tag:blogger.com,1999:blog-22424144.post970957003508353854..comments2023-11-02T04:18:45.711-07:00Comments on blogfish: Oregon ocean dead zone linked to climate changeMark Powellhttp://www.blogger.com/profile/08121566220326246265noreply@blogger.comBlogger15125tag:blogger.com,1999:blog-22424144.post-80021289441286932882008-07-06T19:01:00.000-07:002008-07-06T19:01:00.000-07:00Thanks Tony!Thanks Tony!Georgehttps://www.blogger.com/profile/05481340910793408299noreply@blogger.comtag:blogger.com,1999:blog-22424144.post-86191151870938748362008-07-06T12:23:00.000-07:002008-07-06T12:23:00.000-07:00George-Hypoxia did return in 2007. Here is a local...George-<BR/><BR/>Hypoxia did return in 2007. Here is a local article on the extent (Oregonian):<BR/>http://www.piscoweb.org/files/Oregonian%20article%208_1_07.pdf<BR/><BR/>Information on Hypoxia monitoring off Oregon is publicly available at the Oregon Coastal Ocean Observing System website (http://agate.coas.oregonstate.edu/) which has realtime ocean conditions and their hypoxia page (http://Anonymoushttps://www.blogger.com/profile/07218584612948399824noreply@blogger.comtag:blogger.com,1999:blog-22424144.post-88423289928396186162008-07-05T20:57:00.000-07:002008-07-05T20:57:00.000-07:00I am interested in if anyone has heard anything co...I am interested in if anyone has heard anything concerning this Oregon Dead Zone for 2007 or 2008. All of the information on the net stops after the 2006 event.Georgehttps://www.blogger.com/profile/05481340910793408299noreply@blogger.comtag:blogger.com,1999:blog-22424144.post-91323541697443425612008-02-20T09:12:00.000-08:002008-02-20T09:12:00.000-08:00ThanksThanksAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-22424144.post-75252354745800613272008-02-18T15:00:00.000-08:002008-02-18T15:00:00.000-08:00Aaron-There is some vertical stratification as col...Aaron-<BR/><BR/>There is some vertical stratification as colder (and sometimes more saline) water is brought up from the bottom to surface waters during upwelling. The vertical stratification is one of the major issues with the Gulf of Mexico hypoxic zone as the less dense Mississippi river water lays on top of the more saline, more dense gulf waters. In contrast, the density difference is not tonydhttps://www.blogger.com/profile/11090716443584416973noreply@blogger.comtag:blogger.com,1999:blog-22424144.post-13881247563733419822008-02-18T08:48:00.000-08:002008-02-18T08:48:00.000-08:00Tonyd maybe you can answer this... Is there vertic...Tonyd maybe you can answer this... <BR/><BR/>Is there vertical stratification in the area where the hypoxia is occurring?<BR/><BR/>From Mark's description of the waters being rough and there being lots of wave, I would get the impression that the water column is well mixed. This mixing would be expected to prevent hypoxia and anoxia from occurring in the area as the system would be re-aerated by Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22424144.post-38459485840592205982008-02-16T21:18:00.000-08:002008-02-16T21:18:00.000-08:00Thanks Tony, good explanation and your doubt of cl...Thanks Tony, good explanation and your doubt of climate change links is credible. Obviously, more needs to be done to nail down causes. The Science paper hypothesis is useful and credible, and it gives everyone something to debate and evaluate. We'll get to answers on climate change links for the Oregon dead zone.Mark Powellhttps://www.blogger.com/profile/10333424116503463839noreply@blogger.comtag:blogger.com,1999:blog-22424144.post-88931092930203025752008-02-16T21:05:00.000-08:002008-02-16T21:05:00.000-08:00As someone who works in the Oregon upwelling syste...As someone who works in the Oregon upwelling system, I think I can fill in some of the gaps from the questions posted here. I can confirm that anthropogenic nutrients are not an issue off the Oregon coast during the upwelling period. First, the rivers here are much smaller (the Columbia River may be the lone exception) and do not have a watershed anywhere near the size of the Mississippi. In tonydhttps://www.blogger.com/profile/11090716443584416973noreply@blogger.comtag:blogger.com,1999:blog-22424144.post-11842937313315499932008-02-15T16:12:00.000-08:002008-02-15T16:12:00.000-08:00Aaron, Have