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1.
Mar Pollut Bull ; 202: 116323, 2024 May.
Article in English | MEDLINE | ID: mdl-38598927

ABSTRACT

Human influence in the deep-sea is increasing as mining and drilling operations expand, and waters warm because of climate change. Here, we investigate how the long-lived deep-sea bivalve, Acesta excavata responds to sediment pollution and/or acute elevated temperatures. A. excavata were exposed to suspended sediment, acute warming, and a combination of the two treatments for 40 days. We measured O2 consumption, NH4+ release, Total Organic Carbon (TOC), and lysosomal membrane stability (LMS). We found suspended sediment and warming interacted to decrease O:N ratios, while sediment as a single stressor increased the release of TOC and warming increased NH4+ release in A. excavata. Warming also increased levels of LMS. We found A. excavata used protein catabolism to meet elevated energetic demands indicating a low tolerance to stress. A. excavata has limited capacity for physiological responses to the stressors of warming and sediment which may lead to decreased fitness of A. excavata.


Subject(s)
Geologic Sediments , Animals , Geologic Sediments/chemistry , Climate Change , Bivalvia/physiology , Stress, Physiological , Carbon/analysis
2.
Mar Pollut Bull ; 196: 115608, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37797537

ABSTRACT

Eutrophication is a worldwide issue that can disrupt ecosystem processes in sediments. Studies have shown that macrofauna influences sediment processes by engineering environments that constrain microbial communities. Here, we explored the effect of different sizes of the Sydney cockle (Anadara trapezia), on bacterial and archaeal communities in natural and experimentally enriched sediments. A mesocosm experiment was conducted with two enrichment conditions (natural or enriched) and 5 cockle treatments (small, medium, large, mixed sizes and a control). This study was unable to detect A. trapezia effects on microbial communities irrespective of body size. However, a substantial decrease of bacterial richness, diversity, and structural and functional shifts, were seen with organic enrichment of sediments. Archaea were similarly changed although the magnitude of effect was less than for bacteria. Overall, we found evidence to suggest that A. trapezia had limited capacity to affect sediment microbial communities and mitigate the effects of organic enrichment.


Subject(s)
Arcidae , Microbiota , Animals , Archaea/genetics , Geologic Sediments/chemistry , Bacteria/genetics , RNA, Ribosomal, 16S
3.
Environ Pollut ; 330: 121731, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37121305

ABSTRACT

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.


Subject(s)
Environmental Monitoring , Waste Products , Humans , Waste Products/analysis , Queensland , Environmental Monitoring/methods , Plastics , Bathing Beaches , Australia
4.
Sci Total Environ ; 871: 161908, 2023 May 01.
Article in English | MEDLINE | ID: mdl-36736403

ABSTRACT

Stormwater drains act as a pathway for anthropogenic debris from land to sea, particularly in urbanised estuaries where impervious surfaces expedite the process. Debris type and abundance in stormwater drains may vary due to land use and human activity, and knowledge of this variation is necessary to manage the growing threat of debris. Surveys of stormwater debris can inform targeted reduction and remediation efforts by intercepting and identifying pollutants near their source. We surveyed replicate stormwater gross pollutant traps across four land use zones (city centre, shopping centre, transportation hub, industrial precinct) before and during COVID-19 measures to assess the effects of changing human activities. Gross pollutant traps were installed in 120 drains in Greater Melbourne, Australia, and citizen scientists trained by Tangaroa Blue Foundation weighed and classified debris at 6-week intervals between October 2019 and October 2020. Four survey cycles were conducted before lockdowns were implemented, then another four during lockdowns. COVID-19 lockdowns and patterns of debris type and abundance across land use revealed how changes in human activity might impact the flow of debris. Cigarette butts were the most abundant macro debris (>5 mm) item in every survey cycle, regardless of lockdowns. Industrial land use zones had the lowest macro debris counts but contained over 90 % of the micro debris (1-5 mm). The amount of total macro debris decreased during lockdowns, however the most abundant and problematic debris items such as cigarettes and single-use plastics did not decrease as much as might be expected from the concomitant reductions in human activity. Occupational health and safety items, such as masks and gloves, increased (144 %) during COVID-19 lockdowns. Micro debris counts did not change in industrial zones during lockdowns, suggesting that workplace interventions may be necessary to reduce this debris leakage. Tracing the pathway of debris from source to sea can inform reduction and long-term management strategies.


