Oceanic Die-Offs

Posted Tuesday, February 19, 2008 9:55 AM by Romo

Oh how the days fly by. I always have "great ideas" for blogging but when will I ever have time to write them? Well, they say you'll never find the time; you have to make the time, so here goes...

First Order of Business: "Tech 'Tards"
Officemate informs me that 'tards is pushing the envelope of good taste in blogging. I make some comment about black humor and how you can actually say things like that when people you've loved dearly your whole life are mentally retarded. But she's right, it is kinda in bad taste--how would a visitor to my blog know what constitutes "black humor" in my world if they didn't know me and my family? So, apologies for any squeamish, angry, or hurt feeling that may have bred. Please know it's a word, not a judgment.

Second Order of Business: The Ocean is Changing
Science Friday last week reported on the dead zone off the Oregon Coast and featured the author of a new study recently published in, um, some respectable scientific journal. I'll look for a source and edit it into this post later, promise. Anyway, since this dead zone floats along the portion of the coast where I spent most of my childhood, I like to keep up to date with the research and developments around this horrifying phenomenon. The quick run down of this is that as global weather patterns change, the water temps in the ocean change. As the deep currents that we once counted on to be very very cold become warmer, the effects are myriad, far reaching and, in the case of dead zones, visible to the naked eye.

I learned quite a bit about dead zones in an Oceanography class in college, but instead of the science behind it, here I'll stick to the basics. Dead zones are so called because of the massive die-offs of countless marine species that normally dwell in these areas. The basic problem is that cold water holds more dissolved oxygen than warm water. As the (used-to-be cold) deep currents meet the coastal shelves and upwell, they bring oxygen and nutrients with them, and these nourish and sustain the plants and animals living in the waters. Now that the upwelling water is warmer it no longer brings with it these vital elements (because, remember, warmer fluids hold fewer dissolved elements and less oxygen per the basic laws of physics). This changes not only the temperature and oxygen levels in the water along the shore, but the pH as well.

From these chemical changes, the whole ecosystem gets thrown out of whack. Marine plants that thrive in this different temperature and pH begin growing rapidly. As they grow, die and decay, they suck the oxygen (already less than ususal) out of the water. This makes fish--the ones that can't swim away--die. This makes birds have trouble finding fish to eat. What one sees when they walk the beach is sand littered with hundreds to thousands of dead birds. After storms, the beach will also be covered with the washed up dead fish.

For the last six summers in a row the dead zone has shown up along the Oregon Coast. In 2006 it lasted for four months (the longest stretch yet). When residents say they've never seen anything like it, you know something is going on. In this scenario, however, there are also several decades worth of daily ocean temperature and chemistry records to quantifiably demonstrate that this is an anomaly. In fact, in the last 60 years, since record keeping began, anaerobic zones have never (until now) been found in this region. Now, they are becoming a predictable event.

Along with changing marine life, temperature changes in the major ocean currents bring with them changes in global air currents, but I think that might be a topic for a different day...



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