Assessing Spatiotemporal Patterns in Fish Assemblages from Acid-Sensitive Streams in the Adirondack and Catskill Mountains

Science Center Objects

Background With few exceptions, the contemporary and past effects of acidification on fish populations and communities in streams across acid-sensitive regions of NY have not been documented. The pervasive lack of information only permits anecdotal insight into the spatial effects of acidification on stream-fish assemblages and essentially precludes any broad effort to quantify temporal tre...

 
Background
 
With few exceptions, the contemporary and past effects of acidification on fish populations and communities in streams across acid-sensitive regions of NY have not been documented. The pervasive lack of information only permits anecdotal insight into the spatial effects of acidification on stream-fish assemblages and essentially precludes any broad effort to quantify temporal trends and potential recovery of fish assemblages in less acidic or less toxic streams. Though the effects of acidification on fish assemblages have been qualified in several streams of the eastern Adirondacks during 1979, the 1980s, and early 2000s,  (Schofield and Driscoll 1987; Simonin et al. 2005) quantitative impacts were only assessed at four headwater sites (Baker et al. 1996; Simonin et al. 1993; Wigington et al. 1996) during the late 1980s. These studies were restricted to headwater streams in the Moose River Drainage. Potential impacts on fish assemblages of the region were also inferred from past and present measures of brook trout survival (Baldigo et al. 2007). Comparable investigations were completed in one Catskill Mt. system – the Neversink River (Baker et al. 1996; Baldigo 2000; Baldigo and Lawrence 2000; Baldigo and Murdoch 1997; Van Sickle et al. 1996). Accordingly, little quantitative stream-fish data are available to: (a) define the normal range (and variability) in metrics that characterize stream-fish assemblages, (b) quantify the present-day effects of acidification on stream-fish assemblages, (c) define the relations between pH, ANC, base-cation surplus (BSC), DOC, and inorganic Al ( A lim )  levels and the condition of stream-fish assemblages, (d) accurately predict the effects that reduced acid deposition may have on stream-fish assemblages, and (e) diagnose or gauge potential recovery (temporal changes) in stream-fish assemblages in the Adirondack and Catskill Mountain Regions. The lack of fishery data is especially problematic because recent increasing trends in DOC concentration  may be changing the underlying relationship between acidity and Alim in surface waters, which could substantially alter the toxicity of acidic waters, and affect the survival and distribution of many acid-sensitive aquatic species.
 
Objectives
 
The main objective of this study is to increase our knowledge of the effects of acidification on fish assemblages in headwater streams of the western Adirondack Mountain Region. Three related goals are to: (1) quantify the contemporary impact of acidification on stream-fish assemblages, (2) define the normal  site-to-site (spatial) and year-to-year  (temporal) variability in important fishery metrics, and (3) design a long-term stream-fish monitoring program to detect unusual changes in fish assemblages caused by either infrequent but extreme events  (e.g., floods or drought) or by more gradual shifts in lotic conditions (e.g., acid-recovery, climate change).
 
Approach
 
The USGS proposes to survey stream-fish assemblages at a minimum of 25 study sites once during 2014-15 to define spatial differences in fish assemblages and the relations between acidification status and population and community condition, and once each year (2014-16) a minimum of 6 sites to quantify the temporal (annual) variability in important fish population and community metric (e.g., community richness, density, and biomass; brook trout density and biomass, proportion of juvenile brook trout). The spatial effort (a) will be limited primarily to streams of the Western Adirondacks that vary widely in their acidification status, whereas, the temporal effort (b) will focus on streams from the Adirondack and Catskill Parks that have previously been sampled or are index or  “reference” streams which are being used for ongoing long-term hydrology and/or chemistry monitoring. Sites with existing stream-discharge gaging stations will be selected, where available, to minimize the need to model hydrologic information.

Publications

George, S.D., Baldigo, B.P., Stich, D.S., 2019, Temporal variablilty in stream fish assemblage metrics and implications for long-term monitoring: Ecological Indicators, v.101,p.661-669.  https://pubs.er.usgs.gov/publication/70203231

 Project Location by County

Adirondack Region:
Clinton County, NY, Essex County, NY, Franklin County, NY, Fulton County, NY,
Hamilton County, NY, Herkimer County, NY , Lewis County, NY, Oneida County, NY,
Saint Lawrence County, NY, Saratoga County, NY, Warren County, NY, Washington
County, NY

Catskill Region:
Delaware County, NY, Greene County, NY, Schoharie County, NY, Sullivan County,
NY, Ulster County, NY