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Zulfahmi I, Batubara AS, Perdana AW, Andalia AP, Nuzulli D, Hidayat M, Nur FM, Sumon KA, Rahman MM. Turbidity derived from Palm Oil Mill Effluent Alters Feeding Ability of Male Siamese Fighting Fish (Betta splendens, Regan 1910). Appl Anim Behav Sci 2022. [DOI: 10.1016/j.applanim.2022.105790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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2
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Berry KLE, Hess S, Clark TD, Wenger AS, Hoogenboom MO, Negri AP. Effects of suspended coal particles on gill structure and oxygen consumption rates in a coral reef fish. MARINE POLLUTION BULLETIN 2021; 169:112459. [PMID: 34022563 DOI: 10.1016/j.marpolbul.2021.112459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 03/15/2021] [Accepted: 05/02/2021] [Indexed: 06/12/2023]
Abstract
Large quantities of coal are transported through tropical regions; however, little is known about the sub-lethal effects of coal contamination on tropical marine organisms, including fish. Here, we measured aerobic metabolism and gill morphology in a planktivorous coral reef damselfish, Acanthochromis polyacanthus to elucidate the sub-lethal effects of suspended coal particles over a range of coal concentrations and exposure durations. Differences in the standard oxygen consumption rates (MO2) between control fish and fish exposed to coal particles (38 and 73 mg L-1) were minimal and generally not dose dependent; however, the MO2 of fish exposed to 38 mg coal L-1 (21 days) and 73 mg coal L-1 (31 days) were both significantly higher than the MO2 of control fish. Chronic coal exposure (31 days) altered gill structure in the higher coal treatments (73 and 275 mg L-1), with fish exposed to 275 mg L-1 exhibiting significant reductions in gill mucous and thinning of lamellar and filament epithelium. These findings contribute to our limited understanding of the potential impacts of coal on tropical reef species; however, most of the observed effects occurred at high coal concentrations that are unlikely under most coal spill scenarios. Future studies should investigate other contamination scenarios such as the impacts of chronic exposures to lower concentrations of coal.
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Affiliation(s)
- K L E Berry
- AIMS@JCU, James Cook University, Australian Institute of Marine Science, Townsville, Queensland 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia; Australian Institute of Marine Science, Townsville, Queensland 4810, Australia.
| | - S Hess
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
| | - T D Clark
- Deakin University, School of Life and Environmental Sciences, Geelong, Victoria 3216, Australia
| | - A S Wenger
- School of Earth and Environmental Sciences, University of Queensland, St. Lucia, Queensland 4072, Australia
| | - M O Hoogenboom
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - A P Negri
- Australian Institute of Marine Science, Townsville, Queensland 4810, Australia
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3
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High turbidity levels alter coral reef fish movement in a foraging task. Sci Rep 2021; 11:5976. [PMID: 33742061 PMCID: PMC7979735 DOI: 10.1038/s41598-021-84814-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 02/09/2021] [Indexed: 11/08/2022] Open
Abstract
Sensory systems allow animals to detect and respond to stimuli in their environment and underlie all behaviour. However, human induced pollution is increasingly interfering with the functioning of these systems. Increased suspended sediment, or turbidity, in aquatic habitats reduces the reactive distance to visual signals and may therefore alter movement behaviour. Using a foraging task in which fish (Rhinecanthus aculeatus) had to find six food sites in an aquarium, we tested the impact of high turbidity (40-68 NTU; 154 mg/L) on foraging efficiency using a detailed and novel analysis of individual movements. High turbidity led to a significant decrease in task efficacy as fish took longer to begin searching and find food, and they travelled further whilst searching. Trajectory analyses revealed that routes were less efficient and that fish in high turbidity conditions were more likely to cover the same ground and search at a slower speed. These results were observed despite the experimental protocol allowing for the use of alternate sensory systems (e.g. olfaction, lateral line). Given that movement underlies fundamental behaviours including foraging, mating, and predator avoidance, a reduction in movement efficiency is likely to have a significant impact on the health and population dynamics of visually-guided fish species.
