Abstract
Coastal seascapes are composed of a diversity of habitats that are linked in space and time by the movement of organisms. The context and configuration of coastal ecosystems shapes many ...important properties of animal assemblages, but potential seascape effects of natural and artificial habitats on nearby habitats are typically considered in isolation. We test whether, and how, the seascape context of natural and urban habitats modified fish assemblages across estuaries. Fish were sampled with underwater videos in five habitat types (mangroves, rock bars, log snags, unvegetated sediments, armoured shorelines) in 17 estuaries in eastern Australia. Different habitats supported distinct fish assemblages, but the spatial context of mangroves and armoured shorelines had pervasive ecological effects that extended across entire estuaries. In most estuarine habitats, fish diversity and abundance was greatest when they were in close proximity of mangroves, and decreased due to the proximity of armoured shorelines. Many cities are centred on estuaries, and urban expansion is often associated with the fragmentation of mangrove forests. Our findings emphasize that these transformations of urban estuarine landscapes are likely to propagate to broader ecological impacts detectable in multiple habitats beyond mangrove forests.
Seascape connectivity (landscape connectivity in the sea) can modify reserve performance in low‐energy marine ecosystems (e.g., coral reefs, mangroves, and seagrass), but it is not clear whether ...similar spatial linkages also shape reserve effectiveness on high‐energy, exposed coastlines. We used the surf zones of ocean beaches in eastern Australia as a model system to test how seascape connectivity and reserve attributes combine to shape conservation outcomes. Spatial patterns in fish assemblages were measured using baited remote underwater video stations in 12 marine reserves and 15 fished beaches across 2000 km of exposed coastline. Reserve performance was shaped by both the characteristics of reserves and the spatial properties of the coastal seascapes in which reserves were embedded. Number of fish species and abundance of harvested fishes were highest in surf‐zone reserves that encompassed >1.5 km of the surf zone; were located < 100 m to rocky headlands; and included pocket beaches in a heterogeneous seascape. Conservation outcomes for exposed coastlines may, therefore, be enhanced by prioritizing sufficiently large areas of seascapes that are strongly linked to abutting complementary habitats. Our findings have broader implications for coastal conservation planning. Empirical data to describe how the ecological features of high‐energy shorelines influence conservation outcomes are lacking, and we suggest that seascape connectivity may have similar ecological effects on reserve performance on both sheltered and exposed coastlines.
Efectos de la Conectividad de Paisajes Marinos sobre el Desempeño de las Reservas a lo largo de Costas Expuestas
Resumen
La conectividad entre paisajes marinos puede modificar el desempeño de las reservas en los ecosistemas marinos de baja energía (p. ej.: arrecifes de coral, manglares, pastos marinos), pero no está claro si las conexiones espaciales similares también moldean la efectividad de las reservas en costas expuestas con alta energía. Usamos las zonas de rompimiento de las playas oceánicas en el este de Australia como sistema modelo para probar cómo la conectividad entre paisajes marinos y los atributos de la reserva se combinan para moldear los resultados de la conservación. Los patrones espaciales en los ensamblados de peces se midieron con estaciones remotas de video subacuático con carnada en doce reservas marinas y 15 playas a lo largo de 2000 km de costas expuestas. El desempeño de las reservas estuvo moldeado por las características de las reservas y las propiedades espaciales de los paisajes costeros en los cuales estaban insertadas las reservas. El número de especies de peces y la abundancia de peces recolectados fue mucho mayor en las reservas en las zonas de rompimiento que abarcaban >1.5 km de la zona de rompimiento; estaban localizadas a <100 m de cabos rocosos; e incluían playas pequeñas entre los cabos en un paisaje marino heterogéneo. Los resultados de conservación para las costas expuestas pueden, por lo tanto, mejorarse con la priorización suficiente de grandes áreas de paisajes marinos que están conectados fuertemente con hábitats complementarios colindantes. Nuestros hallazgos tienen consecuencias más generales para la planeación de la conservación costera. Los datos empíricos para describir cómo las características ecológicas de las costas con alta energía influyen sobre los resultados de conservación son muy pocos, y sugerimos que la conectividad entre paisajes marinos puede tener efectos ecológicos similares sobre el desempeño de las reservas en costas expuestas y resguardadas.
