THE WORLD SEAGRASS ASSOCIATION
Raising global awareness of the importance of seagrasses by facilitating training and information exchange, collecting and making management information readily available for the conservation of seagrass habitats, and providing political support for the sustainability, biodiversity, and resilience of the marine environment.
Green sea turtles (Chelonia mydas) in Abades, Tenerife, Spain | Liam McGuire / Ocean Image Bank
THE WORLD SEAGRASS ASSOCIATION
Green sea turtles (Chelonia mydas) in Abades, Tenerife, Spain | Liam McGuire / Ocean Image Bank
Raising global awareness of the importance of seagrasses by facilitating training and information exchange, collecting and making management information readily available for the conservation of seagrass habitats, and providing political support for the sustainability, biodiversity, and resilience of the marine environment.
What are Seagrasses?
Seagrasses are flowering plants that grow in sediment on the seafloor along the coastal fringes of almost every continent. While called seagrasses, they are in fact, more closely related to lilies and gingers than to true grasses.
Seagrass meadows provide a habitat for small marine animals, like prawns and fish, and food for larger animals like green turtles and dugongs.
The Global Importance of Seagrass
Food Security
Seagrasses are fundamental to many communities around the world, because they and their associated biodiversity support essential commercial and artisanal fisheries, as well as the economies that rely on them.
With 40% of the global population living within 100 km of the coast, fisheries are crucial to food security and alleviating poverty. The loss of seagrass from common human activities, such as coastal development and unsustainable fishing practices, can lead to the loss of fish and invertebrate populations that rely on seagrass.
To help stabilize our climate and ensure long-term food security, we need to protect seagrasses and promote their renewal and recovery.
Grey topshell on seagrass, Coranwall, UK | Credit: Shannon Moran / Ocean Image Bank
Food Security
Seagrasses are fundamental to many communities around the world, because they and their associated biodiversity support essential commercial and artisanal fisheries, as well as the economies that rely on them.
With 40% of the global population living within 100 km of the coast, fisheries are crucial to food security and alleviating poverty. The loss of seagrass from common human activities, such as coastal development and unsustainable fishing practices, can lead to the loss of fish and invertebrate populations that rely on seagrass.
To help stabilize our climate and ensure long-term food security, we need to protect seagrasses and promote their renewal and recovery.
Grey topshell on seagrass, Coranwall, UK | Credit: Shannon Moran / Ocean Image Bank
Grey topshell on seagrass, Coranwall, UK | Credit: Shannon Moran / Ocean Image Bank
Food Security
Seagrasses are fundamental to many communities around the world, because they and their associated biodiversity support essential commercial and artisanal fisheries, as well as the economies that rely on them.
With 40% of the global population living within 100 km of the coast, fisheries are crucial to food security and alleviating poverty. The loss of seagrass from common human activities, such as coastal development and unsustainable fishing practices, can lead to the loss of fish and invertebrate populations that rely on seagrass.
To help stabilize our climate and ensure long-term food security, we need to protect seagrasses and promote their renewal and recovery.
Healthy Climate
These powerhouses of the sea filter vast quantities of nutrients from coastal run-off, stabilize sediment, and provide one of the most efficient oceanic stores of carbon on earth. While it only makes up about 0.2% of the world’s oceans, seagrasses sequester 10% of the carbon buried in ocean sediment.
Up to 83,000 metric tons of carbon is stored in sediments of seagrass meadows per square kilometer; twice as much as the carbon stored in temperate and terrestrial forests. This makes them a vital component in combating global climate change.
Field of seagrass (Syringodium filiforme) in Quintana Roo, Mexico | Credit: Ben Jones / Ocean Image Bank
Field of seagrass (Syringodium filiforme) in Quintana Roo, Mexico | Credit: Ben Jones / Ocean Image Bank
Healthy Climate
These powerhouses of the sea filter vast quantities of nutrients from coastal run-off, stabilize sediment, and provide one of the most efficient oceanic stores of carbon on earth. While it only makes up about 0.2% of the world’s oceans, seagrasses sequester 10% of the carbon buried in ocean sediment.
Up to 83,000 metric tons of carbon is stored in sediments of seagrass meadows per square kilometer; twice as much as the carbon stored in temperate and terrestrial forests. This makes them a vital component in combating global climate change.
Healthy Oceans
Seagrass meadows contribute to human and ocean health. Seagrasses produce oxygen as a byproduct of photosynthesis, which helps rid the waters they grow in of pathogens and bacteria that could be harmful to human health.
Seagrass meadows also regulate the chemistry of seawater by the uptake of dissolved carbon dioxide. This helps regulate the pH of seawater, making it less acidic and less harmful to marine organisms with calcium carbonate skeletons such as corals and crustaceans.