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Chase TJ, Pratchett MS, McWilliam MJ, Hein MY, Tebbett SB, Hoogenboom MO. Damselfishes alleviate the impacts of sediments on host corals. ROYAL SOCIETY OPEN SCIENCE 2020; 7:192074. [PMID: 32431885 PMCID: PMC7211878 DOI: 10.1098/rsos.192074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/24/2020] [Indexed: 06/11/2023]
Abstract
Mutualisms play a critical role in ecological communities; however, the importance and prevalence of mutualistic associations can be modified by external stressors. On coral reefs, elevated sediment deposition can be a major stressor reducing the health of corals and reef resilience. Here, we investigated the influence of severe sedimentation on the mutualistic relationship between small damselfishes (Pomacentrus moluccensis and Dascyllus aruanus) and their coral host (Pocillopora damicornis). In an aquarium experiment, corals were exposed to sedimentation rates of approximately 100 mg cm-2 d-1, with and without fishes present, to test whether: (i) fishes influence the accumulation of sediments on coral hosts, and (ii) fishes moderate partial colony mortality and/or coral tissue condition. Colonies with fishes accumulated much less sediment compared with colonies without fishes, and this effect was strongest for colonies with D. aruanus (fivefold less sediment than controls) as opposed to P. moluccensis (twofold less sediment than controls). Colonies with symbiont fishes also had up to 10-fold less sediment-induced partial mortality, as well as higher chlorophyll and protein concentrations. These results demonstrate that fish mutualisms vary in the strength of their benefits, and indicate that some mutualistic or facilitative interactions might become more important for species health and resilience at high-stress levels.
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Affiliation(s)
- T. J. Chase
- Marine Biology and Aquaculture Group, College of Science and Engineering, James Cook University, Townsville, Queensland, 4811, Australia
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - M. S. Pratchett
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - M. J. McWilliam
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
- Hawai'i Institute of Marine Biology, University of Hawai'i at Manoa, Kaneohe, HI, 96744, USA
| | - M. Y. Hein
- Marine Biology and Aquaculture Group, College of Science and Engineering, James Cook University, Townsville, Queensland, 4811, Australia
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - S. B. Tebbett
- Marine Biology and Aquaculture Group, College of Science and Engineering, James Cook University, Townsville, Queensland, 4811, Australia
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - M. O. Hoogenboom
- Marine Biology and Aquaculture Group, College of Science and Engineering, James Cook University, Townsville, Queensland, 4811, Australia
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
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5
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Bainbridge Z, Lewis S, Bartley R, Fabricius K, Collier C, Waterhouse J, Garzon-Garcia A, Robson B, Burton J, Wenger A, Brodie J. Fine sediment and particulate organic matter: A review and case study on ridge-to-reef transport, transformations, fates, and impacts on marine ecosystems. MARINE POLLUTION BULLETIN 2018; 135:1205-1220. [PMID: 30301020 DOI: 10.1016/j.marpolbul.2018.08.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 07/27/2018] [Accepted: 08/01/2018] [Indexed: 06/08/2023]
Abstract
Studies documenting the effects of land-derived suspended particulate matter (SPM, i.e., particulate organic matter and mineral sediment) on marine ecosystems are typically disconnected from terrestrial studies that determine their origin, transport and fate. This study reviews sources, transport, transformations, fate and effects of SPM along the 'ridge-to-reef' continuum. We show that some of the SPM can be transported over long distances and transformed into large and easily resuspendible organic-rich sediment flocs. These flocs may lead to prolonged reductions in water clarity, impacting upon coral reef, seagrass and fish communities. Using the Great Barrier Reef (NE Australia) as a case study, we identify the latest research tools to determine thresholds of SPM exposure, allowing for an improved appreciation of marine risk. These tools are used to determine ecologically-relevant end-of-basin load targets and reliable marine water quality guidelines, thereby enabling enhanced prioritisation and management of SPM export from ridge-to-reef.
