26 results on '"Figueira W"'
Search Results
2. Marine infrastructure supports abundant, diverse fish assemblages at the expense of beta diversity
- Author
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Porter, A. G., Ferrari, R. L., Kelaher, B. P., Smith, S. D. A., Coleman, R. A., Byrne, M., and Figueira, W.
- Published
- 2018
- Full Text
- View/download PDF
3. Engaging Recreational Fishers in Management and Conservation: Global Case Studies
- Author
-
Granek, E. F., Madin, E. M. P., Brown, M. A., Figueira, W., Cameron, D. S., Hogan, Z., Kristianson, G., de Villiers, P., Williams, J. E., Post, J., Zahn, S., and Arlinghaus, R.
- Published
- 2008
- Full Text
- View/download PDF
4. Complex habitats may not always benefit prey : linking visual field with reef fish behavior and distribution
- Author
-
Rilov, G., Figueira, W. F., Lyman, S. J., and Crowder, L. B.
- Published
- 2007
5. Risk balancing through selective use of social and physical information: a case study in the humbug damselfish
- Author
-
Kent, M. I. A., primary, Burns, A. L., additional, Figueira, W. F., additional, Mazue, G. P. F., additional, Porter, A. G., additional, Wilson, A. D. M., additional, and Ward, A. J. W., additional
- Published
- 2019
- Full Text
- View/download PDF
6. Assessing the trophic ecology of top predators across a recolonisation frontier using DNA metabarcoding of diets
- Author
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Hardy, N., Berry, T., Kelaher, B., Goldsworthy, S., Bunce, Michael, Coleman, M., Gillanders, B., Connell, S., Blewitt, M., Figueira, W., Hardy, N., Berry, T., Kelaher, B., Goldsworthy, S., Bunce, Michael, Coleman, M., Gillanders, B., Connell, S., Blewitt, M., and Figueira, W.
- Abstract
Top predator populations, once intensively hunted, are rebounding in size and geographic distribution. The cessation of sealing along coastal Australia and subsequent recovery of Australian Arctocephalus pusillus doriferus and long-nosed A. forsteri fur seals represents a unique opportunity to investigate trophic linkages at a frontier of predator recolonisation. We characterised the diets of both species across 2 locations of recolonisation, one site an established breeding colony, and the other, a new but permanent haul-out site. Using DNA metabarcoding, high taxonomic resolution data on diets was used to inform ecological trait-based analyses across time and location. Australian and long-nosed fur seals consumed 76 and 73 prey taxa, respectively, a prey diversity greater than previously reported. We found unexpected overlap of prey functional traits in the diets of both seal species at the haul-out site, where we observed strong trophic linkages with coastal ecosystems due to the prevalence of benthic, demersal and reef-associated prey. The diets of both seal species at the breeding colony were consistent with foraging patterns observed in the centre of their geographic range regarding diet partitioning between predator species and seasonal trends typically observed. The unexpected differences between sites in this region and the convergence of both predators’ effective ecological roles at the range-edge haul-out site correlate with known differences in seal population densities and demographics at these and other newly recolonised locations. This study provides a baseline for the diets and trophic interactions for recovering fur seal populations and from which to understand the evolving ecology of predator recolonisation.
