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Human populations near ecosystems are used as both a proxy for dependency on ecosystems, and conversely to estimate threats. Consequently, the number of people living near coral reefs is often used in regional coral reef management, evaluation of risk at regional and global scales, and even considerations of funding needs. Human populations and their statistics, are ever-changing and data relating to coral reefs have not been updated regularly. Here, we present an up-to-date analysis of the abundance, and density of people living within 5-100 km of coral reef ecosystems along with population proportion, using freely available data sets and replicable methods. We present trends of changes in human populations living near coral reefs over a 20-year time period (2000-2020), divided by region and country, along with socio-economic denominations such as country income category and Small Island Developing States (SIDS). We find that across 117 coral reef countries there are currently close to a billion people living within 100 km of a coral reef (~13% of the global population) compared with 762 million people in 2000. Population growth by coral reefs is higher than global averages. The Indian Ocean saw a 33% increase in populations within 100 km of a coral reef and 71% at 5 km. There are 60 countries with 100% of their population within 100 km of coral reefs. In SIDS, the proportion of the total population within 100 km of a coral reef is extremely high: 94% in 2020. Population density 5-10 km from coral reefs is 4× the global average. From 5 to 100 km, more people from lower-middle-income countries live by coral reefs than any other income category. Our findings provide the most up-to-date and extensive statistics on the regional and nation-level differences in population trends that play a large role in coral reef health and survival.

Carnivorous fish are a key part of the Indonesian human population sustenance, and it is important to design marine protected areas that include environmental features that allow these species to thrive. Many studies report the role of coral cover and habitat complexity in determining fish distribution on coral reefs but broader environmental factors such as current velocity and productivity are less studied. Southern Indonesia is characterised by upwellings and strong currents, stemming from the tidal cycle and the Indonesian Throughflow. In this study we investigate how current velocity, chlorophyll-a (chl-a), sea surface height and temperature relate to the biomass of carnivorous fish, considering the influence of habitat complexity and coral cover. Data were collected by surveying seven sites around Nusa Penida MPA for a total of 97 h of observation. Serranids and Lutjanids showed higher dependency on coral cover than fish from family Lethrinidae, Carangidae and Scombridae for which current, sea surface height, chl-a, and temperature were more influential predictors. Considering the similar trophic ecology of these species, the different relationship with oceanographic factors is likely related to different body shapes, living, and feeding habits between fish families. Changes in sea surface temperature and current velocity induced by vertical mixing are affecting coral reef fisheries-targeted species distribution in Nusa Penida and investigating these relationships on a broader scale will better inform marine spatial planning decisions.

Author(s): Rogers, Alex D; Baco, Amy; Escobar-Briones, Elva; Currie, Duncan; Gjerde, Kristina; Gobin, Judith; Jaspars, Marcel; Levin, Lisa; Linse, Katrin; Rabone, Muriel; Ramirez-Llodra, Eva; Sellanes, Javier; Shank, Timothy M; Sink, Kerry; Snelgrove, Paul VR; Taylor, Michelle L; Wagner, Daniel; Harden-Davies, Harriet

Growing human activity in areas beyond national jurisdiction (ABNJ) is driving increasing impacts on the biodiversity of this vast area of the ocean. As a result, the United Nations General Assembly committed to convening a series of intergovernmental conferences (IGCs) to develop an international legally-binding instrument (ILBI) for the conservation and sustainable use of marine biological diversity of ABNJ [the biodiversity beyond national jurisdiction (BBNJ) agreement] under the United Nations Convention on the Law of the Sea. The BBNJ agreement includes consideration of marine genetic resources (MGR) in ABNJ, including how to share benefits and promote marine scientific research whilst building capacity of developing states in science and technology. Three IGCs have been completed to date with the fourth delayed by the Covid pandemic. This delay has allowed a series of informal dialogues to take place between state parties, which have highlighted a number of areas related to MGR and benefit sharing that require technical guidance from ocean experts. These include: guiding principles on the access and use of MGR from ABNJ;the sharing of knowledge arising from research on MGR in ABNJ;and capacity building and technology transfer for developing states. In this paper, we explain what MGR are, the methods required to collect, study and archive them, including data arising from scientific investigation. We also explore the practical requirements of access by developing countries to scientific cruises, including the sharing of data, as well as participation in research and development on shore whilst promoting rather than hindering marine scientific research. We outline existing infrastructure and shared resources that facilitate access, research, development, and benefit sharing of MGR from ABNJ;and discuss existing gaps. We examine international capacity development and technology transfer schemes that might facilitate or complement non-monetary benefit sharing activities. We end the paper by highlighting what the ILBI can achieve in terms of access, utilization, and benefit sharing of MGR and how we might future-proof the BBNJ Agreement with respect to developments in science and technology. © Copyright © 2021 Rogers, Baco, Escobar-Briones, Gjerde, Gobin, Jaspars, Levin, Linse, Rabone, Ramirez-Llodra, Sellanes, Shank, Sink, Snelgrove, Taylor, Wagner and Harden-Davies.