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Affiliation(s)
- Z Bainbridge
- TropWATER, James Cook University, Townsville 4811, Australia.
| | - S Lewis
- TropWATER, James Cook University, Townsville 4811, Australia
| | - R Bartley
- CSIRO, Brisbane, Queensland 4068, Australia
| | - K Fabricius
- Australian Institute of Marine Science, PMB 3, Townsville MC, QLD 4810, Australia
| | - C Collier
- TropWATER, James Cook University, Townsville 4811, Australia
| | - J Waterhouse
- TropWATER, James Cook University, Townsville 4811, Australia
| | - A Garzon-Garcia
- Department of Environment and Science, GPO Box 5078, Brisbane 4001, Australia
| | - B Robson
- Australian Institute of Marine Science, PMB 3, Townsville MC, QLD 4810, Australia
| | - J Burton
- Department of Environment and Science, GPO Box 5078, Brisbane 4001, Australia
| | - A Wenger
- School of Earth and Environmental Sciences, University of Queensland, St. Lucia, QLD 4072, Australia
| | - J Brodie
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville 4811, Australia
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Ricardo GF, Jones RJ, Clode PL, Humanes A, Giofre N, Negri AP. Sediment characteristics influence the fertilisation success of the corals Acropora tenuis and Acropora millepora. MARINE POLLUTION BULLETIN 2018; 135:941-953. [PMID: 30301119 DOI: 10.1016/j.marpolbul.2018.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 07/30/2018] [Accepted: 08/01/2018] [Indexed: 06/08/2023]
Abstract
Elevated suspended sediment concentrations (SSCs) often impact coral fertilisation success, but sediment composition can influence effect thresholds, which is problematic for accurately predicting risk. Here, we derived concentration-response thresholds and cause-effect pathways for SSCs comprising a range of realistic mineral and organic compositions on coral fertilisation success. Effect concentration thresholds (EC10: 10% fertilisation inhibition) varied markedly, with fertilisation highly sensitive to inshore organic-clay rich sediments and bentonite clay at <5 mg L-1. Mineral clays and organic matter within these sediments likely promoted flocculation of the coral sperm, which in turn reduced fertilisation. In contrast, sediments lacking these properties bound less sperm, leading to higher SSC thresholds for coral fertilisation (EC10 > 40 mg L-1). The effect thresholds for relevant sediment types were combined with in situ turbidity data from locations near dredging operations to assess the risks posed by dredging to coral fertilisation at these locations.
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Affiliation(s)
- Gerard F Ricardo
- Centre for Microscopy, Characterisation and Analysis, UWA Oceans Institute, The University of Western Australia, Perth, Western Australia 6009, Australia; Australian Institute of Marine Science, Townsville, 4810, Queensland, and Perth, 6009, Western Australia, Australia; Western Australian Marine Science Institution, Perth, 6009, Western Australia, Australia.
| | - Ross J Jones
- Australian Institute of Marine Science, Townsville, 4810, Queensland, and Perth, 6009, Western Australia, Australia; Western Australian Marine Science Institution, Perth, 6009, Western Australia, Australia
| | - Peta L Clode
- Centre for Microscopy, Characterisation and Analysis, UWA Oceans Institute, The University of Western Australia, Perth, Western Australia 6009, Australia
| | - Adriana Humanes
- Australian Institute of Marine Science, Townsville, 4810, Queensland, and Perth, 6009, Western Australia, Australia; ARC Centre of Excellence for Coral Reef Studies, College of Science and Engineering, James Cook University, 4811 Townsville, Queensland, Australia; AIMS@JCU, Division of Research & Innovation, James Cook University, Australian Institute of Marine Science, Townsville, Queensland 4811, Australia
| | - Natalie Giofre
- Australian Institute of Marine Science, Townsville, 4810, Queensland, and Perth, 6009, Western Australia, Australia; Western Australian Marine Science Institution, Perth, 6009, Western Australia, Australia
| | - Andrew P Negri
- Australian Institute of Marine Science, Townsville, 4810, Queensland, and Perth, 6009, Western Australia, Australia; Western Australian Marine Science Institution, Perth, 6009, Western Australia, Australia
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7
