Ecological Evaluation Technical Guidance - State of New Jersey

point in time. Community function is the measurement of rate processes (e.g.species colonization rates) of the ecosystem. Although both surveys canprovide value depending on the biological questions being asked in the riskassessment, most often, structural surveys are conducted because they aregenerally less resource-intensive in terms of time and cost.In surface water environments, a variety of community surveys can beconducted and these data can be used in various ways. Most commonlyaccepted and often the easiest to conduct and evaluate are statistically basedindices that have been developed by numerous states for a range of ecosystemcomponents. However, other surveys may be applicable based on seasonalvariation, natural characteristics of the site, or other project demands.What is important is that the parameters of the survey accurately reflect thedata acquisition needs of the ERA, including the community selected,sampling methods, and spatial and temporal planning. Surveys that use morethan one taxonomic group and more than one trophic and tolerance level ineach group tend to be more robust. Additionally, sampling protocols thataccount for subhabitats and seasonal life-cycle changes will yield a morerepresentative data set.Generally accepted aquatic community surveys include fish,macroinvertebrates, algae, and zooplankton. Fish and macroinvertebrates aretypically used in lotic environments, plants are generally used in wetlandenvironments, and algae are often used in lentic environments. Samplingmethods for these groups are discussed in Sections 6.2.1.3, 6.2.2.4, and 6.4.1.6.2.1.3 Biological Sampling of Fish and Other Aquatic OrganismsAs part of the completion of an ERA, the investigator may choose to collectaquatic biota for either fish tissue analysis or community survey purposes.When fish are collected for chemical analysis of tissue, whole body analysis isrequired to evaluate the representative dose to predator species. Species basedon feeding guilds and habitats present in the ESNR should be targeted forcollection. For example, it may be appropriate to target water column feeders(e.g. white perch), bottom dwellers (e.g. brown bullhead, channel catfish,white catfish, eel), and large forage range fish (largemouth bass, smallmouthbass, striped bass, rock bass). The analysis of individual fish is paramount,with compositing recommended only when necessary to achieve the minimumtissue mass for chemical analysis. If compositing is used, it is recommendedthat only fish from one habitat or feeding area be combined. Cross-speciescompositing should not be performed.Professional judgment may be needed to decide whether to composite for fullscan analysis versus analysis of individual fish in accordance with a sitespecificanalytical hierarchy. For composite samples, it is recommended thatthe length of the smallest fish in a sample should be > 75% of the largest; thesex, weight, and length of each fish used for each sample should be recorded.Fish tissue data should be reported on a wet-weight basis becauserepresentative contaminant concentrations are needed for dietary modeling toEcological Evaluation Technical Guidance Document 51Version 1.2 8/29/12