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Shima JS, Alonzo SH, Osenberg CW, Noonburg EG, Swearer SE. Lunar rhythms and their carry-over effects may shape environmental sex determination in a coral reef fish. Proc Biol Sci 2024; 291:20240613. [PMID: 39106960 PMCID: PMC11303037 DOI: 10.1098/rspb.2024.0613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 05/22/2024] [Indexed: 08/09/2024] Open
Abstract
Lunar rhythms shape spawning phenology and subsequent risks and rewards for early life-history stages in the sea. Here, we consider a perplexing spawning phenology of the sixbar wrasse (Thalassoma hardwicke), in which parents spawn disproportionately around the new moon, despite the low survival of these larvae. Because primary sex determination in this system is highly plastic and sensitive to social environments experienced early in development, we ask whether this puzzling pattern of spawning is explained by fitness trade-offs associated with primary sexual maturation. We used otoliths from 871 fish to explore how spawning on different phases of the moon shapes the environments and phenotypes of settling larvae. Offspring that were born at the new moon were more likely to settle (i) before other larvae, (ii) at a larger body size, (iii) at an older age, (iv) to the best quality sites, and (v) as part of a social group-all increasing the likelihood of primary maturation to male. Selection of birthdates across life stage transitions suggests that the perplexing spawning phenology of adults may reflect an evolutionarily stable strategy that includes new moon spawning for compensatory benefits later in life, including preferential production of primary males at certain times.
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Affiliation(s)
- Jeffrey S. Shima
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Suzanne H. Alonzo
- Department of Ecology and Evolutionary Biology, University of California at Santa Cruz, Santa Cruz, CA, USA
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2
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Fobert EK, Miller CR, Swearer SE, Mayer-Pinto M. The impacts of artificial light at night on the ecology of temperate and tropical reefs. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220362. [PMID: 37899007 PMCID: PMC10613546 DOI: 10.1098/rstb.2022.0362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/19/2023] [Indexed: 10/31/2023] Open
Abstract
Despite 22% of the world's coastal regions experiencing some degree of light pollution, and biologically important artificial light at night (ALAN) reaching large portions of the seafloor (greater than 75%) near coastal developments, the impacts of ALAN on temperate and tropical reefs are still relatively unknown. Because many reef species have evolved in response to low-light nocturnal environments, consistent daily, lunar, and seasonal light cycles, and distinct light spectra, these impacts are likely to be profound. Recent studies have found ALAN can decrease reproductive success of fishes, alter predation rates of invertebrates and fishes, and impact the physiology and biochemistry of reef-building corals. In this paper, we integrate knowledge of the role of natural light in temperate and tropical reefs with a synthesis of the current literature on the impacts of ALAN on reef organisms to explore potential changes at the system level in reef communities exposed to ALAN. Specifically, we identify the direct impacts of ALAN on individual organisms and flow on effects for reef communities, and present potential scenarios where ALAN could significantly alter system-level dynamics, possibly even creating novel ecosystems. Lastly, we highlight large knowledge gaps in our understanding of the overall impact of ALAN on reef systems. This article is part of the theme issue 'Light pollution in complex ecological systems'.
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Affiliation(s)
- Emily K. Fobert
- School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Colleen R. Miller
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Stephen E. Swearer
- National Centre for Coasts and Climate (NCCC), School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Mariana Mayer-Pinto
- Centre for Marine Science and Innovation, Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Science, University of New South Wales, Sydney, New South Wales 2052, Australia
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Harrison HB, Drane L, Berumen ML, Cresswell BJ, Evans RD, Galbraith GF, Srinivasan M, Taylor BM, Williamson DH, Jones GP. Ageing of juvenile coral grouper ( Plectropomus maculatus) reveals year-round spawning and recruitment: implications for seasonal closures. Proc Biol Sci 2023; 290:20230584. [PMID: 37339745 PMCID: PMC10281809 DOI: 10.1098/rspb.2023.0584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/30/2023] [Indexed: 06/22/2023] Open
Abstract
Temporal patterns in spawning and juvenile recruitment can have major effects on population size and the demographic structure of coral reef fishes. For harvested species, these patterns are crucial in determining stock size and optimizing management strategies such as seasonal closures. For the commercially important coral grouper (Plectropomus spp.) on the Great Barrier Reef, histological studies indicate peak spawning around the summer new moons. Here we examine the timing of spawning activity for P. maculatus in the southern Great Barrier Reef by deriving age in days for 761 juvenile fish collected between 2007 and 2022, and back-calculating settlement and spawning dates. Age-length relationships were used to estimate spawning and settlement times for a further 1002 juveniles collected over this period. Unexpectedly, our findings indicate year-round spawning activity generates distinct recruitment cohorts that span several weeks to months. Peak spawning varied between years with no clear association with environmental cues, and little to no alignment with existing seasonal fisheries closures around the new moon. Given the variability and uncertainty in peak spawning times, this fishery may benefit from additional and longer seasonal closures, or alternative fisheries management strategies, to maximize the recruitment contribution from periods of greatest reproductive success.
