Document Actions
Coasts
Where Land Meets Sea, Protection Offers Hope for Birds
|
|
The State of Coastal Birds
Of 173 bird species that use coastal habitats at any time of year, 53
are species of conservation concern and 14 are federally listed as
endangered or threatened. Fourteen of twenty-seven shorebird species
that primarily use coastal habitats have declined.
Based on 50 species that winter exclusively in coastal habitats, the indicator shows a steady increase over the past 40 years, to roughly 20% above the 1968 baseline. Large increases in Common Eider, Northern Gannet, Laughing, Heermann’s, and Western gulls, contribute to this overall trend. Sea ducks, such as King Eider and White-winged Scoter, as well as wintering shorebirds such as Wandering Tattler and Purple and Rock sandpipers, have shown steep declines.
Wintering Coastal Bird Indicator
Birds in Trouble
 |
| Least Tern by Bill Dalton |
- Plovers, terns, and other beach-nesting birds are vulnerable to
people and pets who inadvertently destroy or disturb nests. Wilson’s
Plovers have declined by 78% in 40 years. With a U.S. population of
about 6,000, they are vulnerable to development and catastrophic
hurricanes.
- Small populations of coastal marsh birds, such as rails and
sparrows, are vulnerable to habitat loss and degradation from pollution
and changing water levels that affect feeding areas and plant cover.
Seaside and Saltmarsh Sharp-tailed sparrows are found only in coastal
saltmarshes of eastern North America.
- Common Murres are still one of the most numerous seabirds in the
Northern Hemisphere, but local populations can be severely reduced by
climate change, disturbance, fishing, introduced nest predators, and
oil spills. They have declined by 76% over the past 40 years.
- East Coast populations of Red Knots have declined by an alarming 82%. Semipalmated Sandpiper, Sanderling, and Dunlin have also shown dramatic declines.
 |
Coastal ecosystems include coastlines, nearshore islands, nearshore waters, estuaries, and tidally-influenced sections of rivers and creeks--productive habitats for abundant wildlife. Photo by Gerrit Vyn |
Major Threats
Development
Nearly half of the U.S. population lives and works in coastal areas,
with resident populations expected to increase by 25 million people by
2015. More than 180 million people visit the shore for recreation every
year. These recreational uses often conflict with the needs of birds
and other wildlife.
Conversion of marsh to open water from dredging, water control, boat
traffic, and a changing climate have caused 93% of the coastal habitat
loss that occurred from 1998 to 2004.
 |
| Common Murres by Gerrit Vyn |
Resource Use
Red Knots and other shorebirds depend on horseshoe crab eggs for food. Overharvesting of horseshoe crabs during the past decade has reduced the density of crab eggs along the eastern seashore by up to 99%, which is believed to be a principal cause of steep declines of many shorebird species.
Diving birds such as loons, grebes, gannets, ducks, and shearwaters die from entanglement in fishing gill nets. Overfishing of forage fish (e.g., menhaden along the Atlantic Coast) and bycatch of fish (e.g., in small-mesh shrimp trawls) may deplete food needed by fish-eating birds.
Pollution and Climate Change
From 1998 to 2002, sediments in about half of estuaries in the U.S. had one or more contaminants exceeding benchmarks for “possible or probable adverse effects” on aquatic life. Excess nutrients from agricultural runoff deplete oxygen in coastal waters, forcing fish, shrimp, crabs, and the birds that feed on them to move from the area or die.
Oil spills, as well as chronic pollution from bilge pumping, outboard engines, and mishandling of petroleum products, kill untold numbers of coastal birds and can be linked to declining or depressed local populations of birds such as Common Murres and Marbled Murrelets.
Global climate change causes sea level rise, increased storm surge events, changes in marsh distribution, and changes in the food resources for some birds. In the Southeast, rising sea levels in the next century are expected to flood 30% of habitat in National Wildlife Refuges.
Additionally, birds nesting on beaches and nearshore islands suffer from some of the same threats as island birds, including predation and habitat damage from invasive species.
Saltmarsh Sharp-tailed Sparrow by Kenneth V. Rosenberg
Solutions
Federal or state incentives can encourage coastal management benefiting people and wildlife. Neighboring communities can cooperate to restrict sprawling development and create greenways and natural areas.
Incentives can be developed to create seaside preserves such as the Cape Cod National Seashore, with private or public ownership and local, state, or federal management.
Nest sites can be protected from unintentional disturbance by fencing and other measures.
Sustainable fishing will prevent overharvest of important food sources for birds, including horseshoe crabs.
Beyond Our Borders
Many of our nation’s coastal birds spend part of the year in Canada, Mexico, and Central and South America. The international Western Hemisphere Shorebird Reserve Network is vital to the conservation of these long-distance travelers.
Reasons for Hope
 |
| Brown Pelican by Jane Ogilvie |
Since 1990, under the Federal Coastal Grants Program, about $183 million in grants have been awarded to acquire, protect or restore more than 250,000 acres of coastal wetlands.
The U.S. Department of Interior Ocean and Coastal Activities Implementation Plan provides better integration of coastal habitat management programs across agencies with ocean, coastal, and Great Lakes stewardship.
Fish-eating birds, such as Brown Pelican and Northern Gannet, rebounded after the pesticide DDT was banned in the U.S.
Whooping Cranes wintering in and around the Aransas National Wildlife Refuge in Texas have increased from 15 birds in 1941 to 266 in 2008, the result of successful endangered species conservation and management.
