The importance of understanding intraspecific behavioral variation in migratory fishes and its impact on the adaptability of these fishes to climate change

AC Winkler, AR Childs¹, M Parkinson¹, M Roberts, C Santos, Professor Warwick Sauer¹, Professor Warren Potts¹

¹Rhodes University, Grahamstown, South Africa, ²Technical University of Denmark, Kongens Lyngby, Denmark

Intraspecific behavioral variation is common throughout numerous animal taxa being referred to using a multitude of terms such as “partial migration” or the “contingent theory” in order to describe habitat use or migratory pattern variation of individuals within the same population. Recent advances in fish tracking technology such as electronic tagging have allowed for the identification of numerous populations exhibiting such variable life history traits. Such a variable strategy is thought to have evolved to buffer a population against unpredictable change in one habitat or migration route opposed to another. Given the current climate change trends observed globally variable migratory strategies may be one way in which organisms may be able to adapt to rapid environmental change. In order to explore this hypothesis, thirty adult Lichia amia were tagged with electronic acoustic tracking transmitters within a climate change hotspot found within the coastal waters of southern Angola during 2013 and tracked over an 18 month period. Results suggest that within this population, three distinct migratory behavioral types were observed, were certain fish remained resident to the tagging location throughout the study while others displayed differing migratory patterns utilizing different habitats. Due to the highly variable temperature conditions exhibited within the study area (14 – 27°C) and the migratory variability exhibited by this population, suggests that each behavioral type exhibited by tagged fish may be a consequence of intrapopulational temperature preferences. These findings therefore highlight the importance of understanding individual behavior when monitoring the potential effects of climate change on marine organisms.

Biography: To be confirmed