage by Seagrasses, Tidal Marshes, Mangroves – Recommendations from the International Working Group on Coastal Blue Carbon
This brief flyer calls for immediate action towards the protection of seagrasses, tidal marshes and mangroves through 1) enhanced national and international research efforts of coastal carbon sequestration, 2) enhanced local and regional management measures based on current knowledge of emissions from degraded coastal ecosystems and 3) enhanced international recognition of coastal carbon ecosystems.  

“Seagrass: A Hidden Treasure.” Fact Sheet produced University of Maryland Center for Environmental Science Integration & Application Network  December 2006.

“Seagrasses: Prairies of the Sea.” produced University of Maryland Center for Environmental Science Integration & Application Network  December 2006.

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Press Releases, Statements, and Policy Briefs

Chan, F., et al. (2016). The West Coast Ocean Acidification and Hypoxia Science Panel: Major Findings, Recommendations, and Actions. California Ocean Science Trust.
A 20-member scientific panel warns that increases in global carbon dioxide emissions are acidifying waters of the North American West Coast at an accelerating rate. The West Coast OA and Hypoxia panel specifically recommends exploring approaches that involve the use of seagrass to remove carbon dioxide from seawater as a primary remedy to OA on the west coast.

Florida Roundtable on Ocean Acidification: Meeting Report. Mote Marine Laboratory, Sarasota, FL September 2, 2015
In September 2015, Ocean Conservancy and Mote Marine Laboratory partnered to host a roundtable on ocean acidification in Florida designed to accelerate the public discussion about OA in Florida. Seagrass ecosystems play a huge role in Florida and the report recommends the protection and restoration of seagrass meadows for 1) ecosystem services 2) as part of a portfolio of activities that move the region toward reducing the impacts of ocean acidification.

Reports

Conservation International. (2008). Economic Values of Coral Reefs, Mangroves, and Seagrasses: A Global Compilation. Center for Applied Biodiversity Science, Conservation International, Arlington, VA, USA.
This booklet compiles the results of a wide variety of economic valuation studies on tropical marine and coastal reef ecosystems around the world. While published in 2008, this paper still provides a useful guide to the value of coastal ecosystems, especially in the context of their blue carbon uptake abilities.

Cooley, S., Ono, C., Melcer, S. and Roberson, J. (2016). Community-Level Actions that Can Address Ocean Acidification. Ocean Acidification Program, Ocean Conservancy. Front. Mar. Sci.
This report includes a helpful table on actions local communities can take to combat ocean acidification, including restoring oyster reefs and seagrass beds.

The Florida Boating Access Facilities Inventory and Economic Study, including a pilot study for Lee County.  August 2009. 
This is an extensive report for the Florida Fish and Wildlife Conservation Commission on the boating activities in Florida, their economic and environmental impact, including the value seagrass brings to the recreational boating community.

Hall, M., et al. (2006). Developing Techniques to Enhance the Recovery Rates of Propeller Scars in Turtlegrass (Thalassia testudinum) Meadows. Final Report to USFWS.
Florida Fish and Wildlife was granted funds to research the direct impacts of human activities on seagrass, specifically boater behavior in Florida, and the best techniques for its speedy recovery.

Laffoley, D.d’A. & Grimsditch, G. (eds). (2009). The management of natural coastal carbon sinks. IUCN, Gland, Switzerland. 53 pp
This report provides thorough yet simple overviews of coastal carbon sinks. It was published as a resource not only to outline the value of these ecosystems in blue carbon sequestration, but also to highlight the need for effective and proper management in keeping that sequestered carbon in the ground.

“Patterns of Propeller Scarring of Seagrass in Florida Bay Associations with Physical and Visitor Use Factors and Implications for Natural Resource Management – Resource Evaluation Report – SFNRC Technical Series 2008:1.”  South Florida Natural Resources Center
The National Park Service (South Florida Natural Resources Center – Everglades National Park) uses aerial imagery to identify propeller scars and the seagrass rate of recovery in the florida Bay, needed by park managers and the public to improve natural resource management.

Photo-interpretation Key for the 2011 Indian River Lagoon Seagrass Mapping Project. 2011. Prepared by Dewberry. 
Two groups in Florida contracted Dewberry for a seagrass mapping project for the Indian River Lagoon to acquire aerial imagery of the entire Indian River Lagoon in digital format and produce a complete 2011 seagrass map by photo-interpreting this imagery with ground truth data.

U.S. Fish & Wildlife Service Report to Congress. (2011). “Status and Trends of Wetlands in the Conterminous United States 2004 to 2009.”
This federal report confirms that America’s coastal wetlands are vanishing at an alarming rate, according to a national coalition of environmental and sportsman’s groups concerned with the health and sustainability of the nation’s coastal ecosystems.

