Discipline: Biological Sciences
Subcategory: Physiology and Health
Madison Bashford - California State University, Monterey Bay
Co-Author(s): Nicholas Carey, Hopkins Marine Station of Stanford University, CA; Jody Beers, California State University, Monterey Bay, CA, and Hopkins Marine Station of Stanford University, CA; Jeremy Goldbogen, Hopkins Marine Station of Stanford University, CA
The northern anchovy, Engraulis mordax, is a critical species in the Pacific coast food web, where they are an important food source to birds, other fish, and large marine mammals, and they also support an important commercial fishery. Anchovy populations appear to follow a cycle of ‘boom-and-bust’ in Monterey Bay, California, which may be related to seawater temperature. Results from previous studies in other forage fish species have shown that swimming speed increases in relation to seawater temperature. Thus, the primary goal of this study was to investigate, if there were changes to swimming kinematics in the northern anchovy in response to temperature. Swimming kinematics play a key role in energy acquisition and utilization during ram filter feeding, and the subsequent compensation for hydrodynamic drag. This has the potential to affect overall fitness. To investigate how seawater temperature may affect the kinematics in the northern anchovy, we conducted several experiments on a school of anchovies under different temperature regimes. Using high-speed video cameras, we filmed fish at ambient (13°C) and high temperatures (18°C) engaging in different swimming behaviors; beat-glide swimming, a passive energetically efficient behavior, and ram filter feeding, an energetically costly feeding behavior. We measured swimming speed, tailbeat frequency, distance per stroke and tailbeat amplitude. While most swimming kinematic parameters were similar in the different temperature regimes, we found tailbeat amplitude to be significantly higher at high temperature under ram swimming (p = 0.02). This suggests that anchovies may be using more energy at high temperature under routine feeding behavior. The effect of temperature on anchovies is important because it will help inform policy makers in implementing better protection and management strategies.Not Submitted
Funder Acknowledgement(s): Funding was provided by the California State University, Monterey Bay Ocean Sciences Research Experience for Undergraduates, which is funded by the National Science Foundation's Division of Ocean Sciences.
Faculty Advisor: Nicholas Carey, firstname.lastname@example.org
Role: For this project I came up with the idea independently and wrote the proposal for the California State University, Monterey Bay Ocean Sciences REU. My mentors helped me with the experimental setup and the statistical analysis. I carried out the experiments independently as well as analyzed the video footage we captured.