Multispectral low altitude remote sensing of wild oyster reefs

Although wild oyster reefs are invasive and are trophic competitors, they are an essential component of intertidal rocky reef systems that support a wide range of biodiversity in some intertidal estuaries. Despite their importance, their population locally and globally are declining, reflecting vari...

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Main Authors: Subhash Chand, Barbara Bollard
Format: Article
Language:English
Published: Elsevier 2021-10-01
Series:Global Ecology and Conservation
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2351989421003607
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author Subhash Chand
Barbara Bollard
author_facet Subhash Chand
Barbara Bollard
author_sort Subhash Chand
collection DOAJ
description Although wild oyster reefs are invasive and are trophic competitors, they are an essential component of intertidal rocky reef systems that support a wide range of biodiversity in some intertidal estuaries. Despite their importance, their population locally and globally are declining, reflecting variations such as increased predation and anthropogenic influence in an estuary, such as excessive nutrients discharge. In addition, spatial assessment and mapping wild oyster reefs can be challenging due to complex and rugged structures that are challenging to access using conventional in-situ, time-extensive techniques. Therefore, the application of remote sensing for ecology and conservation of benthic habitats has emerged as a powerful technique to expedite many challenges. This study investigated VIS (visible spectrum) and VIS+NIR (visible + near-infrared spectrum) remote sensing for spatial assessment and mapping wild oyster reefs in a rocky intertidal reef at low tide. In addition, the study assessed the spectral reflectance signatures of wild oyster reefs from RPAS aerial imagery to in-situ spectral signatures. Although the VIS orthomosaic had a higher spatial resolution, wild oyster reefs detection was less efficient. In contrast, oyster reefs were correctly classified in the VIS+NIR imagery achieving an overall accuracy of 85%. This accuracy implies that the spectral resolution has been more critical to detect and correctly classify oyster reefs than spatial resolution. This remote sensing technique for ecology and conservation offers scale-appropriate spatial assessment, monitoring, and mapping of benthic habitats in challenging and inaccessible marine environments. Furthermore, this technique can be complemented with in-situ and other remote sensing datasets to enhance our understanding of the spatial dynamics of near-shore marine environments.
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spelling doaj.art-c0d4eba2370548e5a70b64dd28e30f4a2022-12-21T22:36:26ZengElsevierGlobal Ecology and Conservation2351-98942021-10-0130e01810Multispectral low altitude remote sensing of wild oyster reefsSubhash Chand0Barbara Bollard1School of Science, The Auckland University of Technology, Auckland, New Zealand; Corresponding author.AUT Drone Lab, School of Engineering, Computer and Mathematical Sciences, Auckland University of Technology, Auckland, New ZealandAlthough wild oyster reefs are invasive and are trophic competitors, they are an essential component of intertidal rocky reef systems that support a wide range of biodiversity in some intertidal estuaries. Despite their importance, their population locally and globally are declining, reflecting variations such as increased predation and anthropogenic influence in an estuary, such as excessive nutrients discharge. In addition, spatial assessment and mapping wild oyster reefs can be challenging due to complex and rugged structures that are challenging to access using conventional in-situ, time-extensive techniques. Therefore, the application of remote sensing for ecology and conservation of benthic habitats has emerged as a powerful technique to expedite many challenges. This study investigated VIS (visible spectrum) and VIS+NIR (visible + near-infrared spectrum) remote sensing for spatial assessment and mapping wild oyster reefs in a rocky intertidal reef at low tide. In addition, the study assessed the spectral reflectance signatures of wild oyster reefs from RPAS aerial imagery to in-situ spectral signatures. Although the VIS orthomosaic had a higher spatial resolution, wild oyster reefs detection was less efficient. In contrast, oyster reefs were correctly classified in the VIS+NIR imagery achieving an overall accuracy of 85%. This accuracy implies that the spectral resolution has been more critical to detect and correctly classify oyster reefs than spatial resolution. This remote sensing technique for ecology and conservation offers scale-appropriate spatial assessment, monitoring, and mapping of benthic habitats in challenging and inaccessible marine environments. Furthermore, this technique can be complemented with in-situ and other remote sensing datasets to enhance our understanding of the spatial dynamics of near-shore marine environments.http://www.sciencedirect.com/science/article/pii/S2351989421003607Oyster reefsRGB & multispectralRemote sensingEstuarineDronesEcology & conservation
spellingShingle Subhash Chand
Barbara Bollard
Multispectral low altitude remote sensing of wild oyster reefs
Global Ecology and Conservation
Oyster reefs
RGB & multispectral
Remote sensing
Estuarine
Drones
Ecology & conservation
title Multispectral low altitude remote sensing of wild oyster reefs
title_full Multispectral low altitude remote sensing of wild oyster reefs
title_fullStr Multispectral low altitude remote sensing of wild oyster reefs
title_full_unstemmed Multispectral low altitude remote sensing of wild oyster reefs
title_short Multispectral low altitude remote sensing of wild oyster reefs
title_sort multispectral low altitude remote sensing of wild oyster reefs
topic Oyster reefs
RGB & multispectral
Remote sensing
Estuarine
Drones
Ecology & conservation
url http://www.sciencedirect.com/science/article/pii/S2351989421003607
work_keys_str_mv AT subhashchand multispectrallowaltituderemotesensingofwildoysterreefs
AT barbarabollard multispectrallowaltituderemotesensingofwildoysterreefs