Abstract
Water development threatens rivers and their biodiversity. Amphidromous shrimp are particularly vulnerable as they require migration between freshwater and estuaries to complete their life cycle. The Fitzroy River is a large tropical intermittent river undergoing water development that is home to the amphidromous shrimp Macrobrachium spinipes (cherabin), yet little is known about its habitat use and flow-ecology making it difficult to inform sustainable water-take. We investigated habitat associations, distributional patterns suggestive of amphidromy, and the influence of water availability by sampling main channel and floodplain pools along a 350-km river length during 2 contrasting flow years. Applying a size-specific abundance model, we estimated abundance per size class, site, and year. We then predicted abundance at the landscape scale with remotely sensed water to reveal the impact of water availability on the meta-population. Our model revealed that juveniles were in greatest abundance in downstream main channel pools, whereas adults were in greatest abundance in upstream floodplain pools. Abundance varied by year with lower numbers predicted in the low-flow year. Longitudinal and habitat patterns remained when our pool-level results were scaled to the landscape, and the positive relationship of abundance to wet-season flow was strengthened. The predominance of smaller cherabin in the lower reaches of the river provides indirect support for an estuarine nursery and amphidromous life history; however, small individuals observed in landlocked pools, during late dry season suggests possible within-river recruitment. The importance of water development policies that protect wet-season flow and passage along the Fitzroy River is supported by this work. These types of policies are likely to be important for this and other amphidromous shrimp species across Australia, Southeast Asia and further afield. Further research detailing the species life history and describing flow–recruitment relationships will be important contributions to understanding this important taxonomic group and refining policies for current and future water resource development.
| Original language | English |
|---|---|
| Pages (from-to) | 61-76 |
| Number of pages | 16 |
| Journal | Freshwater Biology |
| Volume | 68 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 2023 |
Bibliographical note
Funding Information:This project was supported through funding from the Australian Government's National Environmental Science Program through the Northern Australia Environmental Resources Hub.
Funding Information:
We gratefully acknowledge the Traditional Owners of the country on which this work was undertaken, recognise their continuing connection to land, waters and culture, and pay our respects to Elders, past, present and emerging. We thank the Walalakoo, Yanunijarra, Gooniyandi and Yungngora Prescribed Bodies Corporates for providing us with permission to undertake research on their country. We thank Traditional Owners and Indigenous Rangers for accompanying us on country, assisting with data collection and sharing knowledge about the land. We acknowledge the assistance of the Kimberley Land Council in project facilitation, particularly Karen Dayman. We thank the pastoral managers of Jubilee Downs, Myroodah, Mount Anderson, Millijidee, Noonkanbah, and Gogo Stations for their cooperation. We thank the Department of Biodiversity, Conservation and Attractions, and the Department of Primary Industries and Regional Development for equipment storage and thank Mark De Bruyn (University of Sydney) and Helix Molecular Solutions for genetic analysis of juvenile cherabin. Research was carried out under Fisheries exemptions #191-2009-27 and 2974, and The University of Western Australia's Animal Ethics permits RA/3/100/884 and RA/3/100/1536 (Animal Ethics Committee, The University of Western Australia). All researchers conducting field work had a valid Permission to Use Animals (PUA) licence to use animals for scientific purposes as per the Animal Welfare Act 2002 (Western Australia). All field procedures were performed in accordance with relevant guidelines and regulations. Feedback from 2 anonymous reviewers improved on earlier versions of this paper. Open access publishing facilitated by The University of Western Australia, as part of the Wiley - The University of Western Australia agreement via the Council of Australian University Librarians.
Publisher Copyright:
© 2022 The Authors. Freshwater Biology published by John Wiley & Sons Ltd.
