Abstract
Many ray species are threatened with extinction, and so understanding their movement and habitat use is vital for developing effective management and conservation efforts. Globally, rays are known to rely on estuarine habitats, but estuary use by rays has not yet been investigated in South Africa. Thirty-three diamond rays Gymnura natalensis and 25 bull rays Aetomylaeus bovinus, both species anecdotally recorded to occur in estuaries, were acoustically tagged. Individuals were tracked using a nation-wide network of receivers in South Africa, the Acoustic Tracking Array Platform (ATAP), that has acoustic receivers in both marine and estuarine environments. Only six rays (4 diamond and 2 bull rays) were recorded using estuaries, but they displayed seasonal philopatry, returning to specific estuaries during spring to autumn months (September to May) for up to 6 consecutive years. Due to a number of rays entering the Breede Estuary, the fine-scale habitat use in this ecosystem was investigated. Marine-estuarine connectivity was significantly influenced by marine temperatures. Additionally, presence in the upper parts of the Breede Estuary (up to 17 km from the mouth) was influenced by temperature, tides and time of day. Findings suggest estuaries are an important, and previously overlooked, habitat type for a portion of the diamond and bull ray populations on the south coast of South Africa, which has management and conservation implications.
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Data Availability
The datasets created and/or analysed during the current study are available from the corresponding author upon reasonable request.
References
Beck, M., K. Heck, K. Able, et al. 2001. The identification, conservation, and management of estuarine and marine nurseries for fish and invertebrates. Bioscience 51: 633–641.
Brinton, C., and M. Curran. 2017. Tidal and diel movement patterns of the Atlantic stingray (Dasyatis sabina) along a stream-order gradient. Marine and Freshwater Research 68: 1716–1725.
Collins, A.B., M.R. Heupel, and C.A. Simpfendorfer. 2008. Spatial distribution and long-term movement patterns of cownose rays Rhinoptera bonasus within an estuarine river. Estuaries and Coasts 31: 1174–1183. https://doi.org/10.1007/s12237-008-9100-5, passive tracking. Read for tracking analyses.
Cowley, P.D., R.H. Bennett, A.R. Childs, et al. 2017. Reflection on the first five years of south Africa’s Acoustic Tracking Array Platform (ATAP): status, challenges and opportunities. African Journal of Marine Science 39: 363–372. https://doi.org/10.2989/1814232X.2017.1399927.
Daly, R., G. Jordaan, D. Parker, et al. 2022. Movement patterns and catch trends of the diamond ray Gymnura natalensis (Dasyatidae) in South African waters. African Journal of Marine Science 44: 35–48. https://doi.org/10.2989/1814232x.2022.2032826.
Davy, L.E., C.A. Simpfendorfer, and M.R. Heupel. 2015. Movement patterns and habitat use of juvenile mangrove whiprays (Himantura granulata). Marine and Freshwater Research 66: 481. https://doi.org/10.1071/MF14028.
Dulvy, N.K., N. Pacoureau, C.L. Rigby, et al. 2021. Overfishing drives over one-third of all sharks and rays toward a global extinction crisis. Current Biology 31: 4773-4787.e8. https://doi.org/10.1016/j.cub.2021.08.062.
Elston, C., P.D. Cowley, R.G.V. Brandis, et al. 2021. Residency and habitat use patterns by sympatric stingrays at a remote atoll in the Western Indian Ocean. Marine Ecology Progress Series 662: 97–114. https://doi.org/10.3354/meps13632.
Elston, C., P.D. Cowley, R.G. von Brandis, et al. 2022. Stingray habitat use is dynamically influenced by temperature and tides. Frontiers in Marine Science 8. https://doi.org/10.3389/fmars.2021.754404.
Farrugia, T.J., M. Espinoza, and C.G. Lowe. 2011. Abundance, habitat use and movement patterns of the shovelnose guitarfish (Rhinobatos productus) in a restored southern California estuary. Marine and Freshwater Research 62: 648–657. https://doi.org/10.1071/MF10173.
Flowers, K.I., M.J. Ajemian, K. Bassos-Hull, et al. 2016. A review of batoid philopatry, with implications for future research and population management. Marine Ecology Progress Series 562: 251–261. https://doi.org/10.3354/meps11963.
Hamilton, B., C. Peterson, A. Dawdy, et al. 2022. Environmental correlates of elasmobranch and large fish distribution in a river-dominated estuary. Marine Ecology Progress Series 688: 83–98. https://doi.org/10.3354/meps14019.
HaskoningDHV, R. 2016. Breede River Estuarine Management Plan.
Jabado, R., E. Chartrain, G. Cliff, et al. 2021. Aetomylaeus bovinus.
Jirik, K.E., and C.G. Lowe. 2012. An elasmobranch maternity ward: female round stingrays Urobatis halleri use warm, restored estuarine habitat during gestation. Journal of Fish Biology 80:1227–1245. https://doi.org/10.1111/j.1095-8649.2011.03208.x, active and passive tracking (linear array). Read for analyses.
Last, P., G. Naylor, B. Séret, et al. (eds). 2016. Rays of the world. CSIRO.
Marcotte, M.M. 2014. Homing in the New Zealand eagle ray, Myliobatis tenuicaudatus. Marine and Freshwater Research 65: 306–311. https://doi.org/10.1071/MF12288.
