Batemans Bay Fisheries Center

Batemans Bay, Australia

Batemans Bay Fisheries Center

Batemans Bay, Australia
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Beheregaray L.B.,Flinders University | Pfeiffer L.V.,Flinders University | Attard C.R.M.,Flinders University | Sandoval-Castillo J.,Flinders University | And 6 more authors.
Molecular Phylogenetics and Evolution | Year: 2017

Species range limits often fluctuate in space and time in response to variation in environmental factors and to gradual niche evolution due to changes in adaptive traits. We used genome-wide data to investigate evolutionary divergence and species range limits in a generalist and highly dispersive fish species that shows an unusually wide distribution across arid and semi-arid regions of Australia. We generated ddRAD data (18,979 filtered SNPs and 1.725 million bp of sequences) for samples from 27 localities spanning the native range of golden perch, Macquaria ambigua (Teleostei; Percichthyidae). Our analytical framework uses population genomics to assess connectivity and population structure using model-based and model-free approaches, phylogenetics to clarify evolutionary relationships, and a coalescent-based Bayesian species delimitation method to assess statistical support of inferred species boundaries. Addressing uncertainties regarding range limits and taxonomy is particularly relevant for this iconic Australian species because of the intensive stocking activities undertaken to support its recreational fishery and its predicted range shifts associated with ongoing climate change. Strong population genomic, phylogenetic, and coalescent species delimitation support was obtained for three separately evolving metapopulation lineages, each lineage should be considered a distinct cryptic species of golden perch. Their range limits match the climate-determined boundaries of main river basins, despite the ability of golden perch to cross drainage divides. We also identified cases suggestive of anthropogenic hybridization between lineages due to stocking of this recreationally important fish, as well as a potential hybrid zone with a temporally stable pattern of admixture. Our work informs on the consequences of aridification in the evolution of aquatic organisms, a topic poorly represented in the literature. It also shows that genome-scale data can substantially improve and rectify inferences about taxonomy, hybridization and conservation management previously proposed by detailed genetic studies. © 2017 Elsevier Inc.

Gray C.A.,Cronulla Fisheries Research Center | Gray C.A.,WildFish Research | Gray C.A.,University of New South Wales | Barnes L.M.,Cronulla Fisheries Research Center | And 6 more authors.
Aquatic Biology | Year: 2014

This study examined whether differences existed in the depth distributions and reproductive strategies of the co-occurring Sillago robusta and S. flindersi in coastal waters off eastern Australia. Marked spatial and temporal dis similarities in demography and reproduction were observed between the 2 species, with S. robusta being more abundant in the shallow (15-30 m) strata and S. flindersi in the mid (31-60 m) strata, with neither species being consistently abundant in the deep (61-90 m) strata. The size composition of S. robusta was similar across depths, but smaller and immature S. flindersi predominantly occurred in the shallow strata, with larger and mature individuals occurring deeper. These data indicate partitioning of habitat resources, which may aid species coexistence. Both species potentially spawned year-round, which is probably an adaptation to the region's dynamic coastal environment. However, a greater proportion of S. robustawas in spawning condition between September and March, whereas S. flindersi displayed no such temporal pattern. Maturity ogives differed significantly between sexes and locations for both species. Both species displayed similar ovarian development, with females having multiple concurrent oocyte stages, indicating potential multiple spawning events as evidenced in other Sillaginidae. For both species, estimated batch fecundity increased with fish length, but S. robustahad a greater fecundity at any given length than S. flindersi. In contrast, S. flindersi potentially produced larger-sized eggs and invested greater energy into gonad development than S. robusta, indicating the 2 species have evolved slightly different reproductive strategies. Despite this, both species are subjected to substantial trawl fisheries, which may have already impacted their reproductive ecologies. © The authors 2014.

Gray C.A.,WildFish Research | Gray C.A.,University of New South Wales | Gray C.A.,Sydney Institute of Marine Science | Barnes L.M.,Cardno | And 6 more authors.
Fisheries Science | Year: 2014

This study investigated variability in the growth, length, and age compositions and the rates of mortality of Flinders’ sillago Sillago flindersi exploited in a demersal trawl fishery in eastern Australia. Sampling was done over 2 years across three depth strata at two locations approximately 400 km apart. Ageing of sectioned sagittal otoliths indicated that the observed maximum age of females was 6 years and that of males 5 years, that growth was variable and that the von Bertalanffy growth parameters significantly differed according to gender and location. Females attained a greater L than males, but males displayed greater k values. The L values of both sexes and the mean length-at-age for fish aged 3–5 years were greater at the location of highest latitude. Length and age compositions differed according to depth, with smaller (<15 cm FL) and younger (<2 years) fish generally more predominant in the shallow (<30 m) strata than in the deeper (>31 m) strata. S. flindersi appear to use the shallow strata as a juvenile habitat, moving to deeper waters as they grow. This depth stratification between cohorts may reduce intraspecific competition and could potentially be used as a spatial management tool to reduce any fishing-associated impacts on juveniles. Fish between 1 and 3 years old dominated the age compositions of populations combined across all depths, with estimated total mortality ranging between 2.24 and 2.40. Fishing mortality ranged between 1.54 and 1.70 and was more than twice the derived natural mortality. Exploitation rates were approximately 0.70, indicating that the species was heavily fished. © 2014, Japanese Society of Fisheries Science.

