Hornstein Jesse, Pales Espinosa Emmanuelle, Cerrato Robert M, Lwiza Kamazima M M, Allam Bassem
School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, USA.
School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, USA.
Comp Biochem Physiol A Mol Integr Physiol. 2018 Aug;222:66-73. doi: 10.1016/j.cbpa.2018.04.011. Epub 2018 Apr 22.
Atlantic surfclam populations have significantly declined in state and federal waters from the south shore of Long Island, New York to the Delmarva Peninsula since the early 2000s. Previous studies have demonstrated that surfclams in this geographic range show signs of physiological stress, suggested to be a result of increasing ocean temperatures. In this study, we examined the effect of 2 temperature regimes (19 °C and 23 °C) on surfclam physiology. These temperatures were chosen because they represent maximal (23 °C) and minimal (19 °C) temperatures prevailing in New York clamming areas during summer. Results demonstrated enhanced energy metabolism and significant reductions in filtration rate, scope for growth, and immune functions in clams exposed to the warmer temperature treatment. Although net energy gains remained positive in both treatments under our experimental conditions, the findings suggest that temperature stress is involved in the recent observations of surfclams in poor condition. The impact of elevated temperatures on phytoplankton quantity/quality and other environmental variables in combination with the direct impact on surfclam filtration and metabolic rates could lead to a negative energy balance. While some uncertainties remain about population-scale impacts of overall warming trends, we fear that future increases in temperature may lead to the collapse of the Atlantic surfclam between New York and Virginia, especially within inshore regions.
自21世纪初以来，从纽约长岛南岸到德尔马瓦半岛的州属和联邦水域内，大西洋浪蛤的数量显著下降。此前的研究表明，这一地理范围内的浪蛤出现了生理应激迹象，推测这是海洋温度上升所致。在本研究中，我们考察了两种温度条件（19℃和23℃）对浪蛤生理机能的影响。选择这两种温度是因为它们分别代表纽约夏季采蛤区普遍出现的最高温度（23℃）和最低温度（19℃）。结果表明，接受较高温度处理的浪蛤能量代谢增强，滤食率、生长范围和免疫功能显著降低。尽管在我们的实验条件下，两种处理中的净能量增益均保持为正值，但研究结果表明，温度应激与近期观察到的浪蛤状况不佳有关。温度升高对浮游植物数量/质量及其他环境变量的影响，再加上对浪蛤滤食和代谢率的直接影响，可能导致能量负平衡。虽然总体变暖趋势对种群规模的影响仍存在一些不确定性，但我们担心未来温度升高可能导致纽约和弗吉尼亚之间的大西洋浪蛤种群崩溃，尤其是在近海区域。
