Cárdenas-Palomo N, Herrera-Silveira J, Velázquez-Abunader I, Reyes O, Ordoñez U
Centro de Investigación y Estudios Avanzados del IPN, Carr. Antigua a Progreso km. 6 Merida, Yucatan 97310, Mexico.
J Fish Biol. 2015 Feb;86(2):668-686. doi: 10.1111/jfb.12589. Epub 2014 Dec 19.
The relationship between the distribution of the whale shark Rhincodon typus and hydrobiological variables in the Caribbean Sea during 2005-2009 was analysed. Monthly trips were made to the R. typus aggregation area during the months when this species is present in the region (May to September) to record sightings and hydrological data and to collect samples to determine nutrients, chlorophyll a (Chl a) and zooplankton biomass. A total of 2104 R. typus were counted and three zones of high abundance were identified: Cabo-Catoche, Contoy (both within the Whale Shark Biosphere Reserve, WSBR) and the zone knows as Afuera. The zones of greatest R. typus density within the WSBR were characterized by high Chl a concentrations (median: 1·1 mg m , interpercentile range: 0·5-1·8 mg m ) and high nutrient concentrations, such as ammonium (median: 2·5 µmol l , interpercentile range: 0·5-6·4 µmol l ), due to the influence of local upwelling. A generalized additive model (GAM) was used to explore the relationship between R. typus distribution and the environmental variables inside WSBR. Zooplankton biomass was the most influential environmental variable, supporting the close relationship between R. typus distribution and biological productivity. Copepods were the dominant zooplankton group within the WSBR. In the Afuera zone, there were large R. typus aggregations (>80 individuals) associated with zooplankton dominated by fish eggs and significantly higher mean ± s.d. biomass (3356·1 ± 1960·8 mg m ) compared with that recorded inside the WSBR (103·5 ± 57·2 mg m ). The differences among zones generated changes in R. typus distribution patterns and provided opportunities to develop local management strategies for this species.
分析了2005 - 2009年期间加勒比海鲸鲨（Rhincodon typus）分布与水文生物学变量之间的关系。在该物种出现在该地区的月份（5月至9月），每月前往鲸鲨聚集区，记录目击情况和水文数据，并采集样本以测定营养物质、叶绿素a（Chl a）和浮游动物生物量。共统计到2104条鲸鲨，并确定了三个高丰度区域：卡波 - 卡托切、孔托伊（均在鲸鲨生物圈保护区，WSBR内）以及名为阿富埃拉的区域。WSBR内鲸鲨密度最大的区域具有高Chl a浓度（中位数：1.1 mg/m³，百分位数范围：0.5 - 1.8 mg/m³）和高营养浓度，如铵（中位数：2.5 μmol/l，百分位数范围：0.5 - 6.4 μmol/l），这是由于当地上升流的影响。使用广义相加模型（GAM）来探究WSBR内鲸鲨分布与环境变量之间以及该物种分布与生物生产力之间的紧密关系。桡足类是WSBR内占主导地位的浮游动物类群。在阿富埃拉区域，有大型鲸鲨聚集（>80只个体），与以鱼卵为主的浮游动物相关，并且其平均±标准差生物量（3356.1 ± 1960.8 mg/m³）显著高于WSBR内记录的生物量（103.5 ± 57.2 mg/m³）。各区域之间的差异导致了鲸鲨分布模式的变化，并为制定该物种的地方管理策略提供了机会。