- Published
- 2017
7. Global warming and recurrent mass bleaching of corals
- Author
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Hughes, T., Kerry, J., Álvarez-Noriega, M., Álvarez-Romero, J., Anderson, K., Baird, A., Babcock, R., Beger, M., Bellwood, D., Berkelmans, R., Bridge, T., Butler, I., Byrne, M., Cantin, N., Comeau, S., Connolly, S., Cumming, G., Dalton, S., Diaz-Pulido, G., Eakin, C., Figueira, W., Gilmour, J., Harrison, H., Heron, S., Hoey, A., Hobbs, Jean-Paul, Hoogenboom, M., Kennedy, E., Kuo, C., Lough, J., Lowe, R., Liu, G., McCulloch, M., Malcolm, H., McWilliam, M., Pandolfi, J., Pears, R., Pratchett, M., Schoepf, V., Simpson, T., Skirving, W., Sommer, B., Torda, G., Wachenfeld, D., Willis, B., Wilson, S., Hughes, T., Kerry, J., Álvarez-Noriega, M., Álvarez-Romero, J., Anderson, K., Baird, A., Babcock, R., Beger, M., Bellwood, D., Berkelmans, R., Bridge, T., Butler, I., Byrne, M., Cantin, N., Comeau, S., Connolly, S., Cumming, G., Dalton, S., Diaz-Pulido, G., Eakin, C., Figueira, W., Gilmour, J., Harrison, H., Heron, S., Hoey, A., Hobbs, Jean-Paul, Hoogenboom, M., Kennedy, E., Kuo, C., Lough, J., Lowe, R., Liu, G., McCulloch, M., Malcolm, H., McWilliam, M., Pandolfi, J., Pears, R., Pratchett, M., Schoepf, V., Simpson, T., Skirving, W., Sommer, B., Torda, G., Wachenfeld, D., Willis, B., and Wilson, S.
- Abstract
During 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching, the third global-scale event since mass bleaching was first documented in the 1980s. Here we examine how and why the severity of recurrent major bleaching events has varied at multiple scales, using aerial and underwater surveys of Australian reefs combined with satellite-derived sea surface temperatures. The distinctive geographic footprints of recurrent bleaching on the Great Barrier Reef in 1998, 2002 and 2016 were determined by the spatial pattern of sea temperatures in each year. Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016. Consequently, immediate global action to curb future warming is essential to secure a future for coral reefs.
- Published
- 2017
8. Assessing the trophic ecology of top predators across a recolonisation frontier using DNA metabarcoding of diets
- Author
-
Hardy, N, primary, Berry, T, additional, Kelaher, BP, additional, Goldsworthy, SD, additional, Bunce, M, additional, Coleman, MA, additional, Gillanders, BM, additional, Connell, SD, additional, Blewitt, M, additional, and Figueira, W, additional
- Published
- 2017
- Full Text
- View/download PDF
9. Sydney Harbour: A review of anthropogenic impacts on the biodiversity and ecosystem function of one of the world's largest natural harbours
- Author
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Mayer-Pinto, M, Johnston, EL, Hutchings, PA, Marzinelli, EM, Ahyong, ST, Birch, G, Booth, DJ, Creese, RG, Doblin, MA, Figueira, W, Gribben, PE, Pritchard, T, Roughan, M, Steinberg, PD, and Hedge, LH
- Subjects
Marine Biology & Hydrobiology - Abstract
© 2015 CSIRO. Sydney Harbour is a hotspot for diversity. However, as with estuaries worldwide, its diversity and functioning faces increasing threats from urbanisation. This is the first synthesis of threats and impacts in Sydney Harbour. In total 200 studies were reviewed: 109 focussed on contamination, 58 on habitat modification, 11 addressed non-indigenous species (NIS) and eight investigated fisheries. Metal concentrations in sediments and seaweeds are among the highest recorded worldwide and organic contamination can also be high. Contamination is associated with increased abundances of opportunistic species, and changes in benthic community structure. The Harbour is also heavily invaded, but invaders' ecological and economic impacts are poorly quantified. Communities within Sydney Harbour are significantly affected by extensive physical modification, with artificial structures supporting more NIS and lower diversity than their natural equivalents. We know little about the effects of fishing on the Harbour's ecology, and although ocean warming along Sydney is among the fastest in the world, we know little about how the ecosystem will respond to warming. The interactive and cumulative effects of stressors on ecosystem functioning and services in the Harbour are largely unknown. Sustainable management of this iconic natural system requires that knowledge gaps are addressed and translated into coherent environmental plans.
