research will permit an evolution towards a landscape assessment approach for examining critical 
environmental problems over larger spatial scales and the assessment of the cumulative risk 
resulting from multiple stressors. This approach alFows for a more comprehensive perspective 
for evaluating the condition of communities, watersheds and ecoregions. A landscape 
assessment approach also provides the ability to evaluate the status and trends of a variety of 
ecological resources at multiple scales so that relationships of stressors and effects can be 
developed to establish conditions which are influencing the impacts on wildlife populations. 
Gap Analysis 
A. The following research is within the scope of this plan but outside NHEERL’s current 
manpower, expertise, or sampling capability: 
• Assessment data required to extrapolate habitat-biota relationships studied by ORD to the 
population of all systems for which nutrient, sediment, and biocrheria are required will 
necessitate collaboration with other Federal and State agencies, non-governmental 
organizations, and academic institutions. 
• Near shore fish sampling in Great Lakes (e.g., abundance of commercially and 
recreationally valuable species) to support multiple habitat research will require 
collaboration with entities capable of open-water fish sampling. 
• Development of habitat alteration-population response models for the southern Atlantic 
coast (e.g., Carolinian biogeographic province), the southern Pacific coast (e.g., San 
Diego biogeographic jx'ovince), and Puerto Rico and the U.S. Virgin Islands, especially 
for populations of commercially valuable fish and shellfish. 
• Survey of songbird, hawk, and waterfowl utilization of reference coastal wetlands of high 
ecological integrity, and of disturbed wetlands of varying anthropogenic alteration are 
currently outside NHEERL expertise and/or manpower. Wetlands of interest for the 
surveys are all coastal vegetated habitats such as fresh- and salt-water marshes, SAV, and 
emergent aquatic vegetation. 
• Development of quantitative methods to evaluate the restoration success of the structure 
and function of habitats that support populations of commercially valuable fish, shellfish, 
and wildlife. 
B. The following research is outside the scope of this plan (which focuses primarily on fish, 
shellfish, and wildlife population endpoints of concern to society), but relates to other ecological 
endpoints that may be also relevant to society: 
• Understanding of the effects of habitat alteration on fish and other biotic assemblages 
(e.g., zoobenthos, macroinvertebrates) from both a structural (including biodiversity) and 
functional perspective even where these responses cannot be immediately linked to fish, 
shellfish, and wildlife populations of interest 
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