UMR 7266 LIENSs CNRS La Rochelle University, France.
UMR 7266 LIENSs CNRS La Rochelle University, France.
Sci Total Environ. 2023 Aug 20;887:163819. doi: 10.1016/j.scitotenv.2023.163819. Epub 2023 May 1.
Finding a balance between the preservation of habitat, species and the sustainable development of human activities in Marine Protected Areas (MPAs) is made even more challenging in coastal areas where sediment dynamics entails naturally changing habitats. To achieve this goal, a solid knowledge base is needed, and reviews are essential. Starting from an extensive review of sediment dynamics and coastal evolution at three-time scales (from millenaries to events), in the Gironde and Pertuis Marine Park (GPMP, French Atlantic coast), we investigated the interactions between human activities, sediment dynamics and morphological evolution in the GPMP. Five activities were identified as having a maximum interaction with coastal dynamics: Land reclamation, shellfish farming, coastal defences, dredging and sand mining. In sheltered areas, where natural sediment fill occurs, land reclamation and shellfish farming increase sedimentation through a positive feedback mechanism, leading to instability. Natural coastal erosion and sediment fill in harbours and tidal channels are fought by coastal defences and dredging, respectively, creating negative feedback and stability. However, these activities also generate negative side effects such as upper beach erosion, pollution, and increased turbidity. Sand mining, mainly developed in submarine incised valleys, results in a deepening of the sea floor, which is naturally filled by sediments from surrounding areas, tending towards shoreface profile restoration. However, sand extraction exceeds natural renewal rates, and may impact the stability of coastal ecosystems in the long term. These activities are at the heart of environmental management and preservation issues. This review and a discussion of the interactions between human activities and coastal behaviour enabled us to make recommendations that could counteract instabilities and negative side effects. They mainly include depolderization, strategic retreat, optimization and sufficiency. Given the diversity of the coastal environments and human activities found in the GPMP, this work is transferable to many MPAs and coastal areas whose objective is to foster sustainable human activities compatible with habitat preservation.
在海洋保护区（MPAs）中，平衡栖息地、物种的保护和人类活动的可持续发展变得更加具有挑战性，特别是在沿海地区，那里的沉积物动态导致栖息地自然变化。为了实现这一目标，需要有坚实的知识基础，而综述是必不可少的。我们从广泛的角度出发，研究了人类活动、沉积物动态和形态演化之间的相互作用，涉及三个时间尺度（从千年到事件），研究地点是吉伦特和珀蒂海洋公园（GPMP，法国大西洋海岸）。我们确定了五个与海岸动力相互作用最大的活动：土地开垦、贝类养殖、海岸防御、疏浚和采砂。在受保护的地区，自然沉积物的填充会发生，土地开垦和贝类养殖通过正反馈机制增加了沉积物的沉降，导致不稳定。自然的海岸侵蚀和港口和潮汐通道中的沉积物填充分别由海岸防御和疏浚来对抗，形成负反馈和稳定性。然而，这些活动也会产生负面的副作用，如上部海滩侵蚀、污染和增加的浊度。采砂主要在海底切蚀谷中进行，导致海底加深，而周围地区的沉积物自然填充，倾向于恢复滨面剖面。然而，采砂的速度超过了自然更新的速度，从长远来看可能会影响海岸生态系统的稳定性。这些活动是环境管理和保护问题的核心。本综述以及对人类活动与海岸行为之间相互作用的讨论，使我们能够提出一些建议，以抵消不稳定性和负面副作用。这些建议主要包括退圩还湖、战略性撤退、优化和适度。考虑到 GPMP 中发现的海岸环境和人类活动的多样性，这项工作可以推广到许多 MPA 和沿海地区，这些地区的目标是促进与栖息地保护相兼容的可持续人类活动。
