237 research outputs found

    Effects of harvesting methods on sustainability of a bay scallop fishery: dredging uproots seagrass and displaces recruits

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    Fishing is widely recognized to have profound effects on estuarine and marine ecosystems (Hammer and Jansson, 1993; Dayton et al., 1995). Intense commercial and recreational harvest of valuable species can result in population collapses of target and nontarget species (Botsford et al., 1997; Pauly et al., 1998; Collie et al. 2000; Jackson et al., 2001). Fishing gear, such as trawls and dredges, that are dragged over the seafloor inflict damage to the benthic habitat (Dayton et al., 1995; Engel and Kvitek, 1995; Jennings and Kaiser, 1998; Watling and Norse, 1998). As the growing human population, over-capitalization, and increasing government subsidies of fishing place increasing pressures on marine resources (Myers, 1997), a clear understanding of the mechanisms by which fishing affects coastal systems is required to craft sustainable fisheries management

    De novo reefs: Fish habitat provision by oyster aquaculture varies with farming method

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    Aquaculture industries have the capacity to produce positive ecosystem service benefits, such as the provision of habitat to wild animals. Oyster cultivation is the oldest and largest aquaculture industry in south-eastern Australia. Oyster spat are grown to marketable size in rack-and-rail (‘racks’) or longline-and-basket (‘baskets’) configurations, which add structure to estuarine waters. This study assessed: (1) how the fish communities associated with oyster farms vary with production method; (2) how communities of fish utilise oyster infrastructure, as compared to adjacent natural habitats; and (3) whether oyster infrastructure can serve as de facto oyster reefs by supporting similar fish communities. Remote underwater video surveys, conducted during summer and winter of 2 study years, revealed that fish observations and species richness were generally greater for rack than basket cultivation. Both types of oyster farms supported at least as many species of fish as adjacent natural habitats, including oyster reef, seagrass, mangrove and bare sediment. Fish communities were, in general, most similar between racks and baskets and most dissimilar between racks and bare sediments. Oyster farms supported species of fish otherwise limited to habitats with wild oysters, and unique harvested fish species were observed more frequently at racks. Fish use of oyster-growing infrastructure for foraging and shelter mirrored use of natural biogenic habitats. Overall, this study suggests that the oyster aquaculture infrastructure can support fish communities with species composition similar to those of natural biogenic habitats, although this service is dependent on farming method. Ecosystem services provided by aquaculture should be considered in estuarine habitat enhancement, conservation and restoration

    Response of benthic assemblages to multiple stressors : comparative effects of nutrient enrichment and physical disturbance

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    J.M.K. was supported by an International Macquarie University Research Excellence Scholarship during this research. Research funding was provided through the Department of Biological Sciences Macquarie University and an ARC Discovery Project DP1093444 to MJB. D.M.P. received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland) and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions.Stressors to ecological communities often overlap in time and space and may have additive, synergistic or antagonistic effects. Nutrient enrichment and physical disturbance are 2 commonly co-occurring stressors to estuarine ecosystems, but their combined effects have mainly been investigated in mesocosm experiments of unknown relevance to field scenarios. Here, the interacting effects of these 2 stressors were examined at 2 field locations (Botany Bay and Lane Cove, New South Wales, Australia) using a fully orthogonal manipulative experiment. All possible combinations of zero, low and high intensities of nutrient enrichment and physical disturbance on macrofaunal and microphytobenthic communities were examined. Effects of stressors were generally site-specific and additive, differing in terms of magnitude of effects, although some idiosyncratic interactive effects were demonstrated for selected species. Where effects of stressors were observed, nutrient enrichment generally increased microphytobenthic biomass and altered the macrofaunal community structure while physical disturbance produced limited impacts. The divergent results of this and previous mesocosm experiments, which found primarily interactive effects of the stressors, highlights the importance of undertaking field experiments that offer a greater element of realism. Furthermore, this study, in finding differing responses to stressors at the 2 sites, highlights the importance of environmental context in mediating effects.PostprintPeer reviewe

    Bioengineering promotes habitat heterogeneity and biodiversity on mussel reefs

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    Loss of biodiversity is among the most pressing global problems. Yet, despite its pertinent nature, the biological processes involved in the maintenance of biodiversity are poorly understood. Habitat heterogeneity is widely regarded as a key factor underpinning the biodiversity of land- and sea-scapes. However, it remains unclear how species coexist in many of those ecosystems that lack conspicuous heterogeneity. We demonstrate how spatially self-organized mussel reefs create microhabitats/heterogeneity that facilitate diverse invertebrate communities. By comparing seawater filled pools with open inlets in a mussel reef, we found that natural reef pools, emerging due to the habitat engineering of the mussels, strongly increased variation in organic enrichment and promoted beta-diversity compared to the surrounding tidal flat. These findings significantly extend the scale of influence typically described for self-organized habitats and highlight the importance of bioengineering and its positive effects on habitat heterogeneity and community diversity

