Aerial photogrammetry of whale sharks (Rhincodon typus) in the Bay of La Paz, using an unoccupied aerial vehicle

Whitehead, Darren A.; Ayres, Kathryn A.; Gayford, Joel H.; Galván‐Magaña, Felipe; Christiansen, Fredrik

doi:10.1007/s00227-022-04085-0

Cited by 6 publications

(3 citation statements)

References 40 publications

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“…Aerial photogrammetry has gained increasing popularity in the studies of aquatic megafauna to estimate their size, volume, and mass, which are vital parameters to assess health and nutritional status for conservation management (e.g., blue whale, Balaenoptera musculus , by Durban et al, 2016; manta ray, Mobula alfredi , by Setyawan et al, 2022; whale sharks, Rhincodon typus , by Whitehead et al, 2022; sea turtles, Dermochelys coriacea , by Schofield et al, 2019). Many cetaceans occur in large pods, with individuals changing positions in the frame throughout a single drone flight (Cheney et al, 2022; Durban et al, 2015; Fearnbach et al, 2018; Fiori et al, 2017; Laborie et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

Computer vision‐assisted photogrammetry and one‐image 3D modeling in marine mammals

Zhang,

Zhou,

Shah

et al. 2023

Marine Mammal Science

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Image processing using traditional photogrammetric methods is a labor‐intensive process. The collection of photogrammetry images during aerial surveys is expanding rapidly, creating new challenges to analyze images promptly and efficiently, while reducing human error during processing. Computer vision‐assisted photogrammetry, a field of artificial intelligence (AI), can automate image processing, greatly enhancing the efficiency of photogrammetry. Here, we present a practical and efficient program capable of automatically extracting the fine‐scale photogrammetry of East Asian finless porpoises (Neophocaena asiaeorientalis sunameri). Our results indicated that computer vision‐assisted photogrammetry could achieve the same accuracy as traditional photogrammetry, and the results of the comparisons were validated against the direct measurements. Three‐dimensional (3D) models using computer vision‐assisted photogrammetric morphometrics generated trustworthy body volume estimates. We also explored the one image‐based 3D modeling technique, which is less accurate, but still useful when only one image of the animal is available. Although several limitations exist in the current program, improvements could be made to narrow the virtual‐reality gap when more images are available for machine learning and training. We recommend this program for analyzing images of marine mammals possessing a similar morphological contour.

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Section: Discussionmentioning

confidence: 99%

Computer vision‐assisted photogrammetry and one‐image 3D modeling in marine mammals

Zhang,

Zhou,

Shah

et al. 2023

Marine Mammal Science

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“…In addition, the study species would have to have to remain stationary during surveys, in high densities, and in a predictable location for some period of time, which is unlikely in dynamic aquatic environments. However, it is possible to use UAVs to estimate the 2D body size of fully-aquatic species such as cetaceans (Gray et al, 2019), whale sharks (Whitehead et al, 2022) and corals (Levy et al, 2018). It is also possible to estimate body volume in cetaceans by creating a 3D model of the study species and scaling the model to different individuals using 2D body size estimates (Hirtle et al, 2022).…”

Section: Discussionmentioning

confidence: 99%

An unmanned aerial vehicle pipeline to estimate body volume at scale for ecological monitoring

Stone,

Davis

2023

Preprint

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Demographic data are essential to construct mechanistic models to understand how populations change over time and in response to global threats like climate change. Existing demographic data are either lacking or insufficient for many species, particularly those that are challenging to study, such as marine mammals. A pipeline for collecting accurate demographic data to construct robust demographic models at scale would fill this knowledge gap for many species, including marine mammals like pinnipeds (seals, sea lions, and walruses).We introduce a non-invasive pipeline to estimate the 3D body size (volume) of species that will allow monitoring at high spatial and temporal scales. Our pipeline integrates 3D structure-from-motion photogrammetry data collected via planned flight missions using off-the-shelf, multirotor unmanned aerial vehicles (UAVs). We apply and validate this pipeline on the grey sealHalichoerus grypus, a marine species that spends much of its time at sea but is predictably observable during its annual breeding season. We investigate the optimal ground sampling distance (GSD) for surveys by calculating the success rates and accuracy of volume estimates of individuals at different elevations.We establish an optimal GSD of 0.8 cm px-1for animals similar in size to UK grey seals (∼1.4 - 2.5 m length), making our pipeline reproducible and applicable to a broad range of organisms. Volume estimates were accurate and could be made for up to 68% of hauled-out seals in the study areas. Finally, we highlight six key traits that make a species well-suited to estimating body volume following this pipeline. Good candidates include large reptiles like crocodiles, large mammals such as hippopotamus, and shrubs or bushes in deserts and Mediterranean habitats.Our pipeline accurately estimates individual body volume of marine macrovertebrates in a time-and cost-effective manner whilst minimising disturbance. Whilst the approach is applied to pinnipeds here, the pipeline is adaptable to many different taxa that are otherwise challenging to study. Our proposed approach therefore opens up previously inaccessible areas of the Tree of Life to demographic studies, which will improve our ability to protect and conserve these species into the future.

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“…The governance of these areas in general and fall within the responsibility of CO-NANP, although it is also carried out with the support of other governments and civil society institutions [33]. In addition, different academic institutions are also involved in the evaluation of the protected species populations [35][36][37][38]. .…”

Section: Other Effective Area-based Conservation Measures (Oecms) Fis...mentioning

confidence: 99%

Mexico on Track to Protect 30% of Its Marine Area by 2030

Perera-Valderrama,

Rosique-de la Cruz,

Caballero-Aragón

et al. 2023

Sustainability

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Mexico has committed to protecting 30% of its marine territory by 2030 to comply with Target 3 of the Kunming–Montreal Global Biodiversity Framework, adopted during the 15th Conference of the Parties to the Convention on Biological Diversity. In this paper, we demonstrate the feasibility of meeting this commitment by determining the marine extent of conservation measures based on legally established Marine Protected Areas and areas that meet the criteria to be considered as Other Effective area-based Conservation Measures (OECMs) and determining the marine extent of areas proposed in various conservation planning exercises that can be created as any of the area-based instruments that exist in Mexico. The total coverage of existing and proposed areas was calculated by merging the dataset to remove duplicates and dissolving the boundaries between polygons to determine the total area. Spatial analysis was carried out in ArcGIS using geoprocessing tools. Currently, more than 25% of Mexico’s marine area is legally protected or conserved, with federal marine protected areas covering more than 22% of the Exclusive Economic Zone. The legally established areas that can be considered OECMs cover about 3% of the marine territory. We found that more than 9% of Mexico’s Economic Exclusive Zone contains areas of high conservation importance that are not covered by any area-based instrument. This study shows that Mexico has the potential to protect or conserve 32.8% of its marine territory by 2030.

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Aerial photogrammetry of whale sharks (Rhincodon typus) in the Bay of La Paz, using an unoccupied aerial vehicle

Cited by 6 publications

References 40 publications

Computer vision‐assisted photogrammetry and one‐image 3D modeling in marine mammals

Computer vision‐assisted photogrammetry and one‐image 3D modeling in marine mammals

An unmanned aerial vehicle pipeline to estimate body volume at scale for ecological monitoring

Mexico on Track to Protect 30% of Its Marine Area by 2030

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