Monken children, Myeik Archipelago, Myanmar | Credit: Ben Jones / Ocean Image Bank
Monken children, Myeik Archipelago, Myanmar Credit: Ben Jones / Ocean Image Bank
Healthy Oceans
Seagrass meadows contribute to human and ocean health. Seagrasses produce oxygen as a byproduct of photosynthesis, which helps rid the waters they grow in of pathogens and bacteria that could be harmful to human health.
Seagrass meadows also regulate the chemistry of seawater by the uptake of dissolved carbon dioxide. This helps regulate the pH of seawater, making it less acidic and less harmful to marine organisms with calcium carbonate skeletons such as corals and crustaceans.
Biodiversity
Seagrass form habitats that support an amazing array of plants and animals. Crustacean and fish abundances are seven to twenty times higher in seagrass meadows compared to adjacent bare sand areas.
Many species of commercially important mangrove and reef fish rely on seagrass meadows as nurseries and foraging grounds. Seagrass are also an essential food source for endangered species such as sea turtles, manatees, and dugongs.
Damselfish school dominate the deep seagrass meadow, Greece | Credit: Dimitris Poursanidis / Ocean Image Bank
Damselfish school dominate the deep seagrass meadow, Greece | Credit: Dimitris Poursanidis / Ocean Image Bank
Biodiversity
Seagrass form habitats that support an amazing array of plants and animals. Crustacean and fish abundances are seven to twenty times higher in seagrass meadows compared to adjacent bare sand areas.
Many species of commercially important mangrove and reef fish rely on seagrass meadows as nurseries and foraging grounds. Seagrass are also an essential food source for endangered species such as sea turtles, manatees, and dugongs.
Communities and Culture
Globally, many traditional livelihoods and cultural traditions are intricately linked to seagrass meadows. Seagrass meadows are an important cultural resource for coastal communities and are intrinsic to the socio-economic-cultural landscape of these communities.
Seagrass meadows also provide many educational, recreational, and tourism benefits and opportunities.
Fisher in seagrass (Enhalus acoroides) Sanur, Bali, Indonesia | Credit: Ben Jones / Ocean Image Bank
Communities and Culture
Globally, many traditional livelihoods and cultural traditions are intricately linked to seagrass meadows. Seagrass meadows are an important cultural resource for coastal communities and are intrinsic to the socio-economic-cultural landscape of these communities.
Seagrass meadows also provide many educational, recreational, and tourism benefits and opportunities.
Fisher in seagrass (Enhalus acoroides) Sanur, Bali, Indonesia | Credit: Ben Jones / Ocean Image Bank
Fisher in seagrass (Enhalus acoroides) Sanur, Bali, Indonesia | Credit: Ben Jones / Ocean Image Bank
Communities and Culture
Globally, many traditional livelihoods and cultural traditions are intricately linked to seagrass meadows. Seagrass meadows are an important cultural resource for coastal communities and are intrinsic to the socio-economic-cultural landscape of these communities.
Seagrass meadows also provide many educational, recreational, and tourism benefits and opportunities.
Changes in Seagrass Observed Over the Last Century
There is extensive global evidence of seagrass loss. In 2007, a global review of available seagrass data clearly articulated the rapid loss of seagrass (Waycott et al. 2009). Since then we’ve seen more records of historic, recent, and current seagrass loss, degradation, and fragmentation around the world.
Researcher in seagrass, Greece | Dimitris Poursanidis / Ocean Image Bank
For example, there was a loss of 2.6 km2 of seagrass in Biscayne Bay (Florida, USA) between 1938 and 2009 (Santos et al. 2016).
Other recent examples in the literature come from a lagoon in the southeast of France where up to 38% of the seagrass may have been lost since the 1920s (Holon et al. 2015) and from the nearshore waters of Singapore where some 45% of seagrass has been lost over the past 5 decades (Yaakub et al. 2014).
Similar examples of extensive loss have been reported from Canada (Matheson et al. 2016), and the Caribbean (van Tussenbroek et al. 2014). In the British Isles, seagrasses have been found to be in a widespread perilous state (Jones & Unsworth 2016). Even the Great Barrier Reef Marine Park has suffered periods of widespread decline and loss of seagrass over the past decade, particularly along its central and southern developed coasts.
These declines resulted from multiple years of above-average rainfall, poor water quality, and climate-related impacts followed by extreme weather events. The most recent (published) monitoring surveys (McKenzie et al. 2015) showed that the majority of seagrass meadows across Great Britain, which cover approximately 3,063 km2, remain in a vulnerable state, with weak resistance, low abundance, and a low capacity to recover (McKenzie et al. 2015).
