Sea Level Rise and Shorebirds: A Look at Grays Harbor, WA Danika Didur-Tate, Nisqually National Wildlife Refuge Complex Shorebirds are • Members of the avian order Charadriiformes (gulls, auks included). Used to be suborder Charadrii. Called ‘waders’ everywhere but NA, where term means storks and herons. ‘shorebirds’ in NA. • ~220 species worldwide, ~50 in NA • Characterized by long legs for wading in wetland, coastal areas. Typically skinny, varying-lengthed bills for probing in mud/sand for invertebrates (worms, early planktonic forms of bivalves, crustaceans, barnacles, etc) • Fairly small, well camouflaged • Niche order, only living on shoreline, mudflat “edges”. Each species more niche, length of leg determines precise depth of water they use. Length of beak relates to which specific organisms they can eat. GLC does not favor niche sp. • Long distance migrants. Brief stop overs. Huge energy requirements. Little stint breeds in arctic, over- winters in s. hemisphere. Greater yellowlegs breeds in northern NA, overwinters tip of SA. Shorebirds need • Shallow gradient estuarine mud flats, forming wide bands of useable habitat. • Open areas. Too many trees in mud flat make them less maneuverable. Too many birds in small area make them less maneuverable. Can’t escape predators. • Open ocean shoreline ok, but less abundant food than mudflats. Also, not all shorebirds are adapted to coastal wave action. • Can’t use open ocean. Can’t use enclosed or crowded areas. SLR and estuaries • SLR creates estuaries. Coastal plain, or drowned river, estuaries created when ocean fills existing river valley. GH estuary is drowned river estuary created after last ice age. • SLR in the short term means current mud flats will be inundated more frequently and for longer periods of time • B/c of steep topography surrounding GH, the new mudflats potentially created would be extremely narrow. • As sea continues inland, upland and salt marsh converted to mudflat. Trees in upland die in salt water, create obstacles blocking in shorebirds and perches for raptors. • Salt marsh → mudflat → open water (never recedes, even at low tide) • B/c of topography, mud flat may be created with SLR, but probably not as much as is being lost SLR in Grays Harbor • The topography around the harbor is very steep, very quickly. Sheer walls. “Bathtub” effect. • GHNWR’s mission statement is about conserving shorebirds, specific shorebirds. If/when there is no longer mud flat in NWR, GHNWR is legally bound to find a way to continue to conserve. General ideas: o Purchasing more land o Building dike/impoundment to maintain mudflat (no inflow of nutrients) Breakwaters influence erosion o “beach nourishment”, adding sediment and building up mudflat elevation