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Journal Articles

Cullen-Insworth, L. and Unsworth, R. 2018. “A call for seagrass protection”. Science, Vol. 361, Issue 6401, 446-448.
Seagrasses provide habitat to many species and provide key ecosystem services such as filtering sediments and pathogens in the water column, as well as attenuating coastal wave energy. The protection of these ecosystems is critical because of the important role seagrasses play in climate mitigation and food security. 

Blandon, A.,  zu Ermgassen, P.S.E. 2014. “Quantitative estimate of commercial fish enhancement by seagrass habitat in southern Australia.” Estuarine, Coastal and Shelf Science 141.
This study looks into the value of seagrass meadows as nurseries for 13 species of commercial fish and aims to grow appreciation for seagrass by coastal stakeholders.

Camp EF, Suggett DJ, Gendron G, Jompa J, Manfrino C and Smith DJ. (2016). Mangrove and seagrass beds provide different biogeochemical services for corals threatened by climate change. Front. Mar. Sci. 
The main point of this study is that seagrasses provide more services against ocean acidification than mangroves. Seagrasses have the ability to reduce the impact of ocean acidification to nearby reefs by maintaining favorable chemical conditions for reef calcification.

Campbell, J.E., Lacey, E.A,. Decker, R.A., Crools, S., Fourquean, J.W. 2014. “Carbon Storage in Seagrass Beds of Abu Dhabi, United Arab Emirates.” Coastal and Estuarine Research Federation.
This study is important because the authors consciously choose to evaluate the undocumented seagrass meadows of the Arabian Gulf, understanding there that research on seagrass may be biased based on the lack of regional data diversity. They find that while the grasses in the Gulf store only modest amounts of carbon, their wide existence as a whole stores a significant amount of carbon.

 Carruthers, T.,van Tussenbroek, B., Dennison, W.2005. Influence of submarine springs and wastewater on nutrient dynamics of Caribbean seagrass meadows. Estuarine, Coastal and Shelf Science 64, 191-199.
A study into the seagrass of the Caribbean and the degree of regional ecological influence of its unique submarine springs have on nutrient processing.

Duarte, C., Dennison, W., Orth, R., Carruthers, T. 2008. The Charisma of Coastal Ecosystems: Addressing the Imbalance. Estuaries and Coasts: J CERF 31:233–238
This article call for more media attention and research to be given to coastal ecosystems, like seagrass and mangroves. The lack of research leads to a lack of action to curb the losses of the valuable coastal ecosystems.

Ezcurra, P., Ezcurra, E., Garcillán, P., Costa, M., and Aburto-Oropeza, O. (2016). Coastal landforms and accumulation of mangrove peat increase carbon sequestration and storage. Proceedings of the National Academy of Sciences of the United States of America.
This study finds that mangroves in Mexico’s arid northwest, occupy less than 1% of the terrestrial area, but store around 28% of the total belowground carbon pool of the whole region. Despite their small are, mangroves and their organic sediments represent a disproportionate to global carbon sequestration and carbon storage.

Fonseca, M., Julius, B., Kenworthy, W.J. 2000. “Integrating biology and economics in seagrass restoration: How much is enough and why?” Ecological Engineering 15 (2000) 227–237
This study looks at the gap of seagrass restoration fieldwork,  and poses the question: how much damaged seagrass needs to be manually restored for the ecosystem to start naturally recovering itself?  This study is important because filling this gap could potentially allow seagrass restoration projects to be less expensive and more efficient. 

Fonseca, M., et al. 2004. Use of two spatially explicit models to determine the effect of injury geometry on natural resource recovery. Aquatic Conserv: Mar. Freshw. Ecosyst. 14: 281–298.
A technical study into the type of injury caused by boats to seagrass and their ability to naturally recover.

Fourqurean, J. et al. (2012). Seagrass ecosystems as a globally significant carbon stock. Nature Geoscience 5, 505–509.
This study affirms that seagrass, currently one of the world’s most threatened ecosystems, is a critical solution to climate change through its organic blue carbon storage abilities.

Greiner JT, McGlathery KJ, Gunnell J, McKee BA. (2013). Seagrass Restoration Enhances “Blue Carbon” Sequestration in Coastal Waters. PLoS ONE 8(8): e72469.
This is one of the first studies to provide concrete evidence of the potential of seagrass habitat restoration to enhance carbon sequestration in the coastal zone. The authors planted seagrass and studied its growth and sequestration over extensive periods of time.

Heck, K., Carruthers, T., Duarte, C., Hughes, A., Kendrick, G., Orth, R., Williams, S. 2008. Trophic transfers from seagrass meadows subsidize diverse marine and terrestrial consumers. Ecosystems.
This study explains that the value of seagrass has been underestimated, as it provides ecosystem services to several species, via its ability to export biomass, and its decline will impact regions beyond where it grows. 

