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Intertidal rock pools support diverse assemblages. While there is much research on the importance of rock pools in supporting mobile diversity on rocky shores, there is limited knowledge regarding the role of physical features (microhabitats) within these habitats. Understanding the features of pools that support diversity is crucial to conserve and potentially mimic these important intertidal habitats in restoration projects. Here, we classified and quantified the types of physical features, hereafter "microhabitats" (overhangs and pits), within rock pools at different locations in and around a highly urbanised estuary, Sydney Harbour, Australia. The use of different microhabitats within rock pools by mobile macro-invertebrates was also examined in one location. We surveyed natural rock pools in summer (2 times) and winter (2 times) at seven sites: two sites from each of the inner and outer zones of Sydney Harbour, and three sites along the open coast of Sydney. We found that the type and size of microhabitats within pools decreased from the coastal towards inner harbour sites. Along the open coast, the richness of mobile taxa increased in rock pools with overhangs or pits. Only rock pools with overhangs had increased mobile abundances, likely driven by the gastropod Nerita melanotragus. Several species occurred in greater frequency in pools with overhangs. There was no effect of pits on abundances. This survey suggests that some microhabitats may play an important role in the diversity and abundance of mobile macro-invertebrates in rock pools. A detailed understanding of the local and regional scales of microhabitats should be used to inform eco-engineering of intertidal foreshores. [ABSTRACT FROM AUTHOR]

Coastal systems such as estuaries are threatened by multiple anthropogenic stressors worldwide. However, how these stressors and estuarine hydrology shape benthic bacterial communities and their functions remains poorly known. Here, we surveyed sediment bacterial communities in poorly flushed embayments and well flushed channels in Sydney Harbour, Australia, using 16S rRNA gene sequencing. Sediment samples were collected monthly during the Austral summer-autumn 2014 at increasing distance from a large storm drain in each channel and embayment. Bacterial communities differed significantly between sites that varied in proximity to storm drains, with a gradient of change apparent for sites within embayments. We explored this pattern for embayment sites with analysis of RNA-Seq gene expression patterns and found higher expression of multiple genes involved in bacterial stress response far from storm drains, suggesting that bacterial communities close to storm drains may be more tolerant of localised anthropogenic stressors. Several bacterial groups also differed close to and far from storm drains, suggesting their potential utility as bioindicators to monitor contaminants in estuarine sediments. Overall, our study provides useful insights into changes in the composition and functioning of benthic bacterial communities as a result of multiple anthropogenic stressors in differing hydrological conditions. [ABSTRACT FROM AUTHOR]

Humans depend on earth's ecosystems and in the Anthropocene, ecosystems are increasingly impacted by human activities. Sustainability—the long-term integrity of social–ecological systems—depends on effective environmental stewardship, yet current conceptual frameworks often lack empirical validation and are limited in their ability to show progress towards sustainability goals. In this study we examine institutional and local stewardship actions and their ecological and social outcomes along 7000 km of Australia's coastline. We use empirical mixed methods and grounded theory to show that the combination of local and institutional stewardship leads to improved ecological outcomes, which in turn enhance social values and motivate further stewardship to form a virtuous cycle. Virtuous cycles may proceed over multiple iterations, which we represent in a new spiral model enabling visualisation of progress towards sustainability goals over time. Our study has important implications for collaborative earth stewardship and the role of policy in enabling virtuous cycles to ultimately realise sustainable futures. [ABSTRACT FROM AUTHOR]

