In the past couple of weeks, the sunsets over Monterey Bay, California, were noticeably redder than usual. It was popular to speculate whether this could be due to Southern California fires that were so rampant at the time. It seemed plausible, but they also seemed really far away. (We’re located just south of San Francisco, about 450 miles [725 km] north of San Diego.) The answer became clear when the spectacular satellite images of the fire were released, particularly the one from 22 Oct 2007. (Notice several fires in Baja California as well.) There was indeed a plume reaching to the mouth of the bay.
The environmental influence of the fires, beyond the charred ground left behind, was impressive: I measured the area covered by the heavy white smoke in this satellite image as about 168,000 square km (41 million acres). Moderate smoke covers at least 600,000 sq. km (~232,000 sq. mi; 60M hectares), and it stretches offshore more than 950 km (almost 600 miles).
Given their scale, what long-term effects might such fires have on the oceans?
In one week, these Southern California fires were estimated to have released 7.9 million metric tons of carbon dioxide. About 5% of that amount would have been released as ash [ref]. Upon entering the ocean, these sooty particulates can have many effects, potentially both increasing or decreasing productivity via shading, sedimentation, adsorbing molecules, decreased albedo (less light reflection), and the input of nutrients. In one study, smoke from fires was implicated in a large coral reef die-off. The authors speculate that iron, a nutrient that can stimulate growth in trace amounts, was deposited with the soot, leading to an algal red tide and coral asphyxiation. Who needs butterfly wings when you have a raging inferno?
Once the rains begin, the increased ash and silt in runoff entering the ocean will give the fire another chance to affect marine ecosystems, potentially interfering with benthic filter-feeders, altering productivity, tweaking kelp forest dynamics, and annoying surfers. It will be interesting to monitor the residual effects through the coming year and beyond.
While the local marine impact remains to be seen, in a global context, the environmental effects of these episodic fires may be relatively minor: smoke regularly clouds the skies over large parts of Brazil and Indonesia.
As distinct as the elements seem, there is no way to escape the many interconnections between them.
Interesting! I never thought about the effects of the fires on the ocean and its inhabitants …
Deborah
The satellite image of the smoke plumes is impressive, but I definitely wasn’t thinking about where all that smoke would go when it falls. Thank you for the reminder that it all ends up somewhere.
Hi, I linked you to my blog, http://www.thesalp.blogspot.com . Writing as a salp sometimes washed up on the beach up near Tillamook Head in Oregon, I tend to be a bit opinionated about the ocean, and I really liked finding this post of yours about smoke. Seems obvious, but how many people are making a note of it? Recently visiting the beach in Santa Monica on a low tide, I found myself wheezing and my one good eye quite cloudy. I was perturbed by the odd color of the underside of the ocean’s top (I was under water) - kind of a weird gelid mauve, and the flavor was all wrong. Back up north on the 100 mph winds, in a jiffy, the next week, I found dead adolescent raccoons on the beach for the first time - washed off Tillamook Head by wave action taking away the ancient cliffs, with little raccoons perched on the cliffside trees, kersplash, and too young to know how to swim with the current and so to the beach. Not good. I hope you keep writing: I will keep reading as long as I can find a dog who can help me get online to keep up with your blog. Thanks.