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Foundation species are being restored into inherently variable landscapes with multiple, interspersed habitats. However, understanding of the influence of different neighbouring habitats on community assembly and the survival of restored species is limited, despite their significant potential to affect restoration outcomes. We tested how habitat‐setting (being next to seagrass, seagrass and mangroves, or unvegetated sediments) and predation (by meso‐ and/or large predators) influenced macroinvertebrate community assembly and the survival of juvenile Sydney rock oysters (Saccostrea glomerata) on experimental oyster reef units in the Port Hacking estuary, New South Wales, Australia. Each habitat‐setting produced a distinct macroinvertebrate community on experimental reefs, whereas predation had limited effects on community structure. Juvenile oysters were instead highly predated everywhere, and oyster predation was dominated by the large, transient fish Acanthropagrus australis. Our findings allow practitioners to predict and tailor the communities which establish on restored oyster reefs by strategically placing them next to different habitats. If sites have a high predation risk but require seeding for reefs to establish, then caging or complex substrates must be used to increase seeded oyster survival. [ABSTRACT FROM AUTHOR]

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If this is the case, restoration and conservation of these threatened oyster reefs may enhance ontogenetic movement opportunities for the species by providing key juvenile habitats, which could further aid in the long-term stability and protection of blue groper populations. Conservation, demography, life history, recruitment, charismatic megafauna, estuarine ecosystem, intertidal reef, temperate reef, threatened species This observation of an iconic and threatened species using threatened oyster reefs as a juvenile habitat is significant, not only because it enhances our understanding of I A. viridis i and their ontogenetic movement, but because of the opportunity that this presents for the engagement and funding of ongoing and future oyster reef restoration projects. Keywords: charismatic megafauna; conservation; demography; estuarine ecosystem; intertidal reef; life history; recruitment; temperate reef; threatened species EN charismatic megafauna conservation demography estuarine ecosystem intertidal reef life history recruitment temperate reef threatened species 1 5 5 12/05/22 20221201 NES 221201 Understanding the life cycle and the demography of individual species is critical for the management of threatened populations and integral to understanding the ecology of various ecosystems and habitats (Kimirei et al., [11]; Perez & Munch, [15]). [Extracted from the article]

Population characteristics (e.g. density and body sizes) of foundation species can affect their own persistence and provisioning of ecosystem functions. Understanding the drivers of population characteristics of foundation species at multiple spatial scales is therefore critical for maximizing ecosystem functions of restored habitats. We analyzed variation in population characteristics (densities, 95th percentile, and median lengths of live oysters) of the Sydney rock oyster, Saccostrea glomerata, on remnant oyster reefs at regional scales (among three estuaries) along an approximately 250 km of coastline in New South Wales, Australia. We then analyzed how population characteristics were further related to spatial attributes at smaller spatial scales including within‐patches (rugosity, distance to patch‐edge, and elevation), whole‐patches (size and shape), and among‐patch (connectivity) within each estuary. The densities and body sizes of S. glomerata were related to spatial attributes occurring within‐patch (e.g. elevation), whole‐patch (e.g. shape), and landscape (i.e. connectivity) scales, but these relationships varied among estuaries. The greatest variation in oyster density and size occurred at regional scales, suggesting that processes acting at larger spatial scales (e.g. water quality and/or climate) set the context for smaller scale influences on oyster characteristics. Our results highlight the potential importance of incorporating site‐specific, spatial attributes in the design of restored oyster reefs to maximize ecosystem services and functions provided by restoration efforts. [ABSTRACT FROM AUTHOR]

