GC Marine Program
Blog
03.28.2018

Dealing with dynamic habitats: recovering temperature data loggers within Baja California mangroves

Blog, Coastal & Marine, General

The Gulf of California (GoC) is a very interesting place to study the effects climate change has on fish because it presents one the world’s most extreme environments in terms of temperature. From February to August, water temperatures here can swing a full 17°C. Despite this radical change in temperature, the GoC is among one of the most productive marginal seas worldwide.

Map showing the latitudinal temperature gradient in the Sea of Cortez (left) as well as the chlorophyll-a concentration (right) which is a proxy for primary productivity that sustains high abundance of marine organisms in this region. White dots represent some of the mangrove sites in the region.

The Gulf of California is home to many mangrove forests that play an important role as nurseries for fish, crabs, and shrimps. But, these environments are subjected to huge variations in temperature that may affect the way these animals grow. Understanding this relationship is critical, as climate change will be particularly strong on semi-enclosed seas, like the GoC, and in shallow environments, like mangroves and rocky reefs. So far, there are no available studies that show how warmer waters inside mangroves might affect the growth and development of the marine organisms living there.

Mangrove at the Santispac beach, Bahia Concepción.

In the third week of January 2018, I traveled to La Paz, Baja California Sur, with Gabriel Castro (SIO), Oscar Pena (UABCS), and Amilcar Huelgas (UABCS). We had two main goals in mind; recover small temperature data loggers (roughly the size of a matchboxes) that I had placed in the mangrove’s roots one year prior (January 2017), and collect juvenile fish.

 

From left to right: Oscar, Amilcar, Leticia and Gabriel at Bahia Concepción – Baja California Sur.

With the temperature loggers recovered, I can use their data from the past year to estimate how the daily and seasonal variability of water temperature inside the mangroves affects the growth of juvenile fish. The hypothesis behind this it is that the warmer the water, the faster the fish babies will grow, until a certain threshold be reached. This study can help me to understand and predict how global warming may affect the way fish are growing. Such knowledge can help advise fisheries managers and readjust strategies to maintain sustainable fish populations. While I recovered less temperature loggers than I had hoped, I am excited to see the data that I’ve collected and what I will learn about temperature variations in the Gulf!

Juveniles of yellow snappers Lutjanus argentiventris, a very common species found between the mangrove roots.

Author:

Leticia Cavole obtained a BS in Oceanography from Federal University of Rio Grande (Brazi) in 2012. In 2014 she completed a MS in Biological Oceanography from the same university. In 2015, Leticia moved to San Diego-California to pursue her doctorate studies in marine biology at Scripps Institution of Oceanography, in the Aburto’s Lab. Her academic interest is fish biology, fisheries and conservation.