The Impact of Climate Change on Aquatic Ecosystems and their Resilience Strategies

Abstract

Climate change is now and increasingly will become a significant global threat to marine, estuarine, and freshwater aquatic ecosystems, due to elevated SST, OA, and increasing chronic and long-term hypoxic events, leading to dramatic chemical, thermal, and biological restructuring of aquatic ecosystems structurally and functionally. We present a synthesis of long-term, multi-regional marine monitoring data that quantifies climate-driven alterations in food web architecture, species phenologies, and geographic ranges of communities. Extreme marine heat waves increase stress on foundation species such as hermatypic corals and biogenic kelp beds, causing an erosion of functional redundancy and ecological stability. Mass phenological mismatches and geographic species redistributions will contribute to the loss of stability in ecosystem function and services. To counter the detrimental impact on ecosystem health and function, we review specific resilience strategies. These include the use of resilient MPA network design and placement; habitat restoration, such as the introduction of climate-resilient foundation species; the development of assistance in evolution for keystone species; and the implementation of an adaptive and dynamic fisheries management based on environmental conditions. We draw on empirical evidence to illustrate that ecosystems that benefit from robust, effective, and climate-sensitive conservation regimes will be characterized by significantly more rapid recovery and greater retention of species and ecosystem function. This paper integrates macro-ecological climate models with on-site management efforts in a systematic framework that elucidates the interaction between ecosystem function and predicted ecological changes resulting from climate change. We identify those conditions under which conservation efforts will be most effective to promote adaptive capacity, ecosystem services, and human dependence.