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GENERAL CHARACTERIZATION OF BIOLOGICAL RESOURCES, HABITAT CONDITIONS, AND FISH CONSUMPTION ADVISORIES



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GENERAL CHARACTERIZATION OF BIOLOGICAL RESOURCES, HABITAT CONDITIONS, AND FISH CONSUMPTION ADVISORIES

BIOLOGICAL CONDITION


The science and practice of stream monitoring, assessment, and evaluation has grown substantially since passage of the Clean Water Act in 1972. Biological and habitat assessment methods have been added to the traditional chemical and physical measurements of stream water quality, and water resource and fisheries management professionals now have an expanded and enhanced toolbox for evaluating water resource conditions. Biological assessment methods incorporate a variety of taxonomic groups including algae, benthic macroinvertebrates, and fishes, all of which reflect stream water quality through the composition, structure, and functional relationships of their biological communities (Barbour and others, 1999). In particular, the Index of Biotic Integrity (IBI) method, based on the fish community (Karr, 1981), has proven to be an effective tool for evaluating stream health and in some states to provide a scientifically credible basis for numerically regulating and managing stream water quality.

In Alabama, the IBI has been used by the Tennessee Valley Authority throughout the Tennessee River basin since 1986 (Saylor and Ahlstedt, 1990) to evaluate stream biological conditions. The IBI has also been used by the GSA to assess biological conditions in the upper Cahaba River system (Shepard and others, 1997), lower Cahaba River system (O’Neil and Shepard, 2000a), the upper Black Warrior River system (O’Neil and Shepard, 2000b; Shepard and others, 2002; Shepard and others 2004), Hatchet Creek (O’Neil and Shepard, 2004), Choccolocco Creek (O’Neil and Chandler, 2005), and the Choctawhatchee-Pea River system (Cook and O’Neil, 2000). The ADEM uses the IBI for stream screening assessments in their water-quality monitoring activities.

Based on historical IBI collection data in the GSA database, biological condition was determined for 35 sites (table 43) in the CPYRW by calculating the IBI using metrics (table 44) and scoring criteria (table 45) presented in O’Neil and Shepard (2012). Four sites rated very poor (12%), nine sites rated poor (26%), nine sites rated fair (26%), 11 sites rated good (30%), and two sites rated excellent (6%) (fig. 93). Samples taken at these 35 sites represented a range of stream water quality and habitat conditions and were taken for different reasons in the CPYRW. The distribution of these sampling sites is shown in figure 94. Around one-third of the sites had poor to very poor biological condition while two-thirds of the sites were fair or better. The IBI varies seasonally reflecting natural fish community changes due to reproduction cycles, population recruitment and growth, and climate-related flood and drought cycles. As such, several samples should ideally be collected from different seasons to adequately characterize the statistical distribution of IBIs at any one site.

AQUATIC HABITAT ASSESSMENT


Habitat evaluations are an integral part of efforts to describe biological condition because good biological condition is quite often predicated on the presence of stable and diverse habitat. The term habitat, as applied herein, incorporates several features and processes in streams including the physical components such as rock and rubble, logs, mud, channel, and substrate condition; the chemical and physical components of water quality such as pH, dissolved chemical constituents, temperature, and dissolved gasses; and flow components such as flood and drought frequencies, velocity regimes, and discharge. For quantitative assessment, the habitat concept is generally narrowed to include the physical components of habitat and substrate structure, the degree of channel alteration, and the condition of banks and the adjacent riparian corridor. All of these components directly affect the structure and function of the aquatic biological community and they can be visually assessed for quality and relative degree of impairment.

Stream habitat assessments entail evaluating the structure of the surrounding physical habitat that influences water resource quality and thus the condition of the resident biological community (Barbour and others, 1999). Generally, three characteristics of habitat contribute to the maintenance and persistence of aquatic biological communities: the availability and quality of the habitat-substrate components and instream cover, morphology of the instream channel, and structure of the bank and riparian vegetation zone (Plafkin and others, 1989). Barbour and others (1999) developed two sets of habitat metrics, one for evaluating upland stream habitat dominated by riffle-run microhabitats and hard substrates and the other for evaluating lowland and Coastal Plain streams that are dominated by glide-pool and run-pool habitats with unconsolidated sandy substrates. The glide-pool method was used for assessing aquatic habitat in this evaluation.

A rapid habitat assessment was completed for each of the IBI bioassessment sites in table 45 plus an additional eight sites in the CPYRW. Habitat quality varied from poor to optimal with only 1 site in the optimal range (>75% of the maximum habitat score), 8 sites in the suboptimal range (65 to 75% of the maximum habitat score), 26 sites in the marginal range (50 to 64% of the maximum habitat score), and 8 sites in the poor range (<50% maximum habitat score) (fig. 95). The high percentage of sites in the poor to marginal habitat classes is reflective of the generally degraded aquatic habitat experienced throughout the CPYRW which can be generally attributed to the high percentage of agriculture and associated sediment runoff issues in the region.