Gannon R.,University of New South Wales | Gannon R.,Sydney Institute of Marine Science | Taylor M.D.,University of New South Wales | Taylor M.D.,Port Stephens Fisheries Institute | And 9 more authors.
Journal of Experimental Biology | Year: 2014

Theoretical and laboratory studies generally show that ectotherm performance increases with temperature to an optimum, and subsequently declines. Several physiological mechanisms probably shape thermal performance curves, but responses of free-ranging animals to temperature variation will represent a compromise between these mechanisms and ecological constraints. Thermal performance data from wild animals balancing physiology and ecology are rare, and this represents a hindrance for predicting population impacts of future temperature change. We used internally implanted accelerometers near the middle of a species' geographical distribution and gill-net catch data near the species' latitudinal extremes to quantify temperature-related activity levels of a wild predatory fish (Platycephalus fuscus). We examined our data in the context of established models of thermal performance, and the relationship between thermal performance thresholds and biogeography. Acceleration data approximated a thermal performance curve, with activity peaking at 23° C but declining rapidly at higher temperatures. Gill-net catch data displayed a similar trend, with a temperature-associated increase and decrease in catch rates in temperate and tropical regions, respectively. Extrapolated estimates of zero activity (CTmin and CTmax) from the accelerometers were similar to the minimum and maximum mean monthly water temperatures experienced at the southern and northern (respectively) limits of the species distribution, consistent with performance-limited biogeography in this species. These data highlight the fundamental influence of temperature on ectotherm performance, and how thermal performance limits may shape biogeography. Biologging approaches are rarely used to examine thermal performance curves in freeranging animals, but these may be central to understanding the tradeoffs between physiology and ecology that constrain species' biogeographies and determine the susceptibility of ectotherms to future increases in temperature. © 2014. Published by The Company of Biologists Ltd.

Payne N.L.,Japan National Institute of Polar Research | Payne N.L.,University of New South Wales | Smith J.A.,University of New South Wales | van der Meulen D.E.,University of New South Wales | And 10 more authors.
Functional Ecology | Year: 2016

1. Temperature strongly regulates the distribution and fitness of ectotherms, and many studies have measured the temperature dependence of physiological performance in controlled laboratory settings. In contrast, little is known about how temperature influences ectotherm performance in the wild, so the ecological significance of physiological performance as measured in the laboratory is unclear. 2. Our aim was to measure the temperature dependence of performance in the wild for several species of fishes and to explore how temperatures that maximize performance in the wild (ToptE) are related to species biogeographies. 3. We gathered body activity and growth data from the wild for nine tropical and temperate fish species, and by fitting thermal performance curves to these data, compared ToptE to species- specific warm range boundary temperatures (the average temperature of the warmest month at equatorward range limits). To explore the degree to which trends in the wild reflect trends in physiological performance measured in the laboratory, we also compiled published data on the temperature dependence of aerobic metabolic scope in fishes and compared these to our wild fish data. 4. We found ToptE in the wild was strongly correlated with warm range boundary temperatures, and that the difference between these two temperatures (the ‘environmental heating tolerance’) was smaller for more-tropical species. Comparison with laboratory data revealed that ToptE approaches warm boundary temperatures in the wild at the same rate that the optimal temperature for aerobic scope (ToptAS) approaches upper critical temperatures (upper Tcrit) for aerobic scope in the laboratory, meaning that environmental heating tolerances in wild fishes closely mirror physiological heating tolerance (i.e. upper Tcrit – ToptAS) in captive fishes. 5. Our comparison of field- and laboratory-derived data highlights the ecological significance of aerobic metabolic scope in fishes and suggests wild fish species tend to perform best near the highest temperatures encountered in their range while maintaining a safety margin from the deleterious effects of upper critical temperatures. © 2015 The Authors.

Stocks J.R.,University of New South Wales | Stocks J.R.,Batemans Bay Fisheries Center | Gray C.A.,University of New South Wales | Gray C.A.,WildFish Research | And 2 more authors.
Journal of Sea Research | Year: 2014

Spatial and temporal variation in the growth of a widely distributed temperate marine herbivore, Girella elevata, was examined using length-at-age data and multi-decadal otolith increment growth chronologies. In total 927 G. elevata were collected from three regions of the Australian south-east coast, extending 780. km and covering the majority of the East Australian Current, a poleward-flowing western boundary current of the Southern Pacific Gyre and climate change hotspot. A validated ageing method using sectioned sagittal otoliths was developed to enumerate both daily (juvenile fish) and annual otolith increments. G. elevata exhibited great longevity with a maximum recorded age of 45. +. yrs. Spatial variation in growth from length-at-age data was observed with the highest growth rates within the centre of the species distribution. Analysis of otolith growth chronologies of 33. yrs showed a positive relationship with the Southern Oscillation Index. Identifying links between life-history characteristics and variation in oceanographic conditions across latitudinal gradients may shed light on potential impacts of expected climate shifts on fish productivity. © 2014 Elsevier B.V.