Interactions among selection, gene flow, and drift affect the trajectory of adaptive evolution. In natural populations, the direction and magnitude of these processes can be variable across different spatial, temporal, or ontogenetic scales. Consequently, variability in evolutionary processes affects the predictability or stochasticity of microevolutionary outcomes. We studied an intertidal fish, Bathygobius cocosensis (Bleeker, 1854), to understand how space, time, and life stage structure genetic and phenotypic variation in a species with potentially extensive dispersal and a complex life cycle (larval dispersal preceding benthic recruitment). We sampled juvenile and adult life stages, at three sites, over three years. Genome‐wide SNPs uncovered a pattern of chaotic genetic patchiness, that is, weak‐but‐significant patchy spatial genetic structure that was variable through time and between life stages. Outlier locus analyses suggested that targets of spatially divergent selection were mostly temporally variable, though a significant number of spatial outlier loci were shared between life stages. Head shape, a putatively ecologically responsive (adaptive) phenotype in B. cocosensis also exhibited high temporal variability within sites. However, consistent spatial relationships between sites indicated that environmental similarities among sites may generate predictable phenotype distributions across space. Our study highlights the complex microevolutionary dynamics of marine systems, where consideration of multiple ecological dimensions can reveal both predictable and stochastic patterns in the distributions of genetic and phenotypic variation. Such considerations probably apply to species that possess short, complex life cycles, have large dispersal potential and fecundities, and that inhabit heterogeneous environments. [ABSTRACT FROM AUTHOR]

Aim: Climate change is redistributing species globally, resulting in altered community structures and ecosystem functioning. The current paradigm is that species should track temperature isoclines along latitudinal and depth gradients to remain within their thermal niches. However, the many exceptions to this rule point to complex ecological and environmental processes often overlooked in statistical models predicting species redistributions. We tested the contributions of natural versus anthropogenic climate change to the long‐term spatio‐temporal dynamics of assemblages of range‐shifting tropical fishes at the leading edge of redistribution fronts. Location: East coast of Australia. Taxon: Tropical coral‐reef fishes. Methods: We analysed 16 years (2003–2018) of tropical species occurrences at two temperate locations using traditional diversity metrics (richness, accumulation curves and β‐diversity). We also quantified the role of primary environmental covariates and estimated species associations using joint species distribution models. Results: We reveal that tropical species richness has increased in this temperate ecosystem over time. Furthermore, we show that the richness of tropical vagrant species increased with the sea‐surface temperature experienced by both local vagrants and their putative source populations at the southern Great Barrier Reef, which accounted for 23.1% and 22.1% of the explained variance, respectively. We also detected a signal from El Niño‐Southern Oscillation, as species turnover and richness peaked during the strong La Niña event of 2010–2011. Main conclusions: While the increases in ocean temperature and strength of the surface ocean current due to anthropogenic climate change are gradually favouring the poleward redistribution of tropical species, natural climatic oscillations can have a strong additive effect by rapidly modifying the pool of incoming species and potentially disrupting local communities. [ABSTRACT FROM AUTHOR]

Climate change is promoting fast poleward expansion in many tropical marine fish species. With projected increases in sea surface temperatures, there is significant scope for increased range expansions in the future. However, the strength and consequences of density‐driven competitive interactions between vagrant and resident fishes are largely unknown. Here, we investigate how the density effects resulting from the addition of tropical fishes to temperate assemblages may alter patterns of habitat and behaviour usage by both tropical vagrant and temperate resident species. We explore these impacts for two ecologically similar (diet, habitat and behaviour) pairs of vagrant and resident species (the territorial species Stegastes gascoynei and Parma microlepis, and the shoaling species Abudefduf vaigiensis and Atypichthys strigatus, respectively). We compare situations where the other member of each of these ecological pairs was present or absent. There was a shift in the type and structural complexity of habitat occupied, with all species displaying some characteristics of occupying seemingly less‐preferred habitats in the presence of their pair species than without them. Behavioural effects were only apparent for the territorial species, which had altered feeding and vigilance patterns in the presence of their pair. These data indicate that the increased density of ecologically similar fish which results from the annual arrival of vagrant fishes is likely driving shifts away from optimal habitat usage and alterations in activity of both residents and vagrants, suggesting resource competition. The degree to which this competition was evident depended on the life history of the species, being stronger for the more territorial species. While similar research on additional species would be required to determine to what degree these results could be generalised to other territorial or shoaling species, this work suggests to highlight the important role that competition will play in determining both the ability of the vagrant species to become established within temperate communities, as well as the impact they may have once they have done so. [ABSTRACT FROM AUTHOR]