Long held notions of the universally asocial octopus are being challenged due to the identification of high-density and interacting octopus populations in Australia, Indonesia, Japan and the deep sea. This study experimentally assessed the social tolerance and presence of potential prey items of Caribbean reef octopus, Octopus briareus, in a tropical marine lake (25°21′40″N, 76°30′40″W) on the island of Eleuthera, The Bahamas, by deploying artificial dens in multi-den groups or ‘units’ in the months of May and June 2019. Fifteen octopus were observed occupying dens (n = 100), resulting in 13 den units being occupied (n = 40). Two examples of adjacent occupation within a single den unit were identified but with zero examples of cohabitation/den sharing. Ecological models showed den and den unit occupation was predicted to increase with depth and differ between sites. Octopus also displayed no preference for isolated or communal units but preferred isolated dens over dens adjacent to others. Additionally, 47 % of occupied dens contained bivalve or crustacean items with no epifauna on their interior surface. The lack of epifauna suggests that these items have been recently ‘cleaned’ by occupying octopus and so represent likely prey. This study presents evidence of possible antisocial den use by O. briareus, a modification of the default ‘asocial’ ignoring of conspecifics typically attributed to octopus. This is likely in response to the high population density and may imply behavioural plasticity, making this system appropriate for further scrutiny as a research location on the influence of large, insular environments on marine species.

Significance Until now, all of the ca. 1,800 known modern scleractinian coral species were thought to produce skeletons exclusively of aragonite. Asymbiotic Paraconotrochus antarcticus living in the Southern Ocean is the first example of an extant scleractinian that forms a two-component carbonate skeleton, with an inner structure made of high-Mg calcite and an outer structure composed of aragonite. This discovery adds support to the notion that the coral skeletal formation process is strongly biologically controlled. Mitophylogenomic analysis shows that P. antarcticus represents an ancient scleractinian clade, suggesting that skeletal mineralogy/polymorph of a taxon, once established, is a trait conserved throughout the evolution of that clade., One of the most conserved traits in the evolution of biomineralizing organisms is the taxon-specific selection of skeletal minerals. All modern scleractinian corals are thought to produce skeletons exclusively of the calcium-carbonate polymorph aragonite. Despite strong fluctuations in ocean chemistry (notably the Mg/Ca ratio), this feature is believed to be conserved throughout the coral fossil record, spanning more than 240 million years. Only one example, the Cretaceous scleractinian coral Coelosmilia (ca. 70 to 65 Ma), is thought to have produced a calcitic skeleton. Here, we report that the modern asymbiotic scleractinian coral Paraconotrochus antarcticus living in the Southern Ocean forms a two-component carbonate skeleton, with an inner structure made of high-Mg calcite and an outer structure composed of aragonite. P. antarcticus and Cretaceous Coelosmilia skeletons share a unique microstructure indicating a close phylogenetic relationship, consistent with the early divergence of P. antarcticus within the Vacatina (i.e., Robusta) clade, estimated to have occurred in the Mesozoic (ca. 116 Mya). Scleractinian corals thus join the group of marine organisms capable of forming bimineralic structures, which requires a highly controlled biomineralization mechanism; this capability dates back at least 100 My. Due to its relatively prolonged isolation, the Southern Ocean stands out as a repository for extant marine organisms with ancient traits.