Subject(s)
COVID-19 , Environmental Pollutants , Humans , Waste Products/analysis , Environmental Monitoring , COVID-19/epidemiology , Communicable Disease Control , Plastics
5.
Environ Pollut ; 316(Pt 1): 120533, 2023 Jan 01.
Article in English | MEDLINE | ID: mdl-36341829

ABSTRACT

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.


Subject(s)
Fires , Wildfires , Ecosystem , Australia , Carbon , Forests
6.
PLoS One ; 17(12): e0274512, 2022.
Article in English | MEDLINE | ID: mdl-36576908

ABSTRACT

Records of anthropogenic marine debris and the threats it poses are increasing worldwide, yet we know relatively little about the distribution of benthic debris. The seafloor is the final destination for a large proportion of debris due to the degradation and sinking of items. A more detailed understanding of debris distributions in hotspots such as urbanised estuaries can help decision makers target management and remediation activities. We selected sites frequented by fishers and boaters in Sydney Harbour, an urbanised estuary, to investigate the impacts of recreational activities on debris abundance. The aim of this study was to examine variation in macro debris (>5mm in diameter) type and abundance at two habitat types (piers and non-piers). We chose five locations at various distances from the estuary mouth. In each location SCUBA teams performed fixed transects at two sites, one under a pier and one over nearby soft-sediment habitat. Debris was recovered by the divers and brought to the surface for classification and disposal. Surveys were repeated multiple times at each location between November 2019 and February 2020, recording a total of 2803 debris items over 36 survey events. Overall, piers had more than ten times the debris abundance of soft-sediment sites, and much higher proportion of debris types related to recreational fishing. Over half of the debris items in this study were plastic (65%), and approximately 70% of the total debris was classified as related to recreational fishing. This trait was most prominent in debris at sites closest to the estuary mouth, likely reflecting increased fishing activity in this area. This study indicates that policy makers and community groups in urbanised estuaries should focus monitoring, reduction, and remediation efforts near artificial structures such as piers, and that public awareness campaigns should target the behaviour of recreational users of these structures.


Subject(s)
Estuaries , Plastics , Ecosystem , Environmental Monitoring , Waste Products/analysis
7.
Frontline Gastroenterol ; 13(5): 392-401, 2022.
Article in English | MEDLINE | ID: mdl-36051959

ABSTRACT

Background: Sequential drug treatment with biological agents in ulcerative colitis (UC) is becoming increasingly complex. There are few studies comparing head-to-head outcomes in second-line treatments. The study assesses whether using anti-tumour necrosis factor (anti-TNF)-α therapy following the α4ß7 integrin blocker vedolizumab (VDZ) or VDZ after an anti-TNF has more favourable clinical outcomes in UC in a real-world outpatient setting. Methods: Patients with UC who were exposed to first-line anti-TNF (adalimumab or infliximab) or VDZ who subsequently switched to the alternate class between May 2013 and August 2020 were identified by reviewing patient databases at 10 hospitals. Data were collected retrospectively using patient records. Baseline demographics, disease activity indices, biochemical markers, endoscopic Mayo score, colectomy rates, treatment persistence and urgent hospital utilisation composite endpoint (UHUC) rates were examined over a 52-week period. Results: Second-line week 52 treatment persistence was higher in the VDZ group (71/81, 89%) versus the anti-TNF group (15/34, 44%; p=0.0001), as were week 52 colectomy-free survival (VDZ: 77/80, 96%, vs anti-TNF: 26/32, 81%; p=0.009), week 52 UHUC survival (VDZ: 68/84, 81%, vs anti-TNF: 20/34, 59%; p=0.002) and week 52 corticosteroid-free clinical remission (CFCR) rates (VDZ: 22/34, 65%, vs anti-TNF: 4/20, 20%; p=0.001). Conclusion: Compared with second-line anti TNF usage, the VDZ second-line cohort had significantly higher 52-week treatment persistence, UHUC survival, higher colectomy-free survival rates and higher week 52 CFCR. These data suggest that VDZ is an effective biologic in UC as a second-line therapy after anti-TNF exposure. It highlights the effect of biological order on clinically important outcomes.

