Genetic hotspots for conserving Southern Ocean benthic biodiversity.

Greenstreet, S. P. R., Fraser, H. M., and Piet, G. J. 2009. Using MPAs to address regional-scale ecological objectives in the North Sea: modelling the effects of fishing effort displacement. – ICES Journal of Marine Science, 66: 90–100. The use of Marine Protected Areas (MPAs) to address regional-scale objectives as part of an ecosystem approach to management in the North Sea is examined. Ensuring that displacement of fishing activity does not negate the ecological benefits gained from MPAs is a major concern. Two scenarios are considered: using MPAs to safeguard important areas for groundfish species diversity and using them to reduce fishing impacts on benthic invertebrates. Appropriate MPAs were identified using benthic invertebrate and fish abundance data. Fishing effort redistribution was modelled using international landings and fishing effort data. Closing 7.7% of the North Sea to protect groundfish species diversity increased the fishing impact on benthic invertebrates. Closing 7.3% of the North Sea specifically to protect benthic invertebrates reduced fishing mortality by just 1.7–3.8%, but when combined with appropriate reductions in total allowable catch (TAC), 16.2–17.4% reductions in fishing mortality were achieved. MPAs on their own are unlikely to achieve significant regional-scale ecosystem benefits, because local gains are largely negated by fishing effort displacement into the remainder of the North Sea. However, in combination with appropriate TAC reductions, the effectiveness of MPAs may be enhanced.

Protecting Antarctica through Co-production of actionable science: Lessons from the CCAMLR marine protected area process

Establishing Marine Protected Areas (MPAs) in international waters is critical for the conservation of marine biodiversity. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is a global leader in high seas conservation, having established two international MPAs in Antarctica’s Southern Ocean, as part of a commitment to establish a representative system of MPAs for the CAMLR Convention Area. CCAMLR MPAs are adopted by consensus. However, consensus decision-making has slowed the MPA adoption process, and since 2016 the Commission has been unable to agree and implement further MPAs, which has stalled the development of the circumpolar representative system. The key aim of this study was to identify how features of the planning process contribute to outcomes, problems and solutions. We conducted semi-structured interviews with 18 scientists, policymakers, and expert observers from fisheries and environmental non-government organisations involved in CCAMLR MPA planning, to explore their perceptions (experiences, opinions, impressions) of the planning process. Our results identify four key features that are influential across multiple areas of the CCAMLR MPA planning and decision-making process: i) a lack of common understanding; ii) the influence of historical relationships and legacy in subsequent planning processes; iii) inconsistencies between expectations of and requirements for MPA planning; and iv) the degree to which CCAMLR principles and practices, norms, and values are shared. We demonstrate how these four features may help or hinder the effectiveness of the current planning process. We then make suggestions regarding how the planning process could be adapted to capitalise on these features.

The conservation of biodiversity ultimately depends on the conservation of its cornerstone, genetic diversity. The central dogma of conservation genetics postulates that genetic variability is beneficial, hence worth preserving to the greatest extent, while the increase of genetic variance enhances the probability of population survival. The genetic indicators proposed by the Post-2020 Kunming-Montreal Global Biodiversity Framework need complementary approaches for a full assessment of adaptive potential. Comprehensive genetic monitoring assesses the state of the maintenance of genetic variation in natural populations and the success of gene conservation actions. Genetic monitoring, the quantification of temporal changes in population genetic variation and structure, elucidates processes that maintain genetic variation and adaptive potential in natural populations, introduces prognosis and helps define tools for the management of genetic resources. Herein, we present genetic monitoring results focusing on south-eastern marginal populations of three perennial woody angiosperms and two conifers, namely chestnut (Castanea sativa), sessile oak (Quercus petraea), pedunculate oak (Quercus robur), as well as hybrid fir (Abies borisii regis) and umbrella pine (Pinus pinea), that are expected to face particular challenges in the future due to climatic change and anticipated changes in their future climatic envelop. These species have been evaluated in a time interval of 15-17 years (baseline and contemporary genetic data). The genetic diversity parameters employed for genetic monitoring were effective number of alleles (Ae), allelic richness (AR), Shannon’s information index (I), observed heterozygosity (Ho), gene diversity (Hs), latent genetic potential (LGP), and effective population size (Ne), In the majority of comparisons, extant genetic diversity was found reduced, however the differences were not statistically significant. In the genetically depauperate Pinus pinea the already very low genetic diversity did not recover. Moreover, fructification and natural regeneration were strong and abundant respectively in the former four species, while being weak and scattered in the latter. Results overall depict dynamic and idiosyncratic species outcomes and call for the maintenance and intensification of genetic monitoring assessments in the future.

