Our trip to the Farallon Islands was certainly eventful: seasickness (me), bug bites (me) and immersion in one of the most unique wildlife habitats in the world (which made it all worth it). This chain of windblown rocks, about 27 miles from San Francisco, is teeming with 300,000 seabirds in the spring and summer.
The noise of all these nesting and breeding birds is almost overwhelming (check out the slideshow below for a firsthand look), but these birds speak for a lot more than themselves. Our guides, PRBO Conservation Science, have been studying these birds for 40 years. As Biologist Russell Bradley explained, these seabirds are environmental samplers. In order to raise their chicks, they depend on the food web that blooms in the spring when coastal upwelling brings nutrient-rich water to the surface. If that is disrupted or delayed, the first place scientists will see it is in these bird populations, who will either have poor or non-existent breeding seasons.
Those changes in the upwelling patterns can be due to natural variability in the system. But increasing, scientists are asking whether the changes are due to climate change. That’s not an easy question to answer. There are a lot of different factors in the mix.
I spoke with Zack Powell, a professor at UC Berkeley who studies climate and upwelling, and he said it all comes down to the timing of natural cycles. First, there’s El Nino – where warm water spreads across the equator and heads up the California coast. That can happen every two to seven years and when it does, it acts a barrier to upwelling, interfering with the marine food web. Scientists recently confirmed that El Nino will return this year.
Looking at changes on a longer time frame, there’s the Pacific Decadal Oscillation. It’s a pattern of ocean warming and cooling that can last 30 years. Powell says it can also have an effect on marine life and fisheries.
And finally, there’s climate change, which comparably may cause changes on the longest time frame. Powell says there’s about 100 years of historical data about the ocean conditions off the California coast and it’s not much when looking at such long-lived patterns. Powell and others work on climate modeling to help answer these questions. Some of the models show that the seasonal winds may become stronger, meaning upwelling patterns could be altered. And ocean temperatures could rise significantly, changing the way warmer surface water and nutrient-rich deep water mix.
Powell says right now his focus is the granularity of the climate models. They simply can’t predict changes on a small geographic scale. “For most models, the smallest footprint is about 100km and all the upwelling takes place closer to shore than that.” But he’s hoping there will be drastic improvements over the next few years. And if extreme changes do take place, for whatever reason, the birds will certainly tell us.
Listen to the Journey to the Farallones radio report online, and check out our Farallon Islands Interactive Map for the sights and sounds of the island. Or watch the audio slideshow below for a first-hand look.