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Sediment pollution impacts sensory ability and performance of settling coral-reef fish. Oecologia 2015; 180:11-21. [PMID: 26080759 DOI: 10.1007/s00442-015-3367-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 06/02/2015] [Indexed: 10/23/2022]
Abstract
Marine organisms are under threat globally from a suite of anthropogenic sources, but the current emphasis on global climate change has deflected the focus from local impacts. While the effect of increased sedimentation on the settlement of coral species is well studied, little is known about the impact on larval fish. Here, the effect of a laterite "red soil" sediment pollutant on settlement behaviour and post-settlement performance of reef fish was tested. In aquarium tests that isolated sensory cues, we found significant olfaction-based avoidance behaviour and disruption of visual cue use in settlement-stage larval fish at 50 mg L(-1), a concentration regularly exceeded in situ during rain events. In situ light trap catches showed lower abundance and species richness in the presence of red soil, but were not significantly different due to high variance in the data. Prolonged exposure to red soil produced altered olfactory cue responses, whereby fish in red soil made a likely maladaptive choice for dead coral compared to controls where fish chose live coral. Other significant effects of prolonged exposure included decreased feeding rates and body condition. These effects on fish larvae reared over 5 days occurred in the presence of a minor drop in pH and may be due to the chemical influence of the sediment. Our results show that sediment pollution of coral reefs may have more complex effects on the ability of larval fish to successfully locate suitable habitat than previously thought, as well as impacting on their post-settlement performance and, ultimately, recruitment success.
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Chivers DP, Ramasamy RA, McCormick MI, Watson SA, Siebeck UE, Ferrari MCO. Temporal constraints on predation risk assessment in a changing world. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 500-501:332-338. [PMID: 25237790 DOI: 10.1016/j.scitotenv.2014.08.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 08/12/2014] [Accepted: 08/18/2014] [Indexed: 06/03/2023]
Abstract
Habitat degradation takes various forms and likely represents the most significant threat to our global biodiversity. Recently, we have seen considerable attention paid to increasing global CO2 emissions which lead to ocean acidification (OA). Other stressors, such as changing levels of ultraviolet radiation (UVR), also impact biodiversity but have received much less attention in the recent past. Here we examine fundamental questions about temporal aspects of risk assessment by coral reef damselfish and provide critical insights into how OA and UVR influence this assessment. Chemical cues released during a predator attack provide a rich source of information that other prey animals use to mediate their risk of predation and are the basis of the majority of trait-mediated indirect interactions in aquatic communities. However, we have surprisingly limited information about temporal aspects of risk assessment because we lack knowledge about how long chemical cues persist after they are released into the environment. Here, we showed that under ambient CO2 conditions (~385 μatm), alarm cues of ambon damselfish (Pomacentrus amboinensis) did not degrade within 30 min in the absence of ultraviolet radiation (UVR), but were degraded within 15 min when the CO2 was increased to ~905 μatm. In experiments that used filters to eliminate UVR, we found minimal degradation of alarm cues within 30 min, whereas under ambient UVR conditions, alarm cues were completely degraded within 15 min. Moreover, in the presence of both UVR and elevated CO2, alarm cues were broken down within 5 min. Our results highlight that alarm cues degrade surprisingly quickly under natural conditions and that anthropogenic changes have the potential to dramatically change rates of cue degradation in the wild. This has considerable implications for risk assessment and consequently the importance of trait-mediated indirect interactions in coral-reef communities.
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Affiliation(s)
- Douglas P Chivers
- Department of Biology, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada.