you ever seen the coast in this area ...Aaron, Have you ever seen the coast in this area during heavy wind/upwelling periods? It's rough and the ocean is in motion. Great for windsurfing. <BR/><BR/>Upwelling is so dominant that changes in wind and upwelling are much more likely to affect productivity and hypoxia than anthropogenic nutrient runoff. Wind and upwelling change currents and mixing also, so you can't just assume that Mark Powellhttps://www.blogger.com/profile/10333424116503463839noreply@blogger.comtag:blogger.com,1999:blog-22424144.post-3812459084651122842008-02-15T15:37:00.000-08:002008-02-15T15:37:00.000-08:00Just as a quick follow-up comment. I believe you a...Just as a quick follow-up comment. I believe you are right that upwelling dominates runoff for the nutrient loads on the Oregon coast. <BR/><BR/>Using the operational definition of hypoxia in the Gulf of Mexico and Chesapeake Bay (DO < 2 mg/l) the Oregon shelf has been experiencing hypoxia for quite awhile. DO<1 mg/l is not unheard on the shelf based on Fig. 1A. I wonder how much of an increase Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22424144.post-66093903356348367182008-02-15T15:29:00.000-08:002008-02-15T15:29:00.000-08:00I doubt the global warming link (but don't totally...I doubt the global warming link (but don't totally reject it as a possibility) because they don't appear to consider any other possible causes for the presence of hypoxia and anoxia on the Oregon shelf. Thus, they haven't eliminated other causes of hypoxia and anoxia as likely causes. They also haven't proven that it is a lack of sampling which prevented us from seeing this in the past. <BR/><BR/Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22424144.post-3129754938147033452008-02-15T14:33:00.000-08:002008-02-15T14:33:00.000-08:00Bit of speculation here...the Oregon coast has fas...Bit of speculation here...the Oregon coast has fast currents, strong winds and rough, turbulent water, and I suspect the residence time of coastal waters on the shelf can be fairly short. Also, the watershed area contributing nutrient runoff is smaller than the Mississippi basin. I think upwelling dominates nutrient levels, not runoff, but I'm not sure. The Oregon coast ain't the Gulf of Mark Powellhttps://www.blogger.com/profile/10333424116503463839noreply@blogger.comtag:blogger.com,1999:blog-22424144.post-72889942004848013942008-02-15T13:55:00.000-08:002008-02-15T13:55:00.000-08:00I don't know if your argument about it being open ...I don't know if your argument about it being open ocean makes sense. They talk about the hypoxia/anoxia occurring on the continental shelf in waters 60 m deep and within 2 km of the surf zone. The hypoxic area in the Northern Gulf of Mexico extends 50 to 100 km offshore and the plume of nutrients from the Mississippi River extends at least that far offshore and most of the distance along the Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-22424144.post-26547671995939473902008-02-15T12:35:00.000-08:002008-02-15T12:35:00.000-08:00Climate change link seems compelling to me. Human...Climate change link seems compelling to me. Human nutrient loading is a non-issue in this open ocean area. <BR/><BR/>Historical data are imperfect, but adequate to support the climate change link IMHO. And for oxygen, 0 is worse than 1ppm. Many animals can probably tolerate 1 longer than zero, and perhaps flee or wait out the problem.Mark Powellhttps://www.blogger.com/profile/10333424116503463839noreply@blogger.comtag:blogger.com,1999:blog-22424144.post-24876761836921299342008-02-15T12:27:00.000-08:002008-02-15T12:27:00.000-08:00I read the paper and watched the video today. I th...I read the paper and watched the video today. I think it's worrisome that they are starting to have issues with hypoxia and anoxia, but I'm wondering if they invoked global warming a little too quickly. Any idea if there is any coring data from the affected region that would provide a longer term perspective on what the history of dissolved oxygen is in the region? I realize their data goes back Anonymousnoreply@blogger.com