- Published
- 2015
10. High-resolution photo-mosaic time-series imagery for monitoring human use of an artificial reef
- Author
-
Wood, G, Lynch, TP, Devine, C, Keller, K, Figueira, W, Wood, G, Lynch, TP, Devine, C, Keller, K, and Figueira, W
- Abstract
© 2016 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Successful marine management relies on understanding patterns of human use. However, obtaining data can be difficult and expensive given the widespread and variable nature of activities conducted. Remote camera systems are increasingly used to overcome cost limitations of conventional labour-intensive methods. Still, most systems face trade-offs between the spatial extent and resolution over which data are obtained, limiting their application. We trialed a novel methodology, CSIRO Ruggedized Autonomous Gigapixel System (CRAGS), for time series of high-resolution photo-mosaic (HRPM) imagery to estimate fine-scale metrics of human activity at an artificial reef located 1.3 km from shore. We compared estimates obtained using the novel system to those produced with a web camera that concurrently monitored the site. We evaluated the effect of day type (weekday/weekend) and time of day on each of the systems and compared to estimates obtained from binocular observations. In general, both systems delivered similar estimates for the number of boats observed and to those obtained by binocular counts; these results were also unaffected by the type of day (weekend vs. weekday). CRAGS was able to determine additional information about the user type and party size that was not possible with the lower resolution webcam system. However, there was an effect of time of day as CRAGS suffered from poor image quality in early morning conditions as a result of fixed camera settings. Our field study provides proof of concept of use of this new cost-effective monitoring tool for the remote collection of high-resolution large-extent data on patterns of human use at high temporal frequency.
- Published
- 2016
11. Sydney Harbour: What we do and do not know about a highly diverse estuary
- Author
-
Johnston, EL, Mayer-Pinto, M, Hutchings, PA, Marzinelli, EM, Ahyong, ST, Birch, G, Booth, DJ, Creese, RG, Doblin, MA, Figueira, W, Gribben, PE, Pritchard, T, Roughan, M, Steinberg, PD, Hedge, LH, Johnston, EL, Mayer-Pinto, M, Hutchings, PA, Marzinelli, EM, Ahyong, ST, Birch, G, Booth, DJ, Creese, RG, Doblin, MA, Figueira, W, Gribben, PE, Pritchard, T, Roughan, M, Steinberg, PD, and Hedge, LH
- Abstract
Sydney Harbour is a global hotspot for marine and estuarine diversity. Despite its social, economic and biological value, the available knowledge has not previously been reviewed or synthesised. We systematically reviewed the published literature and consulted experts to establish our current understanding of the Harbour's natural systems, identify knowledge gaps, and compare Sydney Harbour to other major estuaries worldwide. Of the 110 studies in our review, 81 focussed on ecology or biology, six on the chemistry, 10 on geology and 11 on oceanography. Subtidal rocky reef habitats were the most studied, with a focus on habitat forming macroalgae. In total 586 fish species have been recorded from the Harbour, which is high relative to other major estuaries worldwide. There has been a lack of process studies, and an almost complete absence of substantial time series that constrains our capacity to identify trends, environmental thresholds or major drivers of biotic interactions. We also highlight a lack of knowledge on the ecological functioning of Sydney Harbour, including studies on microbial communities. A sound understanding of the complexity, connectivity and dynamics underlying ecosystem functioning will allow further advances in management for the Harbour and for similarly modified estuaries around the world.
