scholarly journals Regional High-Resolution Benthic Habitat Data from Planet Dove Imagery for Conservation Decision-Making and Marine Planning

2021 ◽  
Vol 13 (21) ◽  
pp. 4215
Author(s):  
Steven R. Schill ◽  
Valerie Pietsch McNulty ◽  
F. Joseph Pollock ◽  
Fritjof Lüthje ◽  
Jiwei Li ◽  
...  
Keyword(s):  
High Resolution ◽  
Marine Protected Area ◽  
Accuracy Assessment ◽  
Marine Conservation ◽  
Benthic Habitat ◽  
Storm Damage ◽  
Ecological Data ◽  
Management Actions ◽  
Marine Habitats ◽  
High Resolution Imagery

High-resolution benthic habitat data fill an important knowledge gap for many areas of the world and are essential for strategic marine conservation planning and implementing effective resource management. Many countries lack the resources and capacity to create these products, which has hindered the development of accurate ecological baselines for assessing protection needs for coastal and marine habitats and monitoring change to guide adaptive management actions. The PlanetScope (PS) Dove Classic SmallSat constellation delivers high-resolution imagery (4 m) and near-daily global coverage that facilitates the compilation of a cloud-free and optimal water column image composite of the Caribbean’s nearshore environment. These data were used to develop a first-of-its-kind regional thirteen-class benthic habitat map to 30 m water depth using an object-based image analysis (OBIA) approach. A total of 203,676 km2 of shallow benthic habitat across the Insular Caribbean was mapped, representing 5% coral reef, 43% seagrass, 15% hardbottom, and 37% other habitats. Results from a combined major class accuracy assessment yielded an overall accuracy of 80% with a standard error of less than 1% yielding a confidence interval of 78%–82%. Of the total area mapped, 15% of these habitats (31,311.7 km2) are within a marine protected or managed area. This information provides a baseline of ecological data for developing and executing more strategic conservation actions, including implementing more effective marine spatial plans, prioritizing and improving marine protected area design, monitoring condition and change for post-storm damage assessments, and providing more accurate habitat data for ecosystem service models.

scholarly journals Semiautomated Mapping of Benthic Habitats and Seagrass Species Using a Convolutional Neural Network Framework in Shallow Water Environments

2020 ◽  
Vol 12 (23) ◽  
pp. 4002
Author(s):  
Hassan Mohamed ◽  
Kazuo Nadaoka ◽  
Takashi Nakamura
Keyword(s):  
High Resolution ◽  
Satellite Images ◽  
Benthic Habitat ◽  
Seagrass Species ◽  
Benthic Habitats ◽  
Ecological Processes ◽  
Species Detection ◽  
Management Actions ◽  
Marine Habitats ◽  
High Resolution Satellite Images

Benthic habitats are structurally complex and ecologically diverse ecosystems that are severely vulnerable to human stressors. Consequently, marine habitats must be mapped and monitored to provide the information necessary to understand ecological processes and lead management actions. In this study, we propose a semiautomated framework for the detection and mapping of benthic habitats and seagrass species using convolutional neural networks (CNNs). Benthic habitat field data from a geo-located towed camera and high-resolution satellite images were integrated to evaluate the proposed framework. Features extracted from pre-trained CNNs and a “bagging of features” (BOF) algorithm was used for benthic habitat and seagrass species detection. Furthermore, the resultant correctly detected images were used as ground truth samples for training and validating CNNs with simple architectures. These CNNs were evaluated for their accuracy in benthic habitat and seagrass species mapping using high-resolution satellite images. Two study areas, Shiraho and Fukido (located on Ishigaki Island, Japan), were used to evaluate the proposed model because seven benthic habitats were classified in the Shiraho area and four seagrass species were mapped in Fukido cove. Analysis showed that the overall accuracy of benthic habitat detection in Shiraho and seagrass species detection in Fukido was 91.5% (7 classes) and 90.4% (4 species), respectively, while the overall accuracy of benthic habitat and seagrass mapping in Shiraho and Fukido was 89.9% and 91.2%, respectively.

scholarly journals Assessing Riyadh’s Urban Change Utilizing High-Resolution Imagery

Land ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 193
Author(s):  
Ali Alghamdi ◽  
Anthony R. Cummings
Keyword(s):  
Maximum Likelihood ◽  
High Resolution ◽  
Accuracy Assessment ◽  
Middle Eastern ◽  
Object Oriented ◽  
Training Data ◽  
High Resolution Imagery ◽  
Significant Research ◽  
Desert Areas ◽  
Spot 5