Climate change is altering the latitudinal distributions of species, with their capacity to keep pace with a shifting climate depending on the stochastic expression of population growth rates, and the influence of compensatory density feedback on age‐specific survival rates. We use population‐abundance time series at the leading edge of an expanding species' range to quantify the contribution of stochastic environmental drivers and density feedbacks to the dynamics of life stage‐specific population growth.Using a tropical, range‐shifting Indo‐Pacific damselfish (Abudefduf vaigiensis) as a model organism, we applied variants of the phenomenological Gompertz‐logistic model to a 14‐year dataset to quantify the relative importance of density feedback and stochastic environmental drivers on the separate and aggregated population growth rates of settler and juvenile life stages.The top‐ranked models indicated that density feedback negatively affected the growth of tropical settlers and juveniles. Rates of settlement were negatively linked to temperatures experienced by parents at potential source populations in the tropics, but their subsequent survival and that of juveniles increased with the temperatures experienced at the temperate sink. Including these stochastic effects doubled the deviance explained by the models, corroborating an important role of temperature. By incorporating sea‐surface temperature projections for the remainder of this century into these models, we anticipate improved conditions for the population growth of juvenile coral‐reef fishes, but not for settlers in temperate ecosystems.Previous research has highlighted the association between temperature and the redistribution of species. Our analyses reveal the contrasting roles of different life stages in the dynamics of range‐shifting species responding to climate change, as they transition from vagrancy to residency in their novel ranges. [ABSTRACT FROM AUTHOR]

Sea‐level rise, storm surges, ageing and wear are forcing upgrades to breakwaters and sea walls to protect coastal areas from erosion and inundation. Such upgrades involve the introduction of new material which may consequently act as an ecological disturbance that can alter established marine communities and ecosystem function. Mitigating ecological impacts requires an understanding of how species assemblages are affected by such works.Here, we use the major upgrade of a regularly wave‐overtopped breakwater as a case study to evaluate the impacts of upgrades to hard coastal protective infrastructure on benthic rocky reef communities. An asymmetrical Before‐After Control‐Impact (BACI) experimental design was used to test interactive effects of the infrastructure upgrades on benthic communities.While benthic assemblages were not significantly different from controls prior to the upgrade, improving the defensive capacity of the breakwater significantly changed community structure. Notably, most taxonomic groups showed higher cover at the control sites than at the impacted site post‐upgrade, with articulated calcareous algae (e.g. Corallina officinalis and Amphiroa anceps) showing an opposite trend.Synthesis and applications. Ecological implications and structural limitations make regular upgrading of existing infrastructure unsuitable as a long‐term management strategy. More sustainable alternatives need to be considered, such as decommissioning of structures and retreat from flood‐prone areas. This transition, however, will take time and requires a change of mindset and policies. Where upgrades are urgent, eco‐engineering techniques can mitigate impacts to habitats and associated taxa. [ABSTRACT FROM AUTHOR]

Biogenic structures that persist post‐mortem are ubiquitous, but rarely considered as key ecological features. Post‐mortem structures in many ecological systems exert community‐level effects and thus the dynamics of their degradation (i.e. taphonomy) become important in affecting community functions and ecosystem services, and these often‐overlooked effects may rival the influence of recruitment and typical post‐recruitment processes. Moreover, in some highly researched habitat types, post‐mortem structures may be mistaken for living organisms, thus introducing significant error into our understanding of population processes. We examined widespread patterns and processes in marine assemblages with calcareous tubeworms and brackish‐water assemblages with bryozoans, in order to test the importance of taphonomy for populations and communities. In tubeworm assemblages, taphonomic variability caused differential accumulation of post‐mortem structures, exerting community‐level influence, and importantly it negated effects from recruitment on the community functions. For tubeworms and bryozoans, proportions of post‐mortem structures varied between sheltered and exposed habitats with overall distributional variability being caused by the share of post‐mortem structures, not living animals. Population‐level inferences in such systems would be extremely problematic without careful differentiation of dead/living structures. Dynamics emerging from the interaction of taphonomic processes and recruitment ecology are relevant for many other important biogenic habitats, especially coral reefs with death assemblages of bleached corals; a failure to consider variability in processes acting on the death assemblages, alongside the living, may severely distort understanding of patterns and processes in populations and communities. [ABSTRACT FROM AUTHOR]

