Showing posts with label sharks. Show all posts
Showing posts with label sharks. Show all posts

Conservation of Fish is a Losing Battle

Conservation: Overfishing is just as toxic as pollution. G+
We are already running out of food.  If carbon dioxide doesn't kill us diminishing fish stocks will.  Soon, the humble fish and chips will cost too much for most people.  When the crunch comes the decline will be sudden over a period of five years.  It will not be possible to increase fish stocks in the medium term and some fish species will disappear forever.
Overfishing
People must eat and in Asia in particular daily fishing is part of everyday life.  There will be little chance of a freeze on fishing.  It they are allowed to keep fishing and Western countries stop they will export to the lucrative fishing markets and nothing will change.

Manufacturers like Birds Eye are alreading putting "rubbish" fish in their food products rather than the old reliable species.  When you get a fishy taste that is the second rate fish formally called baitfish.  It is so bad that major predators have fallen by 90 percent over the last 50 years.  There is not enough out there for them to eat and sustain themselves.

It is not only fishing that is reducing available stocks, pollution such as plastic bags is also killing fish.  Human control their environment,  they also destroy it.  Soon you will be able to swim safely on beaches because there will not be any sharks left.  Or there could be the odd one looking for his last dinner which could be you!
 Conservation by Ty Buchanan 
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Drones Used to Control Sharks in Australia

Australians tend to be early adopters of new technology because they have inquisitive minds. Our old enemy, the shark, will always be around, so it is not surprising that drone technology is being used to solve this problem.
Shark caught by baited hook attached to a drum
It is not the buzzing sound that will scare sharks off. Drones are being used to gather visual information about where sharks are and the number swimming around, the theory being that if we know this we can be more careful.

At the moment hooks are baited on lines attached to floating drums. This method is a simple way to catch sharks, but other creatures are also caught such as dolphins. Unfortunately, sharks not tempted by the bait remain in the area. Baited hooks have warning devices in them that notify watchers on a boat when sharks take them.

This is a clumsy way to keep sharks at bay. Targeting sharks observed by drones is a better solution. Drones are far cheaper than helicopters and do a better job, going right down to sea level to collect data.
 Technology by Ty Buchanan 
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Sharks Struggle in Freshwater

Sharks may seem to be invincible, yet they have some significant weaknesses. While some dolphins succumb to their attacks, acting as a group they can kill a shark by ramming it. Sharks
also have to keep moving otherwise they die.
Now it has been discovered that fresh water is their enemy. They get dehydrated and cannot remain alert. Breeding is out of the question in non-salty water. A terrific battle for survival ensues as sharks continually keep sinking.

The reason for this is that sharks do not have air bladders. This "device" enables fish to swim at mid-depths. Sharks use their oily livers to stay afloat - very inefficient. They have to work 50 per cent harder when they leave the sea.

Freshwater species of shark have refined the evolution of their livers. The organs are flatter than their ocean cousins. There is a penalty for a flatter liver. A fatter body means a less sleek body which makes river and estuary species slower. Even with fatter livers, they live close to the bottom of the water.
Biology by Ty Buchanan
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Study on Bony Fish, Sharks and Lungfish Clarifies Evolutionary Development

A study on lungfish, bony fish and cartilaginous fish has a great deal to offer in understanding development of legs for life on land. Lungfish are ancient ancestors of tetrapods - four legged animals. Walking on their fins and breathing air, lungfish bravely moved onto the land.

Research has relied on bones preserved as fossils, but muscles cannot be "saved" in this way. A fetus shows ancient stages in a creatures development. This is why a human fetus seems to be reptile-like in its early stages. Examining muscle development of modern lungfish is very informative. Tests were also done on cartilaginous fish such as sharks and ordinary fish.

Embryos of cartilaginous and bony fish were genetically altered to promote growth of precursor pelvic fins that in lungfish became legs. Engineered cells were made to emit red and green light. The study on muscles highlighted the fact that bony fish evolved legs while cartilaginous fish did not. Pelvic muscles of bony fish are a transitory stage between cartilaginous fish and land animals.
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Biology