Marine and Freshwater Research
Volume 68 Number 12 2017
MF17012Assessment of rivers as social–ecological systems: a response to ‘The imperative need for nationally coordinated bioassessment of rivers and streams’, by Susan J. Nichols et al.
In a recent paper in Marine and Freshwater Research, Nichols et al. called for a reinvestment in national-scale bioassessment in Australia. We agree that the absence of national-scale bioassessment impedes the ability to detect slow-acting impacts such as climate and land-use change. We argue that a reinvigorated national program should go beyond bioassessment and assess river resilience, including the social and ecological parameters that influence river health.
Scarcity of iron limits phytoplankton growth in approximately two-thirds of the world’s oceans. Hydrothermal plumes have recently gained recognition as a long-range source of iron to the deep oceans that, importantly, may also affect surface ocean phytoplankton growth in some regions. This review brings into focus current understanding of hydrothermal systems and their contribution to the global oceanic iron budget.
MF16083Assessing the water-purification service in an integrated agricultural wetland within the Venetian Lagoon drainage system
Constructed wetlands could play a crucial role in integrated agro-environmental management of intensive agricultural landscapes. An experimental wetland was created within the Venetian drainage system to reduce nutrient runoff and test the adaptability of seven macrophyte species in a floating treatment wetland system. A promising depurative effect emerges from the concentration trends throughout the system. Carex spp. adapted best to the floating wetlands.
MF17051Grass carp (Ctenopharyngodon idella) translocations, including hitchhiker introductions, alter zooplankton communities in receiving ponds
Reducing invasion rates of aquatic species is an important conservation concern. In this study we investigated whether zooplankton assemblages in ponds subject to fish releases from aquaculture facilities are affected by ‘hitchhiking’ species from these farms, and found differences between ponds with and without carp releases. Management is required to prevent unintentional introductions of invertebrate from aquaculture facilities from which fish are released.
MF16247Hydrographic characteristics and community structure of epipelagic mesozooplankton in the Dongsha (Pratas) Atoll, South China Sea
Zooplankton play an important role in transferring energy from primary producers to upper trophic levels. By investigating epipelagic mesozooplankton community and hydrographic features of the Dongsha Atoll, we found that temporal pattern of mesozooplankton community is likely to be more dependent on physical variable than on primary production due to the semi-enclosed topography. Abundant decapod larvae and fish eggs confirmed the importance of the pelagic–benthic coupling in the tropical reef ecosystem.
MF17038Ecological and behavioural traits of the Sri Lankan water monitor (Varanus salvator) in an urban landscape of Western Province, Sri Lanka
The Asian water monitor is widespread on the island of Sri Lanka. The present study was a 7-month survey within a 5-km stretch at an urban riverscape in Sri Lanka. The most monitor sightings were made in aquatic habitats. Given variable sighting frequencies of distinct life history stages across different major habitat types, it is likely that there is substantial age-structured niche partitioning among these monitors.
MF16372Sediment accretion and accumulation of P, N and organic C in depressional wetlands of three ecoregions of the United States
Atmospheric nuclear testing added the radioisotope caesium-137 to the global environment. We sampled depressional wetland soils across three regions of the United States (Southeast, Atlantic Coast, and Midwest) and quantified accumulated sediment, carbon, nitrogen and phosphorus compounds in wetland soil since ‘peak caesium’ deposition in 1964. Substantial accumulation occurred, with only phosphorus differing by region. Depressional wetland management is, thus, important for landscape-scale sediment, nutrient and carbon dynamics.
MF16346Effects of aeration, sediment grain size and burial on stream litter breakdown and consumer performance: a microcosm study
Reduced turbulence and aeration can affect stream ecosystems, but their effects can differ from the surface to subsurface habitats, and depend, among other things, on sediment size and the availability of organic matter (OM). A microcosm experiment showed that lack of aeration reduced OM consumption, especially on the surface, and sediment size caused differences in performance between the two invertebrate species studied, namely mayfly (Habroleptoides) and stonefly (Capnioneura).
