Anyone who lives in the United States or Canada knows that this has been an exceptionally warm fall. For many, this is further evidence that global warming is real, but no matter where you stand on the issue of climate change, you may be interested to learn how warmer temperatures are already affecting our oceans, ponds, and fish life.
As temperatures rise, water becomes warmer and it holds less oxygen than cool water. These temperature increases and the resulting oxygen scarcity affect fish. As cold-blooded animals, fish cannot regulate their own body temperatures. Consequently, warmer water also means warmer fish. And as fish become warmer, their metabolism accelerates. This higher metabolic rate causes them to need to draw more oxygen from the water in order to sustain their body functions. Unable to get enough oxygen to support their normal growth, fish stop growing larger. Instead, they adjust to higher water temperatures by becoming smaller. They shrink in size--a change sometimes referred to as "dwarfing."
Indeed, many scientists have linked higher ocean temperatures and lower oxygen levels to smaller fish sizes. According to William Cheung, a University of British Columbia scientist, "the body size of fish decreases by 20 to 30 percent for every 1 degree Celsius increase in water temperature." And fish experts confirm that over the last few decades, fish such as tuna, haddock, whiting, herring, sole, tilapia, have seen a significant loss in size in parts of the oceans where there is less oxygen.
Just as an increase in water temperature and the corresponding decrease in oxygen levels affects the ocean, it also affects your pond. Oxygen equals life. Properly oxygenated water is necessary for fish to breathe, and to maintain a clean and healthy pond environment. The best way to know if there is enough oxygen in your pond is to perform routine oxygen tests as part of regular maintenance.
Here are some ways to improve the oxygen content in your pond.
--Plant oxygenating plants.
--Clean pond filters regularly.