- Published
- 2015
12. Australian sea-floor survey data, with images and expert annotations (vol 2, 150057, 2015)
- Author
-
Bewley, M, Friedman, A, Ferrari, R, Hill, N, Hovey, R, Barrett, N, Marzinelli, EM, Pizarro, O, Figueira, W, Meyer, L, Babcock, R, Bellchambers, L, Byrne, M, Williams, SB, Bewley, M, Friedman, A, Ferrari, R, Hill, N, Hovey, R, Barrett, N, Marzinelli, EM, Pizarro, O, Figueira, W, Meyer, L, Babcock, R, Bellchambers, L, Byrne, M, and Williams, SB
- Published
- 2015
13. Australian sea-floor survey data, with images and expert annotations
- Author
-
Bewley, M, Friedman, A, Ferrari, R, Hill, N, Hovey, R, Barrett, N, Marzinelli, EM, Pizarro, O, Figueira, W, Meyer, L, Babcock, R, Bellchambers, L, Byrne, M, Williams, SB, Bewley, M, Friedman, A, Ferrari, R, Hill, N, Hovey, R, Barrett, N, Marzinelli, EM, Pizarro, O, Figueira, W, Meyer, L, Babcock, R, Bellchambers, L, Byrne, M, and Williams, SB
- Abstract
This Australian benthic data set (BENTHOZ-2015) consists of an expert-annotated set of georeferenced benthic images and associated sensor data, captured by an autonomous underwater vehicle (AUV) around Australia. This type of data is of interest to marine scientists studying benthic habitats and organisms. AUVs collect georeferenced images over an area with consistent illumination and altitude, and make it possible to generate broad scale, photo-realistic 3D maps. Marine scientists then typically spend several minutes on each of thousands of images, labeling substratum type and biota at a subset of points. Labels from four Australian research groups were combined using the CATAMI classification scheme, a hierarchical classification scheme based on taxonomy and morphology for scoring marine imagery. This data set consists of 407,968 expert labeled points from around the Australian coast, with associated images, geolocation and other sensor data. The robotic surveys that collected this data form part of Australia's Integrated Marine Observing System (IMOS) ongoing benthic monitoring program. There is reuse potential in marine science, robotics, and computer vision research.
- Published
- 2015
14. Sydney Harbour: a review of anthropogenic impacts on the biodiversity and ecosystem function of one of the world
- Author
-
Mayer-Pinto, M., primary, Johnston, E. L., additional, Hutchings, P. A., additional, Marzinelli, E. M., additional, Ahyong, S. T., additional, Birch, G., additional, Booth, D. J., additional, Creese, R. G., additional, Doblin, M. A., additional, Figueira, W., additional, Gribben, P. E., additional, Pritchard, T., additional, Roughan, M., additional, Steinberg, P. D., additional, and Hedge, L. H., additional
- Published
- 2015
- Full Text
- View/download PDF
15. Sydney Harbour: what we do and do not know about a highly diverse estuary
- Author
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Johnston, E. L., primary, Mayer-Pinto, M., additional, Hutchings, P. A., additional, Marzinelli, E. M., additional, Ahyong, S. T., additional, Birch, G., additional, Booth, D. J., additional, Creese, R. G., additional, Doblin, M. A., additional, Figueira, W., additional, Gribben, P. E., additional, Pritchard, T., additional, Roughan, M., additional, Steinberg, P. D., additional, and Hedge, L. H., additional
- Published
- 2015
- Full Text
- View/download PDF
16. The tropicalization of temperate marine ecosystems: Climate-mediated changes in herbivory and community phase shifts
- Author
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Vergés, A, Steinberg, PD, Hay, ME, Poore, AGB, Campbell, AH, Ballesteros, E, Heck, KL, Booth, DJ, Coleman, MA, Feary, DA, Figueira, W, Langlois, T, Marzinelli, EM, Mizerek, T, Mumby, PJ, Nakamura, Y, Roughan, M, van Sebille, E, Gupta, AS, Smale, DA, Tomas, F, Wernberg, T, Wilson, SK, Vergés, A, Steinberg, PD, Hay, ME, Poore, AGB, Campbell, AH, Ballesteros, E, Heck, KL, Booth, DJ, Coleman, MA, Feary, DA, Figueira, W, Langlois, T, Marzinelli, EM, Mizerek, T, Mumby, PJ, Nakamura, Y, Roughan, M, van Sebille, E, Gupta, AS, Smale, DA, Tomas, F, Wernberg, T, and Wilson, SK
- Abstract
Climate-driven changes in biotic interactions can profoundly alter ecological communities, particularly when they impact foundation species. In marine systems, changes in herbivory and the consequent loss of dominant habitat forming species can result in dramatic community phase shifts, such as from coral to macroalgal dominance when tropical fish herbivory decreases, and from algal forests to 'barrens' when temperate urchin grazing increases. Here, we propose a novel phase-shift away from macroalgal dominance caused by tropical herbivores extending their range into temperate regions. We argue that this phase shift is facilitated by poleward-flowing boundary currents that are creating ocean warming hotspots around the globe, enabling the range expansion of tropical species and increasing their grazing rates in temperate areas. Overgrazing of temperate macroalgae by tropical herbivorous fishes has already occurred in Japan and the Mediterranean. Emerging evidence suggests similar phenomena are occurring in other temperate regions, with increasing occurrence of tropical fishes on temperate reefs. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
