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Context: Successful fish stocking relies upon releasing cohorts directly into habitat containing suitable supporting resources. To facilitate this, an emerging trend has seen fish released onto artificial reefs. Aims: We compared the residency and movement patterns of juvenile sparids (yellowfin bream – Acanthopagrus australis), stocked on artificial reefs and natural habitat, to determine the suitability of incorporating artificial structures as release sites in future stocking programs. Methods: Forty hatchery-reared yellowfin bream were evenly divided and stocked on either artificial reef or natural habitat within an east-Australian estuary, and tracked using acoustic telemetry. Key results: Artificial reefs provided greater habitat complexity than the natural habitat and fish stocked onto these structures showed greater fidelity to their release site and were detected for longer periods of time than those stocked into less complex natural habitat. Conclusions: The high residency levels of fish around artificial reef sites indicate they contain resources to support stocked juvenile sparids. Implications: Stocked yellowfin bream can tolerate a range of salinity and temperatures, allowing flexibility in stocking programs. Future stocking of bream or other sparids should consider releasing fish onto artificial reefs where available. Additionally, the deployment of reefs could aid existing stocking programs. Successful fish stocking relies upon releasing cohorts directly into habitat containing suitable supporting resources. We compared residency and movement patterns of juvenile yellowfin bream stocked on artificial reefs and less complex natural habitat. Fish stocked on artificial reefs showed greater fidelity to their release site and were detected for longer periods. Future stocking of bream or other sparids should consider releasing fish onto artificial reefs, with benefits these structures provide likely to be greater for estuaries lacking naturally complex habitats. [ABSTRACT FROM AUTHOR]

Context: Researchers studying animals need to ensure that sampling procedures and the methods they use are as harmless and non-disruptive as possible, particularly when their focal species are threatened or protected. White sharks (Carcharodon carcharias) are Vulnerable under the IUCN Red List, protected globally, and are frequently studied by marine ecologists. Aims: To assess white shark responses to research activities (i.e. tagging and biopsy procedures, and electric deterrent trials) conducted at the Neptune Islands Group Marine Park (South Australia, Australia). Methods: Trends in shark residency following research activities were assessed by comparing shark abundance (number of sharks detected by acoustic receivers and sighted by cage-diving operators) before, during, and after scientific expeditions, and to natural fluctuations in the absence of research activities using 8 years (2013–2021) of acoustic tracking and daily sighting reports from a wildlife tourism industry. Key results: Number of white sharks and residency decreased after sampling. However, changes observed following research activities were similar to natural fluctuations, suggesting that these changes reflected natural variations rather than being due to sharks responding negatively to the research activities. Conclusions: Our study showed that external tagging, biopsies, or deterrent trials do not affect short- and long-term residency or abundance of white sharks, probably owing to the research activities being minimally intrusive and to sharks having efficient immune systems and remarkable ability to heal from injuries. Implications: Re-evaluating study methods forms part of the researcher's responsibilities to ensure best practice and to abide by national and international codes for the care and use of animals for scientific purposes. Researchers studying animals, particularly threatened or protected species, must ensure their activities are as harmless and non-disruptive as possible. We evaluated changes in white shark residency following three types of research activities and found evidence that none of them might have negatively affected these animals. Similar assessments should be performed when working with other species to ensure best practice and abide by codes for the care and use of animals. Photograph by Andrew Fox. [ABSTRACT FROM AUTHOR]