Ontogenetic spatial constraints of sub‐arctic marine fish species

Abstract

Climate change influences ecological processes and biogeochemical cycles of marine environments. Species may respond and adapt to these changes through shifting spatial distributions, but options may be limited by the required occupancy of essential habitats which are anchored in space. Marine fish species typically have complex life cycles composed of multiple life stages with different degrees of habitat preferences. Limited knowledge of when spatial constraints are most likely to occur in marine fish life cycles has impeded the development of realistic distribution forecasts. In this study, we develop and implement analytical techniques to identify spatial constraints, defined by both the consistency through which a particular geographic area is used year after year, and by the extent of such area with respect to the entire population range. This approach is applied to ten case studies including six groundfish species from the Eastern Bering Sea, three from the Scotian Shelf, and one from the Barents Sea. Our analyses illustrate that the early phase of the species' life cycle is more spatially constrained than older life stages, and that adult stages are more closely associated with particular temperatures or climate velocities. We detected significant species-specific variability in both the degree to which species are anchored in space throughout their life cycle, and the ontogenetic changes of the geographic association. Some of this variability can be explained by the species life history strategy and this provides promising avenues to extend similar analyses to data poor species. The presence of life history spatial constraints, particularly during early life stages, indicates restrictions exist to changes of spatial distribution and thus questions the assertion that global warming will uniformly result in an increase of harvest at higher latitudes and decreases at lower latitudes. Species distribution models are often parameterized from data based on life stages that are highly variable in space, such as the adult stages during summer months which may result in unrealistic forecasts of distribution. Our study develops ecological and analytical insights that are Life History Constraints 3/41 critical for developing accurate projections of species distributions under different climate change scenarios.

Greater exposure of nearshore habitats in the Bering Sea makes fish early life stages vulnerable to climate change

“…For marine fish, behavioral responses can occur when individuals move from less suitable toward more suitable areas. The rate at which these responses occur varies not only across species and marine systems (Cheung et al 2009) but also over life history stages (Ciannelli et al 2022). During ontogenetic development, marine fish species occupy different habitats and exhibit different vulnerabilities to climate change (Petitgas et al 2013).…”

An age‐ and length‐structured statistical catch‐at‐length model for hard‐to‐age fisheries stocks

“…The three-dimensional structure gives ALSCL extra flexibility compared to most existing integrated models that are based on two-dimensional (i.e., age-time or length-time) dynamics. For some species, different age classes may reside in different habitats due to ontogenetic shifts (Ciannelli et al, 2022), which may cause them to be subject to different levels of fishing pressure. Additionally, fish growing to asymptotic size may have different natural mortalities among ages due to senescence.…”

Predicting Pacific cod spawning habitat in a changing climate

“…For example, reductions in the amount of suitable thermal habitat due to warming disproportionately affects Nassau Grouper (Epinephelus striatus) spawners, whose thermal range is narrower than that of nonspawners (Asch & Erisman, 2018). Additionally, compared to other life stages, eggs typically occupy the least amount of habitat area (lowest habitat extent) and have the highest habitat consistency (same locations) over time (Ciannelli et al, 2015(Ciannelli et al, , 2021. In turn, these narrow thermal preferences of spawners and embryos collectively result in spatial or temporal (or both) constraints on spawning habitat, which encompasses the habitat of both eggs and spawners (Ciannelli et al, 2021;Rijnsdorp et al, 2009).…”

“…Additionally, compared to other life stages, eggs typically occupy the least amount of habitat area (lowest habitat extent) and have the highest habitat consistency (same locations) over time (Ciannelli et al, 2015(Ciannelli et al, , 2021. In turn, these narrow thermal preferences of spawners and embryos collectively result in spatial or temporal (or both) constraints on spawning habitat, which encompasses the habitat of both eggs and spawners (Ciannelli et al, 2021;Rijnsdorp et al, 2009). Thus, spawning habitat has been suggested to not only underlie reproductive potential, but also may represent a limit on species' ability to adapt to changing environmental conditions (Ciannelli et al, 2021;Dahlke et al, 2020;Porter & Ciannelli, 2018).…”

“…Thus, spawning habitat has been suggested to not only underlie reproductive potential, but also may represent a limit on species' ability to adapt to changing environmental conditions (Ciannelli et al, 2021;Dahlke et al, 2020;Porter & Ciannelli, 2018). Spawning habitat may even act as a 'thermal bottleneck' that determines species' vulnerability to a changing climate (Asch & Erisman, 2018;Ciannelli et al, 2021;Dahlke et al, 2020). Temperature-driven distributional shifts are linked to changes in population dynamics and fisheries productivity, ecosystem dynamics (e.g., species interactions), and socioeconomic aspects such as increased fishing effort and altered management practices (Cheung et al, 2009;García Molinos et al, 2016;Pinsky, Rogers, et al, 2020;.…”