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Affiliation(s)
- H. B. Harrison
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
- Marine Biology and Aquaculture, College of Science & Engineering, James Cook University, Townsville 4811, Queensland, Australia
| | - L. Drane
- Marine Biology and Aquaculture, College of Science & Engineering, James Cook University, Townsville 4811, Queensland, Australia
| | - M. L. Berumen
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia
| | - B. J. Cresswell
- Marine Biology and Aquaculture, College of Science & Engineering, James Cook University, Townsville 4811, Queensland, Australia
- Commonwealth Scientific and Industrial Research Organisation, Townsville 4811, Queensland, Australia
| | - R. D. Evans
- Department of Biodiversity Conservation and Attractions, 17 Dick Perry Ave, Kensington 6151, Australia
- Oceans Institute, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - G. F. Galbraith
- Marine Biology and Aquaculture, College of Science & Engineering, James Cook University, Townsville 4811, Queensland, Australia
- Centre for Tropical Water and Aquatic Ecosystem Research (TropWATER), James Cook University, Townsville 4811, Queensland, Australia
| | - M. Srinivasan
- Marine Biology and Aquaculture, College of Science & Engineering, James Cook University, Townsville 4811, Queensland, Australia
- Centre for Tropical Water and Aquatic Ecosystem Research (TropWATER), James Cook University, Townsville 4811, Queensland, Australia
| | - B. M. Taylor
- University of Guam Marine Laboratory and UOG Sea Grant, 303 University Drive, UOG Station, Mangilao, Guam 96923, USA
| | - D. H. Williamson
- Great Barrier Reef Marine Park Authority, Townsville 4810, Queensland, Australia
| | - G. P. Jones
- Marine Biology and Aquaculture, College of Science & Engineering, James Cook University, Townsville 4811, Queensland, Australia
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Tidau S, Whittle J, Jenkins SR, Davies TW. Artificial light at night reverses monthly foraging pattern under simulated moonlight. Biol Lett 2022; 18:20220110. [PMID: 35892207 PMCID: PMC9326264 DOI: 10.1098/rsbl.2022.0110] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Mounting evidence shows that artificial light at night (ALAN) alters biological processes across levels of organization, from cells to communities. Yet, the combined impacts of ALAN and natural sources of night-time illumination remain little explored. This is in part due the lack of accurate simulations of the complex changes moonlight intensity, timing and spectra throughout a single night and lunar cycles in laboratory experiments. We custom-built a novel system to simulate natural patterns of moonlight to test how different ALAN intensities affect predator–prey relationships over the full lunar cycle. Exposure to high intensity ALAN (10 and 50 lx) reversed the natural lunar-guided foraging pattern by the gastropod mesopredator Nucella lapillus on its prey Semibalanus balanoides. Foraging decreased during brighter moonlight in naturally lit conditions. When exposed to high intensity ALAN, foraging increased with brighter moonlight. Low intensity ALAN (0.1 and 0.5 lx) had no impact on foraging. Our results show that ALAN alters the foraging pattern guided by changes in moonlight brightness. ALAN impacts on ecosystems can depend on lunar light cycles. Accurate simulations of night-time light cycle will warrant more realistic insights into ALAN impacts and also facilitate advances in fundamental night-time ecology and chronobiology.
