Full report - Conservation Gateway

Chapter 2 - Coastal Ecosystemsresources and ecological services desired and required byhuman communities (Leslie and Kinzig 2009). Theseundesirable states are now being observed in coastal ecosystemsaround the world.Our challenge is to set ambitious and achievable conservationand restoration goals, in clear recognition of all thethreats that degrade coastal ecosystems. At many locations,habitat and species-focused restoration will not besuccessful without prior substantial and successful work toconserve land within coastal watersheds and to abate pointand non-point pollution impacts. Policy-focused strategiesto reduce water pollution, habitat loss and harvestof threatened species, as well as place-based projects toplant eelgrass and oysters, to restore salt marshes, and toimprove fish passage are urgently needed. An invigoratedwhole-ecosystem approach offers much promise for increasingecological resilience - the ability of an ecosystemto rebound from disturbances (Leslie and Kinzig 2009).We have an opportunity now to learn from history andmove forward with coordinated science and policy to avoidand reverse undesirable ecosystem state conditions so thatour coastal habitats continue to support life and producethe material and aesthetic goods and services that peoplewant and need.Human impacts have pushed estuarine and coastal ecosystemsfar from their historical baseline of rich, diverse, andproductive ecosystems. The severity and synchrony ofdegradation trends and the commonality of causes andconsequences of change provide reference points andquantitative targets for ecosystem based management andrestoration. Overexploitation and habitat destruction havebeen responsible for the large majority of historical changes,and their reduction should be a major management priority.Eutrophication, although severe in the last phase of estuarinehistory, largely followed rather than drove observed declinesin diversity, structure, and functioning. Despite someextinctions, most species and functional groups persist, albeit ingreatly reduced numbers. Thus, the potential for recoveryremains, and where human efforts have focused on protectionand restoration, recovery has occurred, although often withsignificant lag times. (Lotze et al. 2006)Ecosystem Interactions andEcological DependenciesNatural ShorelinesVegetated Tidal Wetlands – Salt, Brackish,and Freshwater Emergent MarshesAmong the most biologically productive ecosystems onearth (Teal 1962; Odum 1970; Valiela et al. 1976; Nixon1980), salt marshes perform many ecosystem services thatare highly valued by society. Salt marshes protect estuarinewater quality by acting as a sink for land-derived nutrientsand contaminants (Valiela et al. 2004; O’Connorand Terry 1972; Teal and Howes 2000). They are alsoan important component of the estuarine food web: thereis a strong positive relationship between the productivityof salt marshes and the productivity of coastal fisheries(Peterson et al. 2000). During high tide, salt marshes andthe network of tidal creeks and pools within them providefood and important nursery grounds for shellfish and finfish,including many commercially harvested species (Teal1962; Weisburg and Lotrich 1982; Dionne et al. 1999;Able et al. 2000; Cicchetti and Diaz 2000). Juvenilemenhaden, for example, derive much of their energy frommarsh plant detritus rather than from a phytoplankton–basedfood web (Pernell and Peters 1984). Able et al.(2000) found that the guts of striped bass (Morone saxatilis)caught in marsh creeks were full of killifish (Fundulusheteroclitus), a common marsh resident. During low tide,salt marshes provide foraging opportunities for terrestrialspecies, including songbirds and shorebirds. Salt marshesalso provide valuable wildlife habitat and nesting areas forosprey, the sharp-tailed sparrow and the clapper rail.Typical northeastern salt marshes are described byNiering and Warren (1980), Edinger et al. (2002),Bertness (2006), and others. The low marsh zone, whichis flooded on a daily basis by the tides, is dominated by thecordgrass, Spartina alterniflora. Low marsh grades into highsalt marsh habitat. At slightly higher elevations, these areflooded periodically by spring and flood tides (Edinger etal. 2002). High salt marsh habitat occurs in a band fromthe mean high tide level to the landward limit of the2-12Northwest Atlantic Marine Ecoregional Assessment • Phase 1 Report