The ocean is the linchpin supporting life on Earth, but it is in declining health due to an increasing footprint of human use and climate change. Despite notable successes in helping to protect the ocean, the scale of actions is simply not now meeting the overriding scale and nature of the ocean's problems that confront us.Moving into a post‐COVID‐19 world, new policy decisions will need to be made. Some, especially those developed prior to the pandemic, will require changes to their trajectories; others will emerge as a response to this global event. Reconnecting with nature, and specifically with the ocean, will take more than good intent and wishful thinking. Words, and how we express our connection to the ocean, clearly matter now more than ever before.The evolution of the ocean narrative, aimed at preserving and expanding options and opportunities for future generations and a healthier planet, is articulated around six themes: (1) all life is dependent on the ocean; (2) by harming the ocean, we harm ourselves; (3) by protecting the ocean, we protect ourselves; (4) humans, the ocean, biodiversity, and climate are inextricably linked; (5) ocean and climate action must be undertaken together; and (6) reversing ocean change needs action now.This narrative adopts a ‘One Health’ approach to protecting the ocean, addressing the whole Earth ocean system for better and more equitable social, cultural, economic, and environmental outcomes at its core. Speaking with one voice through a narrative that captures the latest science, concerns, and linkages to humanity is a precondition to action, by elevating humankind's understanding of our relationship with ‘planet Ocean’ and why it needs to become a central theme to everyone's lives. We have only one ocean, we must protect it, now. There is no ‘Ocean B’.

The ocean plays a crucial role in the functioning of the Earth System and in the provision of vital goods and services. The United Nations (UN) declared 2021–2030 as the UN Decade of Ocean Science for Sustainable Development. The Roadmap for the Ocean Decade aims to achieve six critical societal outcomes (SOs) by 2030, through the pursuit of four objectives (Os). It specifically recognizes the scarcity of biological data for deep-sea biomes, and challenges the global scientific community to conduct research to advance understanding of deep-sea ecosystems to inform sustainable management. In this paper, we map four key scientific questions identified by the academic community to the Ocean Decade SOs: (i) What is the diversity of life in the deep ocean? (ii) How are populations and habitats connected? (iii) What is the role of living organisms in ecosystem function and service provision? and (iv) How do species, communities, and ecosystems respond to disturbance? We then consider the design of a global-scale program to address these questions by reviewing key drivers of ecological pattern and process. We recommend using the following criteria to stratify a global survey design: biogeographic region, depth, horizontal distance, substrate type, high and low climate hazard, fished/unfished, near/far from sources of pollution, licensed/protected from industry activities. We consider both spatial and temporal surveys, and emphasize new biological data collection that prioritizes southern and polar latitudes, deeper (>2000 m) depths, and midwater environments. We provide guidance on observational, experimental, and monitoring needs for different benthic and pelagic ecosystems. We then review recent efforts to standardize biological data and specimen collection and archiving, making “sampling design to knowledge application” recommendations in the context of a new global program. We also review and comment on needs, and recommend actions, to develop capacity in deep-sea research; and the role of inclusivity - from accessing indigenous and local knowledge to the sharing of technologies - as part of such a global program. We discuss the concept of a new global deep-sea biological research program‘Challenger 150,’ highlighting what it could deliver for the Ocean Decade and UN Sustainable Development Goal 14.

