@article{pandolfo_cope_weaver_kwak_hoeksema_2024, title={Thermal Threats to Freshwater Mussels: An Empirical Stream Assessment}, volume={16}, ISSN={["1424-2818"]}, url={https://doi.org/10.3390/d16010037}, DOI={10.3390/d16010037}, abstractNote={Freshwater mussels fulfill an important ecological role in aquatic ecosystems, but they currently face many threats, including thermal regime alteration. Thermal transformation of the aquatic environment is associated with climate change, land use alteration, and other pervasive anthropogenic global changes. To enhance our understanding of ecological thermal impacts, we combined extensive field measurements of temperature in the stream water column and substrate depths (5 and 15 cm) at sites where mussels occur, measures of abundance and species richness for mussels and fish, and thermal tolerance knowledge for mussels and fish to generate a comprehensive assessment of the potential threats mussels face as temperatures continue to rise as a result of global change. Mean summer (June–August 2010–2012) temperatures at mussel-occupied sites in the upper Tar River basin of North Carolina, USA, ranged from 16.2 to 34.7 °C. The mean temperature from the hottest 96 h at each site ranged from 23.5 to 31.5 °C. At 80% of sites, a period of moderate drought coincided with the hottest 96 h period. Temperature threshold exceedance durations indicated that chronic, combined chronic/acute, and acute freshwater mussel thermal tolerance thresholds (i.e., 28 °C, 30 °C, and 33 °C, respectively) based on laboratory exposures of glochidia (larvae) and juveniles were commonly exceeded. Water temperatures exceeded 28 °C for at least 24 h at 55% of sites and for at least 96 h at 35% of sites, and they exceeded 30 °C for at least 24 h at 15% of sites. We quantified a thermal buffering effect of the substrate that may be protective of mussels. There was a mean difference of 0.5 °C between the water column and the upper substrate (5 cm) and a mean difference of 0.9 °C between the water column and the lower substrate (15 cm). Maximum differences of up to 5.5 °C between the water column and the upper substrate and 11.5 °C between the water column and the lower substrate were observed. Our models estimating the relation between the water column and substrate temperatures more realistically characterize ambient temperature exposures and have widespread implications for mussel conservation and climate change risk assessment in similar streams. Freshwater mussels currently exist on the edge of their thermal limits, but their abundance and species richness cannot be explained by temperature patterns alone. Fish species richness was related to the thermal regime, indicating that species interactions may be an important driver of freshwater mussel responses to global change.}, number={1}, journal={DIVERSITY-BASEL}, author={Pandolfo, Tamara J. and Cope, W. Gregory and Weaver, Daniel M. and Kwak, Thomas J. and Hoeksema, Bert W.}, year={2024}, month={Jan} }
 @article{pandolfo_kwak_cope_heise_nichols_pacifici_2016, title={Species traits and catchment-scale habitat factors influence the occurrence of freshwater mussel populations and assemblages}, volume={61}, ISSN={0046-5070}, url={http://dx.doi.org/10.1111/fwb.12807}, DOI={10.1111/fwb.12807}, abstractNote={Summary


Conservation of freshwater unionid mussels presents unique challenges due to their distinctive life cycle, cryptic occurrence and imperilled status. Relevant ecological information is urgently needed to guide their management and conservation.

We adopted a modelling approach, which is a novel application to freshwater mussels to enhance inference on rare species, by borrowing data among species in a hierarchical framework to conduct the most comprehensive occurrence analysis for freshwater mussels to date. We incorporated imperfect detection to more accurately examine effects of biotic and abiotic factors at multiple scales on the occurrence of 14 mussel species and the entire assemblage of the Tar River Basin of North Carolina, U.S.A.

The single assemblage estimate of detection probability for all species was 0.42 (95% CI, 0.36–0.47) with no species‐ or site‐specific detection effects identified. We empirically observed 15 mussel species in the basin but estimated total species richness at 21 (95% CI, 16–24) when accounting for imperfect detection.

Mean occurrence probability among species ranged from 0.04 (95% CI, 0.01–0.16) for Alasmidonta undulata, an undescribed Lampsilis sp., and Strophitus undulatus to 0.67 (95% CI, 0.42–0.86) for Elliptio icterina. Median occurrence probability among sites was <0.30 for all species with the exception of E. icterina. Site occurrence probability generally related to mussel conservation status, with reduced occurrence for endangered and threatened species.

Catchment‐scale abiotic variables (stream power, agricultural land use) and species traits (brood time, host specificity, tribe) influenced the occurrence of mussel assemblages more than reach‐ or microhabitat‐scale features.

