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Abstract

Invasive bivalves can drastically alter freshwater ecosystems and affect ecosystem services, but they can be influenced by external factors including calcium concentrations. When a common road salt, calcium chloride (CaCl2), enters freshwater ecosystems, it may be toxic to organisms or facilitate bivalves by serving as a calcium source. Therefore, CaCl2 could benefit invasive mollusks tolerant to chloride that require calcium to grow. We used mesocosms to investigate the impacts of CaCl2 (35–187 mg Ca²⁺ L⁻¹) and invasive bivalves (Asian clams, Corbicula fluminea; zebra mussels, Dreissena polymorpha) on a native lake food web. We hypothesized that invasive bivalves facilitate benthic algae because they reduce phytoplankton and excrete waste. These changes in primary producers would subsequently impact consumers. We also hypothesized that low to moderate CaCl2 concentrations promote the survival, growth, and reproduction of native and invasive mollusks, while causing few toxic effects. If so, we hypothesized that invaded communities exposed to CaCl2 experience stronger impacts from the invasive bivalves. We found that invasive bivalves decreased phytoplankton, which led to decreases in periphyton, zooplankton, and native clams. They caused increases in filamentous algae and isopods. While zebra mussels survived poorly in all treatments, moderate concentrations of CaCl2 substantially reduced Asian clams, which reduced their community effects. Our highest CaCl2 treatments also reduced zooplankton densities. Thus, while freshwater salinization from road salts poses a concern, we observed no indication that CaCl2 road salt will benefit Asian clams and zebra mussels. However, the community-wide consequences from Asian clams at low CaCl2 emphasize the extensive effects that invasive bivalves can have on freshwater communities and the immense concern surrounding their invasions.
ORIGINAL PAPER
Calcium chloride pollution mitigates the negative effects
of an invasive clam
Kayla D. Coldsnow .William D. Hintz .Matthew S. Schuler .
Aaron B. Stoler .Rick A. Relyea
Received: 20 December 2019 / Accepted: 19 December 2020 / Published online: 2 January 2021
ÓThis is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply 2021
Abstract Invasive bivalves can drastically alter
freshwater ecosystems and affect ecosystem services,
but they can be influenced by external factors includ-
ing calcium concentrations. When a common road
salt, calcium chloride (CaCl
2
), enters freshwater
ecosystems, it may be toxic to organisms or facilitate
bivalves by serving as a calcium source. Therefore,
CaCl
2
could benefit invasive mollusks tolerant to
chloride that require calcium to grow. We used
mesocosms to investigate the impacts of CaCl
2
(35–187 mg Ca
2?
L
-1
) and invasive bivalves (Asian
clams, Corbicula fluminea; zebra mussels, Dreissena
polymorpha) on a native lake food web. We hypoth-
esized that invasive bivalves facilitate benthic algae
because they reduce phytoplankton and excrete waste.
These changes in primary producers would subse-
quently impact consumers. We also hypothesized that
low to moderate CaCl
2
concentrations promote the
survival, growth, and reproduction of native and
invasive mollusks, while causing few toxic effects. If
so, we hypothesized that invaded communities
exposed to CaCl
2
experience stronger impacts from
the invasive bivalves. We found that invasive bivalves
Supplementary Information The online version contains
supplementary material available at https://doi.org/10.1007/
s10530-020-02443-x.
K. D. Coldsnow (&)W. D. Hintz
M. S. Schuler A. B. Stoler R. A. Relyea
Department of Biological Sciences, Darrin Fresh Water
Institute, Rensselaer Polytechnic Institute, 110 8th St.,
Troy, NY 12180, USA
e-mail: kaylacoldsnow@gmail.com
Present Address:
K. D. Coldsnow
Office of Pesticide Programs, Health Effects Division,
U.S. Environmental Protection Agency,
Research Triangle Park, NC, USA
Present Address:
W. D. Hintz
Department of Environmental Sciences and Lake Erie
Center, University of Toledo, Oregon,
OH, USA
Present Address:
M. S. Schuler
Department of Biology, Montclair State University,
Montclair, NJ, USA
Present Address:
A. B. Stoler
School of Natural Sciences and Mathematics, Stockton
University, Galloway, NJ, USA
123
Biol Invasions (2021) 23:1349–1366
https://doi.org/10.1007/s10530-020-02443-x(0123456789().,-volV)(0123456789().,-volV)
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... However, most studies are single-organisms toxicity studies. A few community studies have investigated low concentrations and found few biotic effects (Coldsnow et al., 2021;Schuler et al., 2017), but moderate to high concentrations of these alternatives need to be examined to fully understand their effects on freshwater biota. In addition to biotic consequences, there are also abiotic consequences, such as changes in dissolved oxygen, pH, and nutrient concentrations Terry et al., 2020). ...
... Calcium is vital to the shells of many organisms and in the laboratory, low concentrations of CaCl 2 (relative to many road salt experiments; <130 mg Cl − /L) increased the growth and survival of bivalve species (Davis et al., 2015;Ferreira-Rodríguez et al., 2017). However in another mesocosm experiment, low to medium concentrations of CaCl 2 (30-260 mg Cl − /L) did not benefit any organisms in the community (Coldsnow et al., 2021), which is similar to what we found at our medium concentration. Despite the importance of magnesium in the carapace of ostracods, they did not increase when exposed to MgCl 2 . ...
... In addition, high NaCl (1000 mg Cl − /L) decreased amphipod abundance in a community study . While no long-term study has investigated high concentrations of the alternatives, one study that investigated low concentrations of MgCl 2 (50 and 100 mg Cl − /L) actually found an increase in amphipod abundance and one that investigated low to medium concentrations of CaCl 2 (30-260 mg Cl − /L) found no effect on amphipod abundance (Coldsnow et al., 2021). We also found no effects at medium concentrations. ...
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