摘要
海洋景观连接度会影响低能量的海洋生态系统 (如珊瑚礁、红树林、海草生态系统) 保护区的保护成效, 但目前尚不清楚高能量、裸露海岸线的保护区成效是否也受到类似空间关联的影响。我们以澳大利亚东部海滩的碎波区为模型, 分析了海洋景观连接度和保护区特性如何共同决定保护成效。我们利用 2000 公里裸露海岸线沿线的 12 个海洋保护区和 15 个钓鱼海滩的诱饵式远程水下视频监控位点, 测定了鱼类群落的空间格局。保护区的特性及其所在海岸线景观的空间特性共同影响着保护区成效。在含有超过 1.5 公里碎波带、距离多岩石的海角不足 100 米, 或是在异质性景观中含有小海滩的碎波带保护区中, 鱼类物种数和渔获量最高。因此, 优先保护那些与毗邻的互补生境紧密相连, 且面积足够大的海洋景观, 可以提高裸露海岸线的保护成效。我们的研究结果对海岸带的保护规划有广泛的意义。目前, 描述高能量海岸线的生态学特性如何影响保护成效的数据仍十分缺乏, 我们提出, 海洋景观连接度对受保护和未受保护海岸线可能有相似的生态学影响并决定保护区的保护成效。【翻译: 胡怡思; 审校: 聂永刚】
Article impact statement: Conservation along exposed coastlines may be enhanced by prioritizing large seascapes that are strongly linked to abutting complementary areas.
Coastal salt marshes are distributed widely across the globe and are considered essential habitat for many fish and crustacean species. Yet, the literature on fishery support by salt marshes has ...largely been based on a few geographically distinct model systems, and as a result, inadequately captures the hierarchical nature of salt marsh pattern, process, and variation across space and time. A better understanding of geographic variation and drivers of commonalities and differences across salt marsh systems is essential to informing future management practices. Here, we address the key drivers of geographic variation in salt marshes: hydroperiod, seascape configuration, geomorphology, climatic region, sediment supply and riverine input, salinity, vegetation composition, and human activities. Future efforts to manage, conserve, and restore these habitats will require consideration of how environmental drivers within marshes affect the overall structure and subsequent function for fisheries species. We propose a future research agenda that provides both the consistent collection and reporting of sources of variation in small-scale studies and collaborative networks running parallel studies across large scales and geographically distinct locations to provide analogous information for data poor locations. These comparisons are needed to identify and prioritize restoration or conservation efforts, identify sources of variation among regions, and best manage fisheries and food resources across the globe.
Whether and how landscape context and habitat traits combine to shape animal assemblages and the rate and distribution of ecological functions remains unresolved in many aquatic settings. Saltmarshes ...are one such ecosystem in which these considerations are frequently acknowledged as important, but quantitative studies of these effects are rare, especially for ecological functions. In this study, the influence of landscape configuration and habitat traits on the composition of fish assemblages and rates of predation were quantified around 30 saltmarshes in three estuaries (i.e., 10 per estuary) in eastern Australia. Fish assemblages were surveyed using unbaited underwater video cameras, and predation was quantified using videoed “Squidpop” predation assays at 10 sites at each saltmarsh. The structure of fish assemblages was best explained by the estuary in which saltmarsh was located, the proximity of sites to estuary mouth, and the area of nearby saltmarsh and mangroves. Predation was dominated (90% of total predation events) by yellowfin bream
Acanthopagrus australis
(Sparidae), and so rates of predation correlated positively with yellowfin bream abundance. Predation peaked in the lower reaches of estuaries at saltmarshes with lower vegetation cover. These findings suggest that the mouths of estuaries might function as key transition zones that concentrate prey, the products of trophic relay, and the ecological effects of predators near the estuarine-sea interface.