Our findings reflect the complexity of mussel ecology and indicate that habitat restoration alone may not be adequate for mussel conservation. Catchment‐scale management can benefit an entire assemblage, but species‐specific strategies may be necessary for successful conservation. The hierarchical multispecies modelling approach revealed findings that could not be elucidated by other means, and the approach may be applied more broadly to other river basins and regions. Accurate measures of assemblage dynamics, such as occurrence and species richness, are required to create management plans for effective conservation.

}, number={10}, journal={Freshwater Biology}, publisher={Wiley}, author={Pandolfo, Tamara J. and Kwak, Thomas J. and Cope, W. Gregory and Heise, Ryan J. and Nichols, Robert B. and Pacifici, Krishna}, year={2016}, month={Aug}, pages={1671–1684} }
 @article{daraio_bales_pandolfo_2014, title={Effects of land use and climate change on stream temperature II: Threshold exceedance duration projections for freshwater mussels}, volume={50}, DOI={10.1111/jawr.12178}, abstractNote={AbstractWe developed a stochastic hourly stream temperature model (SHSTM) to estimate probability of exceeding given threshold temperature (T) for specified durations (24 and 96 h) to assess potential impacts on freshwater mussels in the upper Tar River, North Carolina. Simulated daily mean stream T from climate change (CC) and land‐use (LU) change simulations for 2021‐2030 and 2051‐2060 were used as input to the SHSTM. Stream T observations in 2010 revealed only two sites with T above 30°C for >24 h and Ts were never >31°C for more than 24 h at any site. The SHSTM suggests that the probability, P, that T will exceed 32°C for at least 96 h in a given year increased from P = 0, in the 20th Century, to P = 0.05 in 2021‐2030 and to P = 0.14 in 2051‐2060. The SHSTM indicated that CC had greater effects on P for 24 and 96 h durations than LU change. Increased P occurred primarily in higher order stream segments in the downstream reaches of the basin. The SHSTM indicated that hourly stream T responded to LU change on the daily scale and did not affect stream T for durations >24 h. The SHSTM indicated that known thermal thresholds for freshwater mussels could be exceeded within the next 50 years in many parts of the upper Tar River basin in North Carolina, which could have negative consequences on the recruitment of freshwater mussels.}, number={5}, journal={Journal of the American Water Resources Association}, author={Daraio, J. A. and Bales, J. D. and Pandolfo, T. J.}, year={2014}, pages={1177–1190} }
 @article{hazelton_cope_mosher_pandolfo_belden_barnhart_bringolf_2013, title={Fluoxetine alters adult freshwater mussel behavior and larval metamorphosis}, volume={445}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2012.12.026}, abstractNote={We used acute and partial-lifecycle tests to examine the effects of the pharmaceutical fluoxetine on freshwater mussels (Unionida). In acute tests lasting 24–48 h, we determined median effective concentrations (EC50s) for fluoxetine with larval (glochidia viability) and juvenile (survival) life-stages of fatmucket (Lampsilis siliquoidea) and black sandshell (Ligumia recta). In a 28-d behavioral test we exposed brooding adult female wavy-rayed lampmussels (Lampsilis fasciola) to 0.37 and 29.3 μg/L fluoxetine to determine effects on adult behavior (foot protrusion, mantle lure display and glochidia parturition). We also assessed the effects of 24-h exposure of 1 and 100 μg/L fluoxetine on glochidia viability duration and metamorphosis success for the wavy-rayed lampmussel. Fluoxetine EC50s ranged from 62 μg/L for juveniles (96 h) to 293 μg/L for glochidia (24 h). In adults, statistically significant increases were observed in foot protrusion at 0.37 and 29.3 μg/L fluoxetine and lure display rates at 29.3 μg/L; glochidia parturition was not significantly affected at any test concentration. Twenty-four hour exposure of glochidia to fluoxetine did not affect viability duration, but likelihood of metamorphosis to the juvenile stage significantly increased with 1 and 100 μg/L treatments. Our results demonstrated effects of fluoxetine to unionid mussels at concentrations less than previously reported and approaching concentrations measured in surface waters.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Hazelton, Peter D. and Cope, W. Gregory and Mosher, Shad and Pandolfo, Tamara J. and Belden, Jason B. and Barnhart, M. Christopher and Bringolf, Robert B.}, year={2013}, month={Feb}, pages={94–100} }
