Department of Civil Engineering, The University of Hong Kong, Room 6-18A, Haking Wong Building, Pokfulam, Hong Kong.
Department of Civil Engineering, The University of Hong Kong, Room 6-18A, Haking Wong Building, Pokfulam, Hong Kong.
Sci Total Environ. 2018 Mar 15;618:439-450. doi: 10.1016/j.scitotenv.2017.10.325. Epub 2017 Nov 11.
Anthropogenic activities such as land reclamation are threatening tidal marshes worldwide. This study's hypothesis is that land reclamation in a semi-enclosed bay alters the seasonal dynamics of intertidal benthic infauna, which is a key component in the tidal marsh ecosystem. Mai Po Tidal Marsh, Deep Bay, Pearl River Estuary, China was used as a case study to evaluate the hypothesis. Ecological models that simulate benthic biomass dynamics with governing environmental factors were developed, and various scenario experiments were conducted to evaluate the impact of reclamations. Environmental variables, selected from the areas of hydrodynamics, meteorology, and water quality based on correlation analysis, were used to generate Bayesian regression models for biomass prediction. The best-performing model, which considered average water age (i.e., a hydrodynamic indicator of estuarine circulation) in the previous month, salinity variation (i.e., standard deviation of salinity), and the total sunny period in the current month, captured well both seasonal and yearly trends in the benthic infauna observations from 2002 to 2008. This model was then used to simulate biomass dynamics with varying inputs of water age and salinity variation from coastal numerical models of different reclamation scenarios. The simulation results suggest that the reclamation in 2007 decreased the spatial and annual average benthic infauna biomass in the tidal marsh by 20%, which agreed with the 28% biomass decrease recorded by field survey. The range of biomass seasonal variation also decreased significantly from 2.1 to 230.5g/m (without any reclamation) to 1.2 to 131.1g/m (after the 2007 reclamation), which further demonstrates the substantial ecological impact of reclamation. The ecological model developed in this study could simulate seasonal biomass dynamics and evaluate the ecological impact of reclamation projects. It can therefore be applied to evaluate the ecological impact of coastal engineering projects for tidal marsh management, conservation, and restoration.
人为活动，如填海造地，正在威胁着全球的潮汐沼泽。本研究的假设是，在半封闭海湾进行的填海造地会改变潮间带底栖无脊椎动物的季节性动态，而这些动物是潮汐沼泽生态系统的关键组成部分。中国珠江口的米埔潮间带湿地、后海湾作为案例研究来验证该假设。我们建立了模拟底栖生物量动态及其控制环境因素的生态模型，并进行了各种情景实验来评估填海造地的影响。基于相关分析，从水动力、气象和水质等方面选择环境变量，用于生成用于生物量预测的贝叶斯回归模型。表现最佳的模型考虑了前一个月的平均水龄（即河口环流的水动力指标）、盐度变化（即盐度的标准差）以及当前月的总晴天期，很好地捕捉到了 2002 年至 2008 年期间底栖无脊椎动物观测数据的季节性和年际趋势。然后，我们使用该模型模拟了不同填海造地情景下的沿海数值模型输入的水龄和盐度变化对生物量动态的影响。模拟结果表明，2007 年的填海造地使潮汐沼泽的底栖无脊椎动物的空间和年平均生物量减少了 20%，这与实地调查记录的 28%的生物量减少量一致。生物量季节性变化的范围也从没有填海造地时的 2.1 到 230.5g/m2 显著减少到 2007 年填海造地后的 1.2 到 131.1g/m2，这进一步证明了填海造地的重大生态影响。本研究中开发的生态模型可以模拟季节性生物量动态，并评估填海造地项目的生态影响。因此，它可以用于评估沿海工程项目对潮汐沼泽管理、保护和恢复的生态影响。