HABITAT


NatureServe [explanation—who/what is NatureServe? REF?] has identified 66 ecological systems in Alabama based on the National Vegetation Classification (ADCNR, 2008). Of these 66 ecological systems, 15 are considered habitats important to wildlife in Alabama (ADCNR, 2008). These 15 habitats include Dry Hardwood Forest, Mesic Hardwood Forest, Wet Pine Savanna and Flatwoods, Floodplain Forest, Dry Longleaf Pine Forest, Swamp, Maritime Forest and Coastal Scrub, Bogs and Seepage Communities, Glades and Prairies, Caves and Mines, Isolated Wetlands, Artificial Habitats, Beach and Dune, Estuarine and Marine, and Cliffs and Rockhouses (ADCNR, 2008).

AQUATIC BIODIVERSITY


The Choctawhatchee River Basin is home to 119 freshwater fish species and 25 mussel species, with recent surveys conducted by the GSA documenting 21 mussel species. The aquatic fauna is largely intact due to the absence of large impoundments in the CPYRW (ADCNR, 2008). Issues affecting aquatic habitats and species within this basin include degradation of water quality, habitat fragmentation, degradation and modification, and the impoundment on the Pea River (ADCNR, 2008).

The Yellow River Basin is home to 84 freshwater fish species and 18 crayfish species, with the aquatic fauna largely intact due to the absence of large impoundments in the drainage basin (ADCNR, 2008). Issues affecting aquatic habitats and species within this basin include degradation of water quality, habitat fragmentation, degradation and modification, lack of knowledge of species life history, biology, distribution, and status, and failure to control non-native crayfish (ADCNR, 2008).


FISH CONSUMPTION ADVISORIES


The ADPH publishes yearly lists regarding fish consumption advisories. The 2013 advisory guideline is available online (ADPH, 2014). Table 46 lists the 2013 fish consumption advisories for the CPYRW, with only three counties (Coffee, Covington, and Dale) having fish advisories.

GENERAL ECOSYSTEM CONDITIONS (DCNR STRATEGIC HABITAT PLAN)


The ADCNR has developed a Comprehensive Wildlife Conservation Strategy (CWCS) that addresses the current wildlife conditions and actions to conserve wildlife and vital habitat, including elements of the Strategic Habitat Plan, which is currently being updated and revised (ADCNR, 2008). The CWCS has identified 314 aquatic and terrestrial wildlife species in Alabama in greatest conservation need, including 24 mammals, 26 reptiles, 14 amphibians, 28 birds, 57 fish, 93 mussels, 34 aquatic snails, and 28 crayfishes throughout Alabama which are associated with 15 key habitats and 15 river basins (ADCNR, 2008). Table 47 lists the 15 species in greatest conservation need in the Choctawhatchee and Yellow Rivers Basins: 7 mussels, 4 fishes, 2 amphibians, and 2 reptiles (ADCNR, 2008). Threats to these species in greatest conservation need include habitat loss and fragmentation, loss of natural community integrity, impacts from disturbances and exotic species, and lack of adequate protection information, which are addressed through the CWCS by educational outreach and conservation actions (ADCNR, 2008).

Under this CWCS, conservation actions were proposed for these species of greatest conservation need, and included statewide conservation activities for all habitats, statewide conservation activities for rivers and streams (of which Alabama’s 15 river basins are addressed separately), and statewide conservation activities for terrestrial and estuarine habitats (ADCNR, 2008).

General ecosystem conditions in the Choctawhatchee River include a largely intact fauna (ADCNR, 2008), 233 miles of streams within the basin listed as impaired on the current 303(d) list (ADEM, 2014b), and one major impoundment on the Pea River in Elba, Alabama (ADCNR, 2008). Issues affecting species and habitats within this basin include degradation of water quality, especially from nutrient enrichment; degradation and alteration of habitat from river dredging operations and drainage of bottomland forests and swamps, and fragmentation-loss of stream connectivity through fish passage barriers such as the Elba Dam on the Pea River, and lack of life history knowledge of many species (ADCNR, 2008). The CWCS addresses these issues by identifying research and monitoring needs for the species of greatest conservation concern in this basin.

General ecosystem conditions in the Yellow River includes a good water quality (ADCNR, 2008), with a little more than 18 miles of streams within the basin listed as impaired on the current 303(d) list (ADEM, 2014b). Issues affecting species and habitats within this basin include degradation of water quality, especially from sedimentation and nutrient enrichment, degradation and alteration of habitat from river dredging operations and drainage of bottomland forests and swamps, lack of life history knowledge for many species, and failure to control non-native crayfish (ADCNR, 2008). The CWCS addresses these issues by identifying research and monitoring needs for the species of greatest conservation concern in this basin.


RECOMMENDATION


The CPYRWMA should establish dialogs with responsible parties, including USFWS, ADCNR, Alabama Rivers Alliance, Nature Conservancy, Troy University, Auburn University, and the University of Alabama regarding the current biological and ecosystem resources and preserving these resources for the future.


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