 @article{pandolfo_cope_young_jones_hua_lingenfelser_2012, title={Acute effects of road salts and associated cyanide compounds on the early life stages of the unionid mussel Villosa iris}, volume={31}, ISSN={["0730-7268"]}, DOI={10.1002/etc.1876}, abstractNote={AbstractThe toxicity of cyanide to the early life stages of freshwater mussels (order Unionida) has remained unexplored. Cyanide is known to be acutely toxic to other aquatic organisms. Cyanide‐containing compounds, such as sodium ferrocyanide and ferric ferrocyanide, are commonly added to road deicing salts as anticaking agents. The purpose of the present study was to assess the acute toxicity of three cyanide compounds (sodium cyanide, sodium ferrocyanide, and ferric ferrocyanide), two road salts containing cyanide anticaking agents (Morton and Cargill brands), a brine deicing solution (Liquidow brand), and a reference salt (sodium chloride) on glochidia (larvae) and juveniles of the freshwater mussel Villosa iris. Sodium ferrocyanide and ferric ferrocyanide were not acutely toxic to glochidia and juvenile mussels at concentrations up to 1,000 mg/L and 100 mg/L, respectively. Lowest observed effect concentrations (LOECs) for these two chemicals ranged from 10 to >1,000 mg/L. Sodium cyanide was acutely toxic to juvenile mussels, with a 96‐h median effective concentration (EC50) of 1.10 mg/L, although glochidia tolerated concentrations up to 10 mg/L. The EC50s for sodium chloride, Liquidow brine, Morton road salt, and Cargill road salt were not significantly different for tests within the same life stage and test duration (range, 1.66–4.92 g/L). These results indicate that cyanide‐containing anticaking agents do not exacerbate the toxicity of road salts, but that the use of road salts and brine solutions for deicing or dust control on roads may warrant further investigation. Environ. Toxicol. Chem. 2012; 31: 1801–1806. © 2012 SETAC}, number={8}, journal={ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY}, author={Pandolfo, Tamara J. and Cope, W. Gregory and Young, George B. and Jones, Jess W. and Hua, Dan and Lingenfelser, Susan F.}, year={2012}, month={Aug}, pages={1801–1806} }
 @article{hazelton_cope_pandolfo_mosher_strynar_barnhart_bringolf_2012, title={Partial life-cycle and acute toxicity of perfluoroalkyl acids to freshwater mussels}, volume={31}, ISSN={["1552-8618"]}, DOI={10.1002/etc.1866}, abstractNote={AbstractFreshwater mussels are among the most sensitive aquatic organisms to many contaminants and have complex life‐cycles that include several distinct life stages with unique contaminant exposure pathways. Standard acute (24–96 h) and chronic (28 d) toxicity tests with free larva (glochidia) and juvenile mussels are effective at generating data on contaminant effects at two discrete life stages but do not incorporate effects on brooded glochidia. We developed a novel partial life‐cycle assay that incorporates exposures to brooding adult female mussels and used this method in combination with acute toxicity tests to assess adverse effects of perfluoroctanesulfonic acid (PFOS) and perfluoroctanoic acid (PFOA) on freshwater mussels. Fatmucket (Lampsilis siliquoidea) were exposed to PFOS at two life stages: brooding glochidia (in marsupia) for 36 d and free glochidia in water for 24 h. In standard acute tests with glochidia (24–48 h exposures) and juveniles (48–96 h exposures) of fatmucket and black sandshell (Ligumia recta), glochidia were 8 to 25 times more sensitive than juveniles. Perfluoroctanesulfonic acid significantly reduced the duration of glochidia viability and reduced probability of metamorphosis at concentrations 3,000 times lower than the most sensitive acute endpoint (24‐h EC50). The partial life‐cycle test is adaptable to a variety of endpoints and research objectives and is useful for identifying adverse effects at contaminant concentrations below those required for an acute lethal response. Environ. Toxicol. Chem. 2012; 31: 1611–1620. © 2012 SETAC}, number={7}, journal={ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY}, author={Hazelton, Peter D. and Cope, W. Gregory and Pandolfo, Tamara J. and Mosher, Shad and Strynar, Mark J. and Barnhart, M. Christopher and Bringolf, Robert B.}, year={2012}, month={Jul}, pages={1611–1620} }
 @article{pandolfo_cope_arellano_2010, title={THERMAL TOLERANCE OF JUVENILE FRESHWATER MUSSELS (UNIONIDAE) UNDER THE ADDED STRESS OF COPPER}, volume={29}, ISSN={["1552-8618"]}, DOI={10.1002/etc.92}, abstractNote={AbstractFreshwater mussels fulfill an essential role in aquatic communities, but are also one of the most sensitive and rapidly declining faunal groups in North America. Rising water temperatures, caused by global climate change or industrial discharges, can further challenge impaired unionid communities, but thermal stress is almost certainly not the only stressor affecting freshwater mussels. Metals, such as copper (Cu), are a common source of toxicant exposure in aquatic environments. The toxic effects of Cu on the early life stages of freshwater mussels have been well studied, and freshwater mussels are more sensitive to Cu than most aquatic organisms. The purpose of the present study was to determine the effect of a sublethal copper concentration on the upper thermal tolerance of three species, Lampsilis siliquoidea, Potamilus alatus, and