    Oyster reef restoration fails to recoup global historic ecosystem losses despite substantial biodiversity gain

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    Human activities have led to degradation of ecosystems globally. The lost ecosystem functions and services accumulate from the time of disturbance to the full recovery of the ecosystem and can be quantified as a “recovery debt,” providing a valuable tool to develop better restoration practices that accelerate recovery and limit losses. Here, we quantified the recovery of faunal biodiversity and abundance toward a predisturbed state following structural restoration of oyster habitats globally. We found that while restoration initiates a rapid increase in biodiversity and abundance of reef-associated species within 2 years, recovery rate then decreases substantially, leaving a global shortfall in recovery of 35% below a predisturbed state. While efficient restoration methods boost recovery and minimize recovery shortfalls, the time to full recovery is yet to be quantified. Therefore, potential future coastal development should weigh up not only the instantaneous damage to ecosystem functions but also the potential for generational loss of services

    Turning a lost reef ecosystem into a national restoration program

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    Achieving a sustainable socioecological future now requires large-scale environmental repair across legislative borders. Yet, enabling large-scale conservation is complicated by policy-making processes that are disconnected from socioeconomic interests, multiple sources of knowledge, and differing applications of policy. We considered how a multidisciplinary approach to marine habitat restoration generated the scientific evidence base, community support, and funding needed to begin the restoration of a forgotten, functionally extinct shellfish reef ecosystem. The key actors came together as a multidisciplinary community of researchers, conservation practitioners, recreational fisher communities, and government bodies that collaborated across sectors to rediscover Australia's lost shellfish reefs and communicate the value of its restoration. Actions undertaken to build a case for large-scale marine restoration included synthesizing current knowledge on Australian shellfish reefs and their historical decline, using this history to tell a compelling story to spark public and political interest, integrating restoration into government policy, and rallying local support through community engagement. Clearly articulating the social, economic, and environmental business case for restoration led to state and national funding for reef restoration to meet diverse sustainability goals (e.g., enhanced biodiversity and fisheries productivity) and socioeconomic goals (e.g., job creation and recreational opportunities). A key lesson learned was the importance of aligning project goals with public and industry interests so that projects could address multiple political obligations. This process culminated in Australia's largest marine restoration initiative and shows that solutions for large-scale ecosystem repair can rapidly occur when socially valued science acts on political opportunities

    Use of an electronic patient-reported outcome measure in the management of patients with advanced chronic kidney disease:the RePROM pilot trial protocol

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    INTRODUCTION Chronic kidney disease (CKD) affects up to 16% of adults in the UK. Patient quality of life is particularly reduced in end-stage renal disease and is strongly associated with increased hospitalisation and mortality. Thus, accurate and responsive healthcare is a key priority. Electronic patient-reported outcome measures (ePROMs) are online questionnaires which ask patients to self-rate their health status. Evidence in oncology suggests that the use of ePROM data within routine care, alongside clinical information, may enhance symptom management and improve patient outcomes. However, National Health Service (NHS)-based ePROM research in CKD is lacking. This pilot trial will assess the feasibility of undertaking a full-scale randomised controlled trial (RCT) in patients with CKD within the NHS. METHODS AND ANALYSIS The renal ePROM pilot trial is an investigator-led single-centre, open-label, two-arm randomised controlled pilot trial of 66 participants ≄18 years with advanced CKD. Participants will be randomised to receive either usual care or usual care supplemented with an ePROM intervention. Participants within the intervention arm will be asked to submit monthly self-reports of their health status using the ePROM system. The system will provide tailored information to patients in response to each report and notify the clinical team of patient deterioration. The renal clinical team will monitor for ePROM notifications and will respond with appropriate action, in line with standard clinical practice. Measures of study feasibility, participant quality of life and CKD severity will be completed at 3 monthly intervals. Health economic outcomes will be assessed. Clinicians will record treatment decision-making. Acceptability and feasibility of the protocol will be assessed alongside outcome measure and intervention compliance rates. Qualitative process evaluation will be conducted. ETHICS AND DISSEMINATION The findings will inform the design of a full-scale RCT and the results will be submitted for publication in peer-reviewed journals. The study has ethical approval. TRIAL REGISTRATION NUMBERS ISRCTN12669006; Pre-results

    Invasion Expansion: Time since introduction best predicts global ranges of marine invaders.

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    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
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