Aim: The shape of the diversity–disturbance relationship is context dependent, but the mechanisms driving this context dependence are unclear due to limited standardized empirical assessments across different environmental and ecological settings. At seven sites and over 20° of latitude, spanning both temperate and tropical systems, we measured community response to a fine‐scale experimental disturbance gradient in communities of benthic invertebrates. Location: East coast of Australia (16.48–36.43° S). Time period: Sixty‐six weeks (August 2012–November 2013). Major taxa studied: Benthic marine invertebrates. Methods: Communities were grown on acrylic tiles and subjected to four experimental disturbance events over a 66‐week period. At the end of this period, the effect of increasing disturbance extent (from 0% to 100% community clearance) on measures of alpha and beta diversity were assessed. Results: In the tropics, richness and diversity increased with disturbance because the creation of free space allowed for the colonization of new recruits. In temperate communities, increasing disturbance led to a monotonic loss in species richness and a more hump‐shaped relationship in evenness and diversity. In the tropics, compositional change with increasing disturbance was driven by changes in species identities and abundances as the cover of rare species increased. In temperate regions, however, differences in species abundances were primarily responsible for compositional changes, reflecting the shift to algal dominance in conditions of high disturbance. Main conclusions: The shape of the diversity–disturbance relationship changed over latitude, indicating that the concept of "intermediate" disturbance differs amongst these communities. Faster rates of increases in bare space, loss of species richness and a shift to algal dominance suggest that, in these systems, higher‐latitude communities are more susceptible to negative outcomes of high levels of disturbance than lower‐latitude communities. We discuss how differences in community dynamics, including competition, regional diversity and availability of propagules, help to explain this pattern. [ABSTRACT FROM AUTHOR]

Marine protected areas (MPAs) are a primary tool for the stewardship, conservation, and restoration of marine ecosystems, yet 69% of global MPAs are only partially protected (i.e., are open to some form of fishing). Although fully protected areas have well‐documented outcomes, including increased fish diversity and biomass, the effectiveness of partially protected areas is contested. Partially protected areas may provide benefits in some contexts and may be warranted for social reasons, yet social outcomes often depend on MPAs achieving their ecological goals to distinguish them from open areas and justify the cost of protection. We assessed the social perceptions and ecological effectiveness of 18 partially protected areas and 19 fully protected areas compared with 19 open areas along 7000 km of coast of southern Australia. We used mixed methods, gathering data via semistructured interviews, site surveys, and Reef Life (underwater visual census) surveys. We analyzed qualitative data in accordance with grounded theory and quantitative data with multivariate and univariate linear mixed‐effects models. We found no social or ecological benefits for partially protected areas relative to open areas in our study. Partially protected areas had no more fish, invertebrates, or algae than open areas; were poorly understood by coastal users; were not more attractive than open areas; and were not perceived to have better marine life than open areas. These findings provide an important counterpoint to some large‐scale meta‐analyses that conclude partially protected areas can be ecologically effective but that draw this conclusion based on narrower measures. We argue that partially protected areas act as red herrings in marine conservation because they create an illusion of protection and consume scarce conservation resources yet provide little or no social or ecological gain over open areas. Fully protected areas, by contrast, have more fish species and biomass and are well understood, supported, and valued by the public. They are perceived to have better marine life and be improving over time in keeping with actual ecological results. Conservation outcomes can be improved by upgrading partially protected areas to higher levels of protection including conversion to fully protected areas. Article impact statement: Partially protected areas create an illusion of protection and consume conservation resources for little or no social–ecological gain. [ABSTRACT FROM AUTHOR]

We describe the design and structure of a web-based visualization tool for an Australian marine debris database and its application in environmental research, management and science communication. We give examples of its use in generating hypotheses regarding processes driving the distribution of marine debris, identifying source reduction opportunities and communicating science to the public and stakeholders. We suggest this as a model for utilizing other latent environmental data sets, enabling users to implement the five 'source-to-sea' steps to characterize, engage, diagnose, design, act and adapt when addressing leading environmental concerns. [ABSTRACT FROM AUTHOR]

