Department of Biology, University of Cádiz, Campus of International Excellence of the Sea (CEIMAR), Polígono Rio San Pedro s/n, 11510 Puerto Real, Cádiz, Spain; Instituto Tecnológico Superior de Tela, Universidad Nacional Autónoma de Honduras, Boulevard Suyapa, Tegucigalpa, Honduras.
Department of Biology, University of Cádiz, Campus of International Excellence of the Sea (CEIMAR), Polígono Rio San Pedro s/n, 11510 Puerto Real, Cádiz, Spain; Instituto Universitario de Investigación Marina (INMAR), University of Cádiz, Campus of International Excellence of the Sea (CEIMAR), Polígono Rio San Pedro s/n, 11510 Puerto Real, Cádiz, Spain..
Sci Total Environ. 2020 Jun 25;723:138014. doi: 10.1016/j.scitotenv.2020.138014. Epub 2020 Mar 21.
Temporarily open-closed estuaries and estuarine lagoons are among the most complex aquatic ecosystems, prone to undergo rapid changes in response to global change and other anthropogenic impacts. Nonetheless, studies on the factors that control annual cycles of phytoplanktonic biomass and primary production in such systems, especially tropical ones, are still scarce. Even less information exists on the effect increasingly frequent extreme climatic events (ECE) might have on their dynamics. For this purpose, we monitored the changes in ecological conditions in the Los Micos estuarine lagoon (Honduras) by sampling monthly during an annual cycle that included several changes in the lagoon's mouth phase and attempted to understand which environmental factors affect phytoplanktonic biomass and primary production. We also evaluated the impact of, and recovery from, a tropical storm ECE. Annual mean net production (Pn), integrated for the euphotic zone, (4.3 ± 2.8 gC m d) and Chlorophyll a (27.1 ± 19.1 mg m) values in Los Micos place it as one of the more productive estuaries worldwide. The physico-chemical characteristics of the lagoon clearly depended on mouth phase; however, the values of Chla and Pn did not show significant differences between the open and closed phases. The application of distance-based multivariate linear models did not show any clear dominant model being able to explain the observed Chla and Pn patterns. The most parsimonious models included among others, salinity, particulate organic carbon and PO, which suggests that primary production is controlled by multiple factors. During the ECE, about 19% of DIN, 91% of DSi and PO, 60% of particulate organic carbon and nitrogen, and 86% of Chla were exported to the sea, greatly reducing Pn. However, Chla and Pn values recovered to pre-storm levels within 30 days, indicating that these biological variables are highly resilient in Los Micos Lagoon.
半闭/开敞型河口和河口湾是最复杂的水生生态系统之一，容易受到全球变化和其他人为影响的快速变化的影响。尽管如此，对于控制此类系统（尤其是热带系统）浮游植物生物量和初级生产力年周期的因素的研究仍然很少。关于日益频繁的极端气候事件（ECE）对其动态可能产生的影响的信息就更少了。为此，我们通过在一个包括几个河口阶段变化的年周期中每月进行采样，监测了 Los Micos 河口湾（洪都拉斯）的生态条件变化，并试图了解哪些环境因素会影响浮游植物生物量和初级生产力。我们还评估了热带风暴 ECE 的影响及其恢复情况。Los Micos 的年平均净生产力（Pn），整合了光区，（4.3±2.8 gC m d）和叶绿素 a（27.1±19.1 mg m）的值使其成为世界上生产力较高的河口之一。该河口的理化特性明显取决于河口阶段；然而，Chla 和 Pn 值在开/闭阶段之间没有显著差异。基于距离的多元线性模型的应用并没有显示出任何能够解释观察到的 Chla 和 Pn 模式的明显主导模型。最简约的模型包括盐度、颗粒有机碳和 PO，这表明初级生产力受多种因素控制。在 ECE 期间，约 19%的 DIN、91%的 DSi 和 PO、60%的颗粒有机碳和氮、86%的 Chla 被输出到海洋，极大地降低了 Pn。然而，Chla 和 Pn 值在 30 天内恢复到风暴前的水平，表明这些生物变量在 Los Micos 泻湖具有很强的恢复力。
