Animal and plant species around the world are being challenged by the deleterious effects of inbreeding, loss of genetic diversity, and maladaptation due to widespread habitat destruction and rapid climate change. In many cases, interventions will likely be needed to safeguard populations and species and to maintain functioning ecosystems. Strategies aimed at initiating, reinstating, or enhancing patterns of gene flow via the deliberate movement of genotypes around the environment are generating growing interest with broad applications in conservation and environmental management. These diverse strategies go by various names ranging from genetic or evolutionary rescue to provenancing and genetic resurrection. Our aim here is to provide some clarification around terminology and to how these strategies are connected and linked to underlying genetic processes. We draw on case studies from the literature and outline mechanisms that underlie how the various strategies aim to increase species fitness and impact the wider community. We argue that understanding mechanisms leading to species decline and community impact is a key to successful implementation of these strategies. We emphasize the need to consider the nature of source and recipient populations, as well as associated risks and trade‐offs for the various strategies. This overview highlights where strategies are likely to have potential at population, species, and ecosystem scales, but also where they should probably not be attempted depending on the overall aims of the intervention. We advocate an approach where short‐ and long‐term strategies are integrated into a decision framework that also considers nongenetic aspects of management.

Rising ocean temperatures and extreme temperature events have precipitated declines and local extinctions in many marine species globally, but patterns of loss are often uneven across species ranges for reasons that are poorly understood. Knowledge of the extent of local adaptation and gene flow may explain such patterns and help predict future trajectories under scenarios of climate change. We test the extent to which local differentiation in thermal tolerance is influenced by gene flow and local adaptation using a widely distributed intertidal seaweed (Hormosira banksii) from temperate Australia. Population surveys across ~2,000 km of the species range revealed strong genetic structuring at regional and local scales (global F_ST = 0.243) reflecting extremely limited gene flow, while common garden experiments (14‐day exposures to 15, 18, 21°C) revealed strong site differences in early development and mortality in response to elevated temperature. Embryos from many sites spanning a longitudinal thermal gradient showed suppressed development and increased mortality to elevated water temperatures, but populations originating from warmer and more variable thermal environments tended to be less susceptible to warming. Notably, there was significant local‐scale variation in the thermal responses of embryos within regions which was corroborated by the finding of small‐scale genetic differences. We expect the observed genetic and phenotypic differentiation to lead to uneven responses to warming sea surface temperatures in this important marine foundation species. The study highlights the challenges of predicting species responses to thermal stress and the importance of management strategies that incorporate evolutionary potential for “climate‐proofing” marine ecosystems.

The white shark (Carcharodon carcharias) is one of the world's largest apex predators found throughout the world's temperate and subtropical marine environments. However, the species has suffered significant declines in recent decades and effective conservation programs require a sound knowledge of white shark biology and ecology. In particular, information on white shark diet across life stages and the species' range is needed to identify critical trophic interactions supporting shark populations and to predict the resilience of white sharks to environmental changes. In this study, we reassess the diet and trophic ecology of white sharks via the genetic analyses of cloacal swabs from 214 juvenile and subadult sharks from eastern Australia. Our findings are largely consistent with those of previous studies based on visual analyses of gut contents but highlight the unprecedented taxonomic resolution of prey items offered by genomic assessments of shark cloacal swabs. Diets consisted primarily of ray‐finned fishes, with Mugiliformes, Carangiformes, Perciformes, and Scombriformes being dominant prey taxa, but with elasmobranchs, marine mammals, and birds also being common dietary constituents. Statistical analyses revealed a significant effect of sex and sampling location on diet composition, indicating biological and spatial variability in diets and predatory behavior. Overall, these findings support the notion that juvenile and subadult white sharks are opportunistic predators, which may provide some level of resilience to shifts in marine resources. However, frequently consumed ray‐finned fishes, many of which are commercially targeted, may be key to supporting white shark populations in eastern Australia. This study represents the most comprehensive analysis of juvenile and subadult white shark diets performed to date and provides added confidence in the genomic analysis of cloacal swabs for dietary assessments of predatory species. These results are expected to help inform management geared toward conserving this important marine predator across the world's oceans.

The health of the world's oceans is intrinsically linked to the biodiversity of the ecosystems they sustain. The importance of protecting and maintaining ocean biodiversity has been affirmed through the setting of the UN Sustainable Development Goal 14 to conserve and sustainably use the ocean for society's continuing needs. The decade beginning 2021–2030 has additionally been declared as the UN Decade of Ocean Science for Sustainable Development. This program aims to maximize the benefits of ocean science to the management, conservation, and sustainable development of the marine environment by facilitating communication and cooperation at the science–policy interface. A central principle of the program is the conservation of species and ecosystem components of biodiversity. However, a significant omission from the draft version of the Decade of Ocean Science Implementation Plan is the acknowledgment of the importance of monitoring and maintaining genetic biodiversity within species. In this paper, we emphasize the importance of genetic diversity to adaptive capacity, evolutionary potential, community function, and resilience within populations, as well as highlighting some of the major threats to genetic diversity in the marine environment from direct human impacts and the effects of global climate change. We then highlight the significance of ocean genetic diversity to a diverse range of socioeconomic factors in the marine environment, including marine industries, welfare and leisure pursuits, coastal communities, and wider society. Genetic biodiversity in the ocean, and its monitoring and maintenance, is then discussed with respect to its integral role in the successful realization of the 2030 vision for the Decade of Ocean Science. Finally, we suggest how ocean genetic diversity might be better integrated into biodiversity management practices through the continued interaction between environmental managers and scientists, as well as through key leverage points in industry requirements for Blue Capital financing and social responsibility.