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将如何在下个世纪发生变化，以及我们如何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，从人类对海洋生态系统的影响来看，确定未来一个世纪可能展开的合理途径。这些因素既包括社会经济发展将如何影响气候变化和捕捞活动等广泛的因素，也包括人类与海洋生态系统之间相互作用的更详细的细节。我的研究计划将开发这样的情景，既用于探索性的未来，也用于“目标寻求”的未来，在这种未来中，一个期望的终点（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。为了实现这些目标，我们将与利益相关者和专家合作，制定涵盖一系列可能未来的协作方案。然后，我们将仔细量化这些情景，以提供所需的输入，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、捕捞量和生物多样性的全球尺度预测，以及它们将如何、在哪里以及为什么会发生变化。使用生态系统模型的集合而不是单一的模型可以更有力地理解海洋未来的不确定性，这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，我们将使用一种新的动态生态系统模型来探索临界点和营养级联，即生态系统转变为完全不同状态的情况（例如，20世纪90年代加拿大东部海域的鳕鱼崩溃），以补充这些方法。我们将测试该模型在气候和开发的历史条件下重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它，以在考虑气候变化和未来捕捞量的情况下产生未来生态系统状态的模拟。然后，这些可以用来制作“风险图”，显示营养级联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加拿大如何履行其在这些条约下的义务，并有助于制定政策选择，使加拿大在未来一个世纪中朝着海洋生态系统更可持续的未来迈进。

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.