Talk:Dead zone (ecology)
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I removed the following quote from the article as it doen't seem to contribute much in the way of information to the article. If there is a strong opinion from wikipedians that it should be back in, you can get it from below:
- “Humankind is engaged in a gigantic, global experiment as a result of the inefficient and often overuse of fertilizers, the discharge of untreated sewage and rising emissions from vehicles and factories,” the executive director of the UN program, Klaus Toepfer, wrote in a statement introducing the 2004 report.
I didn't see any mention of sewage discharge in the article.
I think the source section here needs work.
The photo caption is misleading too, it makes it sound like dead zones are caused by sediment as well as fertilizer. Also, I thought that the Mississippi River didn't deposit as much sediment as it used to because it is more humanly controlled? Whereas the fertilizer output has increased... 126.96.36.199 00:52, 8 July 2007 (UTC)Ze
Please don't merge this article with anything else -- the phrase 'dead zone' is becoming widely adopted in the media and among the general public as a way to refer to areas of the world's oceans that can't support life. I found this article by searching for 'dead zone'. --Kbedell 12:59, 31 July 2007 (UTC)
I agree about not merging. I was also looking for an explanation of what a dead zone is and if it got stuck into another article without anything in the article's title about dead zones I wouldn't have known that was the article to look at.
There is also a dead zone that is forming now for the sixth year in a row off the coast of Oregon that is not related to fertilizer. This one's related to winds and some other things that are being affected by global warming and since that isn't talked about as a cause in the article it should definitely be added. I'm not enterprising enough to write it in myself, though, so please someone take some time to update it with this info! There's a good Seattle Times article about it today (07/31/07): http://seattletimes.nwsource.com/html/localnews/2003813875_deadzone31m.html
I agree with the user above who stated that sewage discharge is not mentioned. Also, I believe the "causes" section is extremely inaccurate to not mention chemical fertilizer runoff and animal manure as the source of over 50 percent of why many dead zones (especially in the United States) exist. I'd like to create a few additional paragraphs though I currently lack the time. If anyone approves and/or would like to work on the "causes" section with me, please comment. I also believe that a section describing preventative measures should be added under the "reversal" section. Shikamimagic 07:39, 29 August 2007 (UTC)
Mis-referenced information: Anyone know the true source?
I removed the following paragraph as I could not verify the reference, which I also removed:
Another study by the University of Texas at Austin Marine Science Institute was done on the Atlantic croaker fish in Pensacola Bay, Florida. The study was of year-old croakers that live in an estuary that has summer-long hypoxic conditions. During the study, none of the fish spawned at the expected time, or later. Examination of sample fish determined that they lacked mature eggs or sperm. (Murphy, et al., 2004) —Preceding unsigned comment added by Hydrorellen (talk • contribs) 23:47, 21 August 2008 (UTC)
The article (cited below) in fact deals with PCB, a contaminant that interferes with the endocrine system of many organisms and does not touch on the topic of hypoxia. If anyone knows anything about the estuary referred to in the para above, could you please update the article?
- Murphy, C. . . . P. Thomas, et al. 2004. Modeling the effects of multiple anthropogenic and environmental stressors on Atlantic croaker populations using nested simulation models and laboratory data. Fourth SETAC World Congress, 25th Annual Meeting in North America. Nov. 14-18. Portland, Ore. Abstract.
CNN article about dead zones
Does cellular respiration deplete water from oxygen?
Is the following sentence really true?
- ... during the night hours algae continue to undergo cellular respiration and can therefore deplete the water column of available oxygen.
http://www.madsci.org/posts/archives/2000-10/971667498.Gb.r.html suggests this is not the case. Does anyone know more? 188.8.131.52 (talk) 13:40, 17 September 2010 (UTC)
The page you point to is talking about the oxygen in the water within the cells of a plant (I think in this case a land plant), not within the water column. There is enough oxygen dissolved in each cell's water for respiration and that oxygen can be replenished the next day. Within the ocean, conditions are different. Heterotrophic bacterial respiration will continue at night (numbers are likely as high or higher than the algae) and combined with the algal respiration will draw down oxygen from the water column. Picosaur (talk) 01:03, 11 June 2011 (UTC)
To what extent do dead zones apply only to sea versus fresh water? Do they occur only in shallow areas (continental shelf?) Also, would there be any semipermanent dead zones in a world without man? I.e. places where just the rivers flowing into ocean would make one? Or is it only happening with fertilizers?