Compound extremes of temperature and acidity that extend over substantial fractions of the water column can be particularly damaging to marine organisms, as they experience not only additional stress by the potentially synergistic effects of these two stressors, but also a reduction in habitable vertical space. Here, we detect and analyze such column‐compound extremes (CCX) in the Southern Ocean between 1980 and 2019, and characterize their duration, intensity, and spatial extent. To this end, we use daily output from a hindcast simulation of the Regional Ocean Modeling System (ROMS), coupled with the Biological Elemental Cycling (BEC) model. We first detect extremes in temperature and acidity ([]) within the top 300 m using a relative threshold of 95% and then identify CCX where conditions are extreme for both stressors for at least 50 m of the water column. When analyzed on a fixed baseline, positive trends in ocean warming and acidification caused CCX to last longer, intensify, and expand throughout the Southern Ocean. In the Antarctic zone, CCX expanded between 1980 and 2019 more than ten times in volume, lasted up to 120 days longer, and doubled in anomaly. Some of the largest and longest events occurred in Antarctic Marine Protected Areas (MPAs), covering more than 200,000 km 2 and persisting for over 500 days. CCX in the Subantarctic and Northern zones quadrupled in volume and increased by more than 30% in anomaly. Across the Southern Ocean, the increasing occurrence of CCX exacerbates the risks to marine ecosystems from warming and acidification.

Bathymetric distribution patterns of Southern Ocean macrofaunal taxa: Bivalvia, Gastropoda, Isopoda and Polychaeta

Remote, high‐latitude oceans can prove challenging for the designation and implementation of marine protected areas (MPAs), partly due to issues in monitoring inaccessible localities and large spatial scales. A lack of protection combined with damage from growing human activities has contributed to the degradation of some of the Earth's richest marine biodiversity and highlights the urgent need to support improved marine conservation. High‐resolution satellite imagery (VHR; 0.3–0.6 m spatial resolution) provides a much‐needed tool for monitoring sentinel species in remote oceans, which would strengthen current and future MPA research and monitoring programs across the globe. This perspective specifies how recent advances in VHR studies have contributed to knowledge regarding occurrence, habitat suitability, and abundance of mesopredators in the Southern Ocean. We demonstrate how knowledge gained through VHR offers a cost‐effective and easily accessible method for collecting previously unobtainable data to inform a representative network of Southern Ocean MPAs, and how the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) could utilize this technology. As VHR and automated detection algorithms continue to improve, we showcase a promising opportunity to use these methods to complement current research and monitoring efforts, thus strengthening MPA efforts in the Southern Ocean and beyond.

Managing for climate resilient fisheries: Applications to the Southern Ocean

This study assesses the reserve effect on fish assemblages within the Larvotto Marine Protected Area (MPA), a small, fully protected, and highly enforced urban MPA, established in 1976 in Monaco (Mediterranean Sea), a highly urbanised coastal zone. Using a five-year dataset from underwater visual censuses, we analysed fish density, size, and biomass across two key habitats: artificial rocky substrates and Posidonia oceanica meadows, comparing data from within the MPA to nearby unprotected areas. Results show a pronounced habitat-specific response, with significantly higher fish biomass on artificial substrates inside the MPA, while Posidonia oceanica meadows displayed no significant biomass difference between protected and unprotected zones. These findings demonstrate that well-enforced MPAs in urbanized settings can deliver substantial ecological benefits, providing valuable insights for policymakers and advancing our understanding of MPAs in complex coastal environments. Integrating urban MPAs into broader conservation frameworks could enhance the ecological resilience of coastal ecosystems by complementing “residual” MPAs typically located in less disturbed areas. This approach can help reconcile the intensifying use of coastal zones with ambitious 2030 global conservation targets, contributing meaningfully toward the effective protection of 30% of Earth’s surface.