8.
Nat Ecol Evol ; 6(9): 1262-1270, 2022 09.
Article in English | MEDLINE | ID: mdl-35798839

ABSTRACT

The biodiversity of marine and coastal habitats is experiencing unprecedented change. While there are well-known drivers of these changes, such as overexploitation, climate change and pollution, there are also relatively unknown emerging issues that are poorly understood or recognized that have potentially positive or negative impacts on marine and coastal ecosystems. In this inaugural Marine and Coastal Horizon Scan, we brought together 30 scientists, policymakers and practitioners with transdisciplinary expertise in marine and coastal systems to identify new issues that are likely to have a significant impact on the functioning and conservation of marine and coastal biodiversity over the next 5-10 years. Based on a modified Delphi voting process, the final 15 issues presented were distilled from a list of 75 submitted by participants at the start of the process. These issues are grouped into three categories: ecosystem impacts, for example the impact of wildfires and the effect of poleward migration on equatorial biodiversity; resource exploitation, including an increase in the trade of fish swim bladders and increased exploitation of marine collagens; and new technologies, such as soft robotics and new biodegradable products. Our early identification of these issues and their potential impacts on marine and coastal biodiversity will support scientists, conservationists, resource managers and policymakers to address the challenges facing marine ecosystems.


Subject(s)
Biodiversity , Ecosystem , Animals , Climate Change , Humans
9.
Environ Sci Technol ; 56(16): 11300-11309, 2022 08 16.
Article in English | MEDLINE | ID: mdl-35880958

ABSTRACT

Large-scale desalination is used increasingly to address growing freshwater demands and climate uncertainty. Discharge of hypersaline brine from desalination operations has the potential to impact marine ecosystems. Here, we used a 7-year Multiple-Before-After-Control-Impact experiment to test the hypothesis that hypersaline discharge from reverse osmosis desalination alters temperate reef communities. Using replicated, video-based, timed searches at eight sites, we sampled fish and invertebrate assemblages before, during, and after the discharge of hypersaline brine. We found that the composition of fish assemblages was significantly altered out to 55 m while the composition of invertebrate assemblages was altered out to 125 m from the outlet during hypersaline discharge. Fish richness and functional diversity increased around the outlet, while the invertebrate assemblages were no less diverse than those on reference reefs. Differences in faunal assemblages between outlet and reference sites during discharging included changes in the frequency of occurrence of both common and rare reef biota. Overall, we found the influence of hypersaline discharge on temperate reef biota to be spatially localized, with the reefs around the outlet continuing to support rich and diverse faunal communities. In some cases, therefore, the marine environmental consequences of large-scale, well-designed, desalination operations may be appropriately balanced against the positive benefits of improved water security.


Subject(s)
Coral Reefs , Ecosystem , Animals , Biodiversity , Biota , Fishes , Invertebrates
10.
Front Physiol ; 13: 804193, 2022.
Article in English | MEDLINE | ID: mdl-35665222