International audience; The South Orkney Islands Southern Shelf (SOISS) Marine Protected Area (MPA) was the first MPA anywhere in the world to be designated entirely within the High Seas and is managed under the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). As part of efforts to undertake research and monitoring in and around the MPA, an international expedition ('SO-AntEco') was undertaken in the austral summer of 2016, on board the British Antarctic Survey research ship RRS James Clark Ross. The focus of the expedition was to contribute towards a better understanding of selected benthic habitats around the South Orkney Islands, and the biodiversity within those habitats, in relation to the geomorphic zones both inside and outside the SOISS MPA. This addresses a key objective set out by the draft SOISS MPA Research and Monitoring Plan (SC-CAMLR, 2014). The benthic assemblages of the SOISS MPA region were found to be strongly correlated with the texture of the seafloor, where hard substrates hosted a greater number of individuals, taxa and biomass with a dominance of filter feeding Vulnerable Marine Ecosystem (VME) taxa, and soft sediments were dominated mostly by deposit feeders. Substantial differences in the abundance of VME taxa were found between two sampling gears used (shallow underwater camera system and Agassiz trawl). We conclude that camera systems may be more suitable for VME assessments than the Agassiz trawl, but in addition where possible, additional trawling is advisable for collecting all faunal types and for higher taxonomic resolution. The designation of VME locations or MPAs based purely on geomorphic classification is not advisable, due to small scale variation in substrate and other local physical influences; however, the utility of such classifications may be improved with the inclusion of additional environmental factors e.g. substrate type.

Watamu Marine National Park (WMNP) is one of the oldest no-take Marine Protected Areas (MPAs) in the world. Since its establishment in 1968, it has been the subject of a number of scientific studies as well as suffering from a range of modern threats to coastal marine habitats. The current state and conservation value of WMNP is documented in terms of habitat, biodiversity, and available scientific literature. There were 101 published references relating to WMNP found, which mostly focus on coral reef ecology, with less attention to other topics, such as biodiversity, socio-economics, or the ecology of non-coral reef habitats. The habitat map produced of WMNP is the first to show this level of detail and the only habitat map of a Kenyan MPA. Nine habitat categories were mapped; revealing that the most dominant habitat type is seagrass and the least is coral reef. Species lists were collected for fish, echinoderms, molluscs, crustaceans, corals, and seagrass, and species abundances were used to estimate total species richness, species diversity and sampling completeness. There were 18 species across all groups that fall into a category of conservation concern (other than Least Concern or Not Evaluated) on the IUCN Red List and 8 species found which are currently undescribed. The findings of this paper emphasise the importance of non-coral habitats in the WMNP, such as seagrass beds, and the need for more research into the ecology and conservation importance of these habitats. The information provided in this paper provides a comprehensive overview to any scientist or conservationist wanting to carry out further work in WMNP.

Antipatharia are a diverse group of corals with many species found in deep water. Many Antipatharia are habitat for associates, have extreme longevity and some species can occur beyond 8500 m depth. As they are major constituents of׳coral gardens’, which are Vulnerable Marine Ecosystems (VMEs), knowledge of their distribution and environmental requirements is an important pre-requisite for informed conservation planning particularly where the expense and difficulty of deep-sea sampling prohibits comprehensive surveys. This study uses a global database of Antipatharia distribution data to perform habitat suitability modelling using the Maxent methodology to estimate the global extent of black coral habitat suitability. The model of habitat suitability is driven by temperature but there is notable influence from other variables of topography, surface productivity and oxygen levels. This model can be used to predict areas of suitable habitat, which can be useful for conservation planning. The global distribution of Antipatharia habitat suitability shows a marked contrast with the distribution of specimen observations, indicating that many potentially suitable areas have not been sampled, and that sampling effort has been disproportionate to shallow, accessible areas inside marine protected areas (MPAs). Although 25% of Antipatharia observations are located in MPAs, only 7-8% of predicted suitable habitat is protected, which is short of the Convention on Biological Diversity target to protect 10% of ocean habitats by 2020.

The polychaete family polynoid is very large and includes a high diversity of behaviours, including numerous examples of commensal species. The comparison between free-living and commensal behaviours and the evolution of the relationships between commensal species and their hosts are valuable case studies of ecological adaptations. Deep-sea species of Polynoidae were sampled at four seamounts in the Southwest Indian Ridge and twenty specimens from seven species were selected to be analysed. Among them, there were free-living species, living within the three-dimensional framework of cold-water coral reefs, on coral rubble and on mobile sediments, and commensal species, associated with octocorals, hydrocorals (stylasterids), antipatharians and echinoderms (holothurian and ophiuroids). We analysed two mitochondrial (COI, 16S) and two nuclear (18S, 28S) ribosomal genetic markers and their combined sequences were compared with other Genbank sequences to assess the taxonomic relationships within the species under study, and the potential role of hosts in speciation processes. Most basal species of the sub-family Polynoinae are obligate symbionts showing specific morphological adaptations. Obligate and facultative commensal species and free-living species have evolved a number of times, although, according to our results, the obligate coral commensal species appear to be monophyletic.