Environmental anomalies that trigger adverse physiological responses and mortality are occurring with increasing frequency due to climate change. At species' range peripheries, environmental anomalies are particularly concerning because species often exist at their environmental tolerance limits and may not be able to migrate to escape unfavourable conditions. Here, we investigated the bleaching response and mortality of 14 coral genera across high‐latitude eastern Australia during a global heat stress event in 2016. We evaluated whether the severity of assemblage‐scale and genus‐level bleaching responses was associated with cumulative heat stress and/or local environmental history, including long‐term mean temperatures during the hottest month of each year (SSTLTMAX), and annual fluctuations in water temperature (SSTVAR) and solar irradiance (PARZVAR). The most severely‐bleached genera included species that were either endemic to the region (Pocillopora aliciae) or rare in the tropics (e.g. Porites heronensis). Pocillopora spp., in particular, showed high rates of immediate mortality. Bleaching severity of Pocillopora was high where SSTLTMAX was low or PARZVAR was high, whereas bleaching severity of Porites was directly associated with cumulative heat stress. While many tropical Acropora species are extremely vulnerable to bleaching, the Acropora species common at high latitudes, such as A. glauca and A. solitaryensis, showed little incidence of bleaching and immediate mortality. Two other regionally‐abundant genera, Goniastrea and Turbinaria, were also largely unaffected by the thermal anomaly. The severity of assemblage‐scale bleaching responses was poorly explained by the environmental parameters we examined. Instead, the severity of assemblage‐scale bleaching was associated with local differences in species abundance and taxon‐specific bleaching responses. The marked taxonomic disparity in bleaching severity, coupled with high mortality of high‐latitude endemics, point to climate‐driven simplification of assemblage structures and progressive homogenisation of reef functions at these high‐latitude locations. [ABSTRACT FROM AUTHOR]

Abstract: Complex life cycles may evolve to dissociate distinct developmental phases in an organism's lifetime. However, genetic or environmental factors may restrict trait independence across life stages, constraining ontogenetic trajectories. Quantifying covariance across life stages and their temporal variability is fundamental in understanding life‐history phenotypes and potential distributions and consequences for selection. We studied developmental constraints in an intertidal fish (Bathygobius cocosensis: Gobiidae) with a discrete pelagic larval phase and benthic juvenile phase. We tested whether traits occurring earlier in life affected those expressed later, and whether larval traits were decoupled from postsettlement juvenile traits. Sampling distinct cohorts from three annual breeding seasons afforded tests of temporally variability in trait covariance. From otoliths (fish ear stones), we measured hatch size, larval duration, pelagic growth (larval traits) and early postsettlement growth (juvenile trait) in 124 juvenile B. cocoensis. We used path analyses to model trait relationships with respect to their chronological expression, comparing models among seasons. We also modelled the effect of season and hatch date on each individual trait to quantify their inherent variability. Our path analyses demonstrated a decoupling of larval traits on juvenile growth. Within the larval phase, longer larval durations resulted in greater pelagic growth, and larger size‐at‐settlement. There was also evidence that larger hatch size might reduce larval durations, but this effect was only marginally significant. Although pelagic and postsettlement growth were decoupled, pelagic growth had postsettlement consequences: individuals with high pelagic growth were among the largest fish at settlement, and remained among the largest early postsettlement. We observed no evidence that trait relationships varied among breeding seasons, but larval duration differed among breeding seasons, and was shorter for larvae hatching later within each season. Overall, we demonstrate mixed support for the expectation that traits in different life stages are independent. While postsettlement growth was decoupled from larval traits, pelagic development had consequences for the size of newly settled juveniles. Temporal consistency in trait covariances implies that genetic and/or environmental factors influencing them were stable over our three‐year study. Our work highlights the importance of individual developmental experiences and temporal variability in understanding population distributions of life‐history traits. [ABSTRACT FROM AUTHOR]

