MEPS 564:9-28 (2017)  -  DOI: https://doi.org/10.3354/meps11967

ABSTRACT: Understanding mechanisms driving biological populations in response to changes in environmental conditions could be insightful to predict ecosystem trajectories under different climate scenarios, which largely rely on modeling approaches. There is a growing consensus on variability among individuals (individual variability, IV) playing an important role in regulating dynamics and stability of populations. As a key component of marine ecosystems, changes in zooplankton dynamics could have a significant effect on ecosystem structures and fisheries production. We developed an individual-based model of a dominant coastal copepod, Acartia tonsa, to explore IV in sustaining a copepod population. We also examined the effects on the population dynamics under different levels of temperature, salinity, and food concentration. Abundance, egg production, and population survival of the species were used as metrics to measure population success. Our simulations suggested that the 3 environmental factors significantly influence the population dynamics of A. tonsa, and IV has implications for population regulation and resilience under unfavorable environmental conditions. Given that marine ecosystems are at risk from environmental changes, knowing the extent of IV in sustaining populations of key species could increase our ability to forecast ecosystem dynamics in a changing environment.

KEY WORDS: Individual variability · Environmental conditions · Natural selection · Population dynamics · Individual-based model · Acartia tonsa