This repository contains code and data to reproduce the figures in the supplementary materials of Sydeman et al. (2021) in ICES Journal of Marine Science (https://doi.org/10.1093/icesjms/fsab231). The data are measures of African penguin (Spheniscus demersus) chick survival and chick condition collected at Robben and Dassen Islands (Western Cape, South Africa) as part of the Island Closures Experiment between 2008 and 2018.
The annual estimates of chick survival were dervied by Mike Bergh (OLSPS Marine, Cape Town, South Africa) from data supplied to the Small Pelagic Working Group of the Department of Forestry, Fisheries and the Environment by Richard B. Sherley (University of Exeter) and numerous collaborators. You are free to use the data, and they appear in the public domain in Appendix B of Ross-Gilespie and Butterworth (2021) and in the Supplementary materials of Sydeman et al. (2021). However, when using the data please cite OLSPS Marine (2020) and Sydeman et al. (2021) as Ross-Gilespie and Butterworth (2021) neither collected the data nor generated the estimates. For information on how the data were collected, please see Sherley et al. (2015, 2018) and cite these papers for that methodology.
The individual chick condition measurements were collected by Richard B. Sherley (University of Exeter) and numerous collaborators including scientists from Oceans and Coasts Branch of the Department of Forestry, Fisheries and the Environment, CapeNature (South Africa), the University of Bristol, the University of the Western Cape, BirdLife South Africa, and the University of Cape Town. The data between 2008 and 2015 were used in Sherley et al. (2018) and were deposited in Dryad (https://datadryad.org/stash/dataset/doi:10.5061/dryad.d4977). The data for 2016–2018 have not been published previously. You are free to use the data, but please cite Sherley et al. (2018) and Sydeman et al. (2021) if you do so. For information on how the data were collected, please see Sherley et al. (2018) and Campbell et al. (2019), and for information on how the chick condition index is calculated please see Lubbe et al. (2014). Please cite these papers for those methodological details.
References:
Campbell, K. J., Steinfurth, A., Underhill, L. G., Coetzee, J. C., Dyer, B. M., Ludynia, K., Makhado, A. B., Merkle, D., Rademan, J., Upfold, L., and Sherley RB. 2019. Local forage fish abundance influences foraging effort and offspring condition in an Endangered marine predator. Journal of Applied Ecology, 56: 1751–1760.
Lubbe, A., Underhill, L. G., Waller, L. J., Veen, J. 2014. A condition index for African penguin Spheniscus demersus chicks. African Journal of Marine Science, 36: 143–154.
OLSPS Marine. 2020. A simple restructuring of penguin chick survival data to estimate survivorship at Dassen and Robben Islands. Department of Forestry, Fisheries and the Environment Report FISHERIES/2020/JAN/SWG-PEL/06 3 pp.
Ross-Gillespie, A., and Butterworth, D. S. 2021. Updated analysis of results from data arising from the Island Closure Experiment. Department of Forestry, Fisheries and the Environment Report: FISHERIES/2021/JUN/SWG-PEL/39rev. 1–15 pp. (available at https://zivahub.uct.ac.za/articles/report/Updated_analysis_of_results_from_data_arising_from_the_Island_Closure_Experiment/15073404)
Sherley, R. B., Winker, H., Altwegg, R., van der Lingen, C. D., Votier, S. C., and Crawford, R. J. M. 2015. Bottom-up effects of a no-take zone on endangered penguin demographics. Biology Letters, 11: 20150237.
Sherley, R. B., Barham, B. J., Barham, P. J., Campbell, K. J., Crawford, R. J. M., Grigg, J., Horswill, C., McInnes, A., Morris, T. L., Pichegru, L., Steinfurth, A., Weller, F., Winker, H., and Votier, S. C. 2018. Bayesian inference reveals positive but subtle effects of experimental fishery closures on marine predator demographics. Proceedings of the Royal Society B-Biological Sciences, 285: 20172443.
Sydeman, W. J., Hunt, G. L., Pikitch, E. K., Parrish, J. K., Piatt, J. F., Boersma, P. D., Kaufman, L., Anderson, D. W., Thompson, S. A., and Sherley, R. B. 2021. South Africa’s fisheries closures and recovery of the endangered African penguin. ICES Journal of Marine Science, 78: 3538–3543. https://doi.org/10.1093/icesjms/fsab231.