Marine match-mismatch: the ecological consequences of climate driven changes in migration and reproductive phenology in the sea

Phenology is the study of seasonal biological events, such as migration, egg laying, or flowering. The iconic ‘match-mismatch hypothesis’ (Cushing, 1974, 1975) predicts that changes in phenology may affect synchronicity with energy sources and so impact fitness. Examples of this may be failure to migrate in time to exploit a food source elsewhere, or to lay eggs to synchronise hatching with seasonally available food. As species rely on different environmental cues to time these events, it is possible that climate change will disrupt important ecological connections with cascading consequences at the level of the ecosystem.

Although originally conceived in the context of marine biology, the match-mismatch hypothesis has since been embraced as a general concept in ecology. As evidence of phenological shifts in response to changing climate mounts (Parmesan & Yohe, 2003), there has been a surge in publications in the ecological literature reviewing and re-evaluating the hypothesis (Kharouba and Wolkovich 2023; Samplonius et al. 2021). In general, the conclusion is that the conditions under which phenological asynchrony leads to effects on fitness depends on the ecosystem context – in particular the extent to which a consumer species or group is bottom-up or top-down regulated.

The central question for this studentship is: under what circumstances will the widely observed climate-related shifts in phenology lead to notable consequences at the level of the ecosystem?

While ecosystem models already include many aspects of known ecology and trophic coupling, the processes governing phenology and the sensitivity of the system to match-mismatch effects are glaringly missing. Ideally, phenological characteristics should be an emergent property of such models. This is the case for phytoplankton and lower trophic levels, but not for mid- and higher trophic levels. The proposed PhD project aims to spearhead a step change in ecosystem modelling by representing these processes.