One of my major interests throughout my degree was fisheries management and aquaculture practices and I thought I would share some facts about the global state of fisheries that is not commonly advertised.
Many, many years ago, fish were considered a common resource. Countries had no jurisdiction over their coastal waters and could rape, pillage and plunder all regions of the world. However, as the value of fish stocks was realised, countries began to turn and lay claim to the waters that surrounded their boundaries. It wasn’t long before international laws were enforced that provided countries with ownership over their coastal waters - and the marine life that resided within it. This ownership was labeled the ‘Exclusive Economic Zone’ (EEZ). Lucky for us Aussies, we lay claim to the third largest EEZ in the world.
In an effort to gather stats on each countries catch effort per year, the Food and Agriculture Organisation (FAO) of the United Nations maintains records of fisheries landings. To do this, the FAO relies heavily on catch statistics provided by member countries... however the accuracy of these stats can be very decieving.
According to the FAO our total annual world harvest has been significantly increasing;
This increase has caused many debates. We are forever being told that wild seafood stocks are in a dramatic decline. So why, if our marine life is disappearing, are we catching more and more tons of seafood each year? The answer: China.
It is commonly expected that most countries UNDER report their catch, but it would seem China has been OVER reporting its catch. From 1980 – 1995 the amount harvested by China each year was reported to be constant. When scientists compared the productivity of the waters in China with similar regions elsewhere it insinuated that catches reported by China could not possibly be as large as reported.
So why would China OVER report? Watson and Pauly (1998) put it down to be an outcome of the socialist political culture of China. The more seafood harvested shows good productivity, and good productivity reflects back on how good the current politician is.
The FAO corrects its data to account for China’s over-reporting and with the corrected data it showed that instead of world catches increasing, that they have in fact been decreasing by 0.33 million tons per year.
So what does all this mean for our marine environment? Basically, a paper published in 1998 by Pauly et al showed that we are fishing down our food webs. That is, we are harvesting fish at increasingly lower trophic levels. Pauly and crew gave different species certain trophic levels, for example, a Snapper has a trophic level of 4.6 whereas a Peruvian Anchovy has a trophic level of 2.2. This study showed that over time, our mean trophic level in our fisheries landings has been decreasing more and more. If we start fishing down the food web in great numbers we eliminate the source that both controls and converts primary production into readily available material. This is unsustainable and will have major implications on the wider ecosystem.
Many people seem to "not stress" about the deteriorating state of our worlds fisheries, thinking that we have Aquaculture practices to fall back on but Aquaculture needs a significant amount of work to become any form of relief to sea (will do my next blog on this).
While it may all seem like its doom and gloom at the moment, I like to end on a positive note and there is a positive spin to associate with this. Fisheries managers, public pressure and an increase in scientific funding are slowly, but surely, leading to better regulations and more severe punishments for violations. If we continue to push for more sustainable seafood from our local fish and chip stores to the massive supermarket chains, we can hopefully change the fate of our oceans.
Sarah Shark :) www.sarahshark.com