菁英獎｜佳作

群眾保育：海龜覓食棲地、定居模式及威脅

馮加伶
國立臺灣師範大學/中央研究院生物多樣性國際研究生博士學程
共同發表人：Daphne Z. Hoh, Huai Su, Peng-Yu Chen, Chia-Chen Tsai, Kelly W. H. Tseng, Hao-Chih Huang, Jun-Yi Wu, Yoko Nozawa, and Benny K. K. Chan

摘要

台灣過往海龜研究多聚焦於產卵沙灘監測與擱淺救護，對近岸覓食海龜族群的瞭解有限。透過與公民科學家合作推動「海龜點點名」，邀請潛水員回報海龜目擊紀錄，目前社團成員已超過兩萬人，實際參與回報的公民科學家超過400位。五年資料顯示小琉球、墾丁、綠島為主要覓食熱區，以青年龜為主（六成）。總共紀錄約750隻海龜個體，超過四成的海龜經常性定居於台灣近岸，且體型越大的綠蠵龜定居時間越久。此外，約10%的目擊事件與受傷海龜有關，包括遭漁線纏繞或螺旋槳擊傷的海龜，也有誤食海廢或患有不明原因外傷、斷肢及疤痕的海龜，顯示人類活動在覓食地熱區對海龜構成威脅，需要更實際的管理保育措施。此計畫的研究相關成果已發表兩篇文章於國際SCI期刊、公開於全球生物多樣性資訊平台GBIF促進資料共享，亦整合至台灣海龜戶口名簿網站（https://turtlespottw.org/），讓回報者能主動協助辨識海龜個體，亦讓有興趣的民眾能認識海龜，提升公眾參與度，深化海洋保育意識。

方法與執行步驟

  1. Photographic identification (photo-ID)：The distinctive facial and flipper scale patterns of sea turtles have been validated as reliable natural markers and unique body patterns for individual identification. We used both manual photo-ID and a computer-based program “HotSpotter” to assist this process.
  2. Age class：To determine the demographic structure of sea turtles, turtle body size was visually estimated from whole-body photographs and categorized into different life history stages (post-hatchling, juvenile, subadult, or adult), combined with the carapace color pattern and marginal scute roundness characteristics and descriptions provided by the reporters.
  3. Residency：To examine the residency of the sea turtles, minimum residency duration (MRD) of green and hawksbill turtles was calculated and plotted separately. The MRD for each turtle was estimated based on total duration (days) between the earliest and latest recorded sighting. Individuals who stayed in the same area for more than 365 days (1 year) were considered residents. To study variations of MRD and number of sightings among estimated age-class groups (i.e., juvenile, subadult, or adult-sized), only green turtles were included due to low sample sizes for other species. Variations in MRD and the number of sightings per individual across different estimated age-class groups were examined using One-Way Analysis of Variance (One-Way ANOVA; factor: estimated age-class groups) in SigmaPlot 11 (Graffiti LLC).
  4. Participation and Retention of Citizen Scientists：The number of new and retained citizen scientists from previous years was analyzed for each year from 2017 to 2022 to assess the recruitment and retention trends of TurtleSpot Taiwan. Retention of citizen scientists was calculated as the total duration (in days), including both the first and the last sightings reported by an individual to the Facebook Group. A Pearson correlation coefficient analysis was conducted to examine the correlation between the number of sightings contributed by each participant and their retention time, visualized with a scatter plot in SigmaPlot 11. To avoid bias, sightings directly provided by citizen scientists to us without posting to the Facebook Group were excluded from the above analysis.

創新作為與跨域合作

This study is Taiwan’s first sea turtle ecological monitoring program integrating citizen science, individual photo-identification, and open data, moving beyond the traditional model dependent on a small number of researchers. Internationally, most sea turtle citizen science projects emphasize ecological results, with limited focus on optimizing participation. Here, we established the Taiwan Sea Turtle Photo-ID Database to allow contributors to engage in data analysis, conducted a quantitative assessment of participation levels, and proposed strategies to improve engagement and retention. Citizen science data also provided evidence of habitat connectivity among sea turtle foraging grounds in the western Pacific, supporting the development of international conservation strategies. During the outreach of this project, we also initiated collaborations with other marine citizen science programs (e.g., Reef Check, Coastal Survey, shark and ray sighting reports) to co-organize the Marine Citizen Science Carnival, serving as a model for cross-program engagement and public outreach.

預期成果與貢獻

  1. Mapping foraging habitats to fill data gaps：
    Sea turtle research in Taiwan has largely focused on nesting beaches and strandings, with limited knowledge of coastal foraging populations. Using five years of citizen science data, we mapped foraging habitats, with Liuqiu accounting for nearly 80% of sightings. The northeastern coast, previously suspected as a foraging area but lacking direct evidence, was confirmed to host resident turtles. The proportion of resident turtles in Liuqiu has risen from 10% in a previous study to over 40% in our data, suggesting improved habitat suitability and/or shifts in population structure.
  2. Quantifying anthropogenic threats and proposing management measures：
    About 10% of reports involved injured turtles, including carapace injuries (5.3%), missing/injured flippers (3.2%), and marine debris entanglement or ingestion (1.5%). Recommended measures include vessel speed reduction in hotspots, propeller guards, and regulating recreative fishing. We also invited the National Museum of Marine Biology and Aquarium’s stranding turtle rescue team to Liuqiu for a workshop on injury cases, stranding treatment, and appropriate responses when encountering injured turtles. Related cases and recommendations have been shared with the Ocean Conservation Administration.
top TOP