Data for: Coherent long-term body-size responses across all Northwest Atlantic herring populations to warming and environmental change despite contrasting harvest and ecological factors
Data files
Feb 16, 2024 version files 63.37 KB
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combined.full.plus.RDS
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dfa4_mod1_fits.RDS
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dfa4_mod2_fits.RDS
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laa4.tmean.df.RDS
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nls.params24.RDS
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README.md
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resdat4.RDS
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SSB.df2.RDS
Abstract
Body size is a key component of individual fitness and an important factor in the structure and functioning of populations and ecosystems. Disentangling the effects of environmental change, harvest, and intra- and inter-specific trophic effects on body size remains challenging for populations in the wild. Herring in the Northwest Atlantic provide a strong basis for evaluating hypotheses related to these drivers given that they have experienced significant warming and harvest over the past century, while also having been exposed to a wide range of other selective constraints across their range. Using data on mean length-at-age 4 for the sixteen principal populations over a period of 53 cohorts (1962-2014), we fitted a series of empirical models for temporal and between-population variation in the response to changes in sea surface temperature. We find evidence for a unified cross-population response in the form of a parabolic function according to which populations in naturally warmer environments have responded more negatively to increasing temperature compared with those in colder locations. Temporal variation in residuals from this function was highly coherent among populations, further suggesting a common response to a large-scale environmental driver. The synchrony observed in this study system, despite strong differences in harvest and ecological histories among populations and over time, clearly indicates a dominant role of environmental change on size-at-age in wild populations, in contrast to commonly reported effects of fishing. This finding has important implications for the management of fisheries as it indicates that a key trait associated with population productivity may be under considerably less short-term management control than currently assumed. Our study, overall, illustrates the need for a comparative approach within species for inferences concerning the many possible effects on body size of natural and anthropogenic drivers in the wild.
README: Data for Coherent long-term body-size responses across all Northwest Atlantic herring populations to warming and environmental change despite contrasting harvest and ecological factors
https://doi.org/10.5061/dryad.c866t1gdx
This Dryad data submission includes datasets needed for the analysis in Coherent long-term body-size responses across all Northwest Atlantic herring populations to warming and environmental change despite contrasting harvest and ecological factors. The information needed to reproduce the analysis is given in the article's main text as well as in the Supplementary Information file.
Description of the data and file structure
laa4.tmean.df:
- stock: population identity (see names in Figure 2)
- cohort: birth year (here, corresponding to year-age = year-4 years old)
- year: year of capture
- location: location for temperature series (see Figure 2a)
- mlen: mean length-at-age (mm)
- mean_temp: mean temperature in the year of capture
- tmean: corresponds to lifetime SST (see Methods)
- colgrad: hexacode for figures which include a fill gradient by cohort
combined.full.plus: as in laa4.tmean.df
nls.params.24:
- model: corresponds to the model variant in Table 2
- mt: corresponds to the mean lifetime SST over the 1962-2014 period (see x-axis in Figure 4)
- k, ymax, topt: estimated model parameters (obtained from R's nls function)
- k.se,ymax.se,topt.se: estimated standard errors for model parameters (obtained from R's nls function)
resdat4:
- rows: each of the 16 stocks
- cols: each of the 53 cohorts
- values: standardized residuals (see Methods subsection 2.4)
dfa4_mod1_fits, dfa4_mod2_fits:
- rows, cols: as in resdat4
- values: model fits from the one-trend and two-trend DFA analyses
SSB.df2:
stock, cohort: as in laa4.tmean.df
age: corresponds to the age classes accounted for by mean.ssb
year: corresponds to the year of SSB (as reported in the reference variable)
SSB: spawning stock biomass (t) for the stock in the year of assessment
reference: origin of the data values
location: location of data within the specified reference
mean.ssb: mean SSB since birth (corresponds to lifetime SSB_agegroups in Figure 6)
Sharing/Access information
The DOI of the article to which these data are related is: 10.1111/gcb.17187
Methods
See Methods section in: Coherent long-term body-size responses across all Northwest Atlantic herring populations to warming and environmental change despite contrasting harvest and ecological factors.