Understanding how climate change affects sensory pathways
Global climate change is affecting marine organism behavior in numerous ways, including alterations in mating, predation, and habitat selection, which could result in major ecological and evolutionary impacts.
Emily Rivest from the Virginia Institute of Marine Science (VIMS) led a study synthesizing the results of 120 journal articles focusing on the effects of climate change on marine sensory pathways. During her postdoctoral research studying different ways climate change affects species, she noticed commonalities in behavioral responses to different stressors, like temperature or ocean acidification.
Although some stressors affected behavior similarly in multiple species, nobody had compared those responses across the wide array of marine species and climate change stressors. Rivest wanted to conduct a literature review to understand those similarities. “That would be a really useful contribution to the community because it would be a framework to design future experiments and identify gaps in knowledge,” Rivest explained.
Interruptions in the sensory pathway
The sensory pathway of an organism consists of four steps: production, transmission, reception/processing, and response. Interruptions to the pathway can occur at each step, but the two steps most vulnerable to climate change are the production step – where an organism is producing a cue or signal – and the reception step – where a cue or signal is detected and processed.
Most studies looked at if the sensory pathway was interrupted at one step, but they did not consider effects on multiple steps. “In order for us as a community to be able to better predict the effect of climate change on species interactions, we need to understand where exactly in the pathway all of this is happening and how all these stressors are interacting,” explained Rivest.
Examples from the Bay
Rivest mentioned there are other researchers looking specifically at climate change effects on behavioral interactions in the Chesapeake Bay, such as blue crab-clam interactions. One of the papers included in Rivest’s review looked at mating sound production of Bay croaker and weakfish. In these species, females get information about the size and quality of the male based on the sound that males produce. Increased temperatures associated with climate change could affect the production, timing, and volume of the sound a male makes, which could trick females into mating with a less fit male.
Future directions for research
Future work should include more physiological studies to understand why the production step of the sensory pathway is more sensitive to changes in the marine environment. “If you look at steps, there’s a lot done on how climate change affects transmission and reception, but we know less about production of cues and signals,” stressed Rivest. To fill the knowledge gap on how stressors are going to interact, Rivest stated it was important to know local populations and environmental conditions.
In conclusion, Rivest emphasized the larger picture consequences of these behavioral interruptions. “It is important for the ecosystem services of marine species and the evolutionary trajectory of these species. Are mates that are less fit being chosen? What are the evolutionary consequences?”