ABSTRACT

Coral reefs are amongst the most biodiverse ecosystems on earth, and while stony corals create the foundational complexity of these ecosystems, octocorals and anemones contribute significantly to their biodiversity and function. Like stony corals, many octocorals contain Symbiodiniaceae endosymbionts and can bleach when temperatures exceed the species' upper thermal limit. Here, we report octocoral bleaching susceptibility and resistance within the subtropical Lord Howe Island coral reef ecosystem during and after marine heatwaves in 2019. Octocoral and anemone surveys were conducted at multiple reef locations within the Lord Howe Island lagoon during, immediately after, and 7 months after the heatwaves. One octocoral species, Cladiella sp. 1, experienced bleaching and mortality, with some bleached colonies detaching from the reef structure during the heatwave (presumed dead). Those that remained attached to the benthos survived the event and recovered endosymbionts within 7 months of bleaching. Cladiella sp. 1 Symbiodiniaceae density (in cells per µg protein), chlorophyll a and c 2 per µg protein, and photosynthetic efficiency were significantly lower in bleached colonies compared to unbleached colonies, while chlorophyll a and c 2 per symbiont were higher. Interestingly, no other symbiotic octocoral species of the Lord Howe Island lagoonal reef bleached. Unbleached Xenia cf crassa colonies had higher Symbiodiniaceae and chlorophyll densities during the marine heatwave compared to other monitoring intervals, while Cladiella sp. 2 densities did not change substantially through time. Previous work on octocoral bleaching has focused primarily on gorgonian octocorals, while this study provides insight into bleaching variability in other octocoral groups. The study also provides further evidence that octocorals may be generally more resistant to bleaching than stony corals in many, but not all, reef ecosystems. Responses to marine heating events vary and should be assessed on a species by species basis.

11.
Environ Pollut ; 308: 119571, 2022 Sep 01.
Article in English | MEDLINE | ID: mdl-35661807

ABSTRACT

Estuaries are one of the most valuable biomes on earth. Although humans are highly dependent on these ecosystems, anthropogenic activities have impacted estuaries worldwide, altering their ecological functions and ability to provide a variety of important ecosystem services. Many anthropogenic stressors combine to affect the soft sedimentary habitats that dominate estuarine ecosystems. Now, due to climate change, estuaries and other marine areas might be increasingly exposed to the emerging threat of megafires. Here, by sampling estuaries before and after a megafire, we describe impacts of wildfires on estuarine benthic habitats and justify why megafires are a new and concerning threat to coastal ecosystems. We (1) show that wildfires change the fundamental characteristics of estuarine benthic habitat, (2) identify the factors (burnt intensity and proximity to water's edge) that influence the consequences of fires on estuaries, and (3) identify relevant indicators of wildfire impact: metals, nutrients, and pyrogenic carbon. We then discuss how fires can impact estuaries globally, regardless of local variability and differences in catchment. In the first empirical assessment of the impact of wildfires on estuarine condition, our results highlight indicators that may assist waterway managers to empirically detect wildfire impacts in estuaries and identify catchment factors that should be included in fire risk assessments for estuaries. Overall, this study highlights the importance of considering fire threats in current and future estuarine and coastal management.


Subject(s)
Ecosystem , Wildfires , Climate Change , Estuaries
12.
Mar Environ Res ; 177: 105640, 2022 May.
Article in English | MEDLINE | ID: mdl-35526360

ABSTRACT

Marine artificial structures such as pilings are replacing natural habitats, and modifying surrounding areas, often resulting in local decreases in species diversity and facilitation of bioinvasion. Most research on the impacts of artificial structures in marine ecosystems has primarily focused on rocky bottom habitats and biodiversity, overlooking the effects of these structures on the functioning of nearby sedimentary habitats. Here we compared, for the first time, benthic metabolism (O2 fluxes) and sediment-water nutrient (inorganic nitrogen, phosphate, and dissolved organic nitrogen) fluxes in shallow water sediments adjacent to pilings and natural reefs. We also measured sediment properties (grain size, total organic carbon, total nitrogen, C:N ratio and chlorophyll-a content). We found that sediments near pilings were generally finer with greater C:N ratios than those near reefs, while differences in other sediment properties between types of habitats were dependent on the site. We found significant differences in the oxygen consumption, primary productivity, and net ecosystem metabolism in sediments around pilings compared to sediments near natural reefs, but these patterns differed by site. Net nutrient fluxes were similar in sediments near pilings and reefs at both sites. This study showed that although pilings can be associated with changes in the functioning of sedimentary habitats, patterns and the direction of change seem to vary depending on local conditions.