Species surrogates, the use of particular species to index habitat condition or to represent ecological assemblages are commonly identified in many ecosystems, but are less tested, and therefore less ...employed in estuaries. Estuaries provide important ecosystem goods (e.g. harvestable species) and services (e.g. carbon processing, coastal armouring), but require protection from multiple human activities, meaning that finding surrogates for estuarine condition or faunal assemblages is a significant knowledge gap. In this study, we test the efficacy of the threatened estuary ray Hemitrygon fluviorum, as a suitable indicator of ecosystem condition and management umbrella surrogate species for conservation prioritisation and monitoring purposes within estuaries. We surveyed fish assemblages and ray presence at ten sites within each of 22 estuaries in southeast Queensland, Australia, using one hour deployments of baited video arrays. We then tested for correlations between ray presence, a series of environmental variables considered important to ecosystem management within estuaries (i.e. testing rays as indicator species), and the co-occurring fish species (i.e. testing rays as umbrella species). Estuary rays function as both umbrella species and ecological indicators of habitat status in subtropical Australian estuaries. As umbrellas, ray occurrence concords with elevated species richness. As ecological indicators, ray distribution concords with habitats of good water quality (especially low turbidity) and more natural vegetation remaining in the catchment. These results highlight the potential for other threatened aquatic vertebrates that are both readily detectable and that are reliable proxies for ecosystems status to be become useful management tools in estuaries. The protection of such large, threatened species in coastal seascapes allows managers to address multiple targets for conservation, especially; (1) protecting species of conservation concern; (2) maintaining diversity; and (3) protecting optimal habitats by better placing reserves.
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Ecosystem functioning is positively linked to biodiversity on land and in the sea. In high‐diversity systems (e.g. coral reefs), species coexist by sharing resources and providing similar functions ...at different temporal or spatial scales. How species combine to deliver the ecological function they provide is pivotal for maintaining the structure, functioning and resilience of some ecosystems, but the significance of this is rarely examined in low‐diversity systems such as estuaries.
We tested whether an ecological function is shaped by biodiversity in a low‐diversity ecosystem by measuring the consumption of carrion by estuarine scavengers. Carrion (e.g. decaying animal flesh) is opportunistically fed on by a large number of species across numerous ecosystems. Estuaries were chosen as the model system because carrion consumption is a pivotal ecological function in coastal seascapes, and estuaries are thought to support diverse scavenger assemblages, which are modified by changes in water quality and the urbanization of estuarine shorelines.
We used baited underwater video arrays to record scavengers and measure the rate at which carrion was consumed by fish in 39 estuaries across 1,000 km of coastline in eastern Australia.
Carrion consumption was positively correlated with the abundance of only one species, yellowfin bream Acanthopagrus australis, which consumed 58% of all deployed carrion. The consumption of carrion by yellowfin bream was greatest in urban estuaries with moderately hardened shorelines (20%–60%) and relatively large subtidal rock bars (>0.1 km2).
Our findings demonstrate that an ecological function can be maintained across estuarine seascapes despite both limited redundancy (i.e. dominated by one species) and complementarity (i.e. there is no spatial context where the function is delivered significantly when yellowfin bream are not present) in the functional traits of animal assemblages. The continued functioning of estuaries, and other low‐diversity ecosystems, might therefore not be tightly linked to biodiversity, and we suggest that the preservation of functionally dominant species that maintain functions in these systems could help to improve conservation outcomes for coastal seascapes.
The authors have highlighted, for the first time in coastal ecosystems, that ecological functions can be maintained across estuarine seascapes despite both limited redundancy and complementarity in the functional traits of animal assemblages. The continued functioning of estuaries, and other low‐diversity ecosystems, might therefore not be tightly linked to biodiversity.
The JAK2 V617F mutation can be found in patients with polycythemia vera, essential thrombocythemia and idiopathic myelofibrosis. Mutation or methylation of other components of JAK/STAT signaling, ...such as the negative regulators suppressor of cytokine signaling 1 (SOCS1) and SOCS3, may contribute to the pathogenesis of both JAK2 V617F positive and negative myeloproliferative disorders.
A cohort of patients with myeloproliferative disorders was assessed for acquired mutations, aberrant expression and/or CpG island hypermethylation of SOCS1 and SOCS3.
No mutations were identified within the coding region of either gene in 73 patients with myeloproliferative disorders. No disease-specific CpG island methylation of SOCS1 was observed. SOCS1 expression was raised in myeloproliferative disorder granulocytes but the level was independent of JAK2 V617F status. Hypermethylation of the SOCS3 promoter was identified in 16 of 50 (32%) patients with idiopathic myelofibrosis but not in patients with essential thrombocythemia, polycythemia vera or myelofibrosis preceded by another myeloproliferative disorder. Confirmation of methylation status was validated by nested polymerase chain reaction and/or bisulphite sequencing. SOCS3 transcript levels were highest in patients with polycythemia vera and other JAK2 V617F positive myeloproliferative disorders, consistent with SOCS3 being a target gene of JAK2/STAT5 signaling. There was a trend towards an association between SOCS3 methylation and lower SOCS3 expression in JAK2 V617F negative patients with idiopathic myelofibrosis but not in JAK2 V617F positive ones. Finally, SOCS3 methylation was not significantly correlated with survival or other clinical variables.
