School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia.
Mar Pollut Bull. 2012;65(4-9):342-54. doi: 10.1016/j.marpolbul.2011.06.017. Epub 2011 Jul 8.
Seagrasses of the Great Barrier Reef predominantly occur in coastal regions where terrestrial inputs modify water quality and photosynthetic light is highly variable. Responses to shading were tested for Cymodocea serrulata, Halodule uninervis, Thalassia hemprichii and Zostera muelleri. In aquaria, four light treatments - high (66% surface light), moderate (31%), low (14%) and very low light (1%) treatments - were applied for 102d. Stress responses in the low and very low light treatments occurred in the following sequence: metabolic and physiological changes (reduced growth, increased pigment concentrations and photosynthetic efficiency); shedding (leaf loss, shoot loss) and production of new, altered tissue (leaves with reduced length, width and thickness). Complete shoot loss was projected after 76 (Z. muelleri) to 130d (T. hemprichii). Responses were slower in the low than in the very low treatment, therefore, efforts to minimize water quality degradation will be rewarded with delayed impacts to seagrasses.
大堡礁的海草主要分布在沿海地区，那里的陆地输入会改变水质，光合光的变化也非常大。对丝叶海龙草、互花米草、海菖蒲和拟珍珠贝的耐荫性进行了测试。在水族箱中，对四种光照处理（高（66%的表面光）、中（31%）、低（14%）和极低（1%））进行了 102 天的处理。在低光和极低光处理下，会发生以下顺序的应激反应：代谢和生理变化（生长减缓、色素浓度和光合作用效率增加）；脱落（叶片损失、茎损失）和产生新的、改变的组织（叶片长度、宽度和厚度减小）。预计在 76 天（拟珍珠贝）到 130 天（海菖蒲）后会完全失去茎。在低光下的反应比在极低光下的反应更慢，因此，努力最小化水质恶化将得到回报，使海草受到的影响延迟。