Anchialine systems are isolated from the sea and often support species' populations distinct from their marine counterparts. Sweetings Pond, an anchialine lake on the island of Eleuthera in The Bahamas was identified as a site of high Caribbean reef octopus, Octopus briareus ( Robson, 1929 ) density, relative to coastal populations. However, observed deterioration in local benthic habitat and increased anthropogenic influence over the last 30 years imply that this octopus population may have undergone density and distribution shifts in response to these changing conditions. Here, we assess the system wide octopus density to provide an updated estimate. We hypothesize that despite depressed habitat availability in the 1980s, it will now support octopus densities less than historical estimates because of increasing human impact on the system. Drivers of abundance were also modelled, testing ecological hypotheses of the relationship between octopus count and prey, habitat coverage, and human disturbance. Octopus briareus were found in 7 of 27 of surveys with a mean survey count of 0.630 ± 1.25 per 900 m2. Octopus density did not vary significantly between sites. Octopus count was predicted to increase with increasing cover of calcareous rubble and the density of a preferred prey species, and intriguingly, counts decreased as a function of natural den abundance. System wide octopus density was comparable to earlier studies from the 1980s (1982 = 717.38 per km2; 1983 = 282.59 per km2; 2019 = 643.81 per km2) with no significant difference between years. Given the ecosystem's unique and closed ecological community and the population dynamics and distribution drivers we present, Sweetings Pond has the potential to act as a ‘natural laboratory’ to explore further questions about marine insular systems and their influence on species populations in terms of ecological and behavioural change.

Sequence data were obtained for five different loci, both mitochondrial (cox1, mtMutS, 16S) and nuclear (18S, 28S rDNA), from 64 species representing 25 genera of the common deep-sea octocoral family Primnoidae. We tested the hypothesis that Primnoidae have an Antarctic origin, as this is where they currently have high species richness, using Maximum likelihood and Bayesian inference methods of phylogenetic analysis. Using a time-calibrated molecular phylogeny we also investigated the time of species radiation in sub-Antarctic Primnoidae. Our relatively wide taxon sampling and phylogenetic analysis supported Primnoidae as a monophyletic family. The base of the well-supported phylogeny was Pacific in origin, indicating Primnoidae sub-Antarctic diversity is a secondary species radiation. There is also evidence for a subsequent range extension of sub-Antarctic lineages into deep-water areas of the Indian and Pacific Oceans. Conservative and speculative fossil-calibration analyses resulted in two differing estimations of sub-Antarctic species divergence times. Conservative analysis suggested a sub-Antarctic species radiation occurred ∼52 MYA (95% HPD: 36–73 MYA), potentially before the opening of the Drake Passage and Antarctic Circumpolar Current (ACC) formation (41–37 MYA). Speculative analysis pushed this radiation back into the late Jurassic, 157 MYA (95% HPD: 118–204 MYA). Genus-level groupings were broadly supported in this analysis with some notable polyphyletic exceptions: Callogorgia, Fanellia, Primnoella, Plumarella, Thouarella. Molecular and morphological evidence supports the placement of Tauroprimnoa austasensis within Dasystenella and Fannyella kuekenthali within Metafannyella.

Female multiple mating, known as polyandry, is ubiquitous and occurs in a wide variety of taxa. Polyandry varies greatly from species in which females mate with one or two males in their lifetime to species in which females may mate with several different males on the same day. As multiple mating by females is associated with costs, numerous hypotheses attempt to explain this phenomenon. One hypothesis not extensively explored is the possibility that polyandrous behavior is captured and "fixed" in populations via genetic processes that preserve the behavior independently of any adaptive benefit of polyandry. Here, we use female isolines derived from populations of Drosophila pseudoobscura from three locations in North America to examine whether different female remating levels are associated with patterns of chromosome inversions, which may explain patterns of polyandry across the geographic range. Populations differed with respect to the frequency of polyandry and the presence of inversion polymorphisms on the third chromosome. The population with the lowest level of female remating was the only one that was entirely comprised of homokaryotypic lines, but the small number of populations prevented us investigating this relationship further at a population level. However, we found no strong relationship between female remating levels and specific karyotypes of the various isolines.

