Imagine a world devoid of bird calls, with mountains, rivers, beaches, and forests missing a soundtrack that has sustained for 150 million years. Although such a scenario, reminiscent of Rachel Carson's influential book "Silent Spring," remains highly unlikely, scientists are sounding alarms about the dramatic decline in bird populations worldwide. A 2019 study published in Science documented those declines, including the loss of nearly 3 billion birds in North America alone since 1970. Habitat loss and degradation, driven by coastal disturbance, pollution, and rising sea levels, are the primary culprits.
And along the world’s shorelines, coastal wetlands play an outsize role in sustaining bird populations. By providing feeding, breeding, and nesting areas for a wide variety of avian species, these ecosystems—in particular salt marshes and mangroves—are sanctuaries for migratory birds facing significant challenges. On World Migratory Bird Day (May 11), here are some reasons it's important to protect and conserve coastal wetlands and the birds that visit them:
Coastal wetlands are brimming with food for avian travelers. Salt marshes, with their cordgrasses, provide a buffet of insects, fish, and crustaceans for shorebirds. The intricate root structures of mangroves harbor shellfish and many fish species, attracting larger birds such as herons and egrets. This abundance—including the healthy plant life in these habitats—is crucial for migration, allowing birds to rest and refuel for the next leg of their journeys. During migration, birds can travel thousands of miles, often facing stretches of harsh weather and limited food.
As pollinators and seed dispersers, birds help a diverse array of plants thrive. Birds also act as natural pest control, keeping insect populations in check. Without this control, some insects could overpopulate, harming crops and driving increased pesticide use, which in turn would harm the environment. Declining bird populations can also disrupt seed dispersal, decreasing plant diversity and overall ecosystem health.
Coastal wetlands are also crucial for human well-being. These ecosystems act as natural barriers, protecting coastal communities from floods and storm surges. The dense vegetation and root networks of healthy wetlands buffer the force of waves, lessening the impact of storms on coastal infrastructure and lives. Coastal wetlands also filter pollutants, which benefits communities that rely on these places for recreation and as sources of drinking water. They act as important carbon sinks as well, with the capacity to sequester more carbon below ground per acre than terrestrial forests.
Healthy coastal wetlands also deliver economic benefits, providing jobs and income for coastal communities by supporting vital fisheries, outdoor recreation, and ecotourism operations. Birdwatching enthusiasts from around the world come to tour coastal wetlands, bringing significant revenue into local economies.
Despite the threats pressing on coastal wetlands, humankind can still turn the tide. Conservation efforts focused on protecting and restoring coastal wetlands are critical. The 2019 Science study also found that increased funding in wetland protection and conservation have led to the recovery of some waterfowl populations in certain parts of the world. To build on this progress, governments should include coastal wetland protection and restoration targets in their nationally determined contributions to the Paris Agreement—that is, their international climate commitments.
There is much more that governments can do to safeguard bird habitats around the world. But by conserving and restoring coastal wetlands, policymakers at all levels can lock in immediate and long-lasting gains for wildlife, nature, and people and help ensure that the songs, calls, and cries of birds continue far into the future.
Michael Latimer works on The Pew Charitable Trusts’ advancing coastal wetlands conservation project.