Plastic pollution poses environmental and socio-economic risks, requiring policy and management interventions. The evidence-base for informing management and evaluation of their effectiveness is limited. Partnerships with citizen scientists provide opportunities to increase the spatio-temporal scale of monitoring programs, where training and standardised protocols provides opportunities for the use of data in addressing multiple hypotheses. Here, we provide a baseline of debris trends and infer debris drivers of abundance across 18° of latitude, using 168 surveys from 17 beaches across Queensland, Australia through the ReefClean project. Plastics were the dominant material (87% of total debris, with hard, soft and foam plastics aggregated), although linking recovered debris to sources was limited, as 67% of items were fragmented. We tested potential drivers of specific debris types (i.e., plastics, commercial fishing items, items dumped at-sea, and single-use items) and identified significant relationships between debris accumulation with distance from the nearest population centre and site characteristics (modal beach state, beach orientation and across-beach section). Management efforts should consider beach type and orientation within site selection, as an opportunity to maximise the amount recovered, alongside other criteria such as the risks posed by debris on environmental, economic, and social values. This study demonstrates the utility of citizen science to provide baselines and infer drivers of debris, through data gathered at scales that are infeasible to most formal monitoring programs. The identified drivers of debris may also differ from regional and global studies, where monitoring at relevant scales is needed for effective management. [Display omitted] • Standardised surveys across 18° latitude were conducted to assess debris drivers. • Site orientation and beach type were key physical drivers of debris trends. • Debris types were linked to different factors driving accumulation on beaches. • Partnerships with citizen science provide the data to infer debris drivers. • The study provides a monitoring approach for State-wide debris management. [ABSTRACT FROM AUTHOR]

Novel combinations of climatic conditions due to climate change and prolonged fire seasons have contributed to an increased occurrence of "megafires". Such large-scale fires pose an unknown threat to biodiversity due to the increased extent and severity of burn. Assessments of wildfires often focus on terrestrial ecosystems and effects on aquatic habitats are less documented, particularly in coastal environments. In a novel application of eDNA techniques, we assessed the impacts of the 2019–2020 Australian wildfires on the diversity of estuarine benthic sediment communities in six estuaries in NSW, Australia, before and after the fires. Estuaries differed in area of catchment burnt (0–92%) and amount of vegetative buffer that remained post-fire between burnt areas and waterways. We found greater dissimilarities in the composition and abundance of eukaryotic and bacterial sediment communities in estuaries from burnt catchments with no buffer compared to those with an intact buffer or from unburnt catchments. Shifts in composition in highly burnt catchments were associated with increased concentrations of nutrients, carbon, including fire-derived pyrogenic carbon, and copper, which was representative of multiple highly correlated trace metals. Changes in the relative abundances of certain taxonomic groups, such as sulfate-reducing and nitrifying bacterial groups, in the most impacted estuaries indicate potential consequences for the functioning of sediment communities. These results provide a unique demonstration of the use of eDNA to identify wildfire impacts on ecological communities and emphasize the importance of vegetative buffers in limiting wildfire-associated impacts. [Display omitted] • Estuarine benthic eukaryotic and bacterial community composition changed post-fire. • Greater differences were observed in severely burnt compared to unburnt catchments. • Changes were associated with increased sediment py-C, TOC, Cu and nutrients. • Shifts in certain bacterial groups may have implications for sediment functioning. • EDNA is a useful tool for rapid assessment of wildfire impacts in aquatic systems. [ABSTRACT FROM AUTHOR]

Aim Non-indigenous species pose a significant threat to the environment and to global economies. Predictive and preventative measures are widely considered more effective in curtailing invasions than are eradication or control measures. Of key importance in the prediction of regional invasion risk are the environmental conditions that enable successful establishment. Location We surveyed native and non-indigenous sessile invertebrate diversity in each of two commercial (600–1500 vessels per year) and two recreational estuaries (seven to nine marinas) in New South Wales, Australia. Methods A nested hierarchical design was employed to investigate variation in sessile invertebrate diversity at the scales of site (1–3 km apart) and estuary (40–180 km apart). Settlement plates (15 × 15 cm) were used to sample invertebrates and background heavy metal loads were assessed using bioaccumulation in experimentally deployed oysters. Other physico-chemical variables were monitored monthly. Manipulative experiments were used to test the direct effects of exposure to copper and tributyltin (TBT) antifouling paints on sessile invertebrates. Results Native and non-indigenous species richness differed at various spatial scales, but showed no consistent difference between commercial and recreational estuaries. Instead, individual species distributions were strongly related to metal contamination, temperature, turbidity and pH. In experimental studies, several species (mostly invaders) were more abundant on plates exposed to copper and/or TBT antifouling paints. We found higher levels of copper (and in some instances TBT) in recreational marinas than in commercial harbours. Main conclusions Our results demonstrate the importance of metal pollution and physico-chemical variables in the establishment of invaders in new regions. We have identified several native Australian species that have been exported overseas and suggested mechanisms contributing to their transport and establishment. Combining physico-chemical information about donor and recipient regions with species tolerances could go some way to predicting where future invasions may occur. [ABSTRACT FROM AUTHOR]

