In:
PLOS ONE, Public Library of Science (PLoS), Vol. 16, No. 8 ( 2021-8-13), p. e0255586-
Abstract:
Dugongs ( Dugong dugon ) are seagrass specialists distributed in shallow coastal waters in tropical and subtropical seas. The area and distribution of the dugongs’ feeding trails, which are unvegetated winding tracks left after feeding, have been used as an indicator of their feeding ground utilization. However, current ground-based measurements of these trails require a large amount of time and effort. Here, we developed effective methods to observe the dugongs’ feeding trails using unmanned aerial vehicle (UAV) images (1) by extracting the dugong feeding trails using deep neural networks. Furthermore, we demonstrated two applications as follows; (2) extraction of the daily new feeding trails with deep neural networks and (3) estimation the direction of the feeding trails. We obtained aerial photographs from the intertidal seagrass bed at Talibong Island, Trang Province, Thailand. The F1 scores, which are a measure of binary classification model’s accuracy taking false positives and false negatives into account, for the method (1) were 89.5% and 87.7% for the images with ground sampling resolutions of 1 cm/pixel and 0.5 cm/pixel, respectively, while the F1 score for the method (2) was 61.9%. The F1 score for the method (1) was high enough to perform scientific studies on the dugong. However, the method (2) should be improved, and there remains a need for manual correction. The mean area of the extracted daily new feeding trails from September 12–27, 2019, was 187.8 m 2 per day (n = 9). Total 63.9% of the feeding trails was estimated to have direction within a range of 112.5° and 157.5°. These proposed new methods will reduce the time and efforts required for future feeding trail observations and contribute to future assessments of the dugongs’ seagrass habitat use.
Type of Medium:
Online Resource
ISSN:
1932-6203
DOI:
10.1371/journal.pone.0255586
DOI:
10.1371/journal.pone.0255586.g001
DOI:
10.1371/journal.pone.0255586.g002
DOI:
10.1371/journal.pone.0255586.g003
DOI:
10.1371/journal.pone.0255586.g004
DOI:
10.1371/journal.pone.0255586.g005
DOI:
10.1371/journal.pone.0255586.g006
DOI:
10.1371/journal.pone.0255586.g007
DOI:
10.1371/journal.pone.0255586.g008
DOI:
10.1371/journal.pone.0255586.g009
DOI:
10.1371/journal.pone.0255586.g010
DOI:
10.1371/journal.pone.0255586.g011
DOI:
10.1371/journal.pone.0255586.g012
DOI:
10.1371/journal.pone.0255586.g013
DOI:
10.1371/journal.pone.0255586.g014
DOI:
10.1371/journal.pone.0255586.g015
DOI:
10.1371/journal.pone.0255586.t001
DOI:
10.1371/journal.pone.0255586.t002
Language:
English
Publisher:
Public Library of Science (PLoS)
Publication Date:
2021
detail.hit.zdb_id:
2267670-3
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