Sundarbans fisheries: a model system for the application of landscape ecology and social science approaches to management

沿海生态系统为人类社区提供重要服务，其中最著名的是渔业提供的食物。渔业至关重要，为世界各地的社区提供粮食安全和收入。然而，捕捞活动对海洋物种的清除和对海洋生境的破坏可能会影响其他服务，如沿海保护和碳捕获。旅游业等依赖健康海洋生态系统和生物多样性的其他行业也可能受到影响。捕鱼活动也会破坏目标鱼种所依赖的资源，包括重要的幼鱼育苗区。为了应对鱼类数量的减少和环境的破坏，许多国家签署了国际协议，采用“生态系统方法”进行渔业。生态系统方法将鱼类与其环境联系起来。要做到这一点，我们需要了解海洋环境的哪些方面对鱼类重要。一个典型的方法是确定“基本鱼类栖息地”-对有关鱼类似乎最重要的海床类型。这种方法确定了一个重要的鱼类栖息地，与陆地上的最佳实践不同，我们长期以来一直认识到物种在其生命中使用不同的栖息地。在陆地上，我们知道不同的栖息地需要联系起来，以便动物可以在它们之间移动。这种“景观生态学”的方法不适用于渔业管理，因为我们缺乏足够的信息，不同的海底类型和生物多样性模式的空间分布在水下landscapes.Using水下摄像系统和海底地图，我们以前已经证明，在英国海洋保护区的鱼类受到影响的海底类型和生物多样性在其附近的区域，也由更广泛的景观。利用水下景观信息在改善发达国家和发展中国家的渔业管理方面具有巨大潜力。但我们需要足够的信息，了解不同的栖息地类型、生物多样性模式以及鱼类如何受到它们的影响。我们如何测试和发展具有巨大科学和实用价值的鱼类景观生态学思想，而不产生与生物多样性和环境测绘相关的巨大费用？在没有更多证据证明海洋景观方法的效用的情况下，我们如何说服其他国家支付必要的测绘费用？幸运的是，一个合适的景观存在于孙德尔本斯红树林森林（SMF）。项目合作伙伴Sarker开展了一个绘图和建模项目，绘制了SMF物理和生物特征的全面地图。这片森林的沃茨是富饶的渔场，为数百万人提供食物和生计。然而，在SMF的渔业正处于困境，缺乏任何有效的管理。我们将在整个SMF的鱼类样本，以了解SMF环境的哪些方面与鱼类的丰度，多样性和大小增加有关。我们将调查鱼类如何受到周围环境的影响，以及它们如何受到周围景观的影响（无论是不同栖息地的拼凑，还是由一种栖息地类型组成的统一环境）。我们还将采访渔民，了解他们如何选择在哪里捕鱼，以及他们是否使用与我们从采样中检测到的相同类型的标志。特别是，我们想知道渔民是否考虑了他们捕鱼地点周围的更广泛的景观，或者仅仅考虑了周围的环境。这些问题很重要，因为我们需要知道如何选择不妨碍渔民的管理措施，同时确保鱼类及其重要栖息地得到保护。这个简短的项目将大大发展鱼类景观生态学，适用于世界各地的渔业。这项工作将为SMF渔业的管理提供信息，以便他们能够提供可持续的粮食供应和生计。

Coastal ecosystems provide important services to human communities, the most well-known being food provision from fishing. Fisheries are critically important, providing food security and income to communities worldwide. However, the removal of marine species and damage to marine habitats from fishing activity may affect other services, like coastal protection and carbon capture. Other industries that depend on healthy marine ecosystems and biodiversity, such as tourism, may also be affected. Fishing activity can also damage resources on which targeted fish species depend, including important nursery areas for young fish.In response to declines in fish numbers and environmental damage many countries have signed international agreements to use an "ecosystem approach" to fisheries. An ecosystem approach links fish and their environment. To do this we need to understand what aspects of the marine environment are important to fish. A typical method has been to identify "essential fish habitat" - the type of seabed which seems to be most important to the fish in question. This method identifies one essential fish habitat and differs from best practice on land, where we have long recognised that species use different habitats through their lives. On land, we understand that different habitats need to be linked so that animals can move between them. This "landscape ecology" approach is not applied to fisheries management, as we lack sufficient information about spatial distribution of different seabed types and biodiversity patterns across underwater landscapes.Using underwater camera systems and seabed maps we have previously demonstrated that fish in a UK marine protected area are affected by the seabed type and biodiversity in their immediate area, and also by the wider landscape. Using underwater landscape information has huge potential to improve management of fisheries in the developed and developing world. But we need sufficient information about the different habitat types, biodiversity patterns and how fish are affected by them.This presents a paradox. How can we test and develop ideas of huge scientific and practical value about fish landscape ecology without incurring the great expense associated with biodiversity and environmental mapping? How can we persuade others to pay for the necessary mapping without more evidence of the usefulness of marine landscape approaches?Fortunately, a suitable landscape exists in the Sundarbans Mangrove forest (SMF). The project partner, Sarker, has carried out a mapping and modelling project which has resulted in a comprehensive map of the physical and biological characteristics of the SMF. The waters in this forest are rich fishing grounds, providing food and livelihoods to millions. However, fisheries in the SMF are in trouble and lack any effective management.We will sample fish throughout the SMF to understand what aspects of the SMF environment are associated with increased abundance, diversity and size of fish. We will investigate how fish are affected by their immediate environment and also how they are affected by the landscape around them (whether it is a patchwork of different habitats, or a uniform environment consisting of one habitat type).We will also interview fishers to understand how they choose where to fish, and whether they use the same types of signs that we detect from our sampling. In particular, we want to know whether fishers consider the wider landscape around their fishing locations, or just the immediate environment. These questions are important as we need to know how to choose management measures which do not hinder fishers, while ensuring that fish and their essential habitat is protected.This short project will greatly develop fish landscape ecology, applicable to fisheries worldwide. The work will inform the management of the SMF fisheries so that they can provide sustainable food supplies and livelihoods.