Overfishing and the Health of the Oceans – June 27

The oceans are in trouble and there are many reasons for that. Global warming is altering the environment and the oceans are becoming warmer and more acidic. This is causing coral reefs to die, and coral reefs are the nurseries of many different species of fish. Coral reefs are like the canary in the coal mine. They are a visible indication of the health of the oceans, and many of the reefs are in danger. “They are being degraded at a rate of 2 per cent a year. About a fifth of the world’s stock has already gone, and nearly half of the remainder is in danger of disappearing within the next 20 years….A lethal combination of pollution, predators, disease, rising sea temperatures, over-fishing and the acidification of the sea have put our coral reefs on the critical list.” http://www.commondreams.org/news/2008/07/17/ocean-quest-race-save-worlds-coral-reefs

The oceans are harmed because of increased population growth. More people -mean more development, more pollution and silt which harms coral. They also fill in wetlands and cut down mangrove swamps which are breeding sites. There are also more people harming coral with anchoring, diving and “harvesting”. But the greatest danger is in overfishing because more people are dependant on fish for their protein. “A new global study concludes that 90 percent of all large fishes have disappeared from the world’s oceans in the past half century, the devastating result of industrial fishing…. I think the point is there is nowhere left in the ocean not overfished,” said Ransom Myers, a fisheries biologist at Dalhousie University in Halifax, Nova Scotia and lead author of the study.” http://www.cnn.com/2003/TECH/science/05/14/coolsc.disappearingfish/

“The demand for fish is growing as our population grows.  We are taking more and more fish and fish numbers are decreasing.  Fishing removes the biggest fish from the ocean, but big female fish produce much more young than smaller females. How do you preserve fish populations if the most fertile individuals are constantly being taken? The answer may be to protect areas where fish can grow and reproduce uninterrupted.” http://web.stanford.edu/group/microdocs/bigfish.html

“In one of the largest global studies of its kind, researchers conducted more than 6,000 reef surveys in 46 countries across the globe and discovered 15 ‘bright spots’ – places where, against all the odds, there were a lot more fish on coral reefs than expected…. By virtue of the breadth of the survey, the researchers identified several characteristics that improved the state of coral reef ecosystems.”

“Many bright spots had strong local involvement in how the reefs were managed, local ownership rights, and traditional management practices,” said co-author Christina Hicks, an affiliated researcher at the Center for Ocean Solutions currently at England’s Lancaster University. The scientists also identified 35 “dark spots.” These were reefs with fish stocks in worse shape than expected.”

“Dark spots also had a few defining characteristics; they were subject to intensive netting activities and there was easy access to freezers so people could stockpile fish to send to the market,” Hicks said.

“Bright spots were typically found in the Pacific Ocean in places like the Solomon Islands, parts of Indonesia, Papua New Guinea and Kiribati. Dark spots were more globally distributed and found in every major ocean basin.” http://news.stanford.edu/2016/06/15/stanford-scientists-discover-coral-reef-bright-spots-marine-life-surprisingly-thriving/

The type of fishing also makes a big difference. In the past individual hooks and lines could be used to catch the species you want and the unwanted species could be thrown back, but modern methods use huge nets which gather up everything that swims and  all of the “undesirable” fish are killed. The term for this is bycatch.

“Some would argue that bycatch is an acceptable consequence of supplying the world with wild-caught seafood. However, too often the scale of mortality is so high that it threatens the very survival of species and their environments. Every year, at least 7.3 million tons of marine life are caught incidentally. In some fisheries, the percentage of bycatch far outweighs the amount of target catch. For example, for every shrimp caught by nets dragged behind trawls in the Gulf of Mexico, over four times its weight is bycatch.” http://bycatch.org/about-bycatch

Dakuwaqa’s Garden – Underwater footage from Fiji & Tonga 4:14min

https://www.youtube.com/watch?v=mcbHKAWIk3I

The effects of overfishing 2:46 min.

https://www.youtube.com/watch?v=VxacxShp3LY

Overfishing Documentary 14 min.

https://www.youtube.com/watch?v=uwYwdqv7A7s

Marine Sanctuaries 4:21 min

https://www.youtube.com/watch?v=1K7iZfGuUKg

 

Advertisements

About altruist1

I am a raging progressive and a writer. I received Bachelors degrees in Mechanical Engineering and Industrial Arts with a Secondary teaching certificate and a minor in Physics. I taught for about ten years, then did various jobs including welding,fabrication and traffic engineering, and am now retired. I am interested in science, energy, the environment, and architecture.
This entry was posted in Problems and tagged , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s