Habitat structural complexity influences biotic diversity and abundance, but its influence on marine ecosystems has not been widely addressed. Recent advances in computer vision and robotics allow quantification of structural complexity at higher‐resolutions than previously achieved. This provides an important opportunity to determine the ecological role of habitat structural complexity in marine ecosystems. We used high‐resolution three‐dimensional (3D) maps to test multiple structural complexity metrics, depth and benthic biota as surrogates of fish assemblages across hundreds of meters on subtropical reefs. Non‐parametric multivariate statistics were used to determine the relationship between these surrogates and the entire fish assemblage. Fish were divided into functional groups, which were used to further investigate the relationship between surrogates and fish abundance using generalized linear models. Fish community composition and abundance were strongly related to habitat complexity metrics, benthic biota and depth. Surface rugosity and its variance had a significant positive influence on the abundance of piscivores and sediment infauna predators, and a negative effect on the abundance of predators, herbivores, planktivores and cleaners. Final models for fish functional groups explained up to 68% of the variance. The best metrics to explain the variance in fish abundance were benthic biota (25 ±7.5% of variance explained, mean ± SE) and complexity metrics (16 ±6.6%, mean ± SE). Our results show that high‐resolution 3D maps and derived metrics can predict a large percentage of variance in fish abundance and potentially serve as useful surrogates of fish abundance across all functional groups in spatially dynamic reefs. [ABSTRACT FROM AUTHOR]

Infrastructure is increasingly being built in marine habitats, with extensive ecological consequences for benthic and fish assemblages alike. The practice of ecological engineering attempts to mitigate the negative impacts of infrastructure through the design of artificial structures that benefit both humans and nature. Although research has primarily focused on the benefits for invertebrates and algae, fish also respond to changes in habitat complexity and benthic biodiversity. We surveyed the scientific literature on natural and artificial reefs to identify key habitat features that fish respond to, and propose a decision tool for ecologists and managers to tailor the structural complexity of marine infrastructure for fish. Inevitably, natural habitats will increasingly be replaced with artificial ones, making ecologically sensitive designs essential for maintaining biodiversity and ecosystem services. Using lessons from natural and artificial reefs, we show that existing and new infrastructure could be designed not only to reduce negative impacts but also to foster positive effects on fish assemblages. [ABSTRACT FROM AUTHOR]

Few studies have examined core-periphery genetic patterns in tropical marine taxa. The core-periphery hypothesis (CPH) predicts that core populations will have higher genetic diversity and lower genetic differentiation than peripheral populations as a consequence of greater population sizes and population connectivity in the core. However, the applicability of the CPH to many tropical marine taxa may be confounded by their complex population histories and/ or high (asymmetric) population connectivity. In this study we investigated genetic patterns (based on mtDNA) across the latitudinal range of the neon damselfish Pomacentrus coelestis (36°N, Japan - 37°S, east Australia). We suggest a novel hypothetical framework for core-periphery genetic patterns and extend typical analyses to include genealogical analyses, partitioned b-diversity measures (total βSOR, turnover βSIM, and nestedness-resultant βSNE), and analyses of nestedness. We found that the existence of two divergent lineages of the neon damselfish led levels of genetic diversity to deviate from CPH expectations. When focusing on the widespread lineage (Pacific clade) nucleotide diversity was higher in the core, supporting the CPH. However, genetic patterns differed toward the northern and southern peripheries of the Pacific clade. The turnover of haplotypes (pairwise-βsim) increased over distance in the north, indicative of historical colonization with little contemporary migration. In contrast, although turnover was still dominant in the south (βSIM), there was no relationship to distance (pairwise-βsim), suggesting the influence of more contemporary processes. Moreover, the haplotype compositions of populations in the south were nested according to latitude, indicating immigration from lower latitudes toward the southern periphery. By extending the typical characterizations of core-periphery genetic patterns we were able to identify the effects of lineage sympatry on measures of genetic diversity and contrasting demographic histories toward the latitudinal peripheries of the neon damselfish's range. [ABSTRACT FROM AUTHOR]