Ligumia recta, of juvenile freshwater mussels in 48‐ and 96‐h tests. Thermal tolerance was determined over a range of experimental temperatures (20–42°C) at three acclimation temperatures (17, 22, and 27°C). Median lethal temperatures (LT50s) were calculated in the absence and presence of Cu, and at 48 h ranged from 34.6 to 44.4°C (mean 37.7°C) without Cu, and from 33.8 to 38.9°C (mean 35.8°C) with Cu. The LT50s at 96 h ranged from 32.5 to 35.6°C (mean 34.5°C) without Cu and from 33.0 to 35.4°C (mean 34.2°C) with Cu. Potamilus alatus had a significantly lower 48 h LT50 with Cu than without Cu at the 22°C acclimation temperature; there were no other significant differences in LT50s attributed to Cu. Survival trends showed limited evidence of interactive effects between copper and temperature for all three species, suggesting the combined stress of elevated temperatures and copper exposure to freshwater mussels should be further explored. Environ. Toxicol. Chem. 2010;29:691–699. © 2009 SETAC}, number={3}, journal={ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY}, author={Pandolfo, Tamara J. and Cope, W. Gregory and Arellano, Consuelo}, year={2010}, month={Mar}, pages={691–699} }
 @article{pandolfo_cope_arellano_bringolf_barnhart_hammer_2010, title={Upper thermal tolerances of early life stages of freshwater mussels}, volume={29}, ISSN={["0887-3593"]}, DOI={10.1899/09-128.1}, abstractNote={Abstract Freshwater mussels (order Unioniformes) fulfill an essential role in benthic aquatic communities, but also are among the most sensitive and rapidly declining faunal groups in North America. Rising water temperatures, caused by global climate change, industrial discharges, drought, or land development, could further challenge imperiled unionid communities. The aim of our study was to determine the upper thermal tolerances of the larval (glochidia) and juvenile life stages of freshwater mussels. Glochidia of 8 species of mussels were tested: Lampsilis siliquoidea, Potamilus alatus, Ligumia recta, Ellipsaria lineolata, Lasmigona complanata, Megalonaias nervosa, Alasmidonta varicosa, and Villosa delumbis. Seven of these species also were tested as juveniles. Survival trends were monitored while mussels held at 3 acclimation temperatures (17, 22, and 27°C) were exposed to a range of common and extreme water temperatures (20–42°C) in standard acute laboratory tests. The average median lethal temperature (LT50) among species in 24-h tests with glochidia was 31.6°C and ranged from 21.4 to 42.7°C. The mean LT50 in 96-h juvenile tests was 34.7°C and ranged from 32.5 to 38.8°C. Based on comparisons of LT50s, thermal tolerances differed among species for glochidia, but not for juveniles. Acclimation temperature did not affect thermal tolerance for either life stage. Our results indicate that freshwater mussels already might be living close to their upper thermal tolerances in some systems and, thus, might be at risk from rising environmental temperatures.}, number={3}, journal={JOURNAL OF THE NORTH AMERICAN BENTHOLOGICAL SOCIETY}, author={Pandolfo, Tamara J. and Cope, W. Gregory and Arellano, Consuelo and Bringolf, Robert B. and Barnhart, M. Christopher and Hammer, Edward}, year={2010}, month={Sep}, pages={959–969} }
 @article{pandolfo_cope_arellano_2009, title={Heart rate as a sublethal indicator of thermal stress in juvenile freshwater mussels}, volume={154}, ISSN={["1531-4332"]}, DOI={10.1016/j.cbpa.2009.07.001}, abstractNote={Freshwater mussels (Unionoida) are one of the most sensitive and rapidly declining faunal groups in the world. Rising water temperatures, caused by industrial discharges, land development, or climate change can further challenge threatened unionid communities. The direct relationship between heart rate and temperature in ectotherms enables the use of heart rate as an indicator of whole-animal thermal stress. The purpose of this study was to assess the utility of heart rate as an indicator of thermal stress in freshwater mussels. Seven species of juvenile mussels (Lampsilis siliquoidea, Potamilus alatus, Ligumia recta, Ellipsaria lineolata, Megalonaias nervosa, Alasmidonta varicosa, and Villosa delumbis) were evaluated in response to a range of experimental temperatures (20–36 °C) at three acclimation temperatures (17, 22, and 27 °C). Heart rate was measured by direct visual observation through transparent mussel shells. The average heart rate for all 7 species at 20 °C was 55 bpm, with a range from 38 bpm (L. recta) to 65 bpm (P. alatus). L. recta and V. delumbis exhibited significant changes in heart rate with increasing temperature at each of the three acclimation temperatures. The use of heart rate appears to be a suitable indicator of thermal stress in some unionid mussels.}, number={3}, journal={COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY}, author={Pandolfo, Tamara J. and Cope, W. Gregory and Arellano, Consuelo}, year={2009}, month={Nov}, pages={347–352} }