Aim For many deep-sea fisheries, there is an urgent management requirement for information on the presence of vulnerable marine ecosystems (VMEs). Gathering deep-sea data using conventional techniques can be expensive and time-consuming. One way to provide a relatively rapid assessment of VME presence is to use data from fisheries by-catch and historical scientific observations. Our aim was to predict suitable habitat for octocorals around South Georgia and to estimate the extent to which octocoral habitat is currently protected by fisheries management measures. In addition, we attempted to determine the types of terrain in which octocorals and fishing activities occur. Location South Georgia, sub-Antarctic. Methods A terrain map of South Georgia was created using Benthic Terrain Modeler (BTM). Georeferenced octocoral data were combined with environmental layers to create an octocoral habitat suitability map using ecological niche factor analysis (ENFA). Results Most octocoral by-catch samples originated from narrow crest (an area representing shelf break and moraines) and steep (continental) slope terrains. Calcite saturation state and apparent oxygen utilization (AOU) were the most influential environmental parameters in determining highly suitable octocoral habitat. The ENFA model highlighted shelf-break areas to be highly suitable habitat for octocorals and that 38% of this habitat around South Georgia lies within areas currently protected by fisheries management; a further 20% is below the 2000-m fishing depth, meaning effectively that 58% of predicted highly suitable octocoral habitat is currently protected. Although these results indicate protection levels for octocoral habitat well above international standards/targets, the fishery remains active within a relatively concentrated shelf area at 700–2000 m, potentially having a large impact on the 42% of highly suitable octocoral habitat predicted to lie at these depths. Main conclusions This research demonstrates the potential for using fisheries by-catch data to create habitat suitability maps that can inform fisheries management and future research.

Aim Three-quarters of Octocorallia species are found in deep waters. These cold-water octocoral colonies can form a major constituent of structurally complex habitats. The global distribution and the habitat requirements of deep-sea octocorals are poorly understood given the expense and difficulties of sampling at depth. Habitat suitability models are useful tools to extrapolate distributions and provide an understanding of ecological requirements. Here, we present global habitat suitability models and distribution maps for seven suborders of Octocorallia: Alcyoniina, Calcaxonia, Holaxonia, Scleraxonia, Sessiliflorae, Stolonifera and Subselliflorae. Location Global. Methods We use maximum entropy modelling to predict octocoral distribution using a database of 12,508 geolocated octocoral specimens and 32 environmental grids resampled to 30 arc-second (approximately 1km 2) resolution. Additionally, a meta-analysis determined habitat preferences and niche overlap between the different suborders of octocorals. Results Suborder Sessiliflorae had the widest potential habitat range, but all records for all suborders implied a habitat preference for continental shelves and margins, particularly the North and West Atlantic and Western Pacific Rim. Temperature, salinity, broad scale slope, productivity, oxygen and calcite saturation state were identified as important factors for determining habitat suitability. Less than 3% of octocoral records were found in waters undersaturated for calcite, but this result is affected by a shallow-water sampling bias. Main conclusions The logistical difficulties, expense and vast areas associated with deep-sea sampling leads to a gap in the knowledge of faunal distributions that is difficult to fill without predictive modelling. Global distribution estimates are presented, highlighting many suitable areas which have yet to be studied. We suggest that approximately 17% of oceans are suitable for at least one suborder but 3.5% may be suitable for all seven. This is the first global habitat suitability modelling study on the distribution of octocorals and forms a useful resource for researchers, managers and conservationists. © 2012 Blackwell Publishing Ltd.

