As part of a collaboration between the Ezcurra Lab at UC Riverside and the GCMP to investigate the effects of river dams along the coastlines of the Gulf of California, I partook in an expedition led by Dr. Exequiel Ezcurra. Accompanied by Sula Maria Vanderplank (BRIT botanical explorer and former PhD student of Dr. Ezcurra), Lorena Villanueva (avid runner and current PhD student of Dr. Ezcurra), and Ana Ezcurra (field photographer and local to our travel regions), I set out to Mazatlan and Sinaloa, Mexico.
After our arrival to the airport, we went to pick up our rental vehicle for the many adventures ahead, which turned out to be a family van… not the four wheel drive Explorer we were expecting. This was our home for over 12 hours of driving up and down the coast of Sinaloa and Mazaltan in search of four different river mouths.
What we found was both astounding and disheartening. The coastlines of the dammed Fuerte and Santiago river mouths were completely degraded. This region has already lost more than a kilometer of coast, and counting. The receding coastlines expose rows of old mangrove to the open ocean, causing a massive die-off. Abandoned termite nests and crab burrows left behind a true mangrove graveyard.
The contrast between this and the healthy coastlines of the free-flowing Acaponeta and San Pedro river mouths was startling. The mangroves were far inland, sometimes so much that we could not access them through the thick bush of flora that grows inland from the coast. Sula and Lorena diligently surveyed and sampled these coastlines, and found abundant biodiversity compared to the relatively barren dammed river coastlines. I gained a newfound appreciation for the work of a botanist after watching Sula and Lorena meticulously collect and survey the flora of each site, only to spend hours each night identifying and describing their collections.
The receding coastlines along dammed rivers can be seen via historical satellite imagery searches. This expedition, however, allowed us to see much more. The area lost also represents a loss in biodiversity, and exposes mangrove forests to open waters, destroying an invaluable habitat.
Getting to these sites proved a challenge in and of itself. Attempting to reach the mouth of the Acaponeta River using iPhone maps worked until discovering that we needed to cross a non-existent bridge! This, along with a few other mishaps (e.g. driving the family van on a sandy road, and inevitably sinking), at least helped break up the monotony of long hours on the road.
The final day of our trip was dedicated to spot cleaning the rental van, washing away any signs of being stuck three feet deep in the sand, scratched by twigs along roads less traveled, and covered with microbeads from a broken travel pillow. We flew home on the Fourth of July, making it home just in time for fireworks.
Paula Ezcurra is a recent graduate from UCSB, where she obtained a B.S. in Aquatic Biology. While there, she aided in research on California kelp forest ecology through the Santa Barbara Channel LTER. Today, Paula continues to pursue her interest in coastal marine ecology and conservation as an intern in the Aburto Lab at SIO where she has focused her work in Mexican desert mangroves as part of her involvement in the Gulf of California Marine Program.