Kristian Metcalfe

Coastal wetlands are critical tropical biodiversity hotspots, providing essential nursery and foraging habitats for species including marine turtles. Yet they are among the most threatened ecosystems globally, creating an urgent need to understand how key species use both modified and protected wetlands. Using fine‐scale GPS telemetry, we quantified residency and habitat use of juvenile green turtles ( Chelonia mydas ) within a coastal wetland and Ramsar site that has been heavily altered by development but is now protected under the Al Qurm Wa Lehhfaiiah Protected Area, Sharjah, United Arab Emirates' Gulf of Oman coast. Juvenile turtles were found to be highly resident, typically remaining within 3 km of the wetland entrance and spending over 80% of their time inside the protected area, confirming its importance as developmental habitat. Spatial and behavioural analyses revealed a strong reliance on artificial habitats, with manmade basins having five times higher odds of use than natural mangrove channels. This basin provides clear ecological value, functioning as a nocturnal refuge and likely foraging habitat, with 77% of core use areas occurring within it. Extending protections to channels linking tidal and oceanic habitats could further improve conservation outcomes, as turtle occupancy followed clear tidal patterns in these corridors. Overall, our findings demonstrate both the importance of coastal wetlands for juvenile turtles and that engineered environments can provide valuable novel habitat, providing connectivity, ecological integrity and resilience are explicitly maintained and integrated into their design.

Growing demands for food, energy, minerals and other natural resources are intensifying pressure on ecosystems. Meeting these demands while reducing biodiversity loss requires making decisions about which areas can simultaneously support sustainable development, conserve biodiversity and maintain or restore ecosystem services. Existing spatial optimization tools in planning contexts offer limited support to accommodate multiple objectives, such as maximizing agricultural production and biodiversity outcomes, because they rely on predefined formulations that lack the flexibility to incorporate objectives from multiple sectors and explicitly characterize trade‐offs and synergies among them. Here, we present a multi‐objective optimization framework for spatial planning. The framework is used to express multiple planning goals and requirements as optimization problems, identify solutions that simultaneously satisfy multiple objectives and explore trade‐offs between them. It provides a flexible structure for specifying objectives within and across sectors and supports multiple multi‐objective optimization approaches—weighted‐sum, hierarchical and reference point approaches. To promote accessibility, we implemented the framework as an update to the prioritizr R package. Using a multiple‐use case study in the European Union, we demonstrate how the framework supports the identification of solutions that balance trade‐offs between ecosystem restoration, agriculture and forestry production. Synthesis and applications. Our framework enables conservation scientists, planners and practitioners to identify spatial plans that achieve multiple objectives. It is designed to help explore trade‐offs across a broad range of domains, including terrestrial, marine and freshwater realms. By reducing technical barriers, the framework facilitates exploration of trade‐offs and identification of co‐benefits across diverse ecological, economic and social planning contexts.

Crawfish ( Palinurus elephas ) were once common across rocky reefs in the North‐East Atlantic, but during the 1980s widespread extirpation reduced the species to a few isolated populations in remote areas. Since 2010, the species has begun to recover and is now recolonizing much of its former range. Owing to its high commercial value, fisheries landings have increased 50% per year since 2019 leading to concerns of overexploitation. In the UK a key management measure is the designation of marine conservation zones (MCZs)—a spatial management tool through which regional fisheries authorities can impose fisheries prohibitions to protect populations. We combined data from multiple sources, including commercial catch recording and various tracking studies (mark recapture and acoustic telemetry) to conduct an integrated analysis of spatial ecology, assessing the efficacy of MCZs and provide broad‐scale baseline data for further studies on population status. We found sex dependent movement characteristics with higher mobility of males during reproductive seasons. Ultimately, however, most individuals occupied small territories (~4 km ² ), with maximum dispersal distances ranging between 94 m and 4.6 km (1.6 ± 1.1 km—mean ± SD). A notable exception was observed in two subadults, which dispersed 164 and 165 km, suggestive that some individuals exhibit nomadic behaviour. While MCZs have strong potential to safeguard localized populations, they are not a complete solution. In particular, the species' reproductive strategy includes a long planktonic larval phase (~12 months), resulting in highly variable recruitment events that a static network of protected areas cannot reliably protect. Consequently, long‐term population persistence will also depend on broad‐scale monitoring of population processes and commercial fisheries effort.

