Evaluating the effectiveness and success of coastal marine habitat restoration is often highly challenging and can vary substantially between different habitat types. The current article presents a state-of-the-art review of habitatlevel restoration in the coastal marine environment. It sets out most successful techniques across habitats and suggestions of better metrics to assess their success. Improvements in restoration approach are outlined, with a particular focus on selective breeding, using recent advancements in genetics. Furthermore, the assessment of ecosystem services, as a metric to determine restoration success on a spatiotemporal scale, is addressed in this article. As the concept of ecosystem services is more tangible for a nonscientific audience, evaluating restoration success in this manner has the potential to greatly contribute to raising awareness of environmental issues and to implement socioeconomic policies. Moreover, habitatbased restoration has been proven to be an effective tool to address the issue of ecosystem service sustainability and poverty alleviation. Appropriate conservation management, prior to the implementation of restoration activities, is crucial to create an environment in which restoration efforts are likely to succeed.

Coastal wetlands restoration is an emerging field which aims to recover the ecological characteristics of degraded ecosystems to natural ones. The recent UN declaration of 2021–2030 as the “Decade on Ecosystem Restoration” will hopefully encourage global implementation of these projects. However, a lack of common indicators of restoration success hinders our knowledge on the ecological outcomes of restoration projects. We conducted a literature review to determine trends in monitoring indicators. We classified indicators following the Society for Ecological Restoration template, adapting it to coastal wetlands. We found that indicators on structural diversity (e.g., tree height, fish size) were the mostly commonly used. Indicators on ecosystem function were the second most investigated, with half of the assessed studies including them, especially those focusing on carbon, nutrient and sediment dynamics. We propose a recovery wheel framework adapted to coastal wetlands. Structural diversity indicators are generally easier to measure and often the traits that recover the fastest. However, ecosystem function indicators could be more important to assess the recovery of ecosystem services, which is a primary objective of restoration. Restoration objectives and goals are variable for each project, and we encourage future restoration projects on coastal wetlands to select the most appropriate indicators on the basis of the recovery wheel proposed in this study to plan a monitoring framework. Future studies assessing coastal wetlands restoration ecological outcomes should include ecosystem function indicators and monitor the sites over periods adequate to their recovery.

Coastal wetland restoration is an important activity to achieve greenhouse gas (GHG) reduction targets, improve water quality, and reach the Sustainable Development Goals. However, many uncertainties remain in connection with achieving, measuring, and reporting success from coastal wetland restoration.We measured levels of carbon (C) abatement and nitrogen (N) removal potential of restored coastal wetlands in subtropical Queensland, Australia. The site was originally a supratidal forest composed of Melaleuca spp. that was cleared and drained in the 1990s for sugarcane production. In 2010, tidal inundation was reinstated, and a mosaic of coastal vegetation (saltmarshes, mangroves, and supratidal forests) emerged. We measured soil GHG fluxes (CH 4 , N 2 O, CO 2 ) and sequestration of organic C in the trees and soil to estimate the net C abatement associated with the reference, converted, and restored sites. To assess the influence of restoration on water quality improvement, we measured denitrification and soil N accumulation. We calculated C abatement of 18.5 Mg CO 2Àeq ha À1 year À1 when sugarcane land transitioned to supratidal forests, 11.0 Mg CO 2Àeq ha À1 year À1 when the land transitioned to mangroves, and 6.2 Mg CO 2Àeq ha À1 year À1 when the land transitioned to saltmarshes. The C abatement was due to tree growth, soil accumulation, and reduced N 2 O emissions due to the cessation of fertilization. Carbon abatement was still positive, even accounting for CH 4 emissions, which increased in the wetlands due to flooding and N 2 O production due to enhanced levels of denitrification.Coastal wetland restoration in this subtropical setting effectively reduces CO 2 emissions while providing additional cobenefits, notably water quality improvement.

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Seagrass meadows represent key ecosystems in coastal areas worldwide, hosting a great biodiversity of associated communities and thereby providing a large range of ecosystem services. In this study we present an experimental approach to investigate the effects of seagrass losses on related macrofauna assemblages. Over a three year period, seagrass canopies were removed in experimental plots and changes in epifauna, infauna and respective functional groups were recorded. The experimental removal of seagrass leaves resulted in a decline of 74% of overall macrofaunal abundance and the loss of several taxa. The immediate response of associated communities was followed by the establishment of an alternative assemblage, characterized by an increased number of bioturbators and deposit feeders. The colonization of disturbed seagrass plots by burrowing shrimps (Callianassidae) might have hindered the reestablishment of seagrass after the removal. Our findings highlight the important role of seagrasses as habitat forming species that provide relevant functioning and services in coastal ecosystems.