This chapter is a synthesis of the current knowledge of the diseases of deep-sea corals. Corals comprise solitary or many individual polyps. Within the tentacle tissues are stinging cells, cnidocytes, each containing a nematocyst. The mesenteries bear the polyp gonads and digestive cells. The arrangement of these cavities, if they are complete and reach the actinopharynx or not, the number of tentacles, and characteristics of the coral skeleton differentiate the coral groups Scleractinia, Octocorallia, Antipatharia and Stylasteridae from each other. Bottom fishing methods are one of the most significant risk factors to the health of deep-sea corals, as it damages or destroys long-lived corals and reduces the three-dimensional habitat complexity leading to decreased species diversity and faunal biomass. Potential effects of climate change are viewed as a significant threat to deep cold-water corals. Little research exists on the physiology, reproductive biology, growth rates, immunology, longevity or disease of deep-sea corals.

The reefs of Rodrigues were some of the few reef areas in the Indian Ocean to escape the mass coral bleaching event of 1997–1998. However, during the last 2 weeks of February 2002 Rodrigues experienced sea-water temperatures over 30°C, clear skies and calm seas. Rapid assessments of the degree of coral bleaching and coral mortality were carried out at 22 sites around the coast of Rodrigues during March 2002. The surveys showed that the bleaching event in Rodrigues was not widespread, occurring at less than one-third of the sites surveyed and that coral mortality was restricted to sites in the north and west of the island. Where mortality did occur, it was severe, affecting up to 75% of corals at some sites. Coral species most vulnerable were Acropora cytherea and Acropora abrotanoides, which suffered up to 100% mortality. These colonies were still standing and had been very recently overgrown with turf algae. At present the reefs around Rodrigues are in good health, however, they are being impacted by ove...

Summary While sexual selection is responsible for the rapid evolution of many characters [1,2], the precise relationship between pre- and post-copulatory sexual selection is unclear [3]. In some species, the two are positively associated and reinforce each other, while in others, the two bouts of selection are antagonistic and cancel each other out. Here we assessed the relationship between female preference for males and male fertilization success during sperm competition in the fly Drosophila simulans . We find that attractive males sired more offspring and also find a positive genetic correlation between male attractiveness and siring success.

The parasite faunas of 12 species of freshwater fish from 17 localities on the island of Jersey were examined. Comparison of the species composition, number, diversity and equitability of the parasite fauna of each species of fish in each locality revealed that community diversity was always low, that most communities were dominated by a single species of parasite, and that community similarity between host species, and often between sites, was generally low. This was not related to unavailability or distribution of potential, invertebrate, intermediate host species, but appeared to be due to chance colonization events. With two exceptions, little exchange of parasites took place between host species, despite vacant niches in the parasite communities and the absence of competitors, and normal parasite specificity was maintained. Comparison of the parasite communities with those on other oceanic islands suggests that they are poorer than would be predicted by island biogeographical theory, and that this is not a very good predictor of parasite community richness on oceanic islands.

The United Nations Decade of Ocean Science for Sustainable Development presents an exceptional opportunity to effect positive change in ocean use. We outline what is required of the deep-sea research community to achieve these ambitious objectives. The health of the global ocean, on which society depends, is in decline. The importance of sustainable use to ocean health has long been recognized1, yet the United Nations (UN) First World Ocean Assessment2 from 2017 highlighted increasing ocean pressures from accelerated expansion of human activities, including climate change. These pressures affect all ocean regions, from the coast to the deep sea3. In response to this concern, and to align with several international policy commitments, the UN General Assembly proclaimed 2021–2030 the Decade of Ocean Science for Sustainable Development4. The roadmap for this Ocean Decade recognizes the deep sea as a frontier of science and discovery, and calls for research to advance understanding of deep-sea ecosystems, their functions, vulnerabilities and services to society. Published in March 2020, the draft implementation plan for the Ocean Decade guides the design and implementation of ‘Actions’ that underpin the desired move from ‘the ocean we have’ to ‘the ocean we want’ (Fig. 1). The draft plan calls on the scientific community to develop Actions, at programme, project, activity or contribution levels, to help deliver on four key objectives: (1) increase capacity to generate, understand, manage and use ocean knowledge; (2) identify and generate required ocean data, information and knowledge; (3) build comprehensive understanding of the ocean and its governance systems; and (4) increase the use of ocean knowledge.