In Small Island Developing States (SIDS), coastal marine resources are particularly vulnerable to overexploitation, with small‐scale fisheries (SSF) providing an irreplaceable source of income and food. However, the decentralized and complex nature of SSF coupled with limited monitoring capacity hinders the design of effective measures to protect marine resources and local livelihoods. To address this knowledge gap, we implemented a participatory mobile device app‐based fisheries survey in 23 coastal communities of São Tomé and Príncipe (STP). Trained fishers and fish traders collected landing data from 12,403 unique fishing trips between 2019 and 2023 and recorded vessel activity on 620 sampling days. Catch and effort varied seasonally, with species composition varying across métiers (fishing types). While fishers demonstrated the ability to switch across métiers to target different species, catches were dominated by a few abundant species, notably blue runner and flying fish. Catch biomass and species richness, as well as biomass of demersal large‐bodied species, were lower on São Tomé Island compared to Príncipe Island, likely reflecting historical impacts of higher fishing effort. By combining community participation with digital tools, this approach generated high‐resolution data previously inaccessible to national authorities and provided actionable insights for fisheries governance in STP. Our findings highlight the value of participatory, mobile device‐based monitoring for filling knowledge gaps in SIDS, demonstrating how such approaches can guide conservation priorities while integrating resource users in fisheries management.

Marine protected areas (MPAs) often lack adequate data on the status of marine assemblages to support evidence‐based management. Stereo baited remote underwater video (BRUV) systems offer a powerful, low‐cost tool for collecting ecological data, yet they remain underutilized in the North East Atlantic, especially compared to more invasive methods such as fisheries surveys. Here, we demonstrate how a spatially comprehensive stereo‐BRUV survey can generate benchmark data to support MPA management at an ecosystem scale, using an ecologically distinct oceanic archipelago as a case study. The archipelago's habitats were found to support high abundances of regionally targeted commercial species, including benthic catsharks (Scyliorhinidae) and European spiny lobster (Palinurus elephas), with ~12,000 individuals recorded representing 64 species and 44 families. Deeper, topographically complex reefs were found to support higher levels of richness and biomass, with sediment‐specific increases in depth also driving demersal abundance. Stereo technology was additionally able to provide body size data for 43 species, with remoteness and shelter from exposure found to be common drivers of increased body size for indicator taxa. Survey results represent a contemporary benchmark for measuring changes in local MPA management, fisheries practices, and climate change impacts. The results also illustrate how spatially robust sampling methods and stereo‐BRUV systems can facilitate more holistic, fisheries‐independent data collection in UK and European waters.

In response to anthropogenic threats to marine ecosystems, governments committed to expand global Marine Protected Area (MPA) coverage to 30% by 2030 (“30✕30”). Although MPAs are perceived to result in economic losses to fisheries, they can mitigate losses through mechanisms such as larval export, which remains underrepresented in fisheries models. To assess how larval export offsets opportunity costs of MPAs, we coupled simulations of larval advection with a global bioeconomic size-spectrum model of fisheries harvest. We show that whilst larval export reduced opportunity costs, benefits depended on management outside MPAs. Under heavy overfishing, larval export increased global catches by ~40% by 2040, whereas under strong fisheries management, larval export moderated global catch losses by ~3%. Benefits were greater close to MPAs, in areas of higher productivity, and where currents were faster. These findings illustrate the importance of accounting for larval export to assess economic trade-offs associated with conservation measures.

Nature conservation is increasingly focused on recovering depleted populations and ecosystems. The United Nations General Assembly has proclaimed 2021–2030 the UN Decade on Ecosystem Restoration, and global commitments to ecosystem restoration in response to biodiversity, climate, and sustainable development targets are now considerable, with over 100 nations committed to halting and reversing forest loss and land degradation by 2030. The impacts of these resources on nature recovery will depend on how actions are identified and implemented. Systematic conservation planning has historically been used to prioritize areas for protection but has shown great potential to guide nature recovery actions that are underpinned by principles of spatial conservation planning. In the present article, we advocate for systematic conservation planning to target resources for nature recovery and show how well-established systematic conservation planning frameworks can be developed appropriately, particularly by integrating models for forecasting ecological, social, and economic conditions with spatial prioritization methods designed to target nature recovery resources.