The implications of change on local processes have attracted significant research interest in recent times. In urban settings, green spaces and forests have attracted much attention. Here, we present an assessment of change within the predominantly desert Middle Eastern city of Riyadh, an understudied setting. We utilized high-resolution SPOT 5 data and two classification techniques—maximum likelihood classification and object-oriented classification—to study the changes in Riyadh between 2004 and 2014. Imagery classification was completed with training data obtained from the SPOT 5 dataset, and an accuracy assessment was completed through a combination of field surveys and an application developed in ESRI Survey 123 tool. The Survey 123 tool allowed residents of Riyadh to present their views on land cover for the 2004 and 2014 imagery. Our analysis showed that soil or ‘desert’ areas were converted to roads and buildings to accommodate for Riyadh’s rapidly growing population. The object-oriented classifier provided higher overall accuracy than the maximum likelihood classifier (74.71% and 73.79% vs. 92.36% and 90.77% for 2004 and 2014). Our work provides insights into the changes within a desert environment and establishes a foundation for understanding change in this understudied setting.

scholarly journals UAS DATA ACQUISITION PROTOCOL FOR MARINE HABITAT MAPPING: AN ACCURACY ASSESSMENT STUDY

2020 ◽  
Vol XLIII-B3-2020 ◽  
pp. 1321-1326
Author(s):  
M. Doukari ◽  
K. Topouzelis
Keyword(s):  
High Resolution ◽  
Data Acquisition ◽  
Marine Environment ◽  
Environmental Conditions ◽  
Accuracy Assessment ◽  
Habitat Mapping ◽  
Marine Habitat ◽  
Acquisition Protocol ◽  
Marine Habitats ◽  
Marine Habitat Mapping

Abstract. Marine habitat mapping is essential for updating existing information, preserving, and protecting the marine environment. Unmanned Aerial Systems (UAS) are an important tool for monitoring and mapping coastal and marine environment because of their ability to provide very high-resolution aerial imagery.Environmental conditions have a critical role in marine mapping using UAS. This is due to the limitations of UAS surveys in coastal areas, i.e. the environmental conditions prevailing in the area. The limitations of weather and oceanographic conditions affecting the quality of marine data led to the creation of a UAS protocol for the acquisition of reliable marine information. The produced UAS Data Acquisition Protocol consists of three main categories: (i) Morphology of the study area, (ii) Environmental conditions, (iii) Flight parameters. These categories include the parameters that must be considered for marine habitat mapping.The aim of the present study is the accuracy assessment of the UAS protocol for marine habitat mapping through experimental flights. For the accuracy assessment of the UAS protocol, flights on different dates and environmental conditions were conducted, over a study area. The flight altitude was the same for all the missions, so the results were comparable. The high-resolution orthophoto maps derived from each date of the experiment were classified. The classification maps show several differences in the shape and size of the marine habitats which are directly dependent on the conditions that the habitats were mapped. A change detection comparison was conducted in pairs to examine the exact changes between the classified maps.The results emphasize the importance of the environmental conditions prevailing in an area during the mapping of marine habitats. The present study proves that the optimal flight conditions that are proposed of the UAS Data Acquisition protocol, respond to the real-world conditions and are important to be considered for an accurate and reliable mapping of the marine environment.

scholarly journals Assessing the Repeatability of Automated Seafloor Classification Algorithms, with Application in Marine Protected Area Monitoring

2020 ◽  
Vol 12 (10) ◽  
pp. 1572 ◽  
Author(s):  
America Zelada Leon ◽  
Veerle A.I. Huvenne ◽  
Noëlie M.A. Benoist ◽  
Matthew Ferguson ◽  
Brian J. Bett ◽  
...  
Keyword(s):  
Marine Protected Areas ◽  
Marine Protected Area ◽  
Marine Conservation ◽  
Benthic Habitat ◽  
Classification Algorithms ◽  
Seabed Classification ◽  
Seafloor Classification ◽  
Habitat Persistence ◽  
Essential Input ◽  
Area Monitoring

The number and areal extent of marine protected areas worldwide is rapidly increasing as a result of numerous national targets that aim to see up to 30% of their waters protected by 2030. Automated seabed classification algorithms are arising as faster and objective methods to generate benthic habitat maps to monitor these areas. However, no study has yet systematically compared their repeatability. Here we aim to address that problem by comparing the repeatability of maps derived from acoustic datasets collected on consecutive days using three automated seafloor classification algorithms: (1) Random Forest (RF), (2) K–Nearest Neighbour (KNN) and (3) K means (KMEANS). The most robust and repeatable approach is then used to evaluate the change in seafloor habitats between 2012 and 2015 within the Greater Haig Fras Marine Conservation Zone, Celtic Sea, UK. Our results demonstrate that only RF and KNN provide statistically repeatable maps, with 60.3% and 47.2% agreement between consecutive days. Additionally, this study suggests that in low-relief areas, bathymetric derivatives are non-essential input parameters, while backscatter textural features, in particular Grey Level Co-occurrence Matrices, are substantially more effective in the detection of different habitats. Habitat persistence in the test area between 2012 and 2015 was 48.8%, with swapping of habitats driving the changes in 38.2% of the area. Overall, this study highlights the importance of investigating the repeatability of automated seafloor classification methods before they can be fully used in the monitoring of benthic habitats.

