Melero-Jiménez Ignacio J, Salvo A Enrique, Báez José C, Bañares-España Elena, Reul Andreas, Flores-Moya Antonio
Departamento de Biología Vegetal (Botánica), Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.
Centro Oceanográfico de Canarias, Instituto Español de Oceanografía, Santa Cruz de Tenerife, Spain.
PeerJ. 2017 Nov 14;5:e4048. doi: 10.7717/peerj.4048. eCollection 2017.
The canopy-forming, intertidal brown (Phaeophyceae) seaweed is distributed along the cold-temperate and warm-temperate coasts of Europe and North Africa. Curiously, an isolated population develops at Punta Calaburras (Alboran Sea, Western Mediterranean) but thalli are not present in midsummer every year, unlike the closest (ca. 80 km), perennial populations at the Strait of Gibraltar. The persistence of the alga at Punta Calaburras could be due to the growth of resilient, microscopic stages as well as the arrival of few-celled stages originating from neighbouring localities, and transported by the permanent Atlantic Jet flowing from the Atlantic Ocean into the Mediterranean. A twenty-six year time series (from 1990 to 2015) of midsummer occurrence of thalli at Punta Calaburras has been analysed by correlating with oceanographic (sea surface temperature, an estimator of the Atlantic Jet power) and climatic factors (air temperature, rainfall, and North Atlantic Oscillation -NAO-, and Arctic Oscillation -AO- indexes). The midsummer occurrence of thalli clustered from 1990-1994 and 1999-2004, with sporadic occurrences in 2006 and 2011. Binary logistic regression showed that the occurrence of thalli at Punta Calaburras in midsummer is favoured under positive NAO index from April to June. It has been hypothesized that isolated population of should show greater stress than their congeners of permanent populations, and to this end, two approaches were used to evaluate stress: one based on the integrated response during ontogeny (developmental instability, based on measurements of the fractal branching pattern of algal thalli) and another based on the photosynthetic response. Although significant differences were detected in photosynthetic quantum yield and water loss under emersion conditions, with thalli from Punta Calaburras being more affected by emersion than those from Tarifa, the developmental instability showed that the population from Tarifa suffers higher stress during ontogeny than that from Punta Calaburras. In conclusion, this study demonstrates the teleconnection between atmospheric oscillations and survival and proliferation of marine macroalgae.
形成冠层的潮间带褐藻（褐藻门）分布在欧洲和北非的寒温带和暖温带海岸。奇怪的是，在卡拉布拉斯角（西地中海阿尔沃兰海）出现了一个孤立的种群，但与直布罗陀海峡距离最近（约80公里）的多年生种群不同，每年仲夏时该种群的藻体并不存在。卡拉布拉斯角的藻类持续存在可能是由于有弹性的微观阶段的生长，以及来自邻近地区的单细胞阶段的到来，这些阶段由从大西洋流入地中海的常年大西洋急流输送而来。通过与海洋学因素（海面温度，大西洋急流强度的一个估计值）和气候因素（气温、降雨量、北大西洋涛动 -NAO- 和北极涛动 -AO- 指数）进行相关性分析，对卡拉布拉斯角1990年至2015年仲夏藻体出现情况的26年时间序列进行了分析。藻体的仲夏出现情况在1990 - 1994年和1999 - 2004年聚集，在2006年和2011年有零星出现。二元逻辑回归表明，4月至6月正的NAO指数有利于卡拉布拉斯角仲夏时藻体的出现。据推测，孤立种群应该比其多年生同类种群表现出更大的压力，为此，采用了两种方法来评估压力：一种基于个体发育过程中的综合反应（发育不稳定性，基于对藻类藻体分形分支模式的测量），另一种基于光合反应。尽管在光合量子产量和暴露条件下的水分损失方面检测到显著差异，卡拉布拉斯角的藻体比塔里法的藻体更受暴露影响，但发育不稳定性表明，塔里法的种群在个体发育过程中比卡拉布拉斯角的种群承受更高的压力。总之，这项研究证明了大气振荡与海洋大型藻类的生存和增殖之间的遥相关。
