Understanding temperature effects on recruitment in the context of trophic mismatch

Abstract

Understanding how temperature affects the relative phenology of predators and prey is necessary to predict climate change impacts and recruitment variation. This study examines the role of temperature in the phenology of a key forage fish, the lesser sandeel (Ammodytes marinus, Raitt) and its copepod prey. Using time-series of temperature, fish larval and copepod abundance from a Scottish coastal monitoring site, the study quantifies how thermal relationships affect the match between hatching in sandeel and egg production of its copepod prey. While sandeel hatch time was found to be related to the rate of seasonal temperature decline during the autumn and winter through effects on gonad and egg development, variation in copepod timing mostly responded to February temperature. These two temperature relationships defined the degree of trophic mismatch which in turn explained variation in local sandeel recruitment. Projected warming scenarios indicated an increasing probability of phenological decoupling and concomitant decline in sandeel recruitment. This study sheds light on the mechanisms by which future warming could increase the trophic mismatch between predator and prey, and demonstrates the need to identify the temperature-sensitive stages in predator-prey phenology for predicting future responses to climate change.

Life in fluctuating environments

“…cross-correlations between temperature and day length) may alter the outcome of species interactions. If individuals evolved to rely heavily on one correlated environmental cue, and that cue is no longer a good indicator of some physiologically relevant condition at a later time, then this may result in the mistiming of important life-history events and lead to phenological shifts [102,[191][192][193]. In a community context, different organisms use different cues for their phenologies (i.e.…”

Temperature and body size affect recruitment and survival of sandeel across the North Sea

“…Temperature affects the physiological rates in adult sandeel, with warming delaying ovarian development (Wright et al, 2017a) and bringing about earlier hatching of eggs due to faster development rates (Régnier et al, 2018). In addition, the indirect impact of elevated temperatures on food availability has been linked to increasing probabilities of trophic mismatch with available prey (Régnier et al, 2019). However, correlation approaches, such as in the present study, are not expected to provide strong evidence for the underlying mechanisms or to map out complicated causation chains.…”

“…Although, such responses have been highlighted for several marine fish (Ciannelli et al, 2004(Ciannelli et al, , 2012Katara et al, 2011;Arula et al, 2016), including sandeel (van der Kooij et al, 2008;Lynam et al, 2013;Lindegren et al, 2018;Régnier et al, 2019). The decision to use linear models was based on the length of the time-series, which are considerably shorter than in the before-mentioned studies (i.e.…”

A fine-scale multi-step approach to understand fish recruitment variability

“…There is, however, a clear interaction between food abundance and its temporal and spatial availability that is often ignored, but which can be essential in understanding and predicting recruitment. Despite the importance of the match-mismatch hypothesis 2 , it has to our knowledge only been rarely demonstrated, whether on a spatial or temporal scale 17,51,52 or both 62 . This should be noted in relation to the vast amounts of studies focusing on marine species recruitment variability 4 .…”