| | - Ryan A Ramasamy
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville Qld4811, Australia; School of Marine and Tropical Biology, James Cook University, Townsville Qld4811, Australia
| | - Mark I McCormick
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville Qld4811, Australia; School of Marine and Tropical Biology, James Cook University, Townsville Qld4811, Australia
| | - Sue-Ann Watson
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville Qld4811, Australia; School of Marine and Tropical Biology, James Cook University, Townsville Qld4811, Australia
| | - Ulrike E Siebeck
- School of Biomedical Sciences, University of Queensland, Brisbane Qld4072, Australia
| | - Maud C O Ferrari
- Department of Biomedical Sciences, WCVM, University of Saskatchewan, Saskatoon, SK S7W 5B4, Canada
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Manikandan B, Ravindran J, Shrinivaasu S, Marimuthu N, Paramasivam K. Community structure and coral status across reef fishing intensity gradients in Palk Bay reef, southeast coast of India. ENVIRONMENTAL MONITORING AND ASSESSMENT 2014; 186:5989-6002. [PMID: 24859909 DOI: 10.1007/s10661-014-3835-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 05/14/2014] [Indexed: 06/03/2023]
Abstract
Coral reef fishes are exploited without the knowledge of their sustainability and their possible effect in altering the community structure of a coral reef ecosystem. Alteration of the community structure could cause a decline in the health of coral reefs and its services. We documented the coral community structure, status of live corals and reef fish assemblages in Palk Bay at the reef fishing hotspots and its nearby reef area with minimum fishing pressure and compared it with a control reef area where reef fishing was banned for more than two decades. The comparison was based on the percent cover of different forms of live corals, their diversity and the density and diversity of reef fishes. The reef fish stock in the reef fishing hotspots and its neighbouring reef was lower by 61 and 38%, respectively compared to the control reef. The herbivore fish Scarus ghobban and Siganus javus were exploited at a rate of 250 and 105 kg month(-1) fishermen(-1), respectively, relatively high comparing the small reef area. Live and dead corals colonized by turf algae were predominant in both the reef fishing hotspots and its nearby coral ecosystems. The percent cover of healthy live corals and live corals colonized by turf algae was <10 and >80%, respectively, in the intensively fished coral ecosystems. The corals were less diverse and the massive Porites and Favia colonies were abundant in the intensive reef fishing sites. Results of this study suggest that the impact of reef fish exploitation was not solely restricted to the intensively fished reefs, but also to the nearby reefs which play a critical role in the resilience of degraded reef ecosystems.
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Affiliation(s)
- B Manikandan
- Regional Centre, CSIR-National Institute of Oceanography, Dr. Salim Ali Road, PB. No. 1913, Kochi, 682018, Kerala, India,
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Petus C, da Silva ET, Devlin M, Wenger AS, Alvarez-Romero JG. Using MODIS data for mapping of water types within river plumes in the Great Barrier Reef, Australia: towards the production of river plume risk maps for reef and seagrass ecosystems. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2014; 137:163-177. [PMID: 24632405 DOI: 10.1016/j.jenvman.2013.11.050] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 10/30/2013] [Accepted: 11/02/2013] [Indexed: 06/03/2023]
Abstract
River plumes are the major transport mechanism for nutrients, sediments and other land-based pollutants into the Great Barrier Reef (GBR, Australia) and are a major threat to coastal and marine ecosystems such as coral reefs and seagrass beds. Understanding the spatial extent, frequency of occurrence, loads and ecological impacts of land-based pollutants discharged through river plumes is essential to drive catchment management actions. In this study, a framework to produce river plume risk maps for seagrass and coral ecosystems, using supervised classification of MODIS Level 2 (L2) satellite products, is presented. Based on relevant L2 thresholds, river plumes are classified into Primary, Secondary, and Tertiary water types, which represent distinct water quality (WQ) parameters concentrations and combinations. Annual water type maps are produced over three wet seasons (2010-2013) as a case of study. These maps provide a synoptic basis to assess the likelihood and magnitude of the risk of reduced coastal WQ associated with the river discharge (river plume risk) and in combination with sound knowledge of the regional ecosystems can serve as the basis to assess potential ecological impacts for coastal and marine GBR ecosystems. The methods described herein provide relevant and easily reproducible large-scale information for river plume risk assessment and management.