- Published
- 2014
17. Engaging recreational fishers in management and conservation: global case studies.
- Author
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Granek, EF, Madin, EMP, Brown, MA, Figueira, W, Cameron, DS, Hogan, Z, Kristianson, G, de Villiers, P, Williams, JE, Post, J, Zahn, S, Arlinghaus, R, Granek, EF, Madin, EMP, Brown, MA, Figueira, W, Cameron, DS, Hogan, Z, Kristianson, G, de Villiers, P, Williams, JE, Post, J, Zahn, S, and Arlinghaus, R
- Abstract
Globally, the number of recreational fishers is sizeable and increasing in many countries. Associated with this trend is the potential for negative impacts on fish stocks through exploitation or management measures such as stocking and introduction of non-native fishes. Nevertheless, recreational fishers can be instrumental in successful fisheries conservation through active involvement in, or initiation of, conservation projects to reduce both direct and external stressors contributing to fishery declines. Understanding fishers' concerns for sustained access to the resource and developing methods for their meaningful participation can have positive impacts on conservation efforts. We examined a suite of case studies that demonstrate successful involvement of recreational fishers in conservation and management activities that span developed and developing countries, temperate and tropical regions, marine and freshwater systems, and open- and closed-access fisheries. To illustrate potential benefits and challenges of involving recreational fishers in fisheries management and conservation, we examined the socioeconomic and ecological contexts of each case study. We devised a conceptual framework for the engagement of recreational fishers that targets particular types of involvement (enforcement, advocacy, conservation, management design [type and location], research, and monitoring) on the basis of degree of stakeholder stewardship, scale of the fishery, and source of impacts (internal or external). These activities can be enhanced by incorporating local knowledge and traditions, taking advantage of leadership and regional networks, and creating collaborations among various stakeholder groups, scientists, and agencies to maximize the probability of recreational fisher involvement and project success.
- Published
- 2008
18. Isolation and sequence of a novel human chondrocyte protein related to mammalian members of the chitinase protein family.
- Author
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Hu, B, Trinh, K, Figueira, W F, and Price, P A
- Abstract
We describe the isolation of a novel protein from the conditioned medium of human articular cartilage chondrocytes in primary culture. This 39-kDa protein has the N-terminal sequence YKL, which we have termed YKL-39. The 1434-nucleotide sequence of the YKL-39 cDNA predicts a 385-residue initial translation product and a 364-residue mature YKL-39. The amino acid sequence of YKL-39 is most closely related to YKL-40, followed by macrophage chitotriosidase, oviductal glycoprotein, and macrophage YM-1. All five proteins share significant sequence identity with bacterial chitinases and have the probable structure of an (alphabeta)8 barrel. YKL-39 lacks the active site glutamate, which is essential for the activity of chitinases, and as expected has no chitinase activity. The highest level of YKL-39 mRNA expression is seen in chondrocytes, followed by synoviocytes, lung, and heart. YKL-39 accounts for 4% of the protein in chondrocyte-conditioned medium, prostromelysin accounts for 17%, and YKL-40 accounts for 33%. In contrast to YKL-40, YKL-39 is not a glycoprotein and does not bind to heparin.
