Navigation Links
Changes in water chemistry leave lake critters defenseless

TORONTO, Sept. 6, 2012 Imagine that the players on your favourite football team were smaller than their opponents, and had to play without helmets or pads. Left defenseless, they would become easy prey for other teams. Similarly, changes in Canadian lake water chemistry have left small water organisms vulnerable to their predators, which may pose a serious environmental threat, according to a new study.

"At low calcium levels the organisms grow slower and cannot build their armour," says study lead author Howard Riessen, professor of biology, SUNY College at Buffalo. "Without suitable armour, they are vulnerable to ambush by predators," he says.

Riessen and colleagues, including York University biology Professor Norman Yan, studied the effect of changes in water chemistry on plankton prey defenses. Specifically, they examined how lower calcium concentrations affect Daphnia (water flea) exoskeleton development. These low calcium levels are caused by loss of calcium from forest soils, a consequence of decades of acid rain and multiple cycles of logging and forest growth. The results are published this week in the Proceedings of the National Academy of Sciences.

"Calcium is a critical element for Daphnia and many other crustaceans," Riessen says. "Daphnia build their exoskeletons, which include some defensive spines, with calcium to protect themselves from predators. Where calcium levels are low, the Daphnia have softer, smaller, exoskeletons with fewer defensive spines, making them an easy snack."

Why do plankton matter? Yan, the study's senior author and a Fellow of the Royal Society of Canada, emphasizes that the tiny creatures are critical to our survival. "Without plankton, humans would be quite hungry, and perhaps even dead. Much of the world's photosynthesis, the basis of all of our food, comes from the ocean's plankton. The oxygen in every other breath we take is a product of phytoplankton photosynthesis," says Yan.

This phenomenon of reduced calcium is also playing out on a much larger scale in the world's oceans, he notes. "Increases in ocean acidity are complicating calcium acquisition by marine life, which is an under-reported effect of global carbon dioxide emissions. Thus marine plankton may also find themselves more vulnerable to predators," he says.

The public is used to stories about changes in water chemistry that lead to large-scale fish kills, says Riessen. "These changes are more insidious. Daphnia might not be a household name, but they are food for fish, and they help keep our lakes clean. Changing the balance between Daphnia and their predators marks a major change in lake systems."

Contact: Janice Walls
416-736-2100 x22101
York University

Related biology news :

1. Height, weight and BMI changes seen in children treated with peginterferon alpha for hepatitis C
2. New milestone book documents changes in the south Florida marine ecosystem
3. New research finds increased growth responsible for color changes in coral reefs
4. Nature: Molecule changes magnetism and conductance
5. Air pollution level changes in Beijing linked with biomarkers of cardiovascular disease
6. Changes in brains blood flow could cause brain freeze
7. Scientists find that neurological changes can happen due to social status
8. How old are these rocks, how were they made, and how long ago did these geologic changes happen?
9. Holding a mirror to brain changes in autism
10. Students create low-cost biosensor to detect contaminated water in developing nations
11. No-till farming helps capture snow and soil water
Post Your Comments:
(Date:5/16/2017)... May 16, 2017  Veratad Technologies, LLC ( ... age and identity verification solutions, announced today they will ... 2017, May 15 thru May 17, 2017, in ... International Trade Center. Identity impacts the ... in today,s quickly evolving digital world, defining identity is ...
(Date:4/24/2017)... Janice Kephart , former 9/11 ... Partners, LLP (IdSP) , today issues the following ... March 6, 2017 Executive Order: Protecting the ... be instilled with greater confidence, enabling the reactivation ... applications are suspended by until at least July ...
(Date:4/17/2017)... , April 17, 2017 NXT-ID, Inc. ... company, announces the filing of its 2016 Annual Report on Form ... Exchange Commission. ... Form 10-K is available in the Investor Relations section of the ... on the SEC,s website at . 2016 ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... SARASOTA, FL (PRWEB) , ... ... ... Inc. (RPS®) today announces publication of a United States multicenter, prospective clinical ... single use, disposable, point-of-care diagnostic test capable of identifying clinically significant acute ...
(Date:10/12/2017)... ... ... AMRI, a global contract research, development and manufacturing organization ... quality of life, will now be offering its impurity solutions as a stand-alone ... for all new drug products, including the finalization of ICH M7 earlier this ...
(Date:10/11/2017)... ... October 11, 2017 , ... At ... Purple announced Dr. Suneel I. Sheikh, the co-founder, CEO and chief research scientist ... has been selected for membership in ARCS Alumni Hall of Fame . ...
(Date:10/11/2017)... ... 11, 2017 , ... Personal eye wash is a basic first aid supply for any work ... which eye do you rinse first if a dangerous substance enters both eyes? It’s one ... with its unique dual eye piece. , “Whether its dirt and debris, or an ...
Breaking Biology Technology: