Thursday, 25 February 2016

Overfishing and it's dangers to coral

Hi Everyone,
In geography, we are learning about coral and their dangers, and I thought it might interest you. I will keep on posting about Florence, because I find it interesting and I hope you do, but if there is anything you want me to post about, I will be happy to oblige.

Overfishing


The Issue

The problem with overfishing is that it is reducing the amount of fish in certain waters, and sometimes, the amounts of fish caught, even in one trawl, can not recover even twelve months later.

Types of overfishing

Types of overfishing include
·      Bottom Trawling
·      Cyanide Fishing
·      Dynamite Fishing and
·      Ghost Fishing.
Bottom trawling is when a trawler goes along a surface, rocky or flat, and simply catches fish in their nets. Attached with rubber wheels, the rockhopper trawls, introduced in the 1980’s can be very damaging, and in Alaska, one single trawl wiped out 55% of the area’s coral, and that coral had not claimed back that space 12 months later. The coral is damaged, because the rockhopper nets that can go to a depth of 2,000 metres, can move boulders that weigh up to 25 tonne meaning that the coral is simply killed. Scars can be found in the ocean for up to 4km where these rockhoppers have passed in the Atlantic Ocean.

Cyanide Fishing is where fishers squirt sodium cyanide into the water, so that the fish are stunned but not killed, meaning that they are easy to catch. This technique is dangerous because for every one fish eaten that has been caught by sodium cyanide, a square metre of coral has been killed.

Dynamite Fishing is a technique where fishermen throw dynamite or other explosives into the water. Once detonated, the explosives kill all the fish around it, as well as reducing the nearby landscape to rubble.

Ghost Fishing is where fishing equipment is lost overboard. This equipment can continue to catch fish, and it is estimated that over a quarter of the rubbish at the bottom of the North Sea is fishing nets. Although it is unknown, the catches made by Ghost fishing is likely to have a large impact on the numbers of fish and wildlife in the sea.

Why is it a problem?

Overfishing is a problem as it kills many fish species. Where fish populations used to be large, they have now been reduce to a far smaller amount, or even totally wiped out. This also has an impact on the coral in the area due to some techniques of fishing. These techniques like Bottom Trawling and dynamite fishing can ruin the coral population.

Where is it a problem?

Overfishing is a problem in Alaska, where 55% of the coral was wiped out, Australia (mainly South Australia), where 90% of the areas where coral used to grow is now bare rock, Southeast Asia, the North Pacific Ocean and the North Sea.

Regards,

Richard Mills