Quantifying the Impact of Light Pollution on Sea Turtle Nesting Using Ground-Based Imagery
Remote sensing of anthropogenic light has substantial potential to quantify light pollution levels and understand its impact on a wide range of taxa. Currently, the use of space-borne night-time sensors for measuring the actual light pollution that animals experience is limited. This is because most...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-06-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/12/11/1785 |
| _version_ | 1797566384985604096 |
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| author | James Vandersteen Salit Kark Karina Sorrell Noam Levin |
| author_facet | James Vandersteen Salit Kark Karina Sorrell Noam Levin |
| author_sort | James Vandersteen |
| collection | DOAJ |
| description | Remote sensing of anthropogenic light has substantial potential to quantify light pollution levels and understand its impact on a wide range of taxa. Currently, the use of space-borne night-time sensors for measuring the actual light pollution that animals experience is limited. This is because most night-time satellite imagery and space-borne sensors measure the light that is emitted or reflected upwards, rather than horizontally, which is often the light that is primarily perceived by animals. Therefore, there is an important need for developing and testing ground-based remote sensing techniques and methods. In this study, we aimed to address this gap by examining the potential of ground photography to quantify the actual light pollution perceived by animals, using sea turtles as a case study. We conducted detailed ground measurements of night-time brightness around the coast of Heron Island, a coral cay in the southern Great Barrier Reef of Australia, and an important sea turtle rookery, using a calibrated DSLR Canon camera with an 8 mm fish-eye lens. The resulting hemispheric photographs were processed using the newly developed Sky Quality Camera (SQC) software to extract brightness metrics. Furthermore, we quantified the factors determining the spatial and temporal variation in night-time brightness as a function of environmental factors (e.g., moon light, cloud cover, and land cover) and anthropogenic features (e.g., artificial light sources and built-up areas). We found that over 80% of the variation in night-time brightness was explained by the percentage of the moon illuminated, moon altitude, as well as cloud cover. Anthropogenic and geographic factors (e.g., artificial lighting and the percentage of visible sky) were especially important in explaining the remaining variation in measured brightness under moonless conditions. Night-time brightness variables, land cover, and rock presence together explained over 60% of the variation in sea turtle nest locations along the coastline of Heron Island, with more nests found in areas of lower light pollution. The methods we developed enabled us to overcome the limitations of commonly used ground/space borne remote sensing techniques, which are not well suited for measuring the light pollution to which animals are exposed. The findings of this study demonstrate the applicability of ground-based remote sensing techniques in accurately and efficiently measuring night-time brightness to enhance our understanding of ecological light pollution. |
| first_indexed | 2024-03-10T19:26:07Z |
| format | Article |
| id | doaj.art-aec093a771a04061a8c8ee74b5abea10 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-10T19:26:07Z |
| publishDate | 2020-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-aec093a771a04061a8c8ee74b5abea102023-11-20T02:32:26ZengMDPI AGRemote Sensing2072-42922020-06-011211178510.3390/rs12111785Quantifying the Impact of Light Pollution on Sea Turtle Nesting Using Ground-Based ImageryJames Vandersteen0Salit Kark1Karina Sorrell2Noam Levin3The Biodiversity Research Group, School of Biological Sciences, Centre for Biodiversity and Conservation Science, The University of Queensland, St Lucia, QLD 4072, AustraliaThe Biodiversity Research Group, School of Biological Sciences, Centre for Biodiversity and Conservation Science, The University of Queensland, St Lucia, QLD 4072, AustraliaSchool of Geography, The University of Melbourne, Parkville, VIC 3010, AustraliaDepartment of Geography, The Hebrew University of Jerusalem, Jerusalem 91905, IsraelRemote sensing of anthropogenic light has substantial potential to quantify light pollution levels and understand its impact on a wide range of taxa. Currently, the use of space-borne night-time sensors for measuring the actual light pollution that animals experience is limited. This is because most night-time satellite imagery and space-borne sensors measure the light that is emitted or reflected upwards, rather than horizontally, which is often the light that is primarily perceived by animals. Therefore, there is an important need for developing and testing ground-based remote sensing techniques and methods. In this study, we aimed to address this gap by examining the potential of ground photography to quantify the actual light pollution perceived by animals, using sea turtles as a case study. We conducted detailed ground measurements of night-time brightness around the coast of Heron Island, a coral cay in the southern Great Barrier Reef of Australia, and an important sea turtle rookery, using a calibrated DSLR Canon camera with an 8 mm fish-eye lens. The resulting hemispheric photographs were processed using the newly developed Sky Quality Camera (SQC) software to extract brightness metrics. Furthermore, we quantified the factors determining the spatial and temporal variation in night-time brightness as a function of environmental factors (e.g., moon light, cloud cover, and land cover) and anthropogenic features (e.g., artificial light sources and built-up areas). We found that over 80% of the variation in night-time brightness was explained by the percentage of the moon illuminated, moon altitude, as well as cloud cover. Anthropogenic and geographic factors (e.g., artificial lighting and the percentage of visible sky) were especially important in explaining the remaining variation in measured brightness under moonless conditions. Night-time brightness variables, land cover, and rock presence together explained over 60% of the variation in sea turtle nest locations along the coastline of Heron Island, with more nests found in areas of lower light pollution. The methods we developed enabled us to overcome the limitations of commonly used ground/space borne remote sensing techniques, which are not well suited for measuring the light pollution to which animals are exposed. The findings of this study demonstrate the applicability of ground-based remote sensing techniques in accurately and efficiently measuring night-time brightness to enhance our understanding of ecological light pollution.https://www.mdpi.com/2072-4292/12/11/1785ecological light pollutionhemispheric photographySky Quality CameramooncloudsGreat Barrier Reef |
| spellingShingle | James Vandersteen Salit Kark Karina Sorrell Noam Levin Quantifying the Impact of Light Pollution on Sea Turtle Nesting Using Ground-Based Imagery Remote Sensing ecological light pollution hemispheric photography Sky Quality Camera moon clouds Great Barrier Reef |
| title | Quantifying the Impact of Light Pollution on Sea Turtle Nesting Using Ground-Based Imagery |
| title_full | Quantifying the Impact of Light Pollution on Sea Turtle Nesting Using Ground-Based Imagery |
| title_fullStr | Quantifying the Impact of Light Pollution on Sea Turtle Nesting Using Ground-Based Imagery |
| title_full_unstemmed | Quantifying the Impact of Light Pollution on Sea Turtle Nesting Using Ground-Based Imagery |
| title_short | Quantifying the Impact of Light Pollution on Sea Turtle Nesting Using Ground-Based Imagery |
| title_sort | quantifying the impact of light pollution on sea turtle nesting using ground based imagery |
| topic | ecological light pollution hemispheric photography Sky Quality Camera moon clouds Great Barrier Reef |
| url | https://www.mdpi.com/2072-4292/12/11/1785 |
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