Climate change and latitudinal patterns of body temperature in rocky intertidal invertebrates

居住在岩石潮间带环境中的物种是海洋起源的，但在退潮时必须定期与陆地环境相抗衡。因此，这些无脊椎动物和藻类被认为生活在非常接近其耐热极限的地方，气候变化导致的热应激增加可能导致其生长、生存和分布模式的变化。最近的生理学研究强调，许多潮间带生物的热损伤主要发生在低潮时的空中暴露，此时体温由多种气候因素驱动。暴露在空中时所经历的温度远远超过潜水时的温度，并且通常与空气温度有很大的不同。我们从温度到群体的生理反应中推断的能力？因此，我们对野外条件下的体温、体温在空间和时间上的变化以及不同物种之间的模式如何变化的有限知识阻碍了尺度过程。Helmuth之前的工作主要集中在纬度？加州贻贝（Mytilus california）体温的尺度模式，是潮间带岩石生态系统中的竞争优势。在东北太平洋进行的测量表明，纬度模式非常复杂，而且由于低潮时间的一致模式，北部地区往往比南部地区更容易受到热压力。此外，潮汐状况的年际变化模式表明，在未来2？这些北方“热点”的5年热应力水平可能接近20？年最大。这些结果对于我们在何处和何时寻找潮间带生态系统中气候变化影响的证据具有重要意义，并表明在不久的将来可能会在几个地点观察到影响。该项目将继续对横跨160个纬度范围的15个地点的温度模式进行研究，并将产生与生态上重要的潮间带物种相关的连续6年以上的温度记录。这项研究将解决几个明确的预测源于我以前的研究，关于贻贝体温的时空模式。作为评估这些热应力变化对生态影响的一种手段，赫尔穆斯博士将监测贻贝的分区高度，并预测北部几个“热点”的分区向下移动。最后，他将运用生物物理技术研究贻贝的热生态，探讨贻贝的重要捕食者——腹足动物Nucella的热生态。该项目产生了一套广泛地理范围内温度模式的独特数据集，是目前监测和预测气候变化对东北太平洋潮间带体温的潜在影响的最佳手段。因为北方“热点”的暴露时间预计将在未来两年达到20年来的最大值。5年后，迫切需要保持将在本研究过程中产生的数据流的连续性。更广泛的影响：作为正在进行的合作的一部分，赫尔穆斯实验室的学生将使用K？教师根据他们的研究、评分标准和评估协议制定课程计划。具体来说，他们将创造活动，让学生调查与气候变化、温度对生物体的影响、物种分布模式和潮汐循环动力学相关的概念。材料将明确与州和国家K？12项科学和数学标准，并将发布在一个推广网站上。老师将在第一年与Helmuth实验室一起在实地进行实验，并在研究过程中与小组保持联系。

Species inhabiting rocky intertidal environments are of marine origin, but must regularly contend with the terrestrial environment during low tide. As a result, these invertebrates and algae are thought to live very close to their thermal tolerance limits, and increases in thermal stress due to climate change could lead to changes in their growth, survival, and distribution patterns. Recent physiological studies have emphasized that thermal damage to many intertidal organisms occurs primarily during aerial exposure at low tide, when body temperatures are driven by multiple climatic factors. Temperatures experienced during aerial exposure far exceed those during submersion, and are often substantially different from air temperature. Our ability to extrapolate from physiological responses to temperature to community?scale processes is thus hampered by our limited knowledge of what body temperatures are under field conditions, how body temperatures change in space and time, and how patterns might vary between species.Dr. Helmuth's previous work has focused on latitudinal?scale patterns of body temperatures of the mussel Mytilus californianus, a competitive dominant in rocky intertidal ecosystems. Measurements in the northeast Pacific show that latitudinal patterns are highly complex, and that, because of consistent patterns in the timing of low tides, northern sites are often more likely to be thermally stressful than are southern sites. Furthermore, models of interannual variability in tidal regimes suggest that in the next 2?5 years levels of thermal stress at these northern "hot spots" may be approaching a 20?year maximum. These results have significant consequences for where and when we look for evidence of the effects of climate change in intertidal ecosystems, and suggest that impacts may potentially be observable in the near future at several sites.The project will extend on ongoing study of temperature patterns at 15 sites spanning a 160 range of latitude, and will produce a continuous 6+ year record of temperatures relevant to an ecologically important intertidal species. The study will address several explicit predictions stemming from my previous research, regarding spatial and temporal patterns of mussel body temperatures. As a means of assessing the ecological impacts of these changes in thermal stress, Dr. Helmuth will monitor zonation heights of mussels, and predict downward shifts in zonation at several northern "hot spots." Finally, he will apply biophysical techniques used for mussels to explore the thermal ecology of the gastropod Nucella, and important predator of Mytilus. The project has produced a unique data set of temperature patterns over a wide geographic scale, and is currently the best means available for monitoring and predicting the potential effects of climate change on intertidal body temperatures in the NE Pacific. Because exposure times at northern "hot spots" are predicted to reach a 20year maximum within the next 2?5 years, there is a critical need to maintain the continuity of the data stream that will be produced during the course of this study.Broader Impacts: As part of an ongoing collaboration, students in the Helmuth lab will work with a K?12 teacher to develop lesson plans based on their research, grading rubrics and assessment protocols. Specifically, they will create activities that allow students to investigate concepts related to climate change, the effects of temperature on organisms, species distribution patterns, and the dynamics of tidal cycles. Materials will be explicitly linked to state and national K?12 science and math standards, and will be posted on a outreach website. The teacher will work with the Helmuth lab in the field in year one to set up experiments, and will remain in contact with the group during the course of the study.