Sunday, April 09, 2006

Fish threatened as climate change warms water

Fish are under threat as climate change causes a rise in temperature. A spokesperson from WWF reported. The report indicated that warmer water means less food, less offspring, less oxygen and more diseases for marine and freshwater fish. Due to fishing the fishes are already stressed and now by climate change, pollution and habitat loss, the fishes are in grave danger eventually affecting us. How are they affecting us? Mainly because they are the still one of the main source of nutritional food.

Fish metabolisms normally speed up in the line with temperature increases, accelerating competition for food and insufficient food supplies can slow growth. Some temperate fish like salmon, catfish and sturgeon cannot spawn at all if winter temperatures do not drop below a certain temperature.

In lakes in particular, warmer temperatures hamper the circulation of oxygen that fish need to breathe. Fish filter oxygen from water but amount of oxygen dissolved in water decreases as temperature rises.

Warming could cause the fishes to dive deeper into cooler waters to maintain their normal habitat. However it will cause a greater strain on other species such as birds who dive into the water to catch fish. However as the fishes are way below the birds will starve and die. In 1993 as fishes moved to cooler waters around 120,000 sea birds died. This figure was posted by WWF.

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