Martins, A.P.B., M.R. Heupel, S.L. Bierwagen, et al. 2020. Diurnal activity patterns and habitat use of juvenile Pastinachus ater in a coral reef flat environment. PLOS ONE 15 (e0228): 280. https://doi.org/10.1371/journal.pone.0228280.
Matern, S.A., J.J. Cech, and T.E. Hopkins. 2000. Diel movements of bat rays, Myliobatis californica, in Tomales Bay, California: evidence for behavioral thermoregulation? Environmental Biology of Fishes 58:173–182. Active tracking.
McCord, M.E., and S.J. Lamberth. 2009. Catching and tracking the world’s largest Zambezi (bull) shark Carcharhinus leucas in the Breede Estuary, South Africa: the first 43 hours. African Journal of Marine Science 31: 107–111. https://doi.org/10.2989/AJMS.2009.31.1.11.782.
Murray, T.S., P.D. Cowley, R.H. Bennett, et al. 2018. Fish on the move: connectivity of an estuary-dependent fishery species evaluated using a large-scale acoustic telemetry array. Canadian Journal of Fisheries and Aquatic Sciences 75: 2038–2052.
Murray, T.S., C. Elston, M.C. Parkinson, et al. 2022. A decade of South Africa’s acoustic tracking array platform: an example of a successful ocean stewardship programme. Frontiers in Marine Science 9: 1–18. https://doi.org/10.3389/fmars.2022.886554.
Ogburn, M.B., C.W. Bangley, R. Aguilar, et al. 2018. Migratory connectivity and philopatry of cownose rays Rhinoptera bonasus along the Atlantic coast, USA. Marine Ecology Progress Series 602: 197–211. https://doi.org/10.3354/meps12686.
Pillans, R.D., G.C. Fry, A.D. Steven, et al. 2020. Environmental influences on long-term movement patterns of a euryhaline elasmobranch (Carcharhinus leucas) within a subtropical estuary. Estuaries and Coasts 43: 2152–2169. https://doi.org/10.1007/s12237-020-00755-8.
Pini-Fitzsimmons, J., N.A. Knott, and C. Brown. 2018. Effects of food provisioning on site use in the short-tail stingray Bathytoshia brevicaudata. Marine Ecology Progress Series 600: 99–110. https://doi.org/10.3354/meps12661.
Pollom, R., R. Bennett, C.D. Silva, et al. 2020. Dasyatis chrysonota, the IUCN red list of threatened species.
Ramsden, S., C.F. Cotton, and M.C. Curran. 2016. Using acoustic telemetry to assess patterns in the seasonal residency of the Atlantic stingray Dasyatis sabina. Environmental Biology of Fishes. https://doi.org/10.1007/s10641-016-0498-5.
R Core Team, R. 2020. R: a language and environment for statistical computing. https://www.r-project.org/.
Simpfendorfer, C.A., M.R. Heupel, W.T. White, et al. 2011. The importance of research and public opinion to conservation management of sharks and rays: a synthesis. Marine and Freshwater Research 62: 518–527. https://doi.org/10.1071/MF11086.
van Niekerk, L., J.B. Adams, N.C. James, S.J. Lamberth, C.F. MacKay, J.K. Turpie, A. Rajkaran, S.P. Weerts, and A.K. Whitfield. 2020. An estuary ecosystem classification that encompasses biogeography and a high diversity of types in support of protection and management. African Journal of Aquatic Science 45 (1–2): 199–216. https://doi.org/10.2989/16085914.2019.1685934.
Whitfield, A.K. 1992. A characterization of Southern African estuarine systems. Southern African Journal of Aquatic Sciences 18: 89–103. https://doi.org/10.1080/10183469.1992.9631327.
Acknowledgements
The Acoustic Tracking Array Platform (ATAP) is hosted by the National Research Foundation-South African Institute for Aquatic Biodiversity (NRF-SAIAB); the Ocean Tracking Network (OTN) in Dalhousie University, Canada; the Department of Science and Innovation-Shallow Marine and Coastal Research Infrastructure (DSI-SMCRI) programme; and the National Research Foundation-South African Environmental Observation Network Elwandle Node (NRF-SAEON Elwandle Node). These organisations are thanked for providing acoustic telemetry hardware that facilitated data collection for this study. Furthermore, the Save Our Seas Foundation (SOSF) and the African Coelacanth Ecosystem Programme (ACEP) are acknowledged for funding to maintain the national ATAP. The authors gratefully acknowledge the ATAP partners who assist in the deployment and maintenance of the ATAP receiver array. We also would like to thank those who assisted in the capture and tagging of the diamond and bull rays, including the South African Shore Angling Association anglers.
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JF, MP and TM contributed towards data collection. CE performed data analyses and wrote the first draft of the manuscript. JF, MP and TM edited the manuscript.
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The tagging and monitoring of animals was approved by the South African Institute for Aquatic Biodiversity Animal Ethics Committee (number 2017-07).
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Communicated by Paul A. Montagna.
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Elston, C., Murray, T.S., Parkinson, M.C. et al. Female Diamond Rays Gymnura natalensis and Bull Rays Aetomylaeus bovinus Display Seasonal Philopatry to South African Estuaries. Estuaries and Coasts 46, 1880–1894 (2023). https://doi.org/10.1007/s12237-023-01239-1
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DOI: https://doi.org/10.1007/s12237-023-01239-1