Dive dry with dr. Bill #643: The blob!

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drbill

The Lorax for the Kelp Forest
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Rest in Peace
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DIVE DRY WITH DR. BILL #643: THE BLOB!

For the past few weeks I've been writing columns about what I saw in Palau as I worked on my 76 minute video using the footage I shot there. I also used my intense editing as an excuse for not diving much in our local waters lately. Heck, I'm an old geezer and it is hard to acclimate to water temperatures more than 20 degrees colder than I experienced on those magical islands. On top of that excuse, the dying invasive Asian seaweed has left a moonscape underwater and very little of our native giant kelp has reappeared.

Yet our waters have been significantly warmer than usual the past 12 months. Bottom temperatures at 100 feet have been as much as 10 degrees warmer than "usual" (whatever that is). I dove the entire "winter" in my 3/2mm wetsuit... much easier to don and doff than my 7mm thanks to my Buddha belly. As I've written in previous columns, the extremely warm water has contributed greatly to the loss of our giant kelp forests and the dominance of the non-native Asian seaweed. But what has caused this event? It is not the first time I've experienced such a thing in my 46 years of diving here, but most have been due to El Niños. Although one was predicted last year it didn't materialize. However, recently I discovered what appears to be the answer for the warmth: The BLOB!

Scientists from universities and NOAA have determined that The Blob does indeed exist. It is not some strange species like the Blobfish or a creation of Marvel comics. The Blob is a large body, in fact several large bodies, of warmer than usual water that exist from the Gulf of Alaska down to Mexican waters on the West Coast of North America. It appeared about a year ago and temperatures have been as much as five degrees warmer than usual. There are actually three Blobs with one centered off southern California that is affecting our region.

The existence of The Blob "way up north to Alaska" has been attributed to the presence of the persistence high pressure ridge in the atmosphere that has been blamed for our drought conditions. This ridge prevented winter storms from reaching us with both much needed rain and winds that might have stirred the surface waters and broken up the Blob. A low pressure trough in the atmosphere between California and Hawaii added insult to injury by further weakening winter winds that might have stirred up the water and caused cold water to upwell along our coast.

Of course this not only affects our winter rainfall, but also my "pets..." the critters that live in the sea (where I don't have to feed them, walk them or worry about them if I go off on a trip). Up in the Gulf of Alaska, where I have NO intention of diving (especially after my time in Palau), people have observed rather unusual critters such as ocean sunfish (Mola mola), thresher sharks and blue sharks. The warmer waters favor sardines and albacore tuna, but negatively impact salmon. Of course these changes impact the entire food web in the affected region.

In our waters species like the "sea nettle" jellies, yellowfin and even bluefin tuna, yellowtail and dorado have been more common. I saw yellowtail feeding on blacksmith in the dive park through much of the winter. And, of course, the warmer waters inhibited the recovery of our giant kelp and further enhanced the near-total dominance of the non-native Sargassum horneri.

I wish I could say that this year will bring a reversal of all this and we will once more see rain coming our way and the recovery of our kelp forests. I'm a lowly marine biologist, not a climatologist or even a physical oceanographer. However those with more knowledge in those fields than I are suggesting this year could indeed herald a true El Niño in our region. That will further impact the giant kelp due to the warm water... but could bring rain, rain, rain. I'll head back to the tropics in winter to avoid the rain and the Sargassum, but hopefully those "left behind" here on the island will at least be able to shower every day!

© 2015 Dr. Bill Bushing. For the entire archived set of nearly 650 "Dive Dry" columns, visit my website Star Thrower Educational Multimedia (S.T.E.M.) Home Page


Image caption: Sea surface temperature (SST) images showing the blobs in the Bering Sea, Gulf of Alaska and off southern California and Mexico (NOAA)


DDDB 643 The Blob sm.jpg
 

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