- Published
- 1996
19. Marine Climate Change in Australia
- Author
-
Howard, W., Salas, M., Church, J., Dowdney, J., Feng, M., Griffiths, S., Hemer, M., Hobday, A., Mapstone, B., Matear, R., Poloczanska, E., Richardson, A., Cheal, A., Ridgway, K., Risbey, J., Thompson, P., Thresher, R., Weller, E., Saintilan, N., Wilson, S., Lenanton, R., Hosja, W., Moore, P., Lough, J., Wernberg, T., Marshall, P., Connolly, R., Mcdonald, J., Hill, K., Congdon, B., Devney, C., Fuentes, M., Graham, N., Hamann, M., Mckinnon, D., Hughes, T., Kingsford, M., Munday, P., Pratchett, M., Sheaves, M., Ian Goodwin, Raftos, D., Jane Williamson, Beardall, J., Brett, S., Meekan, M., Waschka, M., Dann, P., Ward, T., Edgar, G., Swadling, K., Connell, S., Russell, B., Lukoschek, V., Havenhand, J., Mcgregor, S., Sweatman, H., Jenkins, G., Campbell, A., Steinberg, P., Anthony, K., Lovelock, C., Skilleter, G., Figueira, W., Davidson, J., Hallegraeff, G., Holbrook, N., Coleman, M., Booth, D., Doblin, M., Kendrick, G., Smale, D., Parker, L., Ross, P., Chambers, L., and Dunlop, N.
20. Characterization of measurement errors using structure-from-motion and photogrammetry to measure marine habitat structural complexity.
- Author
-
Bryson M, Ferrari R, Figueira W, Pizarro O, Madin J, Williams S, and Byrne M
- Abstract
Habitat structural complexity is one of the most important factors in determining the makeup of biological communities. Recent advances in structure-from-motion and photogrammetry have resulted in a proliferation of 3D digital representations of habitats from which structural complexity can be measured. Little attention has been paid to quantifying the measurement errors associated with these techniques, including the variability of results under different surveying and environmental conditions. Such errors have the potential to confound studies that compare habitat complexity over space and time. This study evaluated the accuracy, precision, and bias in measurements of marine habitat structural complexity derived from structure-from-motion and photogrammetric measurements using repeated surveys of artificial reefs (with known structure) as well as natural coral reefs. We quantified measurement errors as a function of survey image coverage, actual surface rugosity, and the morphological community composition of the habitat-forming organisms (reef corals). Our results indicated that measurements could be biased by up to 7.5% of the total observed ranges of structural complexity based on the environmental conditions present during any particular survey. Positive relationships were found between measurement errors and actual complexity, and the strength of these relationships was increased when coral morphology and abundance were also used as predictors. The numerous advantages of structure-from-motion and photogrammetry techniques for quantifying and investigating marine habitats will mean that they are likely to replace traditional measurement techniques (e.g., chain-and-tape). To this end, our results have important implications for data collection and the interpretation of measurements when examining changes in habitat complexity using structure-from-motion and photogrammetry.
