Climate Change Implications for Tidal Marshes and Food Web Linkages to Estuarine and Coastal Nekton

Abstract

Climate change is altering naturally fluctuating environmental conditions in coastal and estuarine ecosystems across the globe. Departures from long-term averages and ranges of environmental variables are increasingly being observed as directional changes [e.g., rising sea levels, sea surface temperatures (SST)] and less predictable periodic cycles (e.g., Atlantic or Pacific decadal oscillations) and extremes (e.g., coastal flooding, marine heatwaves). Quantifying the short- and long-term impacts of climate change on tidal marsh seascape structure and function for nekton is a critical step toward fisheries conservation and management. The multiple stressor framework provides a promising approach for advancing integrative, cross-disciplinary research on tidal marshes and food web dynamics. It can be used to quantify climate change effects on and interactions between coastal oceans (e.g., SST, ocean currents, waves) and watersheds (e.g., precipitation, river flows), tidal marsh geomorphology (e.g., vegetation structure, elevation capital, sedimentation), and estuarine and coastal nekton (e.g., species distributions, life history adaptations, predator-prey dynamics). However, disentangling the cumulative impacts of multiple interacting stressors on tidal marshes, whether the effects are additive, synergistic, or antagonistic, and the time scales at which they occur, poses a significant research challenge. This perspective highlights the key physical and ecological processes affecting tidal marshes, with an emphasis on the trophic linkages between marsh production and estuarine and coastal nekton, recommended for consideration in future climate change studies. Such studies are urgently needed to understand climate change effects on tidal marshes now and into the future.

Complex Tidal Marsh Dynamics Structure Fish Foraging Patterns in the San Francisco Estuary

“…Secondary production of fish and invertebrates in nearshore habitats indicates process-based ecosystem function and health and thus serves as a composite metric for evaluating the performance of remnant and restored marshes (Weinstein et al 2014;Weinstein and Litvin 2016;Layman and Rypel 2020). Assessing tidal marsh ecosystem function and health using secondary production is becoming increasingly important given the potentially dire effects of climate change and sea level rise on tidal marsh habitats, food webs, and fisheries support (Colombano et al 2021;Baker et al 2020).…”

Ontogenetic Changes in Behavioral and Energetic Responses of Juvenile Atlantic Croaker to an Estuarine Salinity Gradient

“…2020; Colombano et al. 2021). A recent analysis projected that the watersheds of the eastern United States and northern Gulf of Mexico, which already experience relatively high precipitation on a global comparative basis, will experience higher precipitation, particularly from May through September (Konapala et al.…”

“…Climate change effects on global temperature and the level and pattern of regional precipitation have ongoing and predicted effects on estuarine and marine systems (Burrows et al 2011;Trenberth 2011;Konapala et al 2020;Colombano et al 2021). A recent analysis projected that the watersheds of the eastern United States and northern Gulf of Mexico, which already experience relatively high precipitation on a global comparative basis, will experience higher precipitation, particularly from May through September (Konapala et al 2020).…”

Environmental Flow Requirements of Estuaries: Providing Resilience to Current and Future Climate and Direct Anthropogenic Changes

“…Increased salinity may also increase density stratification and persistence of salt wedges (Krvavica et al, 2017), leading to anoxia of bottom sediments and loss of benthic biota (Kimmerer and Weaver, 2013). Where littoral structures (e.g., levees) have been erected, intertidal habitat areas are likely to reduce in size as marine water intrudes up to these barriers (Colombano et al, 2021;Khojasteh et al, 2021). This has implications for intertidal species distributions and associated organisms due to excessive inundation and salinity (Smith et al, 2009;Payne et al, 2019).…”

“…However, shoreline protection structures are expensive to erect and maintain, are susceptible to damage from large storm events, can alter erosion/deposition dynamics and tend to not be as effective as natural shorelines at attenuating wave and tide energy (Koraim et al, 2011). In addition, they can pose a barrier to lateral connectivity and cause intertidal and littoral habitats to retract in response to changes in distribution as a result of sea level rise induced salinity alterations (Colombano et al, 2021;Khojasteh et al, 2021).…”