Stocks J.R.,University of New South Wales | Stocks J.R.,Batemans Bay Fisheries Center | Gray C.A.,University of New South Wales | Gray C.A.,WildFish Research | And 2 more authors.
Journal of Fish Biology | Year: 2015

Latitudinal variation in the reproductive characteristics of a temperate marine herbivore, rock blackfish Girella elevata, was examined from three regions of the south-eastern Australian coast. Biological sampling covered 780 km of coastline, including the majority of the species distribution. The sampling range incorporated three distinct oceanographic regions of the East Australian Current, a poleward-flowing western boundary current of the Southern Pacific Gyre and climate-change hotspot. Girella elevata are a highly fecund, group synchronous (multiple batch)-spawner. Mean fork length (LF) and age at maturity were greater for females than males within all regions, with both male and female G. elevata of the southern region maturing at a greater size and age than those from the central region. Estimates of batch fecundity (FB) were greatest in the northern and southern regions, relative to the central region where growth rates were greatest. Significant positive relationships were observed between FB and LF, and FB and total fish mass. Gonado-somatic indices indicated latitudinal synchrony in spawning seasonality between G. elevata at higher latitudes, spawning in the late austral spring and summer. A late or prolonged spawning period is evident for G. elevata from the northern region. Juvenile recruitment to intertidal rock pools within the central and southern regions was synchronous with the spawning season, however, no juveniles were found within the northern region. The implications of latitudinal variation in reproductive characteristics are discussed in the context of climate and oceanographic conditions of south-east Australia. © 2015 The Fisheries Society of the British Isles.

Taylor M.D.,Port Stephens Fisheries Institute | Taylor M.D.,University of New South Wales | McPhan L.,University of New South Wales | Van Der Meulen D.E.,University of New South Wales | And 3 more authors.
PLoS ONE | Year: 2013

Animal activity patterns evolve as an optimal balance between energy use, energy acquisition, and predation risk, so understanding how animals partition activity relative to extrinsic environmental fluctuations is central to understanding their ecology, biology and physiology. Here we use accelerometry to examine the degree to which activity patterns of an estuarine teleost predator are driven by a series of rhythmic and arrhythmic environmental fluctuations. We implanted free-ranging bream Acanthopagrus australis with acoustic transmitters that measured bi-axial acceleration and pressure (depth), and simultaneously monitored a series of environmental variables (photosynthetically active radiation, tidal height, temperature, turbidity, and lunar phase) for a period of approximately four months. Linear modeling showed an interaction between fish activity, light level and tidal height; with activity rates also negatively correlated with fish depth. These patterns highlight the relatively-complex trade-offs that are required to persist in highly variable environments. This study demonstrates how novel acoustic sensor tags can reveal interactive links between environmental cycles and animal behavior. © 2013 Taylor et al.

Faulks L.K.,Macquarie University | Gilligan D.M.,Batemans Bay Fisheries Center | Beheregaray L.B.,Macquarie University | Beheregaray L.B.,Flinders University
Journal of Biogeography | Year: 2010

Aim: We conducted a range-wide phylogeographic study of a common Australian freshwater fish, the golden perch (Macquaria ambigua), to investigate the relationship between environmental processes and evolutionary history in drainage basins. Location: Inland [Lake Eyre (LEB), Murray-Darling (MDB) and Bulloo (BULL)] and coastal basins [Fitzroy (FITZ)] of eastern Australia. Methods: A total of 590 samples were collected from across the entire species' distribution and a section of the mitochondrial DNA control region was sequenced. In order to reconstruct the evolutionary history of M. ambigua a comprehensive suite of phylogeographic analyses was conducted, including nested clade phylogeographic analysis, mismatch analysis and isolation-with-migration model simulations. Results: Three major lineages corresponding to the major drainage basins, FITZ, MDB and LEB/BULL, were identified (φST = 0.92). Lineages from the coastal basin (FITZ) were highly divergent from those of the inland basins (up to 6%). Levels of genetic diversity in the inland basins were relatively low and our analyses indicate that these populations experienced both demographic and range expansions during the Pleistocene. Main conclusions: Investigation of the range-wide phylogeography of M. ambigua has revealed new insights into the biogeography of the Australian arid zone, particularly with regard to evolutionary events chronologically associated with cyclical moist and dry conditions. We propose that M. ambigua originated on the east coast (FITZ) and crossed a major geographic barrier, the Great Dividing Range (GDR), to colonize the inland basins (MDB, LEB and BULL). We infer a series of demographic and range expansion events for M. ambigua consistent with a scenario of moister Pleistocene conditions and increased connectivity of freshwater environments, both within and among drainage basins. Major lineages then diversified following isolation of freshwater environments under increasingly arid climate conditions. We suggest that management priorities for M. ambigua should include the resolution of taxonomic uncertainties and the maintenance of genetic diversity of both stocked populations in the MDB and native populations of the LEB that may be at risk of further isolation and reduced gene flow due to increased aridification under future climate change scenarios. © 2010 Blackwell Publishing Ltd.

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