Abstract
River sharks (Glyphis spp.) and some sawfishes (Pristidae) inhabit riverine environments, although their long-term habitat use patterns are poorly known. We investigated the diadromous movements of the northern river shark (Glyphis garricki), speartooth shark (Glyphis glyphis), narrow sawfish (Anoxypristis cuspidata), and largetooth sawfish (Pristis pristis) using in situ laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) on vertebrae to recover elemental ratios over each individual's lifetime. We also measured elemental ratios for the bull shark (Carcharhinus leucas) and a range of inshore and offshore stenohaline marine species to assist in interpretation of results. Barium (Ba) was found to be an effective indicator of freshwater use, whereas lithium (Li) and strontium (Sr) were effective indicators of marine water use. The relationships between Ba and Li and Ba and Sr were negatively correlated, whereas the relationship between Li and Sr was positively correlated. Both river shark species had elemental signatures indicative of prolonged use of upper-estuarine environments, whereas adults appear to mainly use lower-estuarine environments rather than marine environments. Decreases in Li:Ba and Sr:Ba at the end of the prenatal growth zone of P. pristis samples indicated that parturition likely occurs in fresh water. There was limited evidence of prolonged riverine habitat use for A. cuspidata. The results of this study support elemental–environment relationships observed in teleost otoliths and indicate that in situ LA-ICP-MS elemental characterization is applicable to a wide range of elasmobranch species as a discriminator for use and movement across salinity gradients. A greater understanding of processes that lead to element incorporation in vertebrae, and relative concentrations in vertebrae with respect to the ambient environment, will improve the applicability of elemental analysis to understand movements across the life history of elasmobranchs into the future.
| Original language | English |
|---|---|
| Pages (from-to) | 1357-1373 |
| Number of pages | 17 |
| Journal | Journal of Fish Biology |
| Volume | 103 |
| Issue number | 6 |
| Early online date | 2023 |
| DOIs | |
| Publication status | Published - Dec 2023 |
Bibliographical note
Funding Information:The authors thank the Save Our Seas Foundation (Keystone Project 388) and James Cook University (CRT grant) for funding this study. Australian samples were collected during work undertaken for the Marine Biodiversity Hub, a collaborative partnership supported through funding from the Australian Government's National Environmental Science Program. They thank all traditional owners, researchers, and field assistants involved and Christy-Louise Davies for assistance in vertebral preparation. Papua New Guinea samples from the Kikori River were collected through the Piku Biodiversity Network, and the authors thank Goare Village for their assistance during fieldwork, Obiri Bottu, Nagai Thomas, Aikaru Ba′au, Baibai, Max Aimari, Kenneth Korokai, and Councilor Buara Esege. Samples from the Sepik River were collected in collaboration with the National Fisheries Authority and University of Papua New Guinea, and the authors thank Jerry from Kopar Village and Nigel Mapmani, Ralph Mana, Jerry Mana, and Paul Apia for assistance in fieldwork. They also thank Jonathan Smart and project members of the Australian Centre for International Agricultural Research project (FIS/2012/102), in which some samples used in the present study were obtained. Australian P. pristis samples were obtained from Charles Darwin University (CDU) in collaboration with the Malak Malak Ranger Group under NT Fisheries Special Permit S17/3252 and Charles Darwin University Animal Ethics Committee A11041. Australian G. glyphis samples from the Adelaide River were collected with approval from the Charles Darwin University Animal Ethics Committee (approval numbers A11041 and A19008) and undertaken through Northern Territory Fisheries Act Special Permits S17/3364 and S17/3467. Samples from Papua New Guinea were collected with permission from traditional landowners and imported to James Cook University under BIOCON permits 0002424804 and 0004378941 issued by the Department of Agriculture, Water, and Environment. Sawfish specimens were imported under the Convention on International Trade in Endangered Species of Wild Flora and Fauna permit PWS2018-AU-002319. Open access publishing facilitated by James Cook University, as part of the Wiley - James Cook University agreement via the Council of Australian University Librarians.
Funding Information:
The authors thank the Save Our Seas Foundation (Keystone Project 388) and James Cook University (CRT grant) for funding this study. Australian samples were collected during work undertaken for the Marine Biodiversity Hub, a collaborative partnership supported through funding from the Australian Government's National Environmental Science Program. They thank all traditional owners, researchers, and field assistants involved and Christy‐Louise Davies for assistance in vertebral preparation. Papua New Guinea samples from the Kikori River were collected through the Piku Biodiversity Network, and the authors thank Goare Village for their assistance during fieldwork, Obiri Bottu, Nagai Thomas, Aikaru Ba′au, Baibai, Max Aimari, Kenneth Korokai, and Councilor Buara Esege. Samples from the Sepik River were collected in collaboration with the National Fisheries Authority and University of Papua New Guinea, and the authors thank Jerry from Kopar Village and Nigel Mapmani, Ralph Mana, Jerry Mana, and Paul Apia for assistance in fieldwork. They also thank Jonathan Smart and project members of the Australian Centre for International Agricultural Research project (FIS/2012/102), in which some samples used in the present study were obtained. Australian samples were obtained from Charles Darwin University (CDU) in collaboration with the Malak Malak Ranger Group under NT Fisheries Special Permit S17/3252 and Charles Darwin University Animal Ethics Committee A11041. Australian samples from the Adelaide River were collected with approval from the Charles Darwin University Animal Ethics Committee (approval numbers A11041 and A19008) and undertaken through Northern Territory Fisheries Act Special Permits S17/3364 and S17/3467. Samples from Papua New Guinea were collected with permission from traditional landowners and imported to James Cook University under BIOCON permits 0002424804 and 0004378941 issued by the Department of Agriculture, Water, and Environment. Sawfish specimens were imported under the Convention on International Trade in Endangered Species of Wild Flora and Fauna permit PWS2018‐AU‐002319. Open access publishing facilitated by James Cook University, as part of the Wiley ‐ James Cook University agreement via the Council of Australian University Librarians. P. pristis G. glyphis
Funding Information:
This study was funded by the Save Our Seas Foundation (Keystone Grant 388) and James Cook University.
Publisher Copyright:
© 2023 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.