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商品和服务在未来一个世纪将发生怎样的变化--以及我们如何才能适应和限制负面影响，同时保持和建立复原力和稳健性。为了回答这个问题，我们需要制定科学严谨的全球情景，确定下个世纪人类对海洋生态系统的影响可能出现的可能途径。这些因素既包括广泛的因素，如社会经济发展将如何影响气候变化和捕鱼努力，也包括关于海洋中人类与生态系统之间相互作用的更细微的细节。我的研究计划将为探索性未来和“寻找目标”的未来制定这样的情景，在这些情景中，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)被反向工作，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，开发跨越一系列看似合理的未来的协作场景。然后，我们将仔细量化这些情景，以提供所需的投入，以推动一系列领先的海洋生态系统模型，以产生海洋生态系统、渔获量和生物多样性的全球规模预测，以及它们将如何、在哪里和为什么发生变化。使用一组生态系统模型而不是单一的生态系统模型，可以更有力地理解围绕海洋未来的不确定性，是气候变化科学的默认方法，但直到最近才应用于海洋生态系统。然后，我们将使用一种新颖和动态的生态系统模型来补充这些方法，以探索转折点和营养级联，即生态系统转变为完全不同状态的情况(例如，加拿大东部20世纪90年代的鳕鱼崩溃)。我们将测试该模型在气候和开发历史条件下再现观察到的临界点的能力，然后在我们开发的全球情景下运行该模型，以产生未来对给定气候变化和未来捕捞努力的生态系统状态的模拟。然后，这些数据可以用来制作“风险图”，显示营养性瀑布和生态系统过渡到新状态的可能性，并帮助确定避免这种情况的政策。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它可能如何履行这些条约规定的义务，并有助于为加拿大如何在下一个世纪迈向海洋生态系统更可持续的未来制定政策选择。

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.