scholarly journals Benthic Habitat Mapping Using Multispectral High-Resolution Imagery: Evaluation of Shallow Water Atmospheric Correction Techniques

Sensors ◽  
2017 ◽  
Vol 17 (11) ◽  
pp. 2639 ◽  
Author(s):  
Francisco Eugenio ◽  
Javier Marcello ◽  
Javier Martin ◽  
Dionisio Rodríguez-Esparragón
Keyword(s):  
High Resolution ◽  
Shallow Water ◽  
Atmospheric Correction ◽  
Habitat Mapping ◽  
Benthic Habitat ◽  
High Resolution Imagery

scholarly journals BENTHIC HABITAT MAPPING AND BIODIVERSITY ANALYSIS IN THE PRIMEIRAS AND SEGUNDAS ARCHIPELAGO RESERVE

2015 ◽  
Vol XL-7/W3 ◽  
pp. 1009-1016 ◽  
Author(s):  
L. Teixeira ◽  
M. Nilsson ◽  
J. Hedley ◽  
A. Shapiro
Keyword(s):  
Protected Area ◽  
Marine Protected Area ◽  
Current Knowledge ◽  
Coral Cover ◽  
Marine Ecosystem ◽  
Eastern Africa ◽  
Benthic Habitat ◽  
Brown Macroalgae ◽  
Marine Habitats ◽  
New Information

The Primeiras and Segundas Archipelago Reserve is a recently established marine protected area, the largest in Africa, located in the waters of Northern Mozambique. This protected area is of significant local economic importance and global ecological relevance, containing the southernmost coral reefs in Eastern Africa. However, information related to the marine ecosystem, notably benthic habitat is very scarce. Twelve atolls were mapped in the region using object-based image classification of very-high resolution satellite imagery (IKONOS, Quickbird, and WorldView-2). Geographically referenced data on benthic cover and depth were gathered in the course of three fieldwork expeditions covering a total of four atolls and two shallow reef structures in the Segundas Archipelago. The resulting map allows the estimation of three distinct types of coral cover (field, patches, spurs and grooves); the differentiation of sand, rubble and rock substrate; and the detection of seagrass and brown macroalgae, identifying up to 24 benthic habitats. Average overall accuracy was above 50%. The high variability of the optical properties on the reef systems, in large due to the connectivity with the mainland via plumes, while interesting from an ecological perspective increases the challenges for remote sensing of bottom cover. New information indicates the presence of deep benthic cover extending from the atolls, suggesting the need for further research on Coastal Eastern African corals, namely on their resilience and connectivity, and supporting current knowledge of the existence of an almost continuous coral reef from Kenya to Mozambique. Coral and fish biodiversity data have been analysed together with the satellite-derived maps. Results support the local perception that ecosystems are in decline and uncover new information about biodiversity’s spatial patterns. Our work provides a detailed depiction of marine habitats that may aid the management of the protected area, namely in the definition of fishing zones and coral cover monitoring.

scholarly journals Early conservation benefits of a de facto marine protected area at San Clemente Island, California

2019 ◽  
Author(s):  
Michael W. Esgro ◽  
James Lindholm ◽  
Kerry J. Nickols ◽  
Jessica Bredvik
Keyword(s):  
Community Composition ◽  
Marine Protected Area ◽  
Marine Conservation ◽  
Marine Spatial Planning ◽  
Linear Modeling ◽  
Remotely Operated Vehicle ◽  
Marine Habitats ◽  
Potential Benefits ◽  
Density And Biomass ◽  
San Clemente Island

