Marine and Environmental Sciences Centre (MARE), Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra, Portugal.
Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes, Castellón 12595 Spain.
Aquat Toxicol. 2019 May;210:148-157. doi: 10.1016/j.aquatox.2019.02.023. Epub 2019 Mar 1.
Although a substantial amount of research exists on pollution and biological invasions, there is a paucity of understanding of how both factors interact. Most studies show that pollution favours the establishment of invasive species, but pollution may also promote local adaptation of native species and prevent the establishment of new incomers. However, evidence for this is extremely limited because most studies focus on successful invasions and very few on cases where an invasion has been resisted. Here we provide evidence of local adaptation of native species to pollution combining life history and physiological data. We focused on the invasion of the North American brine shrimp Artemia franciscana, which is causing a dramatic biodiversity loss in hypersaline ecosystems worldwide, and one of the last native Artemia populations in SW Europe (A. parthenogenetica from the historically polluted Odiel estuary, SW Spain). Life table response experiments were carried out in the laboratory to compare the demographic responses of A. parthenogenetica and a nearby A. franciscana population to long-term Zn exposure (0.2 mg L). We also evaluated oxidative stress by measuring antioxidant defences (catalase, glutathione reductase and superoxide dismutase) and lipid peroxidation (thiobarbituric acid reactive substances). A high concentration of Zn induced strong mortality in A. franciscana, which also showed high levels of lipid peroxidation, suggesting relatively poor physiological resistance to pollution compared with A. parthenogenetica. The age at maturity was shorter in A. parthenogenetica, which may be an adaptation to the naturally high mortality rate observed in the Odiel population. Exposure to Zn accelerated age at first reproduction in A. franciscana but not in A. parthenogenetica. In contrast, Zn had a stimulatory effect on offspring production in A. parthenogenetica,which also showed higher reproductive parameters (number of broods, total offspring and offspring per brood) than A. franciscana. Overall, the results of this study strongly suggest that native Artemia from Odiel estuary is locally adapted (at both, reproductive and physiological levels) to Zn contamination and that A. franciscana is highly sensitive. This is a good example of how pollution may play a role in the persistence of the last native Artemia populations in the Mediterranean.
尽管已经有大量关于污染和生物入侵的研究，但人们对这两个因素如何相互作用的理解还很匮乏。大多数研究表明，污染有利于入侵物种的建立，但污染也可能促进本地物种的适应，并防止新的外来物种的建立。然而，这方面的证据非常有限，因为大多数研究都集中在成功的入侵案例上，而很少有研究关注入侵被抵制的情况。在这里，我们结合生命史和生理学数据提供了本地物种对污染适应的证据。我们专注于北美的卤虫 Artemia franciscana 的入侵，它正在导致全球范围内的高盐度生态系统生物多样性丧失，并且是西班牙西南部历史上受污染的奥德伊尔河口的最后一个本地 Artemia 种群之一（西班牙西南部的 A. parthenogenetica）。在实验室中进行了生命表响应实验，以比较 A. parthenogenetica 和附近的 A. franciscana 种群对长期 Zn 暴露（0.2mg/L）的人口响应。我们还通过测量抗氧化防御（过氧化氢酶、谷胱甘肽还原酶和超氧化物歧化酶）和脂质过氧化（硫代巴比妥酸反应物质）来评估氧化应激。高浓度的 Zn 会导致 A. franciscana 强烈死亡，同时也会导致高水平的脂质过氧化，这表明与 A. parthenogenetica 相比，其对污染的生理抵抗力相对较差。A. parthenogenetica 的成熟年龄较短，这可能是对奥德伊尔种群中观察到的高死亡率的一种适应。Zn 暴露加速了 A. franciscana 的首次繁殖年龄，但对 A. parthenogenetica 没有影响。相比之下，Zn 对 A. parthenogenetica 的后代繁殖产生了刺激作用，其繁殖参数（产卵次数、总后代和每窝后代）也高于 A. franciscana。总的来说，这项研究的结果强烈表明，奥德伊尔河口的本地 Artemia 已经适应了 Zn 污染（在生殖和生理水平上），而 A. franciscana 则非常敏感。这是一个很好的例子，说明污染如何在维持地中海地区最后一批本地 Artemia 种群方面发挥作用。