The author comments on the move being made by three state governments in Australia which involved the exploitative use of national parks. The authors believed that the initiatives will have negative impact on the country's biodiversity. It is mentioned that forming the cornerstone of Australia's biodiversity is a system of terrestrial and marine conservation reserves which is currently being undermined. Examples of exploitative uses of reserves include industrial logging.

The human footprint on earth is now so great that we must become environmental stewards. To encourage stewardship and achieve better conservation outcomes, research is needed to connect practice with sound theory, and to empirically measure stewardship so we can identify its predictors and motivators. In this study, we use mixed methods to develop a new quantitative indicator for local environmental stewardship in a coastal context. We interviewed 111 people in eastern Australia about their knowledge and use of the coast and extracted information on seven generalised stewardship actions. We combined these into a single indicator which allowed us to evaluate and compare stewardship levels between participants and develop quantitative models. We found that stewardship was predicted by four traits: attraction to marine wildlife, self-identifying as local, size of local social network, and norms regarding informal enforcement. High-stewardship individuals exhibited eco-centric and anthropocentric worldviews and were motivated by a combination of intrinsic and extrinsic factors. We combined these with stewardship actions in a refined model which highlights the importance of people, policy and place in environmental stewardship. We believe this is the first study to quantify stewardship behaviour and its motivating factors in a broad social-ecological context spanning both terrestrial and marine realms. Our research allows stewardship to be measured, modelled and analysed via a transferable indicator. This enables a deeper understanding of local environmental stewardship and the factors that predict and motivate it and allows us to propose practical strategies to engage people to improve stewardship and conservation outcomes. In this article we: • Develop a stewardship indicator, allowing stewardship of people at a place to be quantified, compared and analysed. • Identify the significant predictors and motivators of stewardship behaviour. • Identify two categories of high stewardship individuals and their defining characteristics. • Present a refined model for environmental stewardship. [ABSTRACT FROM AUTHOR]

Urbanised estuaries, ports and harbours are often utilised for recreational purposes, notably recreational angling. Yet there has been little quantitative assessment of the footprint and intensity of these activities at scales suitable for spatial management. Urban and industrialised estuaries have previously been considered as having low conservation value, perhaps due to issues with contamination and disturbance. Studies in recent decades have demonstrated that many of these systems are still highly biodiverse and of high value to local residents. As a response, urbanised estuaries are now being considered by coastal spatial management initiatives, where assessments of recreational use in these areas can help avoid 'user-environmental' and 'user-user' conflict. The models of these activities need to be developed at a scale relevant to governments and regulatory authorities, but the few human-use models that do exist integrate fishing intensity to a regional or even continental scale; too large to capture the fine scale variation inherent in complex urban fisheries. Species Distribution Modeling (SDM) is a tool commonly used to assess drivers of species range, but can be applied to models of recreational fishing in complex environments, at a scale relevant to regulatory bodies. Using point-data from 573 visual surveys with recently developed Poisson point process models, we examine the recreational fishery in Australia's busiest estuarine port, Sydney Harbour. We demonstrate the utility of these models for understanding the distribution of boat and shore-based fishers, and the effects of a range of temporally static (geographical) and dynamic (weather) predictors on these distributions. • There has been little quantitative assessment of the footprint and intensity of recreational fishing activities at scales suitable for spatial management in urbanised estuaries. • 2352 observations of shore and boat-based fishing were collected from 573 visual surveys stratified across Australia's busiest urban port over a 6 month period. • The 'niche' of recreational fishing was modeled using a novel point process method, which accounted for the stratification and spatial unevenness of the observation method. • The modelling process identified hotspots of boat and shore fishing that could represent areas of user-user, user-regulator or user-environment conflict if overlooked. • The result highlights the importance of considering fine spatial scales when modelling human use for environmental management applications, including marine spatial planning. [ABSTRACT FROM AUTHOR]