Subject(s)
Biodiversity , Ecosystem , Chlorophyll A , Geologic Sediments/chemistry , Nitrogen , Water
13.
Microbiology (Reading) ; 168(4)2022 04.
Article in English | MEDLINE | ID: mdl-35416764

ABSTRACT

Antarctic sea-ice forms a complex and dynamic system that drives many ecological processes in the Southern Ocean. Sea-ice microalgae and their associated microbial communities are understood to influence nutrient flow and allocation in marine polar environments. Sea-ice microalgae and their microbiota can have high seasonal and regional (>1000 km2) compositional and abundance variation, driven by factors modulating their growth, symbiotic interactions and function. In contrast, our knowledge of small-scale variation in these communities is limited. Understanding variation across multiple scales and its potential drivers is critical for informing on how multiple stressors impact sea-ice communities and the functions they provide. Here, we characterized bacterial communities associated with sea-ice microalgae and the potential drivers that influence their variation across a range of spatial scales (metres to >10 kms) in a previously understudied area in Commonwealth Bay, East Antarctica where anomalous events have substantially and rapidly expanded local sea-ice coverage. We found a higher abundance and different composition of bacterial communities living in sea-ice microalgae closer to the shore compared to those further from the coast. Variation in community structure increased linearly with distance between samples. Ice thickness and depth to the seabed were found to be poor predictors of these communities. Further research on the small-scale environmental drivers influencing these communities is needed to fully understand how large-scale regional events can affect local function and ecosystem processes.


Subject(s)
Microalgae , Microbiota , Antarctic Regions , Bays , Ecosystem , Ice Cover
14.
Environ Sci Technol ; 56(5): 2950-2958, 2022 03 01.
Article in English | MEDLINE | ID: mdl-35129968

ABSTRACT

Pathogens and polymers can separately cause disease; however, environmental and medical researchers are increasingly investigating the capacity of polymers to transfer pathogenic bacteria, and cause disease, to hosts in new environments. We integrated causal frameworks from ecology and epidemiology into one interdisciplinary framework with four stages (colonization, survival, transfer, disease). We then systematically and critically reviewed 111 environmental and medical papers. We show 58% of studies investigated the colonization-stage alone but used this as evidence to classify a substratum as a vector. Only 11% of studies identified potential pathogens, with only 3% of studies confirming the presence of virulence-genes. Further, 8% of studies investigated µm-sized polymers with most (58%) examining less pervasive cm-sized polymers. No study showed bacteria can preferentially colonize, survive, transfer, and cause more disease on polymers compared to other environmental media. One laboratory experiment demonstrated plausibility for polymers to be colonized by a potential pathogen (Escherichia coli), survive, transfer, and cause disease in coral (Astrangia poculata). Our analysis shows a need for linked structured surveys with environmentally relevant experiments to understand patterns and processes across the vectoral stages, so that the risks and impacts of pathogens on polymers can be assessed with more certainty.


Subject(s)
Anthozoa , Bacterial Infections , Animals , Bacteria , Plastics , Polymers
15.
Sci Total Environ ; 807(Pt 2): 150742, 2022 Feb 10.
Article in English | MEDLINE | ID: mdl-34619209

ABSTRACT

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.


Subject(s)
Citizen Science , Australia , Data Accuracy , Ecosystem , Plastics
16.
Front Microbiol ; 12: 661177, 2021.
Article in English | MEDLINE | ID: mdl-34690940

ABSTRACT

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.

17.
Mar Environ Res ; 169: 105391, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34217096

ABSTRACT

Eutrophication is an increasing problem worldwide and can disrupt ecosystem processes in which macrobenthic bioturbators play an essential role. This study explores how intraspecific variation in body size affects the survival, mobility and impact on sediment organic matter breakdown in enriched sediments of an infaunal bivalve. A mesocosm experiment was conducted in which monocultures and all size combinations of three body sizes (small, medium and large) of the Sydney cockle, Anadara trapezia, were exposed to natural or organically enriched sediments. Results demonstrate that larger body sizes have higher tolerance to enriched conditions and can reduce survival of smaller cockles when grown together. Also, large A. trapezia influenced sediment organic matter breakdown although a direct link to bioturbation activity was not clear. Overall, this study found that intraspecific variation in body size influences survival and performance of bioturbators in eutrophic scenarios.


