Acidification and Amphibian Declines Brant Pace WFS 433 March 31, - - PDF document

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Acidification and Amphibian Declines

Brant Pace WFS 433 March 31, 2009

Outline

• Introduction
• Evidence
• Problems
• Importance

Acidification of streams – How can it occur?

• Acid precipitation
• Snow Melt
• Percolation Through Foliage

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Acid Precipitation

• Negatively charged

particles such as sulphur dioxide (SO2), nitrogen

• xide (NOx) and

ammonium (NH4) (

4)

released into the atmosphere

Acid Precipitation

• These particles react in

the atmosphere to form acids

• Acids then transferred to
• Acids then transferred to

the ground by wet deposition (attached to small airborne particles) and wet deposition (attached to droplets of rain, snow, sleet, etc.) Acid Rain Video

Snow Melt

• Acid that has been tied

up in the snow all winter is released into the soil and streams in a relatively short time y

• This causes a rapid spike

in acidity, known as “episodic acidification”

Snow Melt Video 1 Snow Melt Video 2

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Percolation Through Foliage

• Rain filtering through

some types of foliage (particularly pine canopies) can become up to 3x more acidic

Effects of Acidification on Amphibians

• Decrease in activity level, foraging ability,

predator evasion and effectiveness as a predator predator

• Lower recruitment
• Decreased egg distribution
• Inhibition of egg development and

reproductive activity

(Green and Peloquin 2008, Harte and Hoffman 1989, Jung and Jagoe 1995)

Effects of Acidification on Amphibians

• Decreased aquatic invertebrate

populations I d b t lit

• Increased embryo mortality
• Perturbation of sodium metabolism
• Low growth rates
• Weakening of natural defenses

(immunosupression)

(Beebee et al. 1989, Brodkin et al. 2003, Harte and Hoffman 1989)

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Effects of Acidification on Amphibians

• Increased bacterial infection
• Disruption in ion transportation
• Decreased white blood cell count and

viability

• Direct mortality

(Brodkin et al. 2003, Green and Peloquin 2008))

Why Is Acidification So Important?

• Acidification has

negative effects on all types of amphibians yp p and at all life stages

Why Is Acidification So Important?

• Negative effects are

magnified when acidification is coupled with other environmental stressors, such as cold

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Why Is Acidification So Important?

• Acidification has

many direct negative effects on reproduction and development, both of which are essential for species sustainability

Why Is Acidification So Important?

• Acidification causes

direct mortality

References

• Beebee TJC, Flower RJ, Stevenson AC, Patrick ST, Appleby PG, Flectcher C, Marsh

C, Natkanski J, Rippey B, Batterbee RW. 1989. Decline of the Natterjack Toad Bufo calamita in Britain: Palaeoecological, Documentary and Experimental Evidence for Breeding Site Acidification. Biological Conservation 53:1-20.

• Brodkin M, Vatnick I, Simon M, Hopey H, Butler-Holston K, Leonard M. 2003. Effects
• f Acid Stress in Adult Rana pipiens. Journal of Experimental Zoology 298A:16-22.

G LE P l i JE 2008 A t T i it f A idit i L d Ad lt f F

• Green LE, Peloquin JE. 2008. Acute Toxicity of Acidity in Larvae and Adults of Four

Stream Salamander Species (Plethodontidae). Environmental Toxicology and Chemistry 27:2361-2367.

• Harte J, Hoffman E. 1989. Possible Effects of Acidic Deposition on a Rocky Mountain

Population of Tiger Salamander Ambystoma tigrinum. Conservation Biology 3:149- 158.

• Jung RE, Jagoe CH. 1995. Effects of Low pH and Aluminum on Body Size,

Swimming Performance, and Susceptibility to Predation of Green Tree Frog (Hyla cinerea) tadpoles. Can J Zool 73:2171-2183.

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Questions?