Light availability and habitat complexity are two key drivers of community assembly. Urbanisation has been shown to affect both, with important consequences to ecological communities. On the intertidal, for instance, studies have shown that light intensity is greater on natural rocky shores than on less complex artificial habitats (seawalls), though different habitats can also experience similar light intensities, for example when shaded by urban structures. Understanding therefore how these factors individually, and combined, affect communities is important to understand the mechanisms driving changes in community structure, and consequently provide solutions to tackle the increasing homogenisation of habitats and lightscapes in urbanised spaces through smart infrastructure designs. Here, we assessed how different light levels affect the recruitment of communities in rock pools and on emergent rock on an intertidal rocky shore. We cleared 30 patches of emergent rock and 30 rock pools and manipulated light using shades with different light transmissions (full light, procedural control, 75%, 35%, and 15% light transmission, full shade) and assessed mobile and sessile communities monthly for 6 months. Effects of reducing light levels were generally stronger on rock than in pools. Fully shaded plots supported double the amount of mobile organisms than plots in full sunlight, in both habitats. Algal cover was higher in pools compared to rock, and at intermediate light levels, but effects varied with site. This study highlights the importance of variable light conditions and different habitats for rocky shore communities, which should be considered in future coastal developments to retain natural biodiversity., (© 2024. The Author(s).)

