Publisher :
Place of publication :
Publication year : 2009
Thematic : Coastal Biodiversity
Language : English
Note
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 yr1 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% yr1 before 1940 to 7% yr1 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.
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Keywords : Climate change
Encoded by : Pauline Carmel Joy Eje
