Greater Consideration of Animals Will Enhance Coastal Restoration Outcomes

Abstract

As efforts to restore coastal habitats accelerate, it is critical that investments are targeted to most effectively mitigate and reverse habitat loss and its impacts on biodiversity. One likely but largely overlooked impediment to effective restoration of habitat-forming organisms is failing to explicitly consider non-habitat-forming animals in restoration planning, implementation, and monitoring. These animals can greatly enhance or degrade ecosystem function, persistence, and resilience. Bivalves, for instance, can reduce sulfide stress in seagrass habitats and increase drought tolerance of saltmarsh vegetation, whereas megaherbivores can detrimentally overgraze seagrass or improve seagrass seed germination, depending on the context. Therefore, understanding when, why, and how to directly manipulate or support animals can enhance coastal restoration outcomes. In support of this expanded restoration approach, we provide a conceptual framework, incorporating lessons from structured decision-making, and describe potential actions that could lead to better restoration outcomes using case studies to illustrate practical approaches.

Seagrass is protected from ragworm pressure by a newly discovered grazer–ragworm interaction; implications for restoration

“…To improve seagrass restoration success in environments with degraded community structures, we propose a three‐step strategy, followed by monitoring and evaluation, based on a restoration decision model suggested by Sievers et al (2022): (1) Transplant seagrasses, preferably from a donor population with an intact food web, (2) co‐introduce a (historically) native facilitating species to the system, preferably a dominant species from the same donor location ( Littorina in our case) and (3) exclude inhibiting organisms directly (e.g. through manual removal; removal of Sargassum in our case) or indirectly (e.g.…”

“…Recent studies increasingly emphasise the importance of facilitative interactions for coastal restoration success (Chin et al, 2021;Temmink et al, 2020;Valdez et al, 2020), and suggest active inclusion of key interspecific interactions during restoration for higher success rates (Derksen-Hooijberg et al, 2018;Gagnon et al, 2020;Sievers et al, 2022). Examples of direct positive interactions include the detoxification of sediment by Lucinidae in seagrass meadows or alleviation of drought stress for salt marsh plants by ribbed mussels (Angelini et al, 2016;van der Heide et al, 2012).…”

“…These shifts in species composition are similar to those found in other seagrass ecosystems (Moksnes et al, 2008; Riera et al, 2020). As interspecific interactions are increasingly being recognised as crucial for seagrass conservation and restoration (Gagnon et al, 2020; Sievers et al, 2022), the mechanisms responsible for the dominant negative interaction between Platynereis and Zostera found in Lake Grevelingen should be clarified. Moreover, recognising these mechanisms in an early stage could prove important for timely conservation management or increased restoration success.…”

Establishing the relationship between non-human primates and mangrove forests at the global, national, and local scales

“…Systematically mapping mangroves in primate home ranges would provide better validation to our knowledge of their presence in mangrove forests. Likewise, surveying primates while mapping mangroves can improve global conservation actions due to the importance of the role of wildlife in habitat restauration [ 62 ]. Mangrove forests appear to be a critical habitat to more generalist primates, mainly if we assume that terrestrial forests adjacent to mangroves are degraded and diminished in many areas, exposing the importance of mangroves as suitable habitats for primates.…”

Fish use of restored mangroves matches that in natural mangroves regardless of forest age

“…Current monitoring of restored coastal habitats focuses overwhelmingly on the recovery and production of habitat‐forming species (e.g., mangrove trees and seedlings) or physical environment (e.g., pH and temperature) and is typically short term (Zhang et al 2018; Cadier et al 2020). Despite the fundamental role animals play in maintaining healthy ecosystems, few studies measure faunal responses within restored habitats (Gerona‐Daga & Salmo III 2022; Sievers et al 2022). Shifting focus toward animals will improve our understanding of how restored habitats are functioning, inform future restoration efforts to maximize success, and provide a means to quantify gains in several key ecosystem services and thus inform natural capital assessments of restoration (e.g., fisheries enhancement; Kollmann et al 2016; Hale et al 2019; Renzi et al 2019).…”