Hendriks, E. et al. (2014). Photosynthetic Activity Buffers Ocean Acidification in Seagrass Meadows. Biogeosciences 11 (2): 333–46.
This study finds that seagrasses in shallow coastal zones have the ability to use their intense metabolic activity to modify pH within their canopy and beyond. Organisms, such as coral reefs, associated with seagrass communities may therefore suffer from the degradation of seagrasses and their ability to buffer pH and ocean acidification.

Hill, V., et al. 2014. Evaluating Light Availability, Seagrass Biomass, and Productivity Using Hyperspectral Airborne Remote Sensing in Saint Joseph’s Bay, Florida. Estuaries and Coasts (2014) 37:1467–1489
The authors of this study use aerial photography to  to estimate the areal extent of seagrasses and use new innovative technology to quantify productivity of a seagrass meadow in complex coastal waters and provide information on the capacity of these environments to support marine food webs.

Irving AD, Connell SD, Russell BD. 2011. “Restoring Coastal Plants to Improve Global Carbon Storage: Reaping What We Sow.” PLoS ONE 6(3): e18311.
A study into the carbon sequestration and storage abilities of coastal plants. In the context of climate change, the study recognizes the untapped source of these coastal ecosystems as models of carbon transfer in tangent with the fact that 30-50% of coastal habitat loss over the last century has been due to human activities.

van Katwijk, M.M., et al. 2009. “Guidelines for seagrass restoration: Importance of habitat selection and donor population, spreading of risks, and ecosystem engineering effects.” Marine Pollution Bulletin 58 (2009) 179–188.
This study evaluates practiced guidelines and proposes new ones for seagrass restoration – putting emphasis on the selection of habitat and donor populations.  They found that seagrass recovers better in historical seagrass habitats and with genetic variation of donor material.  It shows that restoration plans need to be thought out and contextualized if they are to be successful.

Kennedy, H., J. Beggins, C. M. Duarte, J. W. Fourqurean, M. Holmer, N. Marbà, and J. J. Middelburg (2010). Seagrass sediments as a global carbon sink: Isotopic constraints. Global Biogeochem. Cycles, 24, GB4026.
A scientific study on the carbon sequestration capacity of seagrass. Study found that while seagrass only accounts for a small area of coasts, its roots and sediment sequesters a significant amount of carbon.

Marion, S. and Orth, R. 2010. “Innovative Techniques for Large-scale Seagrass Restoration Using Zostera marina (eelgrass) Seeds,” Restoration Ecology Vol. 18, No. 4, pp. 514–526.
This study explores the method of broadcasting seagrass seeds rather than transplanting seagrass shoots as large scale recovery efforts become more prevalent. They found that while seeds can be scattered over a wide region, there is a low initial rate of seedling establishment.

Orth, R., et al. 2006. “A Global Crisis for Seagrass Ecosystems.” BioScience Magazine, Vol. 56 No. 12, 987-996.
Coastal human population and development pose the most significant threat to seagrasses. The authors agree that while science recognizes the value of seagrass and its losses, the public community is unaware. They call for an educational campaign to inform regulators and the public the value of seagrass meadows, and the need and ways to preserve it.

Palacios, S., Zimmerman, R. 2007. Response of eelgrass Zostera marina to CO2 enrichment: possible impacts of climate change and potential for remediation of coastal habitats. Mar Ecol Prog Ser Vol. 344: 1–13.
Authors look into the impact of CO2 enrichment on seagrass photosynthesis and productivity. This study is important because it puts forth a potential solution to seagrass degradation but admits that more research is needed.

Pidgeon E. (2009). Carbon sequestration by coastal marine habitats: Important missing sinks. In: Laffoley DdA, Grimsditch G., editors. The Management of Natural Coastal Carbon Sinks. Gland, Switzerland: IUCN; pp. 47–51.
This article is part of the Laffoley, et al. IUCN 2009 publication (find above). It provides a breakdown of the importance of ocean carbon sinks and includes helpful diagrams comparing different types of terrestrial and marine carbon sinks. The authors highlights that the dramatic difference between the coastal marine and terrestrial habitats is the ability of marine habitats to perform long term carbon sequestration.

Sabine, C.L. et al. (2004). The ocean sink for anthropogenic CO2. Science 305: 367-371
This study examines the ocean’s uptake of anthropogenic carbon dioxide since the Industrial Revolution, and concludes the ocean is by far the largest carbon sink in the world. It removes 20-35% atmospheric carbon emissions.

Unsworth, R., et al. (2012). Tropical Seagrass Meadows Modify Seawater Carbon Chemistry: Implications for Coral Reefs Impacted by Ocean Acidification. Environmental Research Letters 7 (2): 024026.
Seagrass meadows can protect nearby coral reefs and other calcifying organisms, including mollusks, from the effects of ocean acidification through their blue carbon uptake abilities. This study finds that coral calcification downstream of seagrass has the potential to be ≈18% greater than in an environment without seagrass.

