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Snails from heavy-metal polluted environments have reduced sensitivity to carbon dioxide-induced acidity.

Lefcort H, Cleary DA, Marble AM, Phillips MV, Stoddard TJ, Tuthill LM, Winslow JR - Springerplus (2015)

Bottom Line: We predicted a simple negative additive effect of low pH.In fact, the 48 h survival of snails from polluted sites was so high that it did not significantly differ from the 24 h survival of snails from control sites.We found that snails raised at a pH of 5.5 had a weaker response (less of a decrease in activity) to concentrated heavy metals than did snails raised at their natal pH of 6.5.

View Article: PubMed Central - PubMed

Affiliation: Biology Department, Gonzaga University, 502 E. Boone Avenue, Spokane, WA 99258 USA.

ABSTRACT
Anthropogenic atmospheric CO2 reacts with water to form carbonic acid (H2CO3) which increases water acidity. While marine acidification has received recent consideration, less attention has been paid to the effects of atmospheric carbon dioxide on freshwater systems-systems that often have low buffering potential. Since many aquatic systems are already impacted by pollutants such as heavy metals, we wondered about the added effect of rising atmospheric CO2 on freshwater organisms. We studied aquatic pulmonate snails (Physella columbiana) from both a heavy-metal polluted watershed and snails from a reference watershed that has not experienced mining pollution. We used gaseous CO2 to increase water acidity and we then measured changes in antipredatory behavior and also survival. We predicted a simple negative additive effect of low pH. We hypothesized that snails from metal-polluted environments would be physiologically stressed and impaired due to defense responses against heavy metals. Instead, snails from populations that acclimated or evolved in the presence of heavy metal mining pollution were more robust to acidic conditions than were snails from reference habitats. Snails from mining polluted sites seemed to be preadapted to a low pH environment. Their short-term survival in acidic conditions was better than snails from reference sites that lacked metal pollution. In fact, the 48 h survival of snails from polluted sites was so high that it did not significantly differ from the 24 h survival of snails from control sites. This suggests that the response of organisms to a world with rising anthropogenic carbon dioxide levels may be complex and difficult to predict. Snails had a weaker behavioral response to stressful stimuli if kept for 1 month at a pH that differed from their lake of origin. We found that snails raised at a pH of 5.5 had a weaker response (less of a decrease in activity) to concentrated heavy metals than did snails raised at their natal pH of 6.5. Furthermore, snails raised a pH of 5.5, 6.0, and 7.0 all had a weaker antipredatory response to an extract of crushed snail cells than did the pH 6.5 treatment snails.

No MeSH data available.


Related in: MedlinePlus

Survival of snails in acidic water. Snails were from nine reference and ten heavy metal polluted lakes. Survivability was measured each hour for 48 h; 24 and 48 h values are shown for illustration.
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Fig2: Survival of snails in acidic water. Snails were from nine reference and ten heavy metal polluted lakes. Survivability was measured each hour for 48 h; 24 and 48 h values are shown for illustration.

Mentions: Survivorship values (based on hydrogen ion levels) are displayed in Figure 2. Snails from heavy-metal polluted ponds had higher survival than snails from reference ponds. This occurred at both 24 h (t = 2.43, df = 17, P = 0.032) and 48 h (t = 3.47, df = 17, P = 0.003). The 48 h survival of snails from polluted sites was so high that it not significantly differ from the 24 h survival of snails from control sites (one-way ANOVA F3,36 = 8.85, P < 0.001, Newman-Keuls multiple comparisons P < 0.05). Acidity values of metal-polluted and reference lakes did not differ (t = 1.45, df = 17, P = 0.608). For unknown reasons one reference lake, Deer Lake, had high zinc levels. We included this lake in the above analyses but the results were similar when it was excluded.Figure 2


Snails from heavy-metal polluted environments have reduced sensitivity to carbon dioxide-induced acidity.

Lefcort H, Cleary DA, Marble AM, Phillips MV, Stoddard TJ, Tuthill LM, Winslow JR - Springerplus (2015)

Survival of snails in acidic water. Snails were from nine reference and ten heavy metal polluted lakes. Survivability was measured each hour for 48 h; 24 and 48 h values are shown for illustration.
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4469689&req=5

Fig2: Survival of snails in acidic water. Snails were from nine reference and ten heavy metal polluted lakes. Survivability was measured each hour for 48 h; 24 and 48 h values are shown for illustration.
Mentions: Survivorship values (based on hydrogen ion levels) are displayed in Figure 2. Snails from heavy-metal polluted ponds had higher survival than snails from reference ponds. This occurred at both 24 h (t = 2.43, df = 17, P = 0.032) and 48 h (t = 3.47, df = 17, P = 0.003). The 48 h survival of snails from polluted sites was so high that it not significantly differ from the 24 h survival of snails from control sites (one-way ANOVA F3,36 = 8.85, P < 0.001, Newman-Keuls multiple comparisons P < 0.05). Acidity values of metal-polluted and reference lakes did not differ (t = 1.45, df = 17, P = 0.608). For unknown reasons one reference lake, Deer Lake, had high zinc levels. We included this lake in the above analyses but the results were similar when it was excluded.Figure 2

Bottom Line: We predicted a simple negative additive effect of low pH.In fact, the 48 h survival of snails from polluted sites was so high that it did not significantly differ from the 24 h survival of snails from control sites.We found that snails raised at a pH of 5.5 had a weaker response (less of a decrease in activity) to concentrated heavy metals than did snails raised at their natal pH of 6.5.

View Article: PubMed Central - PubMed

Affiliation: Biology Department, Gonzaga University, 502 E. Boone Avenue, Spokane, WA 99258 USA.

ABSTRACT
Anthropogenic atmospheric CO2 reacts with water to form carbonic acid (H2CO3) which increases water acidity. While marine acidification has received recent consideration, less attention has been paid to the effects of atmospheric carbon dioxide on freshwater systems-systems that often have low buffering potential. Since many aquatic systems are already impacted by pollutants such as heavy metals, we wondered about the added effect of rising atmospheric CO2 on freshwater organisms. We studied aquatic pulmonate snails (Physella columbiana) from both a heavy-metal polluted watershed and snails from a reference watershed that has not experienced mining pollution. We used gaseous CO2 to increase water acidity and we then measured changes in antipredatory behavior and also survival. We predicted a simple negative additive effect of low pH. We hypothesized that snails from metal-polluted environments would be physiologically stressed and impaired due to defense responses against heavy metals. Instead, snails from populations that acclimated or evolved in the presence of heavy metal mining pollution were more robust to acidic conditions than were snails from reference habitats. Snails from mining polluted sites seemed to be preadapted to a low pH environment. Their short-term survival in acidic conditions was better than snails from reference sites that lacked metal pollution. In fact, the 48 h survival of snails from polluted sites was so high that it did not significantly differ from the 24 h survival of snails from control sites. This suggests that the response of organisms to a world with rising anthropogenic carbon dioxide levels may be complex and difficult to predict. Snails had a weaker behavioral response to stressful stimuli if kept for 1 month at a pH that differed from their lake of origin. We found that snails raised at a pH of 5.5 had a weaker response (less of a decrease in activity) to concentrated heavy metals than did snails raised at their natal pH of 6.5. Furthermore, snails raised a pH of 5.5, 6.0, and 7.0 all had a weaker antipredatory response to an extract of crushed snail cells than did the pH 6.5 treatment snails.

No MeSH data available.


Related in: MedlinePlus