McMaster University Fish Scientists Weighed Hamilton

McMaster University Biology Dept. at Hamilton, Ontario

Tuesday November 9 2010

Water Toxicity

Bob's Pike

Dr. Chris Wood is an expert in Fish Physiology. At McMaster the wood Lab is The Physiology of Transport Processes and Metabolism, and the Aquatic Toxicology of Fish and Crustaceans. Here Dr. Wood inspires students with his love of research and his lifetime work has been encouraging and training the next generation of scientists. On April 17th, Dr. Chris Wood and Dr. Adolto Bimchini were recipients of one of eight International Canada Research Chairs recently awarded by the International Development Research Centre and the Canada Research Chair program. Dr. Chris Wood has the “Canada Research Chair in Environment and Health.” They have been awarded $1,000,000.00 to conduct environmental research in Brazil and Canada. Their research program is entitled “Battling pollution in coastal areas.” They were selected from 104 applicants. From what they learn in Brazil in the next five years ( 2,010 – 2.015), they will determine what is applicable to Hamilton Harbour cleanup. Dr. Wood in 2,007 was honored by the Royal Society of Canada, and awarded the Miroslaw Remonowski Medal for his work on metal toxicity in acquatic ecosystems.

Dr. Chris Wood as a PhD candidate himself – (1) Conducted a series of NSERC supported research projects on acid-base regulation, lactate and ammonia transport, and gas exchange in Rainbow Trout. (2) He developed an unique isolated tail-trunk preparation to serve as an in situ physiological moded to investigate metabolic, acid-base and ion regulation in Trout Muscel. The ion is an atom or group of atoms that has acquired a net electic charge by gaining or losing one or more electrons. (3) He played a major role in developing and improving a series of muscel sampling, processing and enzymatic analysis for Fish Muscel. (4) He supported a project on bioavaliability and toxicity of heavy metals in freshwater ecosystems.

His 2,008 study with Bucking on Rainbow Trout showed the net base excretion to the water increased greatly at the same time as a compensaion of a postprandial alkaline tide in the bloodstream. In another study, he indicates the results point out the need to incorporate sulfide into the acute biotic liqand models and to assess its potentially large role in preventing chronic toxicity. Another study ponts to the importance of salt and water absorbtion from the food by the gastrointestinal tract and its impact on ion-osoregulation have been overlooked by fish physiologists. In freshwater fish the quantities of most major electrolytes ingested via a normal ration far exceed those transported from the water by gills, but net absorbtion rates of specific ions vary greatly with a range of influences, including complex intractions involving musins and bile salts. In freshwater the gills and kidnesy are the major organs involved in salt uptake and water loss, respectively. In nature, most fish feed either opportunistically or on a diuranal cycle. And, we know that gut blood flow is elevated following feeding. What Dr. Wood intends to show in this study is when freshwater fish are allowed to feed, the role of gastrointestinal tract in salt and water balance is far more important than previously believed.

Water Quality

In the Saturday, Nov. 6, 2,010 Hamilton Spectator their article is aptly titled ” On the scale of fish scientists, he’s tops.” He uses water chemistry to predict whether or not the metal is going to be toxic to fish. He also pointed out that in Lake Ontario, which is quite rich in clacium, bicarbonate and dissolved organic carbon, there are many substances that will bind up the free ion and prevent it fron going on the fish gills. That means that a level of metal which wold be very benign and not have any effect in Lake Ontario would be very dangerous in a Muskoka Lake, according to the Spectator. In a study of Dr. Woods from Kenya, Africa he found a unique fish where the pH is 10 , that would kill most fish. But this fish, similar to humans excretes urea. This might become useful, said Dr. Woods, because if you take that genetic pathway and put it into aquaculture fish and get the fish to excrete urea instead of ammonia, you would need to have less water flow and less heating of the water , and you could save money.

Our waterways

sources: Web and The Hamilton Spectator


Doug Worrall