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Affiliation(s)
- Svenja Tidau
- School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, UK.,School of Ocean Sciences, University of Bangor, Menai Bridge LL59 5AB, UK
| | - Jack Whittle
- School of Ocean Sciences, University of Bangor, Menai Bridge LL59 5AB, UK
| | - Stuart R Jenkins
- School of Ocean Sciences, University of Bangor, Menai Bridge LL59 5AB, UK
| | - Thomas W Davies
- School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, UK
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How moonlight shapes environments, life histories, and ecological interactions on coral reefs. Emerg Top Life Sci 2022; 6:45-56. [PMID: 35019136 DOI: 10.1042/etls20210237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/05/2021] [Accepted: 12/17/2021] [Indexed: 11/17/2022]
Abstract
The lunar cycle drives variation in nocturnal brightness. For the epipelagic larvae of coral reef organisms, nocturnal illumination may have widespread and underappreciated consequences. At sea, the onset of darkness coincides with an influx of mesopelagic organisms to shallow water (i.e. 'diel vertical migrants') that include predators (e.g. lanternfishes) and prey (zooplankton) of zooplanktivorous coral reef larvae. Moonlight generally suppresses this influx, but lunar periodicity in the timing and intensity of nocturnal brightness may affect vertically migrating predators and prey differently. A major turnover of species occurs at sunset on the reef, with diurnal species seeking shelter and nocturnal species emerging to hunt. The hunting ability of nocturnal reef-based predators is aided by the light of the moon. Consequently, variation in nocturnal illumination is likely to shape the timing of reproduction, larval development, and settlement for many coral reef organisms. This synthesis underscores the potential importance of trophic linkages between coral reefs and adjacent pelagic ecosystems, facilitated by the diel migrations of mesopelagic organisms and the ontogenetic migrations of coral reef larvae. Research is needed to better understand the effects of lunar cycles on life-history strategies, and the potentially disruptive effects of light pollution, turbidity, and climate-driven changes to nocturnal cloud cover. These underappreciated threats may alter patterns of nocturnal illumination that have shaped the evolutionary history of many coral reef organisms, with consequences for larval survival and population replenishment that could rival or exceed other effects arising from climate change.
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Schligler J, Cortese D, Beldade R, Swearer SE, Mills SC. Long-term exposure to artificial light at night in the wild decreases survival and growth of a coral reef fish. Proc Biol Sci 2021; 288:20210454. [PMID: 34102892 PMCID: PMC8187998 DOI: 10.1098/rspb.2021.0454] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 05/16/2021] [Indexed: 11/12/2022] Open
Abstract
Artificial light at night (ALAN) is an increasing anthropogenic pollutant, closely associated with human population density, and now well recognized in both terrestrial and aquatic environments. However, we have a relatively poor understanding of the effects of ALAN in the marine realm. Here, we carried out a field experiment in the coral reef lagoon of Moorea, French Polynesia, to investigate the effects of long-term exposure (18-23 months) to chronic light pollution at night on the survival and growth of wild juvenile orange-fin anemonefish, Amphiprion chrysopterus. Long-term exposure to environmentally relevant underwater illuminance (mean: 4.3 lux), reduced survival (mean: 36%) and growth (mean: 44%) of juvenile anemonefish compared to that of juveniles exposed to natural moonlight underwater (mean: 0.03 lux). Our study carried out in an ecologically realistic situation in which the direct effects of artificial lighting on juvenile anemonefish are combined with the indirect consequences of artificial lighting on other species, such as their competitors, predators, and prey, revealed the negative impacts of ALAN on life-history traits. Not only are there immediate impacts of ALAN on mortality, but the decreased growth of surviving individuals may also have considerable fitness consequences later in life. Future studies examining the mechanisms behind these findings are vital to understand how organisms can cope and survive in nature under this globally increasing pollutant.
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Affiliation(s)
- Jules Schligler
- USR 3278 CRIOBE, BP 1013, PSL Université Paris: EPHE-UPVD-CNRS, 98729 Papetoai, Moorea, French Polynesia
| | - Daphne Cortese
- USR 3278 CRIOBE, BP 1013, PSL Université Paris: EPHE-UPVD-CNRS, 98729 Papetoai, Moorea, French Polynesia
| | - Ricardo Beldade
- USR 3278 CRIOBE, BP 1013, PSL Université Paris: EPHE-UPVD-CNRS, 98729 Papetoai, Moorea, French Polynesia
- Las Cruces, Pontificia Universidad Católica de Chile, Estación Costera de Investigaciones Marinas and Center for Advanced Studies in Ecology and Biodiversity, Santiago de Chile, Chile
| | - Stephen E. Swearer
- National Centre for Coasts and Climate and School of BioSciences, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Suzanne C. Mills
- USR 3278 CRIOBE, BP 1013, PSL Université Paris: EPHE-UPVD-CNRS, 98729 Papetoai, Moorea, French Polynesia
- Laboratoire d'Excellence ‘CORAIL’, France
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