- Published
- 2017
- Full Text
- View/download PDF
21. Climate-driven disparities among ecological interactions threaten kelp forest persistence.
- Author
-
Provost EJ, Kelaher BP, Dworjanyn SA, Russell BD, Connell SD, Ghedini G, Gillanders BM, Figueira W, and Coleman MA
- Subjects
- Animals, Biomass, Climate, Ecosystem, Forests, Nephropidae, Sea Urchins, Climate Change, Food Chain, Kelp growth & development
- Abstract
The combination of ocean warming and acidification brings an uncertain future to kelp forests that occupy the warmest parts of their range. These forests are not only subject to the direct negative effects of ocean climate change, but also to a combination of unknown indirect effects associated with changing ecological landscapes. Here, we used mesocosm experiments to test the direct effects of ocean warming and acidification on kelp biomass and photosynthetic health, as well as climate-driven disparities in indirect effects involving key consumers (urchins and rock lobsters) and competitors (algal turf). Elevated water temperature directly reduced kelp biomass, while their turf-forming competitors expanded in response to ocean acidification and declining kelp canopy. Elevated temperatures also increased growth of urchins and, concurrently, the rate at which they thinned kelp canopy. Rock lobsters, which are renowned for keeping urchin populations in check, indirectly intensified negative pressures on kelp by reducing their consumption of urchins in response to elevated temperature. Overall, these results suggest that kelp forests situated towards the low-latitude margins of their distribution will need to adapt to ocean warming in order to persist in the future. What is less certain is how such adaptation in kelps can occur in the face of intensifying consumptive (via ocean warming) and competitive (via ocean acidification) pressures that affect key ecological interactions associated with their persistence. If such indirect effects counter adaptation to changing climate, they may erode the stability of kelp forests and increase the probability of regime shifts from complex habitat-forming species to more simple habitats dominated by algal turfs., (© 2016 John Wiley & Sons Ltd.)
- Published
- 2017
- Full Text
- View/download PDF
22. Corrigendum: Australian sea-floor survey data, with images and expert annotations.
- Author
-
Bewley M, Friedman A, Ferrari R, Hill N, Hovey R, Barrett N, Marzinelli EM, Pizarro O, Figueira W, Meyer L, Babcock R, Bellchambers L, Byrne M, and Williams SB
- Published
- 2016
- Full Text
- View/download PDF
23. High-resolution photo-mosaic time-series imagery for monitoring human use of an artificial reef.
- Author
-
Wood G, Lynch TP, Devine C, Keller K, and Figueira W
- Abstract
Successful marine management relies on understanding patterns of human use. However, obtaining data can be difficult and expensive given the widespread and variable nature of activities conducted. Remote camera systems are increasingly used to overcome cost limitations of conventional labour-intensive methods. Still, most systems face trade-offs between the spatial extent and resolution over which data are obtained, limiting their application. We trialed a novel methodology, CSIRO Ruggedized Autonomous Gigapixel System (CRAGS), for time series of high-resolution photo-mosaic (HRPM) imagery to estimate fine-scale metrics of human activity at an artificial reef located 1.3 km from shore. We compared estimates obtained using the novel system to those produced with a web camera that concurrently monitored the site. We evaluated the effect of day type (weekday/weekend) and time of day on each of the systems and compared to estimates obtained from binocular observations. In general, both systems delivered similar estimates for the number of boats observed and to those obtained by binocular counts; these results were also unaffected by the type of day (weekend vs. weekday). CRAGS was able to determine additional information about the user type and party size that was not possible with the lower resolution webcam system. However, there was an effect of time of day as CRAGS suffered from poor image quality in early morning conditions as a result of fixed camera settings. Our field study provides proof of concept of use of this new cost-effective monitoring tool for the remote collection of high-resolution large-extent data on patterns of human use at high temporal frequency.
- Published
- 2016
- Full Text
- View/download PDF
24. Quantifying the response of structural complexity and community composition to environmental change in marine communities.
