Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, California, 95039, USA.
College of Arts and Sciences, University of Rhode Island, Kingston, Rhode Island, 02881, USA.
Ecology. 2019 Mar;100(3):e02594. doi: 10.1002/ecy.2594.
Kelp systems dominate nearshore marine environments in upwelling zones characterized by cold temperatures and high nutrients. Worldwide, kelp population persistence and recruitment success generally decreases with rising water temperatures coupled with low nutrients, making kelp populations vulnerable to impending warming of the oceans. This response to climate change at a global scale, however, may vary due to regional differences in temperature variability, acclimation, and differential responses of kelp species to changing conditions. Culture experiments were conducted on 12 eastern Pacific kelp taxa across geographic regions (British Columbia, central California, and southern California) under three nitrate levels (1, 5, and 10 μmol/L) and two temperatures (12°C and 18°C) to determine sporophyte production (i.e., recruitment success). For all taxa from all locations, sporophytes were always present in the 12°C treatment and when recruitment failure was observed, it always occurred at 18°C, regardless of nitrate level, indicating that temperature is the driving factor limiting recruitment, not nitrate. Rising ocean temperatures will undoubtedly cause recruitment failure for many kelp species; however, the ability of species to acclimatize or adapt to increased temperatures at the warmer edge of their species range may promote a resiliency of kelp systems to climate change at a global scale.
海带系统在上升流区域的近岸海洋环境中占主导地位，这些区域的特点是低温和高营养。在全球范围内，随着水温升高和营养物质减少，海带种群的持续存在和繁殖成功率通常会下降，这使得海带种群容易受到海洋变暖的影响。然而，这种全球范围内的气候变化响应可能因温度变化、适应能力和海带物种对变化条件的不同反应的区域差异而有所不同。在 12 个太平洋东部海带分类群上进行了培养实验，这些分类群分布在不同的地理区域（不列颠哥伦比亚省、加利福尼亚中部和加利福尼亚南部），实验在三个硝酸盐水平（1、5 和 10 μmol/L）和两个温度（12°C 和 18°C）下进行，以确定孢子体的产生（即繁殖成功率）。对于所有来自所有地点的分类群，孢子体始终存在于 12°C 的处理中，当观察到繁殖失败时，无论硝酸盐水平如何，总是在 18°C 时发生，这表明温度是限制繁殖的驱动因素，而不是硝酸盐。海洋温度的升高无疑将导致许多海带物种的繁殖失败；然而，物种在其物种分布范围较暖边缘适应或适应温度升高的能力，可能会促进海带系统在全球范围内对气候变化的恢复力。