Uhrin, A., Hall, M., Merello, M., Fonseca, M. (2009). Survival and Expansion of Mechanically Transplanted Seagrass Sods. Restoration Ecology Vol. 17, No. 3, pp. 359–368
This study explores the viability of mechanical planting of seagrass meadows in comparison to the popular method of manual planting. Mechanical planting allows a larger area to be addressed, however based on the reduced density and lack of significant expansion of seagrass that has persisted 3 years posttransplant, the mechanical planting boat method cannot yet be fully recommended.

Short, F., Carruthers, T., Dennison, W., Waycott, M. (2007). Global seagrass distribution and diversity: A bioregional model. Journal of Experimental Marine Biology and Ecology 350 (2007) 3–20.
This study looks into the diversity and distribution of seagrass in 4 temperate bioregions. It gives insight into the prevalence and survival of seagrass on coasts all over the world.

Waycott, M., et al. “Accelerating loss of seagrasses across the globe threatens coastal ecosystems,” 2009. PNAS vol. 106  no. 30  12377–12381
This study places seagrass meadows as one of the most threatened ecosystems on earth. They found that rates of decline have accelerated from 0.9% per year before 1940 to 7% per year since 1990.

Whitfield, P., Kenworthy, WJ., Hammerstrom, K., Fonseca, M. 2002. “The Role of a Hurricane in the Expansion of Disturbances Initiated by Motor Vessels on Seagrass Banks.” Journal of Coastal Research. 81(37),86-99.
One of the main threats to seagrass is bad boater behavior. This study goes into how damaged seagrass and the banks is resides on can be even more vulnerable to storms and hurricanes without restoration.

Magazine Articles

Spalding, M. J. (2015). The Crisis Upon Us. The Environmental Forum. 32(2), 38-43.
This article highlights the severity of OA, its impact on the food web and on human sources of protein, and the fact that it is a present and visible problem. The author, Mark Spalding, discusses US state actions as well as the international response to OA, and ends with a list of small steps that can be taken to help combat OA – including the option to offset carbon emissions in the ocean in the form of blue carbon.

Conway, D. June 2007. “A Seagrass Success in Tampa Bay.” Florida Sportsman.
An article that looks into a specific seagrass regeneration company, Seagrass Recovery, and the methods they use to restore seagrass in Tampa Bay. Seagrass Recovery employs sediment tubes to fill in prop scars, common in recreational areas of Florida, and G.U.T.S. to transplant large plots of seagrass. 

Emmett-Mattox, S., Crooks, S., Findsen, J. 2011. “Grasses and Gases.” The Environmental Forum Volume 28, Number 4, p 30-35.
A simple, overarching, explanatory article highlighting the carbon storage capabilities of coastal wetlands and the need to restore and protect these vital ecosystems. This article also goes into the potential and reality of providing offsets from tidal wetlands on the carbon market.

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Books & Chapters

Waycott, M., Collier, C., McMahon, K., Ralph, P., McKenzie,L., Udy, J., and Grech, A. “Vulnerability of seagrasses in the Great Barrier Reef to climate change.” Part II: Species and species groups – Chapter 8.
A in depth book chapter providing the all one needs to know into the basics of seagrass and their vulnerability to climate change. It finds that seagrasses are vulnerable to changes in air and sea surface temperature, sea level rise, major storms, floods, elevated carbon dioxide and ocean acidification, and changes in ocean currents.

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Guides

Emmett-Mattox, S., Crooks, S. Coastal Blue Carbon as an Incentive for Coastal Conservation, Restoration and Management: A Template for Understanding Options
The document will help guide coastal and land managers in understanding the ways by which protecting and restoring coastal blue carbon can help achieve coastal management goals. It includes discussion of significant factors in making this determination and outlines next steps for developing blue carbon initiatives.

McKenzie, L. (2008). Seagrass Educators Book. Seagrass Watch. 
This handbook provides educators with information on what seagrasses are, their plant morphology and anatomy, where they can be found and how they survive and reproduce in saltwater. 

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Actions You Can Take

Use our SeaGrass Grow Carbon Calculator to calculate your carbon emissions and donate to offset your impact with blue carbon! The calculator was developed by The Ocean Foundation to help an individual or organization calculate its annual CO2 emissions to, in turn, determine the amount of blue carbon necessary to offset them (acres of seagrass to be restored or the equivalent). The revenue from the blue carbon credit mechanism can be used to fund restoration efforts, which in turn generate more credits. Such programs allow for two wins: creation of a quantifiable cost to global systems of CO2-emitting activities and, second, restoration of seagrass meadows that form a critical component of coastal ecosystems and are in sore need of recovery.

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