Lichens of the Callahan Mine, a Copper- and Zinc-Enriched Superfund Site in Brooksville, Maine, U.S.A.

Abstract

Metal-enriched habitats often harbor physiologically distinct biotas able to tolerate and accumulate toxic metals. Plants and lichens that accumulate metals have served as effective indicators of ecosystem pollution. Whereas the diversity of metal-tolerant lichens has been well documented globally, the literature of metal-tolerant lichen communities for eastern North America is limited. We examined the lichen flora of the Callahan Mine, a Cu-, Pb-, and Zn-enriched superfund site in Brooksville, Hancock County, Maine, U.S.A. Through collections along transects across metal-contaminated areas of the mine, we documented 76 species of lichens and related fungi. Fifty species were saxicolous, 26 were terricolous. Forty-three species were macrolichens, 31 were microlichens. Although no globally rare or declining species were encountered at the mine, two regionally rare or declining species, Stereocaulon tomentosum and Leptogium imbricatum, were found. The species found at the Callahan Mine were mostly ecological generalists frequenting disturbed habitats. Two extensively studied Cu-tolerant lichens, Acarospora smaragdula and Lecanora polytropa, and other known Cd-, Cu-, Pb-, and Zn-tolerant taxa, were found at the site. Rhodora [Vol. 113

Cladonia lichens as the most effective and essential pioneers in strongly contaminated slag dumps

“…and Diploschistes muscorum [51][52][53]. Many epigeic lichens, including Cladonia spp., have been reported in Zn/Pb/Cu enriched areas [38,[54][55][56][57][58]; however, previously published records are not associated with sites as strongly affected as the examined dumps.…”

“…The occurrence of some Cladonia species within metal-enriched areas was previously documented in other parts of the world (e.g. [13,18,37,38]); however, the abundance, ecological value and upper limit of tolerance for metal enrichment in the environment of these species have not been resolved thus far. Apart from Cladonia, individuals of only two other epigeic lichen genera were observed on the examined dumps (see Table 4).…”

Spatial Variability of Metal Bioaccumulation in Estuarine Killifish (Fundulus heteroclitus) at the Callahan Mine Superfund Site, Brooksville, ME

“…The site is notable for being one of the few, if not the only, documented open pit hard-rock mining site in an intertidal zone and provides an opportunity to research a metal contamination source in an estuarine environment. As mentioned above, risk assessment evaluations conducted by the US EPA, MACTEC, Inc., and other researchers, indicate that metal concentrations in the Mine Site are elevated above background levels (Dwyer 1973; EPA 2009; MACTEC 2009b; Rajakaruna et al 2011). To better understand the fate of metals in the estuarine food web, specifically bioadvection, we evaluated the spatial distribution of Cu, Zn, Cd, and Pb within the Mine Site in sediments and water and the corresponding transfer of metals to fish as affected by site conditions (e.g.…”

New Method of Environmental Assessment and Monitoring of Cu, Zn, As, and Pb Pollution in Surface Soil Using Terricolous Fruticose Lichens

“…Terricolous lichens cover more than 6% of the land surface of the earth [21], and are found in areas such as tropical forests, desert, alpine regions, polar regions, urban areas, as well as highly polluted areas [24,25]. Lichens found in naturally heavy metal-enriched sites, such as serpentinite and other ultramafic rocks [26][27][28] and metal mines [29,30], may be good model systems for biomonitoring. Accordingly, lichens may have the potential to be broadly used as biomonitors in various terrestrial habitats worldwide.…”