Fish habitat and coastal restoration in Louisiana

The magnitude of changes occurring in Louisiana's estuaries creates a uniqu e set of challenges in fish habitat management. Louisiana leads the nation in rate of coastal land loss, with some 70% of national losses. Both natura l and anthropogenic factors are involved in coastal land loss in Louisiana: subsidence, erosion, sediment and freshwater deficits, channelization, and rising mean sea level. Disruption of the natural deltaic cycles of the Mis sissippi River has been particularly detrimental to estuarine fish habitat. Navigation and flood control needs have resulted in the near-total leveein g of the river, preventing normal overbank flooding, channel filling and sw itching, delta and subdelta development, and sediment nourishment of adjace nt and down-current marshes. The resulting system is one in which the quant ity and quality of estuarine habitat are linked to rapidly degrading wetlan d environments. Although the relative production value of subsiding marsh s urfaces is often very high, this condition is not sustainable. Steep declin es in fish production have been forecast for the next century. Federal, sta te, and local coastal restoration projects are attempting to address the lo ss of estuarine habitat with a number of techniques that may produce locali zed changes in fisheries production and distributions. Temporary resource d isplacements can result in increased harvest costs, and basin-scale changes may be particularly hard to accept for resource users who are satisfied wi th current conditions. Harvesters have demonstrated reluctance, and may lac k the financial flexibility, to forfeit expected current catches for predic ted enhancement of long-term fisheries production. In some instances, both sportfishers and commercial resource users have expressed concern over estu arine freshening and turbidity from restoration inputs from riverine source s. Additional public perception difficulties with restoration efforts arise from misunderstandings of the nature of estuarine functions, particularly of the importance of nursery habitat and of the value of low-salinity marsh es as nursery habitat. Significant improvement in the outlook for estuarine fish habitat in Louisiana will require long-term and large-area vision fro m resource managers and the public.