Deep neural networks based automated extraction of dugong feeding trails from UAV images in the intertidal seagrass beds

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 m2 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

Histological study of seventeen organs from dugong (Dugong dugon)

Background Dugongs are marine mammals with a crescent-shaped tail fluke and a concave trailing margin that belong to the family Dugongidae., They are distributed widely in the warm coastal waters of the Indo-Pacific region. Importantly, the population of dugongs has decreased over the past decades as they have been classified as rare marine mammals. Previous studies have investigated the habitat and genetic diversity of dugongs. However, a comprehensive histological investigation of their tissue has not yet been conducted. This study provides unique insight into the organs of dugongs and compares them with other mammal species. Methods Tissue sections were stained with Harris’s hematoxylin and eosin Y. The histological structure of 17 organ tissues obtained from eight systems was included in this study. Tissue sections were obtained from the urinary system (kidney), muscular system (striated skeletal muscle and smooth muscle), cardiovascular system (cardiac muscle (ventricle), coronary artery, and coronary vein), respiratory system (trachea and lung), gastrointestinal system (esophagus, stomach, small intestine, liver, and pancreas), reproductive system (testis), lymphatic system (spleen and thymus), and endocrine system (pancreas). Results While most structures were similar to those of other mammal species, there were some differences in the tissue sections of dugongs when compared with other mammalian species and manatees. These include the kidneys of dugongs, which were non-lobular and had a smooth, elongated exterior resulting in a long medullary crest, whereas the dugong pyloric epithelium did not have overlying stratified squamous cells and was noticably different from the Florida manatee. Discussion Histological information obtained from various organs of the dugong can serve as an essential foundation of basal data for future microanatomical studies. This information can also be used as high-value data in the diagnosis and pathogenesis of sick dugongs or those with an unknown cause of death

Distribution and Cconnection to other Plant-Communities of Genista radiata (L.) Scop in the South Tyrol (Italy)

Es werden die Genista radiata-Bestände an der Mendel in Südtirol (Italien) beschrieben und ihr Gesellschaftsanschluß diskutiert. Das Genisto-Festucetum alpestris Peer 83 besidelt steile südexponierte Kalkhänge der hochmontanen und subalpinen Stufe und ersetzt z.T. den Zwergstrauchgürtel mit Pinus mugo. Ähnlich zusammengesetzt ist das Genisto-Festucetum alpestris pinetosum Peer 83, das in den ¡lockeren Erika-Kiefernwäldern auftritt und bis in die tiefmontane Stufe hinunterreicht. Keinerlei syntaxonomische Bedeutung besitzt Genista radiata in den thermophilen Buschwaldgesellschaften, in denen die Pflanze lediglich eine Variante zum Orno-Ostryetum seslerietosum Peer 81 darstellt und speziell in der Saumzone anzutreffen ist. Auch in den Lärchenwiesen der Kammlagen kommt Genista radiata nur sporadisch vor. Sie ist hier mit dem Festucetum nigrescentis laricetosum subass. prov. verzahnt.Istražene su vegetacijske sastojine vrste Genista radiata u južnom Tirolu i razmatrana njihova fitocenološka pripadnost. Asocijacija Genisto-Festucetum alpestris Peer 83 nastava strme, južne vapnenačke obronke visokobrdskog i subalpskog pojasa. Subasocijacija Genisto-Festucetum alpestris pinetosum Peer 83 dolazi u rijetkim borovim šumama s crnjušom i spušta se do u niži brdski pojas. Termofilne niske šume, u kojima Genista radiata nema posebno sintaksonomsko značenje, označene su samo kao varijanta zajednice Orno-Ostryetum seslerietosum Peer 81. Genista radiata dolazi također na travnjacima s arišem, ali samo sporadično i to u mješavini sa zajednicom Festucetum nigrescentis laricetosnm subass. prov.The Genista radiata-communities of the Mendel in the South Tyrol (Italy) are described and their connection to other plant-communities is discussed. Genisto-Festucetum alpestris Peer 83 settles on steep, south- exposed colcareous slopes of high-mountain and subalpine altitudes and replaces particularly the dwarf-shrub-belt with Firms mugo. Similar contents aire found in Genisto-F estucetum alpestris pinetasum Peer 83, which occurs in undensed Erico-Pinetum-communities and reaches down to the low-mountain-altitude. In the thermophilic bush-communities, in which Genista radiata is found only as a variant of Orneto-Ostryetum seslerie- tosum (Peer 81), the plant has no syntaxonomic importance. Genista radiata especially is found in the edge-zone. In the grassland of the larch- communities of the ridges Genista radiata appears only sporadically. Here the plant appeals in Festucetum nigrescentis laricetosum subass. prov

Animal-borne telemetry: An integral component of the ocean observing toolkit

Animal telemetry is a powerful tool for observing marine animals and the physical environments that they inhabit, from coastal and continental shelf ecosystems to polar seas and open oceans. Satellite-linked biologgers and networks of acoustic receivers allow animals to be reliably monitored over scales of tens of meters to thousands of kilometers, giving insight into their habitat use, home range size, the phenology of migratory patterns and the biotic and abiotic factors that drive their distributions. Furthermore, physical environmental variables can be collected using animals as autonomous sampling platforms, increasing spatial and temporal coverage of global oceanographic observation systems. The use of animal telemetry, therefore, has the capacity to provide measures from a suite of essential ocean variables (EOVs) for improved monitoring of Earth's oceans. Here we outline the design features of animal telemetry systems, describe current applications and their benefits and challenges, and discuss future directions. We describe new analytical techniques that improve our ability to not only quantify animal movements but to also provide a powerful framework for comparative studies across taxa. We discuss the application of animal telemetry and its capacity to collect biotic and abiotic data, how the data collected can be incorporated into ocean observing systems, and the role these data can play in improved ocean management