Researcher in seagrass, Greece | Dimitris Poursanidis / Ocean Image Bank
Changes in Seagrass Observed Over the Last Century
There is extensive global evidence of seagrass loss. In 2007, a global review of available seagrass data clearly articulated the rapid loss of seagrass (Waycott et al. 2009). Since then we’ve seen more records of historic, recent, and current seagrass loss, degradation, and fragmentation around the world.
For example, there was a loss of 2.6 km2 of seagrass in Biscayne Bay (Florida, USA) between 1938 and 2009 (Santos et al. 2016).
Other recent examples in the literature come from a lagoon in the southeast of France where up to 38% of the seagrass may have been lost since the 1920s (Holon et al. 2015) and from the nearshore waters of Singapore where some 45% of seagrass has been lost over the past 5 decades (Yaakub et al. 2014).
Similar examples of extensive loss have been reported from Canada (Matheson et al. 2016), and the Caribbean (van Tussenbroek et al. 2014). In the British Isles, seagrasses have been found to be in a widespread perilous state (Jones & Unsworth 2016). Even the Great Barrier Reef Marine Park has suffered periods of widespread decline and loss of seagrass over the past decade, particularly along its central and southern developed coasts.
These declines resulted from multiple years of above-average rainfall, poor water quality, and climate-related impacts followed by extreme weather events. The most recent (published) monitoring surveys (McKenzie et al. 2015) showed that the majority of seagrass meadows across Great Britain, which cover approximately 3,063 km2, remain in a vulnerable state, with weak resistance, low abundance, and a low capacity to recover (McKenzie et al. 2015).
Seagrass and coral | Marcelo Johan Ogata / Ocean Image Bank
Current and Future Threats
As our human population rapidly grows and the economies of many countries expand rapidly, there is increasing anthropogenic pressure in our coastal zone. We need to find ways to ensure that this coastal expansion doesn’t negatively influence seagrass meadows.
We already recognize that poor water quality, specifically elevated nutrients, is the biggest threat to seagrasses. These problems are particularly acute in many developing nations with rapidly growing economies, where municipal infrastructure is often limited and environmental legislation is largely weak.
Coastal development is a global problem for seagrass. From Wales to Indonesia, there is increasing competition for finite space in the coastal zone. Boating, tourism, aquaculture, ports, energy projects, and housing all place pressure on seagrass.
These local and regional threats to seagrass all exist with a backdrop of the impacts of environmental change and rising sea levels. Seagrasses need to be protected from human impact so that they have the capacity to remain resilient to the impacts of these global long-term stressors.
Seagrass and coral | Marcelo Johan Ogata / Ocean Image Bank
Current and Future Threats
As our human population rapidly grows and the economies of many countries expand rapidly, there is increasing anthropogenic pressure in our coastal zone. We need to find ways to ensure that this coastal expansion doesn’t negatively influence seagrass meadows.
We already recognize that poor water quality, specifically elevated nutrients, is the biggest threat to seagrasses. These problems are particularly acute in many developing nations with rapidly growing economies, where municipal infrastructure is often limited and environmental legislation is largely weak.
Coastal development is a global problem for seagrass. From Wales to Indonesia, there is increasing competition for finite space in the coastal zone. Boating, tourism, aquaculture, ports, energy projects, and housing all place pressure on seagrass.
These local and regional threats to seagrass all exist with a backdrop of the impacts of environmental change and rising sea levels. Seagrasses need to be protected from human impact so that they have the capacity to remain resilient to the impacts of these global long-term stressors.
Securing a Future for Seagrass
We call for action to be taken to secure a future for seagrass. This means improving local water quality, preventing damage from destructive fishing practices, including seagrasses in MPAs, and ensuring that fisheries aren’t over exploited.
Seagrasses also need to be managed effectively during coastal developments and bold steps must be taken to ensure the recovery and restoration of these habitats in areas where losses have occurred. We as a scientific community need to be more united — sharing global datasets, making information open access, and becoming a team of scientists fighting for the survival of seagrasses. This also means engaging further and more actively with the general public, coastal managers, and conservation agencies.
For our proposed actions to take place, we need seagrass ecosystems to fully pervade the policy sphere around the globe as well as the consciousness of our global coastal communities. This needs genuine committed support from global institutions, the world’s media, governments, and funders. We need to ensure that seagrasses become part of environmental education and that the world’s media build on recent progress so that people begin to recognize the need for sustained commitment to seagrass conservation.
World Seagrass Association Inc.
14-88 McGregor Rd,
Smithfield QLD 4878 Australia
(PO Box 6811, Cairns QLD 4870 Australia)
World Seagrass Association Inc.
14-88 McGregor Rd,
Smithfield QLD 4878 Australia
(PO Box 6811, Cairns QLD 4870 Australia)
© 2024 WORLD SEAGRASS ASSOCIATION