Quantifying and mapping marine biodiversity and ecosystem futures

当今最紧迫的问题之一是，海洋生态系统及其为社会提供的基本货物和服务在下一个世纪将发生怎样的变化，以及我们如何能够适应和限制负面影响，同时保持和建设复原力和稳健性。为了回答这个问题，我们需要制定科学严谨的全球设想方案，确定下一个世纪人类对海洋生态系统影响的可能路径。其中既包括社会经济发展将如何影响气候变化和捕捞努力等大尺度因素，也包括人类与海洋生态系统之间相互作用的更精细细节。我的研究计划将开发这样的场景，无论是探索性的未来，还是“寻求目标”的未来，其中一个理想的终点（例如到2050年对海洋生态系统的可持续管理）然后向后工作，以确定实现这一目标所需的政策和变化。为了建立这些，我们将与利益相关者和专家合作，开发跨越一系列合理未来的协作场景。然后，我们将仔细量化这些情景，以提供驱动一系列领先的海洋生态系统模型所需的输入，从而对海洋生态系统、渔获量和生物多样性以及它们将如何、在何处以及为什么发生变化进行全球规模的预测。使用生态系统模型的集合，而不是一个单一的，提供了一个更强大的了解海洋未来的不确定性，是气候变化科学的默认方法，但最近才应用于海洋生态系统。然后，我们将补充这些方法，使用一种新的和动态的生态系统模型，探索引爆点和营养级联，在这种情况下，生态系统转移到一个完全不同的状态（例如，鳕鱼崩溃的20世纪90年代加拿大东部）。我们将测试该模型在历史气候和开发条件下再现观测到的临界点的能力，然后在我们开发的全球情景下运行该模型，以模拟未来的生态系统状态，考虑到气候变化和未来的捕捞活动。然后，这些可以用来制作“风险地图”，显示营养级联和生态系统过渡到一个新的状态的可能性，并帮助确定政策，以避免这种情况。加拿大是关于气候变化和生物多样性的国际公约的签署国，这项研究有助于确定加拿大如何履行这些条约规定的义务，并有助于制定政策备选方案，说明加拿大如何在下一个世纪实现海洋生态系统更可持续的未来。

One of the most pressing questions of the present day is how marine ecosystems and the essential goods and services that they provide to society will change over the coming century and how we can adapt to and limit negative impacts while maintaining and building resilience and robustness. To answer this question, we need develop scientifically rigorous global scenarios defining plausible pathways in which the coming century may unfold in terms of human impacts on marine ecosystems. These include both broad-scale factors such as how socioeconomic developments will affect climate change and fishing effort, and finer details on interactions between human and ecological systems in the ocean. My research program will develop such scenarios, both for exploratory futures, and for 'target-seeking' futures in which a desired end-point (e.g. sustainable management of ocean ecosystems by 2050) is then worked backwards from in order to determine the policies and changes that are needed to reach that goal. To build these, we will work with stakeholders and experts to develop collaborative scenarios that span a range of plausible futures. We will then carefully quantify these scenarios to provide the inputs needed to drive an ensemble of leading marine ecosystem models to produce global-scale projections of marine ecosystems, catches, and biodiversity, and how, where, and why they will change. Using an ensemble of ecosystem models instead of a single one provides a more robust understanding of the uncertainty around marine futures, and is the default approach in the climate change sciences, yet only recently applied for ocean ecosystems. We will then complement these approaches by using a novel and dynamic ecosystem model to explore tipping-points and trophic cascades, situations in which an ecosystem shifts to an entirely different state (e.g. the cod collapse of the 1990s off eastern Canada). We will test the ability of the model to reproduce observed tipping-points under historical conditions of climate and exploitation, then run it under the global scenarios we developed to produce future simulations of ecosystem state given climate change and future fishing effort. These can then be used to produce 'risk maps' that show the likelihood of trophic cascades and the ecosystem transitioning to a new state, and help to identify policies to avoid this. Canada is a signatory to international conventions on climate change and biodiversity, and this research helps to identify how it may meet its obligations under these treaties, and helps to develop policy options for how Canada may move towards a more sustainable future for marine ecosystems over the coming century.