Interesting post on fellow Brown University professor Heather Leslie's blog regarding the role of ecologists in the science of conservation. Here is the Nature paper she refers to, in which hundreds of top scientist and conservationists from around the world sign a petition to end quarrels and increase the diversity of voices heard in the conservation movement.
Sometimes it's hard to really connect with the lofty and technical terms used in ecology. Words like "transgressive over-yielding" and "type II functional response" elicit glazed eyes more often than not, so it's nice to find opportunities to film some of these interactions first-hand in a visually explicit manner.
Today, the topic is prey refuges. A prey refuge is some structure or behavior that an organism uses to escape from its predator. While going through my video files from the Channel Islands, I came across this great example of a prey refuge: a purple sea urchin using the holdfast of a kelp plant to avoid being eaten by a sheepshead wrasse.
What makes this relationship even more intricate is the fact that the urchin actually eats the kelp, the very thing that provides its refuge. In addition, the sheepshead requires kelp habitat for survival from its own predators, so what seems like a simple interaction really turns out to have far-reaching implications. And this is only taking into account these three species!
Food webs and the ecosystems they maintain are incredibly complex. Figuring out which species and interactions matter most for ecosystem health and function is one of the key areas of focus of our lab.
New article highlighting our science and outreach efforts to support conservation of Cashes Ledge:
At the end of our long field season in the Galapagos Islands this summer, I felt like I hadn’t had my fill of diving and so I flew back to the west coast for a week of collaborating with the Channel Islands National Park in southern California. There I joined director Dave Kushner and staff Josh Sprague and Kelly Morse on the yearly kelp forest monitoring project. One of the longest of its kind, this project has yielded one of the longest running marine ecological datasets in the world, dating back over 30 years. Such a timescale of high-quality data on fish, sessile and mobile invertebrate, and algal abundance, size, recruitment, and diversity is an invaluable tool for defining relationships between fishing, reserve protection, and environmental oscillations as drivers of ecosystem structure and functioning.
I saw many parallels between the yearly monitoring work that we do in the Galapagos and the kelp forest program, but the scale of things was much larger: they monitor 32 sites every summer, taking copious amounts of information from multiple 100 x 20 transects at each site, in addition to recruitment modules and roving fish counts. I held my own and was able to contribute valuable data, and I also got my first taste of a California kelp ecosystem, one of the most productive and diverse in the world. In contrast to the New England kelp forests, which reach a maximum canopy height of about 20 feet, these giant kelp (Macrocystis pyrifera) can grow as much as 2 feet per day and reach maximum heights of 150 feet!
Needless to say, this immense 3-dimensional habitat houses a wide variety of unique, and sometimes familiar, marine life. My first incredible underwater encounter was with a giant black sea bass, a 7-foot behemoth that stood as an example of just what the ocean is capable of producing if we let her be. This amazing fish circled us curiously for about 20 minutes, allowing me to videotape it closely, I even got shots of the parasitic copepods covering it's face and a couple good shots showing divers alongside it for scale. Just a beautiful, powerful animal, what a treat.
I also took some cool film of a California sheepshead wrasse eating a large red urchin. It acted similarly to the triggerfish of the Galapagos, biting into the urchin test and scooping out the insides. Instead of hogfish circling to steal the prey, this wrasse had to deal with dozens of señoritas, small elongate wrasses that were able to get into the bite holes that the sheepshead had made and eat out all the meat before the sheepshead really even had a chance to get it. Very similar interference competition to what we see in the Galapagos, increasing handling time and decreasing the caloric reward for predation, and thus increasing the number of urchins needed to be killed in order to survive.
The Channel Islands are an incredible place and I highly recommend a visit for anyone who loves marine life. Completely worthy of designation as a National Park, I hope that this ecosystem remains healthy and protected long into the future.
IN THE FIELD
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