School of Biological Sciences and Oceans Institute, University of Western Australia, Crawley, Western Australia, Australia; Western Australian Marine Science Institution, Perth, WA 6000, Australia.
Centre for Marine Ecosystems Research and School of Science, Edith Cowan University, Joondalup, Western Australia, Australia; Western Australian Marine Science Institution, Perth, WA 6000, Australia.
Mar Pollut Bull. 2018 Mar;128:508-518. doi: 10.1016/j.marpolbul.2018.01.060. Epub 2018 Feb 6.
Existing mitigations to address deterioration in water clarity associated with human activities are based on responses from single seagrass species but may not be appropriate for diverse seagrass assemblages common to tropical waters. We present findings from a light experiment designed to determine the effects of magnitude and duration of low light on a mixed tropical seagrass assemblage. Mixed assemblages of three commonly co-occurring Indo-West Pacific seagrasses, Cymodocea serrulata, Halodule uninervis and Halophila ovalis were grown in climate-controlled tanks, where replicate pots were subjected to a gradient in light availability (0.9-21.6 mols PAR m day) for 12 weeks. Increased shading resulted in declines in growth and changes in cellular and photosynthesis responses for all species, although time-scale and magnitude of response were species-specific. Applying management criteria (e.g. thresholds) relevant to one species may under- or over-estimate potential for impact on other species and the meadow as a whole.
现有的减轻人类活动导致的水质恶化的措施是基于单一的海草物种的反应，但可能不适用于热带水域常见的多种海草组合。我们提出了一项光实验的结果，该实验旨在确定低光强度和持续时间对混合热带海草组合的影响。三种常见的印度洋-西太平洋海草，Cymodocea serrulata、Halodule uninervis 和 Halophila ovalis 的混合组合在气候控制的水箱中生长，其中重复的盆被置于光可用性梯度（0.9-21.6 mol PAR m day）下 12 周。增加遮荫导致所有物种的生长下降和细胞和光合作用反应的变化，尽管反应的时间尺度和幅度是特定于物种的。应用与单一物种相关的管理标准（例如阈值）可能会低估对其他物种和整个草地的潜在影响。