タイコク アオウミガメ ノ セイタイ ト ホゴ ニ カンスル ケンキュウ

京都大学0048新制・論文博士博士(農学)乙第11467号論農博第2522号新制||農||894(附属図書館)学位論文||H16||N3941(農学部図書室)UT51-2004-G962(主査)教授 田中 克, 教授 藤原 建紀, 助教授 荒井 修亮学位規則第4条第2項該当Doctor of Agricultural ScienceKyoto UniversityDA

The Population Sizes of Indo-Pacific Humpback Dolphins (Sousa chinensis) Around Sukon and Sarai Islands, Thailand Estimated Using Photo-Identification Technique

February 20-21, 2012, BANGKOK, THAILANDThe population sizes of Indo-Pacific humpback dolphins (Sousa chinensis) around Sukon Island, Trang Province and Sarai Island, Satun Province on the Andaman coast of Thailand, were estimated using photo-identification technique. The field survey was conducted during November, 2010 – December, 2011. The survey effort at Sukon Island amounted to 11 days, totaling 59.09 hours of observation, while at Sarai Island the survey effort amounted to 15 days and totaled 57.11 hours. A total of 23 dolphins were identified at Sukon Island and a further 24 identified at Sarai Island via photoidentification. Estimation of dolphin population sizes with the Chapman- modified Peterson's mark and recapture model, showed that there were 56±21.5 and 29±4.2 individuals around Sukon and Sarai Islands respectively. Combining the results of photo-identification from the previous and present surveys, the total number of animals was found to be very similar to the estimated population's size predicted using Chapman's equation

Dugong Aerial Surveys 2011-2012: Declining Trend of the Dugong Population in Muk-Talibong Island, Thaland

March 18-19, 2013The Muk-Talibong Islands in Trang Province is a habitat for the largest group of dugongs on Thailand's Andaman coast. Since 1994, the Phuket Marine Biological Center has regularly conducted aerial surveys over the area with various kinds of aircrafts. In 2011 and 2012, the small aircraft model Tecnum P92J was used in line transect aerial surveys. Survey efforts were four flights (15.01 hours) and seven flights (17.14 hours) respectively. In 2011, the dugong detection rate was 51±50 animals per day, with a maximum count of 122 animals. In 2012, however, the dugong detection rate was 26±14 animals per day, with a maximum count of 54 animals. As a result of comparing the dugong detection rates for both years, we found that the number of dugongs is decreasing, even though the aerial survey periods in each year were the same month and tidal time. Windspeed is likely to be a physical factor that might lead to these results. Ranges of wind speed were 0-6 knot in 2011 and 5-17 knot in 2012. The wind speed affects waves and turbidity, and this may negatively affect visual detection of dugongs. Therefore, further aerial surveys in different weather conditions and dugong stranding reports may help to better understand the declining trends of dugongs in the area

Aquaculture-based Enhancement and Restoration of Giant Clam in Thailand

Giant clams are protected species under Thailand's Wildlife Conservation and Protection Act of B.E. 2535. Natural stock of giant clams has been declining to scarcity in almost every natural distribution area. Among three living giant clam species in Thai waters, Tridacna squamosa was considered the most endangered with less than 1% in existing number. Successful hatchery breeding and seed production of this species has been achieved by Thailand Department of Fisheries since 1993. After that, the giant clam restocking programs have been carried out at several sites both in the Gulf of Thailand and the Andaman Sea with various levels of success. Unlike other fisheries resources, the giant clam seed production and restocking in Thailand have been targeted mainly for conservation purposes. The restocking programs were cooperated by Department of Fisheries and Department of Marine and Coastal Resources. The activities have been conducted in collaboration with local communities, private sectors, as well as conservationists. Details on methodology, constraints, and results will be presented and discussed

Seasonal nesting of green turtles at Huyong Island, Thailand

Organized by Graduate School of Informatics, Kyoto University ; JSPS Bangkok Liaison Office ; Japanese Society of Bio-logging Science ; Informatics Research Center for Development of Knowledge Society InfrastructureDecember 13-14, 2005, Siam City Hotel, Bangkok, ThailandIn this paper, we report the current results of the studies on the reproductive biology of green turtles nested at Huyong Island, Thailand. The Huyong Island is a year-round nesting rookery of green turtles. Although information on year-round nesting population of sea turtles is very important to understand the ecology of sea turtles, there were few comprehensive data sets on year-round nesting populations. Therefore, three methods were used to investigate reproductive features of year-round nesting population of green turtles. Firstly, tagging studies were conducted to examine nesting seasonality of female green turtles. Next, satellite tracking studies were conducted to examine horizontal distributions of the female green turtles during post-nesting periods. In addition, bio-logging studies using data loggers were used to examine diving behavior of the female green turtles during inter-nesting periods. Our results showed that: 1) nesting in the Huyong green turtles occurred more or less at the same time on an individual basis, 2) nesting throughout the season might be attributed to proximity to feeding grounds, 3) there is seasonal difference in reproductive output among individuals, and 4) diving behavior of females during inter-nesting periods may be a key determinant of the seasonal difference in reproductive output