Effects of Acid Rain On Fish

Acidity increase has an array of effects onto the individual fish as well as the population as a whole. Lowered pH levels increase aluminum levels that are directly toxic to fish. These changes cause chronic stress upon the fish lowering their body weight (Charles T. Driscoll).

At very low pH (3 or less) levels coagulation of mucous on gill surfaces and subsequent anoxia would the cause of death, however acidic levels are rarely this low. At less extreme pH levels (4-5) a disturbance of normal ion and acid- base balance may be the more likely cause of death. (Carl L. Schofield 1976)

Some species have a greater tolerance to acidic waters. But those most sensitive face a greater consequence. Often the young are most vulnerable and most fish eggs won’t hatch at a pH of 5 or less. (U.S Environment agency).

There has been observed decreased population density and a shift in size and age structure of fish due to increased acidity. Even a small increase of fish young fish mortality can be sufficient to decrease population and eventually lead to extinction. Often the decrease is not recognizable until the population is close to extinction (Schindler 1988). Spring-spawning fish face more exposure to a strong acid and aluminum pulse due to snowmelt, especially since the sensitive young fish are in shallow near shore waters. (Schindler 1988)

This table shows the pH level tolerance of certain aquatic species

Carl L. Schofield. Acid Precipitation: Effects on Fish. Ambio , Vol. 5, No. 5/6 (1976) , pp. 228-230. Springer on behalf of Royal Swedish Academy of Sciences.

CHARLES T. DRISCOLL, GREGORY B. LAWRENCE, ARTHUR J. BULGER, THOMAS J. BUTLER, CHRISTOPHER S. CRONAN, CHRISTOPHER EAGAR, KATHLEEN F. LAMBERT, GENE E. LIKENS, JOHN L. STODDARD, and KATHLEEN C. WEATHERS. Acidic Deposition in the Northeastern United States: Sources and Inputs, Ecosystem Effects, and Management Strategies. BioScience , Vol. 51, No. 3 (March 2001) , pp. 180-198. University of California Press.

Schindler, David W. "Effects of acid rain on freshwater ecosystems." Science(Washington) 239.4836 (1988): 149-157.

U.S Environmental Agency. Effects of Acid Rain - Surface Waters and Aquatic Animals. December 4, 2012. EPA.

Ottawa River

On August 8^TH, 2013 hundreds of fish washed up dead on shore of the Ottawa River. Ottawa’s health officials are currently investigating the death of these fish.  This could possibly be the result of increase acidity in The Ottawa River, which could be due to acid precipitation or runoff.  One of the main species of fish found death is Catfish who cannot survive in a pH level of lower than 4.

News, C. (2006, August 15). Hundreds of dead fish wash up along Ottawa River. CBCnews. Retrieved February 14, 2014, from http://www.cbc.ca/news/canada/ottawa/hundreds-of-dead-fish-wash-up-along-ottawa-river-1.612913

Testing Ottawa's downtown core’s snow acidity vs. Ottawa's greenbelt’s snow acidity

We wanted to test to see if the acidity of snow can be increased by car emissions. We decided to collect snow from high traffic areas of Ottawa and low traffic areas of Ottawa and compare them to see if car emissions really do affects the acidity of the snow. Morgan and I collected thirty samples of snow from the high traffic area of Bank Street. Yuchan and Sara collected thirty samples from the low traffic suburban area along the greenbelt. We then tested these samples for acidity and graphed the data to compare it. 

maps of the areas in which the snow samples were collected

 map of low traffic area

 map of high traffic area

The red line represents the acidity levels of the snow in the high traffic areas of Bank Street and the blue represents the low traffic area along the Greenbelt.

Ottawa's downtown core’s snow acidity vs. Ottawa's greenbelt’s snow acidity

The numbers on the vertical axis represents the pH level of each sample. Each category represents a snow sample. The red line is the data from the high traffic area and the blue line is from the low traffic area.