Climate change is resulting in rapid poleward shifts in the geographical distribution of many tropical fish species, but it is equally apparent that some fishes are failing to exhibit expected shifts in their geographical distribution. There is still little understanding of the species-specific traits that may constrain or promote successful establishment of populations in temperate regions. We review the factors likely to affect population establishment, including larval supply, settlement and post-settlement processes. In addition, we conduct meta-analyses on existing and new data to examine relationships between species-specific traits and vagrancy. We show that tropical vagrant species are more likely to originate from high-latitude populations, while at the demographic level, tropical fish species with large body size, high swimming ability, large size at settlement and pelagic spawning behaviour are more likely to show successful settlement into temperate habitats. We also show that both habitat and food limitation at settlement and within juvenile stages may constrain tropical vagrant communities to those species with medium to low reliance on coral resources. [ABSTRACT FROM AUTHOR]

The southeast coast of Australia is a global hotspot for increasing ocean temperatures due to climate change. The temperate incursion of the East Australian Current (EAC) is increasing, affording increased connectivity with the Great Barrier Reef. The survival of tropically sourced juveniles over the winter is a significant stumbling block to poleward range shifts of marine organisms in this region. Here we examine the dependence of overwintering on winter severity and prewinter recruitment for eight species of juvenile coral reef fishes which are carried into temperate SE Australia (30–37 °S) by the EAC during the austral summer. The probability of persistence was most strongly influenced by average winter temperature and there was no effect of recruitment strength. Long-term (138 years) data indicate that winter water temperatures throughout this region are increasing at a rate above the global average and predictions indicate a further warming of >2 °C by the end of the century. Rising ocean temperatures are resulting in a higher frequency of winter temperatures above survival thresholds. Current warming trajectories predict 100% of winters will be survivable by at least five of the study species as far south as Sydney (34 °S) by 2080. The implications for range expansions of these and other species of coral reef fish are discussed. [ABSTRACT FROM AUTHOR]

The article presents a meta-analysis of the interspecific relationship between seed size and plant abundance within local communities. The relationship between seed size and abundance within plant communities has received research attention as ecologists have sought to understand the fundamental determinants of species abundance. In addition to understanding patterns of plant abundance, finding predictable relationships between life-history traits such as seed size and plant rarity can yield valuable information for the conservation and management of species. Qualitative assessment of the seed size-abundance relationship within communities has revealed that rare species are neither consistently small nor large seeded.

A correction to the article "Defining patch contribution in source-sink metapopulations: the importance of including dispersal and its relevance to marine systems," that was published in previous issue is presented.

Sediment toxicity tests in the laboratory are an important part of ecological risk assessments, yet how they relate to sediment toxicity in situ has rarely been explored. Using meta-analysis, we examined differences in the toxicity of sediment tested in the laboratory and in situ. Data from four published studies were subjected to rigorous statistical analyses. Overall, the toxicity of sediments in laboratory tests was substantially less than their toxicity in situ. Differences between laboratory and in situ toxicity, expressed using the log odds ratio effect size, varied significantly among published studies. Effect size increased significantly with increasing sediment toxicity, showing that the more toxic the sediment, the greater the disparity between laboratory and field toxicities. Our findings may not apply to all laboratory/field comparisons; however, we consider that the overlying water in field situations is a significant contributor to this relationship through additional contamination and toxicity. Our findings also have important implications for the use of laboratory tests to assess improvements in sediment quality and remediation, because changes in laboratory toxicity may not reflect the true improvements to sediment quality in situ. [ABSTRACT FROM AUTHOR]