Catalina Chronicles Pt 2

Project principle investigator Genoa Sullaway swims above the Sargassum

2/10-11/2016
Catalina Island, California
 
Genoa, Tristin and I awoke in the pre-dawn gloom early on Friday morning. After an incredibly long journey from the mainland to Wrigley Station, with just enough time to get an evening dive in on the night of 9th, we were ready to suit up and flush Genoa’s experimental chambers. We had the dive locker all to ourselves; it seems as though the forecasted weather kept most people off of “The Rock” for the weekend. But not us, we have diving to do and data to collect!
 
Much like the work the Edwards’ Lab has been doing in the Aleutians, Genoa is investigating the effects of an incredibly invasive alga, Sargassum on local patterns of Net Community Production. Since about 2012, Sargassum has rapidly spread along the coast of Southern California, replacing giant kelp as the dominant species on many temperate rocky reefs. Sargassum is an annual species; unlike giant kelp individuals which can live for multiple years, Sargassum dies back each summer. The implications of the loss of giant kelp and the rise of Sargassum on many rocky reef communities in Southern California has yet to be fully understood. 

Genoa and Tristin prepare to flush a chamber

So, for Genoa’s work we’re up at 6am flushing the chambers, surveying the community and keeping the experiments running. Since Genoa’s site is so close to the field station, we have the option of running back in between dives to get out of our wetsuits/drysuits, and grab some food before getting back in the water. A luxury we're not typically used to. 
 
In terms of diving, just to give you an idea of what we’re working with, imagine trying to hike through really, really dense shrubs when you should be strolling through a forest. Now, I’ll be the first to admit that I’ve gotten stuck in giant kelp on almost every dive I’ve been on. But hey, it happens. Sargassum is a whole different beast. The winter months are the peak growing/reproducing time for this annual species; across the reef at Genoa’s site the Sargassum covers just about every surface, from rocks to buoy lines, and even other algae. Not only does is grow in dense, bushy clusters, right now it can be over two-meters tall, blocking almost all of the light on the bottom! 

To hold the chambers down we lay heavy chain around the chamber's skirt. Genoa and Tristin get in their pre-dive workout

Tristin McHugh swims a nearly 15lb bag of (positively buoyant) Sargassum back to the boat

As we were conducting surveys and setting up chambers, we would occasionally have to kick up out of the "Devil Weed" just to make sure we didn’t get separated from on other, even if we were within touching distance. However, recent storms (including last year’s El Niño) have brought cold, nutrient rich waters to Southern California, and it seems as though giant kelp is making a comeback!
 
Be sure to check back in for the final installment of our Catalina Chronicles.
 
Cheers,
 
-Baron von Urchin
 ​

Divers Genoa (left) and Tristin (right) kick above the Sargassum after taking samples