Anthropogenic marine debris is a persistent threat to oceans, imposing risks to ecosystems and the communities they support. Whilst an understanding of marine debris risks is steadily advancing, monitoring at spatial and temporal scales relevant to management remains limited. Citizen science projects address this shortcoming but are often critiqued on data accuracy and potential bias in sampling efforts. Here we present 10-years of Australia's largest marine debris database - the Australian Marine Debris Initiative (AMDI), in which we perform systematic data filtering, test for differences between collecting groups, and report patterns in marine debris. We defined five stages of data filtering to address issues in data quality and to limit inference to ocean-facing sandy beaches. Significant differences were observed in the average accumulation of items between filtered and remaining data. Further, differences in sampling were compared between collecting groups at the same site (e.g., government, NGOs, and schools), where no significant differences were observed. The filtering process removed 21% of events due to data quality issues and a further 42% of events to restrict analyses to ocean-facing sandy beaches. The remaining 7275 events across 852 sites allowed for an assessment of debris patterns at an unprecedented spatial and temporal resolution. Hard plastics were the most common material found on beaches both nationally and regionally, consisting of up to 75% of total debris. Nationally, land and sea-sourced items accounted for 48% and 7% of debris, respectively, with most debris found on the east coast of Australia. This study demonstrates the value of citizen science datasets with broad spatial and temporal coverage, and the importance of data filtering to improve data quality. The citizen science presented provides an understanding of debris patterns on Australia's ocean beaches and can serve as a foundation for future source reduction plans., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors would like to acknowledge that Heidi Tait and Wally Smith are responsible for the coordination of the database used within this study., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Sea-level rise is an inevitable consequence of climate change and threatens coastal ecosystems, particularly intertidal habitats that are constrained by landward development. Intertidal habitats support significant biodiversity, but also provide natural buffers from climate-threats such as increased storm events. Predicting the effects of climate scenarios on coastal ecosystems is important for understanding both the degree of habitat loss for associated ecological communities and the risk of the loss of coastal buffer zones. We take a novel approach by combining remote sensing with the IUCN Red List of Ecosystem criteria to assess this impact. We quantified the extent of horizontal intertidal rocky shores along ~200 km of coastline in Eastern Australia using GIS and remote-sensing (LiDAR) and used this information to predict changes in extent under four different climate change driven sea-level rise scenarios. We then applied the IUCN Red List of Ecosystems Criterion C2 (habitat degradation over the next 50 years based on change in an abiotic variable) to estimate the status of this ecosystem using the Hawkesbury Shelf Marine Bioregion as a test coastline. We also used four individual rocky shores as case studies to investigate the role of local topography in determining the severity of sea-level rise impacts. We found that, if the habitat loss within the study area is representative of the entire bioregion, the IUCN status of this ecosystem is 'near threatened', assuming that an assessment of the other criteria would return lower categories of risk. There was, however, high spatial variability in this effect. Rocky shores with gentle slopes had the highest projected losses of area whereas rocky shores expanding above the current intertidal range were less affected. Among the sites surveyed in detail, the ecosystem status ranged from 'least concern' to 'vulnerable', but reached 'endangered' under upper estimates of the most severe scenario. Our results have important implications for conservation management, highlighting a new link between remote sensing and the IUCN Red List of Ecosystem criteria that can be applied worldwide to assess ecosystem risk to sea-level rise., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Habitat complexity is accepted as a general mechanism for increasing the abundance and diversity of communities. However, the circumstances under which complexity has the strongest effects are not clear. Over 20 degrees of Australia's east coast, we tested whether the effects of within-site structural habitat complexity on the diversity and community structure of sessile marine invertebrates was consistent over a latitudinal gradient where environmental conditions and species composition vary. We used experimental arrays with varied structural treatments to detect whether community cover, species richness, diversity and community composition (β-diversity) changed with increasing complexity. Community response to complexity varied over latitude due to differences in species richness and community development. Increased complexity had the greatest positive effects on community cover and species richness at higher latitudes where recruitment and growth were low. At lower latitudes, community cover and species richness were higher overall and did not vary substantially between complexity treatments. Latitudinal variation in within-treatment β-diversity relative to complexity further suggest divergent community responses. At higher latitudes, increased similarity in more complex treatments suggests community dominance of successful taxonomic groups. Despite limited effects on species richness and community cover at lower latitudes, β-diversity was higher in more complex treatments, signifying potential positive effects of increased complexity at these sites. These results demonstrate the context-dependency of complexity effects in response to variation in species richness and community development and should be taken into consideration to help direct conservation and restoration efforts., (© 2018 by the Ecological Society of America.)

Complexity in physical habitats may modify predation pressure by allowing differential access of predators to prey. Rocky subtidal environments are inherently complex with many cryptic micro habitats, such as overhangs and crevices. Here, we examine the influence of habitat complexity in mediating predation on sessile assemblage structure by experimentally manipulating fish access to a range of crevice orientations and sizes. Nine fish species/families were recorded actively feeding within crevices, but australian mado, eastern stripey, wrasses and sawtail surgeon accounted for almost 70% of all entries. Sessile assemblages were influenced by crevice width, fish predation and surface orientation, with more predation activity in larger crevices. Assemblage similarity on upward facing surfaces decreased as crevice width increased. While assemblage structure on downward and vertical surfaces was influenced by crevice width and caging separately. Thus, crevice size and orientation are important habitat complexity features that act to partition predation pressure. This may allow distinct sessile assemblages to persist, even when predation can be intense., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Microplastics and fibres occur in high concentrations along urban coastlines, but the occurrence of microplastic ingestion by fishes in these areas requires further investigation. Herein, the ingestion of debris (i.e., synthetic and natural fibres and synthetic fragments of various polymer types) by three benthic-foraging fish species Acanthopagrus australis (yellowfin bream), Mugil cephalus (sea mullet) and Gerres subfasciatus (silverbiddy) in Sydney Harbour, Australia has been quantified and chemically speciated by vibrational spectroscopy to identify the polymer type. Ingested debris were quantified using gut content analysis, and identified using attenuated total reflectance Fourier transform infrared (ATR-FTIR) and Raman microspectroscopies in combination with principal component analysis (PCA). The occurrence of debris ingestion at the time of sampling ranged from 21 to 64% for the three species, and the debris number ranged from 0.2 to 4.6 items per fish for the different species, with ∼53% of debris being microplastic. There was a significant difference in the amount of debris ingested among species; however, there was no difference among species when debris counts were standardised to fish weight or gut content weight, indicating that these species ingest a similar concentration of debris relative to their ingestion rate of other material. ATR-FTIR microspectroscopy successfully identified 72% of debris. Raman spectroscopy contributed an additional 1% of successful identification. In addition, PCA was used to non-subjectively classify the ATR-FTIR spectra resulting in the identification of an additional 9% of the debris. The most common microplastics found were polyester (PET), acrylic-polyester blend, and rayon (semi-synthetic) fibres. The potential of using Raman microspectroscopy for debris identification was investigated and provided additional information about the nature of the debris as well as the presence of specific dyes (and hence potential toxicity)., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Strategies for managing biological invasions are often based on the premise that characteristics of invading species and the invaded environment are key predictors of the invader's distribution. Yet, for either biological traits or environmental characteristics to explain distribution, adequate time must have elapsed for species to spread to all potential habitats. We compiled and analyzed a database of natural history and ecological traits of 138 coastal marine invertebrate species, the environmental conditions at sites to which they have been introduced, and their date of first introduction. We found that time since introduction explained the largest fraction (20%) of the variability in non-native range size, while traits of the species and environmental variables had significant, but minimal, influence on non-native range size. The positive relationship between time since introduction and range size indicates that non-native marine invertebrate species are not at equilibrium and are still spreading, posing a major challenge for management of coastal ecosystems.

