Showing posts with label fish. Show all posts
Showing posts with label fish. Show all posts

Monday, June 27, 2011

What are the main effects of overfishing?

Overfishing is becoming a huge environmental issue, especially with the ongoing rapid growth of human population. Millions of people worldwide depend on fish to survive but due to very poor global management of fisheries overfishing is taking heavy toll in almost all of our oceans and seas with many fish species experiencing a significant decline in population.

According to the recent study by the Wildlife Conservation Society overfishing has caused modern fish species to have shorter life spans, faster growth rates, smaller average sizes, and fewer top predators. That was the main conclusion of a recent study in which researchers compared fish recently caught in coastal Kenya with the bones of fish contained in ancient Swahili.

Overfishing has therefore significantly reduced the number of large and long-living fish species that were more commonly caught in the Middle Ages. The only areas where fish population can still somewhat thrive and achieve longer lifespan are marine protected areas, though even in these areas fish communities can only partially achieve its "former glory days".

As said before the fishing pressure is growing all the time and the world still hasn't established the adequate global management to stop deterioration of remaining fisheries.

Particularly worrying is the fact that top predators are mostly affected with overfishing which is already causing severe changes in marine food chain.

One thing is sure - ignorance will not solve this serious issue. World needs to unite and come up with the solution that would ensure the adequate global management of remaining fisheries. Failing to do so could cost us dearly in years to come.

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Thursday, August 26, 2010

How come fish don't freeze in cold water?

There are many fish species that live in cold waters but they do not freeze to death like this would be the case with us humans. Why is that? Well the answer lies in the antifreeze protein in the fish's blood. According to scientists this protein has the ability to protect fish from freezing meaning that there's no such thing as some sort of chemical bond between protein and water, the only thing that is sufficient is the presence of this protein in fish's blood.

This protein has much better properties than any household antifreeze but scientists still do not know how exactly does this protein work. Scientists have concluded that for instance in cold Arctic waters, for some reason, water molecules, which usually perform a permanent dance in liquid water, and constantly enter new bonds, dance a more ordered dance in the presence of this antifreeze protein, and this prevents ice crystallization.

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