Seagrass Meadows Provide a Significant Resource in Support of Avifauna

Abstract

Seagrass meadows are known to be rich in fauna, with complex food webs that provide trophic subsidy to species and habitats way beyond the extent of their distribution. Birds are an often-overlooked part of marine ecosystems; not only are they crucial to the health of marine ecosystems, but their populations are also supported by the productivity and biodiversity of marine ecosystems. The links of birds to specific habitat types such as seagrass meadows are largely not considered except in the context of direct herbivorous consumption. Here, we examine the linkages between seagrass and birds and propose a conceptual framework for how seagrasses may support bird populations beyond their distribution in both direct and indirect pathways. We present evidence that seagrass meadows are globally foraged for fish and invertebrates by coastal birds. They are also targeted by herbivorous wildfowl and potentially benefit birds further afield indirectly as a result of their support for offshore marine fish species at critical times in their life cycle (e.g., Atlantic Cod and King George Whiting). Evidence from the literature indicates that seagrass does provide support for birds, but reveals a field of research requiring much gap filling as studies are globally sparse, mechanistically limited, and small in spatial and temporal scales.

Keywords

• eelgrass
• zostera
• seabirds
• wildfowl
• foraging
• grazing