AbstractDe facto marine protected areas (DFMPAs) are regions of the ocean where human activity is restricted for reasons other than conservation. Although DFMPAs are widespread globally, their potential role in the protection of marine habitats, species, and ecosystems has not been well studied. In 2012 and 2013, we conducted remotely operated vehicle (ROV) surveys of marine communities at a military DFMPA and an adjacent fished reference site at San Clemente Island, the southernmost of California’s Channel Islands. We used data extracted from ROV imagery to compare density and biomass of focal species, as well as biodiversity and community composition, between the two sites. Generalized linear modeling indicated that both density and biomass of California sheephead (Semicossyphus pulcher) were significantly higher inside the DFMPA. Biomass of ocean whitefish (Caulolatilus princeps) was also significantly higher inside the DFMPA. However, species richness and Shannon-Weaver diversity were not significantly higher inside the DFMPA, and overall fish community composition did not differ significantly between sites. Demonstrable differences between the DFMPA and fished site for two highly sought-after species hint at early potential benefits of protection, though the lack of differences in the broader community suggests that a longer trajectory of recovery may be required for other species. A more comprehensive understanding of the potential conservation benefits of DFMPAs is important in the context of marine spatial planning and global marine conservation objectives.

scholarly journals HORIZONTAL ACCURACY ASSESSMENT OF GOOGLE EARTH DATA OVER TYPICAL REGIONS OF ASIA

2020 ◽  
Vol XLIII-B3-2020 ◽  
pp. 1333-1338
Author(s):  
J. Guo ◽  
J. X. Zhang ◽  
H. T. Zhao ◽  
C. Li ◽  
J. Zhou ◽  
...  
Keyword(s):  
High Resolution ◽  
Land Surface ◽  
Accuracy Assessment ◽  
Google Earth ◽  
Large Area ◽  
High Resolution Imagery ◽  
Ground Measurement ◽  
Relative Errors ◽  
Terrain Features ◽  
Apparent Influence

Abstract. Google Earth provide the most accurate and available global high resolution imagery, covering nearly the entire land surface of the earth. However, the precision of Google Earth’s data has not been fully validated.The traditional ground measurement method is difficult to verify the horizontal precision of remote sensing over a large area. This paper focuses on typical regions of Asia, aiming to verify the precision of GE’s data based on purchased WorldView (WV) data by utilization of statistical analysis method.The results show that the highest precision has been estimated as 4.96–6.83 meters over the part of Japan, India and Kazakhstan, respectively. The lowest precision 16.53 and 16.59 meters primarily appear mountainous terrain, including the part of Israel and Syria.The result also presents the horizontal precision estimated in Japan, India and Kazakhstan, which is slightly higher than the precision estimated in Israel and Syria. The regions with larger deviation of relative errors have apparent influence on horizontal accuracy assessment of GE’s imagery. Accuracy assessment may be affected by terrain features and the insignificant feature points over the study area. The results suggest that the most of horizontal accuracy of GE’s high resolution imagery over the most of study regions fulfills precision requirement of 1:50000 maps.

Examining the links between multi-frequency backscatter, geomorphology and benthic habitat associations in Marine Protected Areas

2020 ◽  
Author(s):  
Robert Mzungu Runya ◽  
Chris McGonigle ◽  
Rory Quinn
Keyword(s):  
Marine Protected Area ◽  
Explanatory Power ◽  
Habitat Associations ◽  
Habitat Characteristics ◽  
Single Frequency ◽  
North Coast ◽  
Benthic Habitat ◽  
Infaunal Community ◽  
The North ◽  
Marine Habitats

<p>Acoustic methods are frequently used to provide broad-scale information on the spatial extent, range and distribution of marine habitats and sedimentary environments. Although single frequency multibeam echosounders have dominated seabed mapping for decades, multi-frequency approaches are starting to present in the scientific literature. Multibeam survey strategies are generally optimized for the acquisition of bathymetry data, often overlooking the ecological and geological value of backscatter data. This study examines the benefits of combining multi-frequency backscatter responses to discriminate seabed properties in areas with strong geomorphological gradients and associated ecological variability. The frequency-dependence element of backscatter strength is linked to: (i) the dominant scattering regime, (ii) seabed roughness, and (iii) the input of volume scattering related to signal penetration. In 2019, we collected and analyzed multifrequency (200, 95 and 30-kHz) backscatter data from Hempton’s Turbot Bank, a marine protected area off the north coast of Ireland. We compare these data with legacy 300 kHz backscatter data from 2013 to explore the backscatter variability in the context of geomorphological change. We assess the explanatory power of multi-frequency vis-à-vis single-frequency backscatter data in terms of bathymetry, sediment granulometry and infaunal community structure. Results improve our understanding of the link between backscatter properties and geomorphology, with specific recommendations towards minimizing information loss and establishing minimum data requirements for frequency-based benthic habitat discrimination. Improved discrimination of geomorphology and benthic habitat characteristics enhances the reliability of backscatter data as a monitoring technique for area-based protection of marine resources.</p>

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