Green tide in the Yellow Sea
July 9, 2013 8:43 AM   Subscribe

For the sixth year in a row, green algae have invaded the beaches of Quingdao, China (video). This year's algal bloom covers 28,900 km² (about the size of Massachussets or Albania), more than twice the 2008 record (13,000 km²). Bonus: two research papers (PDF) dealing with the identification of the species (Ulva prolifera) and the origin (possibly aquaculture ponds on land) of the 2008 bloom (5 years ago on MeFi).
posted by elgilito (11 comments total) 2 users marked this as a favorite
They're all swimming in it?!

Is that really a good idea?
posted by coachfortner at 8:59 AM on July 9, 2013

Maybe it's just viral (algal?) marketing for Tsingtao Green Beer, fortified with blue-green spirulina. Yes, really.
posted by Strange Interlude at 9:07 AM on July 9, 2013 [2 favorites]

From the PDF: "The Qingdao bloom is a typical illustration of a green tide, which occurs increasingly along several coasts worldwide... Green tides are developing every spring and summer along several coasts worldwide, and their occurrence has been increasing over recent decades."

Basically they say this is happening more often due to increased nitrogen in the water from human pollution (agriculture and human waste), and increased ocean temperatures from global warming. A toxic brew.
posted by stbalbach at 9:11 AM on July 9, 2013

Is that really a good idea?

Incredibly, some people even EAT plants!
posted by DU at 9:29 AM on July 9, 2013 [4 favorites]

Re: swimming in it, per the NYT:

The State Oceanic Administration said an area larger than Connecticut had been affected by the mat of “sea lettuce,” as it is known in Chinese, which is generally harmless to humans but chokes off marine life and invariably chases away tourists as it begins to rot.

The earlier post on Mefi seemed to assume that this was a toxic bloom. I can't get to the PDFs in this post to see if that's addressed, can anyone speak to that?
posted by emjaybee at 9:36 AM on July 9, 2013

Huh, I always thought that "toxic bloom" just meant that it was sucking up all the nutrients and killing things off that way. Not that it was literally toxic.
posted by DU at 9:40 AM on July 9, 2013 [1 favorite]

It is literally toxic - to fish.
posted by IAmBroom at 9:59 AM on July 9, 2013

Green algae blooms like this aren't all that toxic in and of themselves. It is the anoxic (lacking oxygen) conditions that form as they are broken down that really disrupts the ecosystem. Red tides tend to be more closely tied with directly toxic effects.
posted by C'est la D.C. at 10:24 AM on July 9, 2013 [1 favorite]

The toxicity of green tides has been quite discussed in France, where the coast of Brittany is periodically invaded. The algae are not toxic per se, but their accumulation has complex deleterious effects, notably dead zones. There are also indirect effects on macrofauna (the algal cover may prevent some bird species to feed normally for instance). Putrefying algae release hydrogen sulfide, which has been accused in Britanny to cause the deaths of several animals (two dogs, one horse, several wild boars) and possibly two seaweed collection workers. The horse incident made the headlines: it got caught in algal quicksand and died of respiratory failure. Its rider passed out too but was saved by seaweed workers (pictures of the incident and details about the other deaths cited above, in French). It's a huge political problem in Britanny because the people whose activity is accused of causing the green tides are the pig farmers, who play a major part in the local economy, while the green tides hurt tourism, which is equally important. I wonder if the problem is similar with the Chinese prawn and crab farmers.
posted by elgilito at 10:43 AM on July 9, 2013 [1 favorite]

青岛 Qīngdǎo (lit. "Blue-Green Island"), properly spelled with no "u" after the Q.
posted by jiawen at 11:40 AM on July 9, 2013 [3 favorites]

Eutrophication of the Yellow River Delta isn't just confined to this area, but also is the prime cause behind the tremendous increase in giant Nomura's jellyfish in the Sea of Japan. They weigh a ton or so and cause serious problems for the fishing industry.

I suspect the jellyfish blooms in the Gulf of Mexico are caused by eutrophication of the major North American rivers that drain into the Gulf as well.
posted by KokuRyu at 5:39 PM on July 9, 2013

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