Assessing the size, growth rate and structure of a seasonal population of whale sharks (Rhincodon typus Smith 1828) using conventional tagging and photo identification
Assessing the size, growth rate and structure of a seasonal population of whale sharks (Rhincodon typus Smith 1828) using conventional tagging and photo identification
复制标题
DOI：
10.1016/j.fishres.2006.11.026
复制
发表时间：
2007-03-01
影响因子：
2.4
通讯作者：
Roberts, Callum M.
中科院分区：
文献类型：
--
作者：
Graham, Rachel T.;Roberts, Callum M.
鲸鲨（Rhincodon typus）的种群规模和结构仍然未知，尽管它们对目标旅游业和渔业具有经济重要性，并于2002年被列入《濒危物种公约》附录二。在这里，我们提出了在西半球的第一个鲸鲨种群研究的结果，并描述了固有的困难，在自由放养的鲨鱼使用捕获独立的方法来评估种群。从1998年到2003年，我们确定了106鲸鲨使用其独特的疤痕和斑点模式后，521遇到在一个可预测的季节性聚集在中美洲大堡礁连接到笛鲷产卵聚集在格拉登嘴，伯利兹。遇到的鲨鱼测量的平均总长度为6.3 m +/- 1.7 m S.D.。范围3.0-12.7 m（n = 317）。性别和大小的隔离建议：31%的鲨鱼（n = 162）遇到的性别，其中86%是不成熟的男性。1999年至2002年期间，70条鲨鱼被贴上了72个传统标签，测量的鲨鱼（n = 63）的平均长度为6.0 m +/- 1.6 m S.D.。（范围3.0-9.7米）。三种重定的鲨鱼的生长率估计在0.03-0.70 m年（-1）之间。中美洲大堡礁其他地方的标记鲨鱼的栖息地表明，该种群并不居住在格莱登沙嘴，而是与另外两个具有季节性聚集的地点共享：墨西哥的孔托伊岛和洪都拉斯的乌蒂拉。监测Gladden Spit和中美洲大堡礁其他聚集点的鲸鲨数量是该地区利润丰厚和蓬勃发展的鲸鲨旅游业的基础，也是当地和国际保护鲸鲨的关键。(c)2006 Elsevier B. V.保留所有权利。
Population size and structure of whale sharks (Rhincodon typus) remain unknown despite their economic importance to targeted tourism and fisheries and their 2002 listing on CITES Appendix II. Here, we present results from the first whale shark population study in the Western Hemisphere and describe the inherent difficulties of assessing populations using catch-independent methods in free-ranging sharks. From 1998 to 2003, we identified 106 whale sharks using their distinctive scars and spot patterns following 521 encounters at a predictable seasonal aggregation on the Mesoamerican Barrier Reef linked to snapper spawning aggregations at Gladden Spit, Belize. Encountered sharks measured a mean total length of 6.3 m +/- 1.7 m S.D. and a range of 3.0-12.7 m (n = 317). Sexual and size segregation is suggested: 31 % of encountered sharks (n = 162) were sexed, of which 86% were immature males. Between 1999 and 2002, 70 sharks were tagged with 72 conventional tags and measured sharks (n = 63) possessed a mean length of 6.0 m +/- 1.6 m S.D. (range 3.0-9.7 m). Growth rates for three resighted sharks ranged from an estimated 0.03-0.70 m year(-1). Resightings of tagged sharks elsewhere on the Mesoamerican Barrier Reef indicate that the population is not resident at Gladden Spit and is shared with two other sites possessing seasonal aggregations: Isla Contoy, Mexico and Utila, Honduras. Monitoring whale shark populations at Gladden Spit and the other aggregation sites on the Mesoamerican Barrier Reef underpins the region's lucrative and burgeoning whale shark tourism and is key to their local and international conservation. (c) 2006 Elsevier B.V. All rights reserved.