Kelp forests, one of the world’s most productive ecosystems, have been in decline in many regions in recent years. Climate change, through steady sea warming or marine heatwaves, has led to the disappearance of entire populations, although kelp forest decline may also depend on non-climatic stressors such as grazing. Since the impacts of climate change are projected to continue to intensify for decades, marine protected areas (MPAs) have been suggested as a cost-effective strategy to boost the resilience of marine ecosystems. However, implementing an MPA does not guarantee that all components of the local community will benefit from it. In NW Spain, several stakeholders reported the decline of Laminaria ochroleuca inside the Islas Atlánticas Marine National Park in recent years, but the extent and possible drivers of this decline have not been investigated. Using a combination of quadrat-scale (abundance, biomass) and transect-scale (cover) seasonal surveys over one year, we found striking differences between L. ochroleuca reefs inside and outside the MPA. Populations outside the MPA were the typical canopy forests expected for a perennial kelp, stable year-round and composed mostly of adults. Inside the MPA, however, grazing prevented the canopy phase from being reached. Instead, only mid-sized young plants were detected in autumn, but most had disappeared by winter, and those that remained had been degraded by herbivores to mere blade-less stipes with no growth meristem that eventually perish. Further research seems warranted to monitor whether this phenomenon spreads to nearby kelp beds outside the MPA. Meanwhile, restoring MPA kelp reefs will more likely require efforts to reduce herbivore activity (e.g. translocations, exclusion devices) than to bolster kelp populations. HIGHLIGHTS • Kelp canopies recurrently failed inside a MPA in recent years.• Neither propagule supply nor environmental conditions explain the failure.• Grazers keep a canopy-free state by eradicating recently recruited kelps.

China's changing position towards marine protected areas in the Southern Ocean: Implications for future Antarctic governance

Managing for change: Using vertebrate at sea habitat use to direct management efforts

With the strengthening of the global environmental movement, the Southern Ocean has become an effective international testing ground for the development of spatial planning in marine environments beyond national jurisdiction. This note aims to review the European Union (EU) role in the progress on designation of environmentally representative network of marine protected areas (MPAs) in Antarctica, and the effect of this process on the shaping of Ukraine’s strategy in this region. Following Ukraine’s external vector to European integration, in 2021 the country began formally aligning as a co-proponent with the EU-initiated two MPA proposals — in East Antarctica and the Weddell Sea. This alignment of positions is utterly important, taking into account the approaching of Ukraine's first chairmanship of the Commission for the Conservation of Antarctic Marine Living Resources in 2023–2024, which would be an exceptional opportunity for our country to make a significant progress in designation the largest MPAs ever implemented in Antarctica given national interests, including the creation of an international consortium with the involvement of Ukrainian scientific infrastructure in Antarctica, such as Ukrainian Antarctic Akademik Vernadsky station and the research vessel Noosfera, to implement internationally significant scientific and monitoring programs to evaluate MPAs efficiency with Ukraine as a co-initiator.

Establishing marine protected areas in the southern ocean, lessons for the BBNJ agreement

The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) adopted a conservation measure for establishing a network of marine protected areas (MPAs) in 2011. Since then, a number of proposals have been submitted to the Commission, but their designation has been consistently opposed by some pro-fishing CCAMLR member countries. This article provides an analysis of CCAMLR institutional and decision-making processes in an attempt to explain the obstacles preventing the creation of a network of MPAs. The role of environmental nongovernmental organizations (ENGOs) is examined through their track record in Antarctic environmental governance as well as the extent of their participation within the CCAMLR MPA process.