title: Long-term patterns in estuarine fish growth across two climatically divergent regions.
abstract: Long-term ecological datasets are vital for investigating how species respond to changes in their environment, yet there is a critical lack of such datasets from aquatic systems. We developed otolith growth 'chronologies' to reconstruct the growth history of a temperate estuarine fish species, black bream (Acanthopagrus butcheri). Chronologies represented two regions in south-east Australia: South Australia, characterised by a relatively warm, dry climate, and Tasmania, characterised by a relatively cool, wet climate. Using a mixed modelling approach, we related inter-annual growth variation to air temperature, rainfall, freshwater inflow (South Australia only), and El Niño-Southern Oscillation events. Otolith chronologies provided a continuous record of growth over a 13- and 21-year period for fish from South Australia and Tasmania, respectively. Even though fish from Tasmania were sourced across multiple estuaries, they showed higher levels of growth synchronicity across years, and greater year-to-year growth variation, than fish from South Australia, which were sourced from a single, large estuary. Growth in Tasmanian fish declined markedly over the time period studied and was negatively correlated to temperature. In contrast, growth in South Australian fish was positively correlated to both temperature and rainfall. The stark contrast between the two regions suggests that Tasmanian black bream populations are more responsive to regional scale environmental variation and may be more vulnerable to global warming. This study highlights the importance of examining species response to climate change at the intra-specific level and further validates the emerging use of growth chronologies for generating long-term ecological data in aquatic systems.
authors.affiliation: Southern Seas Ecology Laboratories and The Environment Institute, School of Biological Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia. zoe.doubleday@adelaide.edu.au.
authors.forename: Zoë A
authors.initials: ZA
authors.lastname: Doubleday
authors.affiliation: Southern Seas Ecology Laboratories and The Environment Institute, School of Biological Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Izzo
authors.affiliation: Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Locked Bag 1370, Launceston, TAS, Australia.
authors.forename: James A
authors.initials: JA
authors.lastname: Haddy
authors.affiliation: Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 49, Hobart, TAS, 7001, Australia.
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Lyle
authors.affiliation: South Australian Research and Development Institute (Aquatic Sciences), West Beach, SA, 5024, Australia.
authors.forename: Qifeng
authors.initials: Q
authors.lastname: Ye
authors.affiliation: Southern Seas Ecology Laboratories and The Environment Institute, School of Biological Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia.
authors.forename: Bronwyn M
authors.initials: BM
authors.lastname: Gillanders
mesh_terms: D000818:Animals; D002980:Climate; D057231:Climate Change; D004463:Ecology; D059000:El Nino-Southern Oscillation; D004777:Environment; D063366:Estuaries; D005618:Fresh Water; D010037:Otolithic Membrane / Q000254:growth & development; D010473:Perciformes / Q000254:growth & development / Q000502:physiology*; D011891:Rain; D012623:Seawater; D013021:South Australia; D013648:Tasmania; D013696:Temperature
keywords: Climate change; Growth history; Otolith chronology; Southeast Australia