SOCS3 promoter methylation was detected in 32% of patients with idiopathic myelofibrosis suggesting a possible role for SOCS3 methylation in this disorder. The pathogenetic consequences of SOCS3 methylation in idiopathic myelofibrosis remain to be fully elucidated.
Investigations into how ecotourist resorts and their visitors impact local ecosystems and their wildlife have produced mixed results. One characteristic of ecotourist infrastructure is anthropogenic ...noise, and especially how fluctuations of visitors contribute to it. Furthermore, we do not understand how these noise levels influence animal species richness and/or assemblages. Here, we used passive acoustic recording over nine months to quantify how variation in weekly and seasonal human activity influence local bird assemblages at a popular ecotourist resort situated on K'gari (Fraser Island), Australia, a UNESCO World Heritage site and an Important Bird Area (Birdlife International). Background noise levels were highest during peak tourist season, especially proximate to main buildings. This noise was primarily associated with machinery and vehicles, but not human voices or music. Bird species richness correlated with noise (levels and detections), but did not appear to be sensitive to peak seasons or human voices. Community composition, however, was influenced by temporal and spatial fluctuations across peak tourist seasons. This study has implications for the development and maintenance of ecotourist infrastructure attempting to support visitors seeking sightings of rare or sensitive bird species and highlights anthropogenic noise as an important consideration for the industry.
Introduced species may suppress or enhance ecological functions, or they may have neutral effects in ecosystems where they replace or complement native species. Few studies, however, have explicitly ...tested for these trajectories, and for the effect these might have for native species. In this study, we experimentally test the trajectory and scale of change in the function of ‘carrion removal’ at different carrion loads along ocean beaches in Eastern Australia that have different numbers of introduced red foxes (Vulpes vulpes) and several species of native raptors. We hypothesized that the ‘positive’ effect of foxes on carrion removal would be greatest at high carrion loads, because competition for resources between native and introduced species is lower. Scavenger abundance, fox occurrences, and carrion consumption by these species differed widely between locations and times. Despite distinct spatial differences in the structure of vertebrate scavenger assemblages, total carrion consumption was not significantly different between locations at any carrion load. This lack of variation in functional rates indicates potential functional plasticity in the scavenger assemblage and possible functional accommodation of red foxes. Neutral fox effects on ecological functions or the ecosystem more broadly are, however, very unlikely to extend beyond carrion consumption.
Aim: Disturbance and connectivity shape the structure and spatial distribution of animal populations in all ecosystems, but the combined effects of these factors are rarely measured in coastal ...seascapes. We used surf zones of exposed sandy beaches in eastern Australia as a model seascape to test for combined effects of coastal urbanization and seascape connectivity (i.e. spatial links between surf zones, estuaries and rocky headlands) on fish assemblages. Location: Four hundred kilometres of exposed surf beaches along the eastern coastline of Australia. Methods: Fish assemblages were surveyed from surf zones of 14 ocean-exposed sandy beaches using purpose-built surf baited remote underwater video stations. Results: The degree of coastal urbanization and connectivity were strongly correlated with the spatial distribution of fish species richness and abundance and were of greater importance to surf fishes than local surf conditions. Urbanization was associated with reductions in the abundance of harvested piscivores and fish species richness. Piscivore abundance and species richness were lowest on highly urbanized coastlines, and adjacent to beaches in wilderness areas where recreational fishing is intense. By contrast, seascape connectivity was correlated with the spatial distribution of omnivore and planktivore abundance. Spatial linkages between surf zones and estuaries were also important to two globally threatened guitarfish that are of international conservation significance. Main conclusions: We show for the first time how vulnerable and iconic fish species in surf zones are affected by the presence of coastal cities and the attributes of seascapes in which these cities are embedded. It is possible that greater connectivity may lessen 'Urbanization' impacts for species with broad diets and strong ecological links to other ecosystems – this offers new perspectives in coastal conservation, for fishes and beyond.
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