After joining the Charles Darwin Foundation in April in an expedition to study the mangroves of the Galapagos, it was fun to turn things around this summer and host our new colleagues on our own turf in Baja California Sur. The plan: in our short window of 10 days of field work, we would spend the first half of the expedition working in the mangroves of La Paz near the southern tip of Baja, and the second half 350 km north in Bahia Concepcion.

We had our work cut out for us to cover the mangroves of half of the Gulf of California. Every day’s schedule was packed with potential sites, and each of the six researchers had something to do. Pelayo Salinas and Etienne Rastoin of the Charles Darwin Foundation were out on a panga each day deploying their camera mounts, which they use to quantify the way animals use the mangrove environment. José Cota-Nieto of CBMC and Santiago Domínguez Sánchez, a student from the local university, conducted fish surveys in the mangroves and joined Adrian Munguía in collecting individual yellow snappers for tissue sampling. These samples are being used to assess whether populations of these snappers, known to use the mangroves in the Gulf as critical nursery habitat, are spatially structured across the region. Finally, I was playing in the mud as usual; I sampled each forest we visited using a sediment core with the aim of quantifying the amount of carbon stored underground. Mangroves store tons of carbon in their deep organic sediments, and our sampling efforts will hopefully unearth not just how much carbon is stored in the Gulf’s mangroves, but what processes help ensure that this carbon pool is so well protected from decomposition.

We visited some amazing mangroves in the La Paz region, including the vast forest of San José Island, and camped out one night in a quiet and secluded beach, a notch cut into the side of Isla La Partida. After returning to our home base in La Paz, we made a quick turnaround and headed up to Bahia Concepcion, a six-hour drive through the desert. Well, at least, it would have been a six-hour drive, but no research trip (at least that I’ve been on) can be without its pratfalls. About two hours into the drive, one of the cars (yes, the one that I was driving) broke down. If in the past you’ve ever broken down someplace and described it as “in the middle of nowhere,” it probably wasn’t quite as “in the middle of nowhere” as we were. It was midday, and given how hot it was, I was impressed with the determination of the vultures that gathered to circle overhead. We eventually got towed, and a short time at the mechanic got us patched up and on our way again, but it was night when we arrived. Never a dull moment!

Bahia Concepcion contained a set of mangrove forests I had never visited, and I enjoyed exploring and sampling these central Gulf forests. Before we knew it, our hour days there were up, and it was time for a return drive down to La Paz (this one fortunately less eventful). In all, it was a successful trip, and I look forward to seeing how the results gathered by our colleagues shed light on the multifaceted ecology of the mangroves of the Gulf of California. Every time I visit these amazing systems, I am impressed by the bounty of biodiversity and intensity of life they support. I can’t wait to see what my next visit will teach me. Until next time!

Author: Matthew Coasta
PhD student, SIO
Matthew Costa is a Regents Fellow 2013-4 and NSF Graduate Research Fellow 2014-present, and is pursuing a Ph.D. in biological oceanography as part of the Gulf of California Marine Program. He is interested in community ecology, biodiversity and functional diversity, and coastal ecosystem processes and services. His research focuses on carbon storage in sediments of the mangrove forests in the southern Gulf of California. Prior to study at SIO, he completed a B.A. in Ecology and Evolutionary Biology at Princeton University studying mangrove species zonation in Bermuda.