Subject(s)
Bivalvia , Cardiidae , Animals , Body Size , Ecosystem , Geologic Sediments
18.
Conserv Biol ; 35(3): 921-932, 2021 06.
Article in English | MEDLINE | ID: mdl-33448038

ABSTRACT

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.


Análisis de la Efectividad Social y Ecológica de las Áreas Marinas Parcialmente Protegidas Resumen Las áreas marinas protegidas (AMPs) son una herramienta importante para la administración, conservación y restauración de los ecosistemas marinos; sin embargo, el 69% de las AMPs mundiales solamente están parcialmente protegidas (es decir, están abiertas a alguna forma de pesca). Aunque las áreas completamente protegidas tienen resultados bien documentados, incluyendo el incremento en la diversidad de peces y la biomasa, la efectividad de las áreas parcialmente protegidas está en disputa. Puede que las áreas parcialmente protegidas se justifiquen por razones sociales, aunque los resultados sociales con frecuencia dependen de que las AMPs alcancen sus metas ecológicas para distinguirlas de las áreas abiertas y justificar el costo de la protección. Analizamos las percepciones sociales y la efectividad ecológica de 18 áreas parcialmente protegidas y 19 áreas completamente protegidas a lo largo de 7000 km de costa en el sur de Australia. Usamos métodos mixtos, recopilando información por medio de entrevistas semiestructuradas, encuestas en sitio y censos Reef Life (censos visuales submarinos). Analizamos los datos cualitativos de acuerdo con la teoría fundamentada y los datos cuantitativos con modelos lineales de efectos mixtos multivariados y univariados. No encontramos beneficios sociales o ecológicos para las áreas parcialmente protegidas en relación con las áreas abiertas en nuestro estudio. Las áreas parcialmente protegidas no tuvieron más peces, invertebrados o algas que las áreas abiertas; los usuarios de la costa tenían poco entendimiento de ellas; no eran más atractivas que las áreas abiertas; y no eran percibidas como albergues de mejor vida marina que las áreas abiertas. Estos hallazgos proporcionan un contrapunto importante a algunos metaanálisis a gran escala que concluyen que las áreas parcialmente protegidas pueden ser ecológicamente efectivas, pero llegan a esta conclusión con base en medidas más reducidas. Discutimos que las áreas parcialmente protegidas funcionan como pistas falsas para la conservación marina pues crean una ilusión de estar protegidas y consumen pocos recursos para la conservación, pero proporcionan poca o ninguna ganancia ecológica o social en comparación con las áreas abiertas. Las áreas completamente protegidas, al contrario, tienen más especies de peces y biomasa y están bien comprendidas, respaldadas y valoradas por el público. Este tipo de AMPs son percibidas como albergues de mejor vida marina y como en constante mejora con el tiempo al mantenerse en regla con los resultados ecológicos actuales. Los resultados de la conservación pueden mejorarse si se eleva a las áreas parcialmente protegidas a niveles más altos de protección incluyendo la conversión a áreas completamente protegidas.


Subject(s)
Ecosystem , Fisheries , Animals , Biomass , Conservation of Natural Resources , Fishes , South Australia
19.
J Environ Manage ; 279: 111529, 2021 Feb 01.
Article in English | MEDLINE | ID: mdl-33246754

ABSTRACT

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.


Subject(s)
Conservation of Natural Resources , Estuaries , Biodiversity , Fisheries , Humans , Recreation
20.
MethodsX ; 7: 101141, 2020.
Article in English | MEDLINE | ID: mdl-33294399

ABSTRACT

This method develops a local environmental stewardship indicator (LESI), which represents the level of stewardship action of a person at a place. The goal of the indicator is to quantify stewardship activity and allow it to be compared and modelled. LESI requires a brief interview to ascertain an individual's past and current stewardship activities, which are scored on a frequency scale for each of seven action categories. Scores are then combined using the LESI equation to: • Quantify reported stewardship behaviour (as opposed to attitudes or intentions) as a single number. • Enable comparisons of stewardship between individuals and places. • Allow development of models to understand the predictors of stewardship, and • Inform evidence-based strategies for stewardship improvement.

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