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Affiliation(s)
- Caroline Petus
- Centre for Tropical Water and Aquatic Ecosystem Research, Catchment to Reef Research Group, James Cook University, Townsville, QLD 4811, Australia.
| | - Eduardo Teixeira da Silva
- Centre for Tropical Water and Aquatic Ecosystem Research, Catchment to Reef Research Group, James Cook University, Townsville, QLD 4811, Australia
| | - Michelle Devlin
- Centre for Tropical Water and Aquatic Ecosystem Research, Catchment to Reef Research Group, James Cook University, Townsville, QLD 4811, Australia
| | - Amelia S Wenger
- Centre for Tropical Water and Aquatic Ecosystem Research, Catchment to Reef Research Group, James Cook University, Townsville, QLD 4811, Australia; Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Jorge G Alvarez-Romero
- Centre for Tropical Water and Aquatic Ecosystem Research, Catchment to Reef Research Group, James Cook University, Townsville, QLD 4811, Australia; Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
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11
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Wenger AS, McCormick MI, Endo GGK, McLeod IM, Kroon FJ, Jones GP. Suspended sediment prolongs larval development in a coral reef fish. ACTA ACUST UNITED AC 2013; 217:1122-8. [PMID: 24311818 DOI: 10.1242/jeb.094409] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Increasing sediment input into coastal environments is having a profound influence on shallow marine habitats and associated species. Coral reef ecosystems appear to be particularly sensitive, with increased sediment deposition and re-suspension being associated with declines in the abundance and diversity of coral reef fishes. While recent research has demonstrated that suspended sediment can have negative impacts on post-settlement coral reef fishes, its effect on larval development has not been investigated. In this study, we tested the effects of different levels of suspended sediment on larval growth and development time in Amphiprion percula, a coral reef damselfish. Larvae were subjected to four experimental concentrations of suspended sediment spanning the range found around coastal coral reefs (0-45 mg l(-1)). Larval duration was significantly longer in all sediment treatments (12 days) compared with the average larval duration in the control treatment (11 days). Approximately 75% of the fish in the control had settled by day 11, compared with only 40-46% among the sediment treatments. In the highest sediment treatment, some individuals had a larval duration twice that of the median duration in the control treatment. Unexpectedly, in the low sediment treatment, fish at settlement were significantly longer and heavier compared with fish in the other treatments, suggesting delayed development was independent of individual condition. A sediment-induced extension of the pelagic larval stage could significantly reduce numbers of larvae competent to settle and, in turn, have major effects on adult population dynamics.
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Affiliation(s)
- Amelia S Wenger
- School of Marine and Tropical Biology, James Cook University, Townsville, QLD 4811, Australia
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12
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Chivers DP, Dixson DL, White JR, McCormick MI, Ferrari MCO. Degradation of chemical alarm cues and assessment of risk throughout the day. Ecol Evol 2013; 3:3925-34. [PMID: 24198950 PMCID: PMC3810885 DOI: 10.1002/ece3.760] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 08/06/2013] [Accepted: 08/12/2013] [Indexed: 11/06/2022] Open
Abstract
The use of chemical information in assessment of predation risk is pervasive across animal taxa. However, by its very nature, chemical information can be temporally unreliable. Chemical cues persist for some period of time after they are released into the environment. Yet, we know surprisingly little about the rate of degradation of chemical cues under natural conditions and hence little about how they function in temporal risk assessment under natural conditions. Here, we conducted an experiment to identify a concentration of fresh alarm cues that evoke a strong antipredator response in coral reef damselfish, Pomacentrus ambonensis. We then tested the rate at which these alarm cues degraded under natural conditions in ocean water, paying attention to whether the rate of degradation varied throughout the day and whether the temporal pattern correlated with physicochemical factors that could influence the rate of degradation. Fresh alarm cues released into ocean water evoke strong avoidance responses in juvenile fish, while those aged for 30 min no longer evoke antipredator responses. Fish exposed to cues aged for 10 or 20 min show intermediate avoidance responses. We found a marked temporal pattern of response throughout the day, with much faster degradation in early to mid-afternoon, the time of day when solar radiation, temperature, dissolved oxygen, and pH are nearing their peak. Ecologists have spent considerable effort elucidating the role of chemical information in mediating predator–prey interactions, yet we know almost nothing about the temporal dynamics of risk assessment using chemical information. We are in dire need of additional comparative field experiments on the rate of breakdown of chemical cues, particularly given that global change in UV radiation, temperature, and water chemistry could be altering the rates of degradation and the potential use of this information in risk assessment.
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Affiliation(s)
- Douglas P Chivers
- Department of Biology, University of Saskatchewan Saskatoon, SasKatchewan, S7N 5E2, Canada
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