School of Biological Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia.
School of Earth and Environmental Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia.
Conserv Biol. 2021 Jun;35(3):933-943. doi: 10.1111/cobi.13638. Epub 2021 Jan 21.
Tidal flats are a globally distributed coastal ecosystem important for supporting biodiversity and ecosystem services. Local to continental-scale studies have documented rapid loss of tidal habitat driven by human impacts, but assessments of progress in their conservation are lacking. With an internally consistent estimate of distribution and change, based on Landsat satellite imagery, now available for the world's tidal flats, we examined tidal flat representation in protected areas (PAs) and human pressure on tidal flats. We determined tidal flat representation and its net change in PAs by spatially overlaying tidal flat maps with the World Database of Protected Areas. Similarly, we overlaid the most recent distribution map of tidal flats (2014-2016) with the human modification map (HM ) (range from 0, no human pressure, to 1, very high human pressure) to estimate the human pressure exerted on this ecosystem. Sixty-eight percent of the current extent of tidal flats is subject to moderate to very high human pressure (HM > 0.1), but 31% of tidal flat extent occurred in PAs, far exceeding PA coverage of the marine (6%) and terrestrial (13%) realms. Net change of tidal flat extent inside PAs was similar to tidal flat net change outside PAs from 1999 to 2016. Substantial shortfalls in protection of tidal flats occurred across Asia, where large intertidal extents coincided with high to very high human pressure (HM > 0.4-1.0) and net tidal flat losses up to 86.4 km² (95% CI 83.9-89.0) occurred inside individual PAs in the study period. Taken together, our results show substantial progress in PA designation for tidal flats globally, but that PA status alone does not prevent all habitat loss. Safeguarding the world's tidal flats will thus require deeper understanding of the factors that govern their dynamics and effective policy that promotes holistic coastal and catchment management strategies.
潮滩是一种分布广泛的全球沿海生态系统，对支持生物多样性和生态系统服务至关重要。局部到大陆尺度的研究记录了由于人类活动导致的潮滩生境的快速丧失，但缺乏对其保护进展的评估。现在，基于 Landsat 卫星图像，为全球潮滩提供了一种具有内部一致性的分布和变化估计，我们研究了潮滩在保护区（PA）中的代表性和人类对潮滩的压力。我们通过将潮滩地图与世界保护区数据库进行空间叠加，确定了 PA 中潮滩的代表性及其净变化。同样，我们将最新的潮滩分布地图（2014-2016 年）与人类改造图（HM）（范围从 0 表示没有人类压力到 1 表示人类压力非常高）叠加，以估计该生态系统所受到的人类压力。当前潮滩的 68%受到中度到高度的人类压力（HM>0.1），但有 31%的潮滩位于保护区内，远远超过海洋（6%）和陆地（13%）领域的保护区覆盖范围。1999 年至 2016 年，PA 内和 PA 外的潮滩范围净变化相似。亚洲的潮滩保护存在大量差距，大面积的潮间带与高到非常高的人类压力（HM>0.4-1.0）以及高达 86.4 平方公里（95%置信区间 83.9-89.0）的潮滩净损失同时发生，在研究期间，个别保护区内发生了潮滩净损失。总的来说，我们的研究结果表明，全球范围内为潮滩指定保护区取得了实质性进展，但仅保护区地位并不能防止所有生境丧失。因此，保护世界潮滩将需要更深入地了解控制其动态的因素，并采取有效的政策，促进整体沿海和集水区管理战略。