- Author
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Ferrari R, Bryson M, Bridge T, Hustache J, Williams SB, Byrne M, and Figueira W
- Subjects
- Models, Theoretical, Seasons, Species Specificity, Western Australia, Aquatic Organisms physiology, Biodiversity, Climate Change, Coral Reefs, Hot Temperature adverse effects
- Abstract
Habitat structural complexity is a key factor shaping marine communities. However, accurate methods for quantifying structural complexity underwater are currently lacking. Loss of structural complexity is linked to ecosystem declines in biodiversity and resilience. We developed new methods using underwater stereo-imagery spanning 4 years (2010-2013) to reconstruct 3D models of coral reef areas and quantified both structural complexity at two spatial resolutions (2.5 and 25 cm) and benthic community composition to characterize changes after an unprecedented thermal anomaly on the west coast of Australia in 2011. Structural complexity increased at both resolutions in quadrats (4 m(2)) that bleached, but not those that did not bleach. Changes in complexity were driven by species-specific responses to warming, highlighting the importance of identifying small-scale dynamics to disentangle ecological responses to disturbance. We demonstrate an effective, repeatable method for quantifying the relationship among community composition, structural complexity and ocean warming, improving predictions of the response of marine ecosystems to environmental change., (© 2015 John Wiley & Sons Ltd.)
- Published
- 2016
- Full Text
- View/download PDF
25. Australian sea-floor survey data, with images and expert annotations.
- Author
-
Bewley M, Friedman A, Ferrari R, Hill N, Hovey R, Barrett N, Marzinelli EM, Pizarro O, Figueira W, Meyer L, Babcock R, Bellchambers L, Byrne M, and Williams SB
- Subjects
- Animals, Australia, Biota, Environmental Monitoring, Imaging, Three-Dimensional, Indian Ocean, Pacific Ocean, Aquatic Organisms
- Abstract
This Australian benthic data set (BENTHOZ-2015) consists of an expert-annotated set of georeferenced benthic images and associated sensor data, captured by an autonomous underwater vehicle (AUV) around Australia. This type of data is of interest to marine scientists studying benthic habitats and organisms. AUVs collect georeferenced images over an area with consistent illumination and altitude, and make it possible to generate broad scale, photo-realistic 3D maps. Marine scientists then typically spend several minutes on each of thousands of images, labeling substratum type and biota at a subset of points. Labels from four Australian research groups were combined using the CATAMI classification scheme, a hierarchical classification scheme based on taxonomy and morphology for scoring marine imagery. This data set consists of 407,968 expert labeled points from around the Australian coast, with associated images, geolocation and other sensor data. The robotic surveys that collected this data form part of Australia's Integrated Marine Observing System (IMOS) ongoing benthic monitoring program. There is reuse potential in marine science, robotics, and computer vision research.
- Published
- 2015
- Full Text
- View/download PDF
26. The tropicalization of temperate marine ecosystems: climate-mediated changes in herbivory and community phase shifts.
- Author
-
Vergés A, Steinberg PD, Hay ME, Poore AG, Campbell AH, Ballesteros E, Heck KL Jr, Booth DJ, Coleman MA, Feary DA, Figueira W, Langlois T, Marzinelli EM, Mizerek T, Mumby PJ, Nakamura Y, Roughan M, van Sebille E, Gupta AS, Smale DA, Tomas F, Wernberg T, and Wilson SK
- Subjects
- Animals, Aquatic Organisms, Biodiversity, Fishes, Models, Biological, Seaweed, Climate Change, Ecosystem, Herbivory
- Abstract
Climate-driven changes in biotic interactions can profoundly alter ecological communities, particularly when they impact foundation species. In marine systems, changes in herbivory and the consequent loss of dominant habitat forming species can result in dramatic community phase shifts, such as from coral to macroalgal dominance when tropical fish herbivory decreases, and from algal forests to 'barrens' when temperate urchin grazing increases. Here, we propose a novel phase-shift away from macroalgal dominance caused by tropical herbivores extending their range into temperate regions. We argue that this phase shift is facilitated by poleward-flowing boundary currents that are creating ocean warming hotspots around the globe, enabling the range expansion of tropical species and increasing their grazing rates in temperate areas. Overgrazing of temperate macroalgae by tropical herbivorous fishes has already occurred in Japan and the Mediterranean. Emerging evidence suggests similar phenomena are occurring in other temperate regions, with increasing occurrence of tropical fishes on temperate reefs., (© 2014 The Author(s) Published by the Royal Society. All rights reserved.)
- Published
- 2014
- Full Text
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