Multi-use marine parks achieve conservation through spatial management of activities. Zoning of marine parks in New South Wales, Australia, includes high conservation areas and special purpose zones (SPZ) where maritime activities are concentrated. Although such measures geographically constrain anthropogenic impacts, we have limited understanding of potential ecological effects. We assessed sediment communities and contaminants adjacent to boating infrastructure (boat ramps, jetties and a marina) in a SPZ from the Clyde Estuary in Batemans Marine Park. Metal concentrations and fines content were elevated at boating structures compared to reference sites. Species richness was higher at sites with boating structures, where capitellid polychaetes and nematodes dominated the communities. Changes associated with boating structures were localised and did not extend beyond breakwalls or to reference sites outside the SPZ. The study highlights the benefits of appropriate zoning in a multi-use marine park and the potential to minimise stress on pristine areas through the application of spatial management.

Anthropogenic modifications to waterways are common and their ecological consequences must be understood to effectively conserve local biodiversity. The facilitation of recreational boating activities often requires substantial alteration of natural areas, however the environmental and ecological consequences of such alterations are rarely described in the scientific literature. In this study, ecological and physico-chemical conditions were investigated in a recreational boating marina, located inside a marine park on the south-east coast of Australia. Recruitment panels were deployed for 8 weeks both inside and outside the marina, and differences in the composition of the developing fouling communities were observed. The recruitment of taxa, which often have short-lived larvae, was increased inside the marina (bryozoans, spirorbids and sponges) while the recruitment of taxa, which often have longer-lived larvae, was reduced or absent (barnacles, solitary ascidians and non-spirorbid polychaetes). Differences were also observed in environmental conditions inside the marina cf. directly outside. The marina environment had higher turbidity, temperature and pH along with higher concentrations of lead and copper in suspended sediments, while flow rates and trapped sediment loads were reduced inside the marina. The differences observed in the study suggest that there may be marked environmental changes associated with marina developments. The potential ecological consequences of these changes should be a primary consideration during the planning process, particularly for developments in locations of notable ecological value.

