气候变化导致海洋温度和盐度变化增加,特别是在河口环境中。温度和盐度变化的耐受性相互作用,因此可能会影响生物体的恢复力。人口可以在短期内对多种压力源(即,可塑性)或在更长的时间尺度上(即,adaptation).然而,对高温对急性温度和盐度变化的耐受性的短期或长期影响知之甚少。这里,我们描述了近岸和河口co足类动物的反应,阿卡蒂亚·通萨,温度和盐度胁迫。co足类起源于两组复制的>40代的温度适应线之一:环境(AM,18°C)和海洋变暖(OW,22°C)。来自这些品系的co足类在倒数温度下进行了一代和三代。然后评估来自所有处理的co足类的急性温度和盐度耐受性的差异。发展(一代),三代,与环境条件相比,>40代的变暖增加了耐热性,随着OW的发展,对三代和>40代的OW产生了相同的耐热性。引人注目的是,发育OW和>40代OW对相对于环境的低盐度耐受性没有影响。相比之下,当环境盐度首先降低时,co足类的耐热性较低。这些结果突出了可塑性在co足类气候响应中的关键作用,并表明盐度变化可能会降低co足类对随后变暖的耐受性。
Climate change is resulting in increasing ocean temperatures and salinity variability, particularly in estuarine environments. Tolerance of temperature and salinity change interact and thus may impact organismal resilience. Populations can respond to multiple stressors in the short-term (i.e., plasticity) or over longer timescales (i.e., adaptation). However, little is known about the short- or long-term effects of elevated temperature on the tolerance of acute temperature and salinity changes. Here, we characterized the response of the near-shore and estuarine
copepod, Acartia tonsa, to temperature and salinity stress. Copepods originated from one of two sets of replicated >40 generation-old temperature-adapted lines: ambient (AM, 18°C) and ocean warming (OW, 22°C). Copepods from these lines were subjected to one and three generations at the reciprocal temperature. Copepods from all treatments were then assessed for differences in acute temperature and salinity tolerance. Development (one generation), three generations, and >40 generations of warming increased thermal tolerance compared to Ambient conditions, with development in OW resulting in equal thermal tolerance to three and >40 generations of OW. Strikingly, developmental OW and >40 generations of OW had no effect on low salinity tolerance relative to ambient. By contrast, when environmental salinity was reduced first, copepods had lower thermal tolerances. These results highlight the critical role for plasticity in the
copepod climate response and suggest that salinity variability may reduce
copepod tolerance to subsequent warming.