Accelerating loss of seagrasses across the globe threatens coastal ecosystems

Coastal ecosystems and the services they provide are adversely affected by a wide variety of human activities. In particular, seagrass meadows are negatively affected by impacts accruing from the billion or more people who live within 50 km of them. Seagrass meadows provide important ecosystem services, including an estimated $1.9 trillion per year in the form of nutrient cycling; an order of magnitude enhancement of coral reef fish productivity; a habitat for thousands of fish, bird, and invertebrate species; and a major food source for endangered dugong, manatee, and green turtle. Although individual impacts from coastal development, degraded water quality, and climate change have been documented, there has been no quantitative global assessment of seagrass loss until now. Our comprehensive global assessment of 215 studies found that seagrasses have been disappearing at a rate of 110 km2 yr−1 since 1980 and that 29% of the known areal extent has disappeared since seagrass areas were initially recorded in 1879. Furthermore, rates of decline have accelerated from a median of 0.9% yr−1 before 1940 to 7% yr−1 since 1990. Seagrass loss rates are comparable to those reported for mangroves, coral reefs, and tropical rainforests and place seagrass meadows among the most threatened ecosystems on earth.

[1]  Carlos M. Duarte,et al.  Associations of concern: Declining seagrasses and threatened dependent species , 2009 .

[2]  D. Cahoon,et al.  Coastal wetlands: an integrated ecosystem approach , 2009 .

[3]  G. Kendrick,et al.  Trophic Transfers from Seagrass Meadows Subsidize Diverse Marine and Terrestrial Consumers , 2008, Ecosystems.

[4]  Robert J. Orth,et al.  The Charisma of Coastal Ecosystems: Addressing the Imbalance , 2008 .

[5]  Carrie V. Kappel,et al.  A Global Map of Human Impact on Marine Ecosystems , 2008, Science.

[6]  Frederick T. Short,et al.  Global seagrass distribution and diversity: A bioregional model , 2007 .

[7]  Susan L. Williams.  Introduced species in seagrass ecosystems: Status and concerns , 2007 .

[8]  Iris C. Anderson,et al.  Eutrophication in shallow coastal bays and lagoons: the role of plants in the coastal filter , 2007 .

[9]  Hugh Sweatman,et al.  Thermal Stress and Coral Cover as Drivers of Coral Disease Outbreaks , 2007, PLoS biology.

[10]  Charles H. Peterson,et al.  Supporting Online Material for Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean , 2007 .

[11]  Frederick T. Short,et al.  A Global Crisis for Seagrass Ecosystems , 2006 .

[12]  J. Gattuso,et al.  Light availability in the coastal ocean: Impact on the distribution of benthic photosynthetic organisms and their contribution to primary production , 2006 .

[13]  E. Barbier,et al.  Impacts of Biodiversity Loss on Ocean Ecosystem Services , 2006, Science.

[14]  H. Lenihan,et al.  Depletion, Degradation, and Recovery Potential of Estuaries and Coastal Seas , 2006, Science.

[15]  H. Greening,et al.  Toward Reversal of Eutrophic Conditions in a Subtropical Estuary: Water Quality and Seagrass Response to Nitrogen Loading Reductions in Tampa Bay, Florida, USA , 2006, Environmental management.

[16]  J. Emmett Duffy.  Biodiversity and the functioning of seagrass ecosystems , 2006 .

[17]  D. Raffaelli,et al.  Resilience of Hydrobia ulvae populations to anthropogenic and natural disturbances , 2005 .

[18]  J. Duffy,et al.  Ecosystem consequences of diversity depend on food chain length in estuarine vegetation , 2005 .

[19]  Jack J. Middelburg,et al.  Major role of marine vegetation on the oceanic carbon cycle , 2004 .

[20]  D. Bellwood,et al.  Confronting the coral reef crisis , 2004, Nature.

[21]  P. Rönnbäck,et al.  Links between humans and seagrasses—an example from tropical East Africa , 2004 .

[22]  C. Duarte,et al.  European seagrasses: an introduction to monitoring and management , 2004 .

[23]  G. Turner.  Global marine biological diversity: A strategy for building conservation into decision making , 2004, Reviews in Fish Biology and Fisheries.

[24]  K. Bjorndal,et al.  Global Trajectories of the Long-Term Decline of Coral Reef Ecosystems , 2003, Science.

[25]  A. Grant,et al.  Long-Term Region-Wide Declines in Caribbean Corals , 2003, Science.

[26]  F. Achard,et al.  Determination of Deforestation Rates of the World's Humid Tropical Forests , 2002, Science.

[27]  C. Duarte.  The future of seagrass meadows , 2002, Environmental Conservation.

[28]  I. Valiela,et al.  Mangrove Forests: One of the World's Threatened Major Tropical Environments , 2001 .

[29]  J. Romero,et al.  Effects of fish farm loadings on seagrass (Posidonia oceanica) distribution, growth and photosynthesis. , 2001, Marine pollution bulletin.

[30]  K. Bjorndal,et al.  Historical Overfishing and the Recent Collapse of Coastal Ecosystems , 2001, Science.

[31]  G. Kendrick,et al.  Changes in seagrass cover on Success and Parmelia Banks, Western Australia between 1965 and 1995 , 2000 .

[32]  C. Hopkinson,et al.  Issues in ecology: Nutrient pollution of coastal rivers, bays, and seas , 2000 .

[33]  G. Kendrick,et al.  Landscape-scale changes in seagrass distribution over time: a case study from Success Bank, Western Australia. , 1999 .

[34]  J. Hauxwell,et al.  Macroalgal blooms in shallow estuaries: Controls and ecophysiological and ecosystem consequences , 1997 .

[35]  R. O'Neill,et al.  The value of the world's ecosystem services and natural capital , 1997, Nature.

[36]  R. Coles,et al.  Flood and cyclone related loss, and partial recovery, of more than 1000 km2 of seagrass in Hervey Bay, Queensland, Australia , 1995 .

[37]  Carlos M. Duarte,et al.  Submerged aquatic vegetation in relation to different nutrient regimes , 1995 .

[38]  R. Leemans,et al.  Impacts of climate change on ecosystems and species : marine and coastal ecosystems , 1994 .

[39]  Robert J. Orth,et al.  Assessing Water Quality with Submersed Aquatic Vegetation , 1993 .

[40]  R. Watson,et al.  Simulation Estimates of Annual Yield and Landed Value for Commercial Penaeid Prawns from a Tropical Seagrass Habitat, Northern Queensland, Australia , 1993 .

[41]  L. Yarbro,et al.  Mass mortality of the tropical seagrass Thalassia testudinum in Florida Bay (USA) , 1991 .