Biomonitors are commonly used to assess levels of bioavailable contaminants in the environment, however the relationships between biomonitor tissue concentrations and ecological effects are rarely assessed. The present study investigated metal contamination within a highly industrialised harbour and ecological effects on sessile invertebrates. The native oyster Saccostrea glomerata was deployed as a biomonitor across twenty-six sites to test for correlations between metal levels in their tissues and the recruitment of hard-substrate invertebrates. Concentrations of lead and copper in oyster tissues were negatively correlated with densities of the dominant barnacle, Amphibalanus variegatus, and positively correlated with densities of the dominant polychaete, Hydroides elegans, and the two native encrusting bryozoans Celloporaria nodulosa and Arachnopusia unicornis. Results suggest that highly localised events drive contaminant availability and that these events pose a significant risk to fauna. Biomonitoring studies may be enhanced by running concurrent ecological surveys., (This journal is © The Royal Society of Chemistry 2012)

Anthropogenic stresses such as metal contamination can have profound ecological impacts in a wide range of habitats. Reduced survival of organisms in contaminated habitats has the potential to result in the evolution of genotypes tolerant to deleterious contaminants. Local adaptation to contamination requires directional selection, genetic variation in traits relating to tolerance, spatial variability in exposure to the contaminant and limited gene flow between populations. This study assesses variation in tolerance in the herbivorous marine invertebrate Peramphithoe parmerong whose algal diets in Sydney Harbour readily accumulate the metal copper. A quantitative genetics approach (a full-sib, split family design) was used to quantify variation among families in survival on the contaminated diet. A significant genotype-by-environment interaction in offspring survival between the copper contaminated and uncontaminated diet treatments revealed variation in tolerance to copper by P. parmerong. Amphipods that survived 30 days of exposure to copper contaminated diets were slightly smaller and ate less algae than those reared on uncontaminated food. This reflects an additional sub-lethal effect associated with the consumption of contaminated algae. However, there was no evidence of acclimation to contaminated diets, nor a cost of reduced feeding for those genotypes with increased tolerance. This study provides strong evidence for the potential of a marine invertebrate to evolve tolerance to contaminants found in their diet., (Copyright 2010 Elsevier B.V. All rights reserved.)

We determined metal contents of co-occurring algae Padina crassa and Sargassum sp. in Port Jackson (Australia), and relationships between metal levels and the abundance of epifaunal amphipods. Copper, lead and zinc concentrations were amongst the highest yet recorded in these algae. Copper, manganese and lead concentrations were far greater in P. crassa than Sargassum sp., possibly due to the low growth of P. crassa in proximity to contaminated sediments. However, in manipulative experiments the proximity of algae to sediments did not explain these differences. The abundance of herbivorous amphipods correlated negatively with the copper content of P. crassa, but not with the lower concentrations in Sargassum sp. The greater contamination of P. crassa led to patchy distributions of metals in algal beds and recolonisation experiments showed Sargassum sp. acts as a refuge from contaminants for epifauna. The contamination of macroalgae may pose threats to epifauna in harbours around the world.

Vessel hull fouling is a major vector for the translocation of nonindigenous species (NIS). Antifouling (AF) paints are the primary method for preventing the establishment and translocation of fouling species. However, factors such as paint age, condition and method of application can all reduce the effectiveness of these coatings. Areas of hull that escape AF treatment (through limited application or damage) constitute key areas that may be expected to receive high levels of fouling. The investigation focused on whether small-scale (mm(2) to cm(2)) areas of unprotected surface or experimental 'scrapes' provided sufficient area for the formation of fouling assemblages within otherwise undamaged AF surfaces. Recruitment of fouling taxa such as algae, spirorbids and hydroids was recorded on scrapes as narrow as 0.5 cm wide. The abundance and species richness of fouling assemblages developing on scrapes > or =1 cm often equalled or surpassed levels observed in reference assemblages totally unprotected by AF coatings. Experiments were conducted at three sites within the highly protected and isolated marine park surrounding Lady Elliott Island at the southernmost tip of the Great Barrier Reef, Australia. Several NIS were recorded on scrapes of AF coated surfaces at this location, with 1-cm scrapes showing the greatest species richness and abundance of NIS relative to all other treatments (including controls) at two of the three sites investigated. Slight disruptions to newly antifouled surfaces may be all that is necessary for the establishment of fouling organisms and the translocation of a wide range of invasive taxa to otherwise highly protected marine areas.