MF16375Ontogenetic shifts in habitat use during the dry season by an amphidromous shrimp in a tropical lowland river
The present study examined the dry-season meso-habitat use by the amphidromous shrimp species, Macrobrachium spinipes, in northern Australia. We found that habitat use changed considerably first, with ontogeny, and, second, with the annual colonisation of habitats with algae and macrophytes as the dry season progressed. The study has provided significant insights into the changes in use of key riverine habitats throughout the dry season by an ecologically important species
Hydrodynamics drive the export of estuarine-derived primary production and nutrients to adjacent, less-productive offshore waters. The present study quantified estuary-to-coast fluxes of detritus and nutrients by sampling the water at the mouth of a small temperate estuary. These types of studies are important to determine the ecosystem services provided by temperate estuaries.
Conventional river models typically ignore the effects of groundwater-storage change on river flow, and, hence, predicted declines in river low flows during drought periods are likely to be compromised. The present study undertakes statistical analysis of low flows in the Namoi River, and highlights implications for river modelling more broadly. The results showed the importance of adopting models that explicitly account for groundwater processes when modelling such river systems.
MF16387Lake and species specific patterns of non-diadromous recruitment in amphidromous fish: the importance of local recruitment and habitat requirements
Amphidromous fish live and spawn in streams, but are widely believed to have an oceanic larval period, resulting in wide dispersal and connective populations. In this study we show that when an alternative larval habitat (i.e. a lake or wetland) is present, freshwater larval rearing is the dominant process sustaining many populations. The retention of larvae in lakes has implications for the dispersal, connectivity and management of amphidromous fish.
Climate change modified the spatial distribution of two sympatric Mediterranean fishes. Does this change have indirect effects on trophic niches and trophic interactions between the two species of fish? The two species have different trophic niches and do not interact for food, regardless of forcing of climate change.
MF16424Determining groundwater dependence of the Cooloola Patterned Fens in south-eastern Queensland, and threats posed by groundwater extraction
The Cooloola Patterned Fens are a unique wetland in south-eastern Queensland and are potentially at risk from water extraction for the nearby town. Statistical analysis of regional water-chemistry data was used to determine the groundwater source that the ecosystem depends on. The fens were found to use perched aquifer water, whereas local creeks are connected to the deeper regional aquifer.
MF16259Multisource data for seasonal variability analysis of cyanobacteria in a tropical inland aquatic environment
In this study we investigated the behaviour of cyanobacteria by determining phycocyanin and chlorophyll concentrations using spectroradiometric and fluorometric data. The spectral analyses could only detect phycocyanin at higher concentrations. For lower concentrations, phycocyanin was detected from fluorometric measurements. Therefore, remote sensing complemented by fluorometric analysis seems an effective method for monitoring cyanobacteria in Brazilian inland waters.
MF17023Patterns of dissolved organic matter across the Patagonian landscape: a broad-scale survey of Chilean and Argentine lakes
The concentration and optical properties of dissolved organic matter (DOM) of lakes provide clues as to the water sources and in-lake microbial and photochemical processes. The present study is the first broad-scale survey of DOM from Patagonian lakes (Chile and Argentina) across a strong west–east precipitation gradient. We conclude that this set of lakes provides a convenient observational system to investigate the effects of contemporary climate change.
Mangroves are one of the most widely distributed types of plants that grow along the coast of Australia. Low winter temperatures and frost are thought to limit the stature and productivity of mangroves in Victoria. Because air and water temperatures will increase markedly over coming decades, it is likely that Victorian mangroves will be among the first plant communities to be noticeably affected by climate change in coastal south-eastern Australia.
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MF17006A multiscale, hierarchical, ecoregional and floristic classification of arid and semi-arid ephemeral wetlands in New South Wales, Australia
Using a two-step statistically based, hierarchical, multiscaled approach to the floristic classification of ephemeral wetlands within western New South Wales, Australia, we define three ecoregions and 18 vegetation groups. Our approach shows that a consistent objective classification can be derived for vegetation systems with good data within regions that are otherwise poorly sampled.
Dissolved oxygen depletion is a rising concern in global aquatic ecosystems. In this study we used high-resolution, multiyear observations of a coastal environment to show prolonged periods of anoxia, with rare re-oxygenation events being caused by unusual combinations of climatic and oceanographic conditions. These findings highlight that dissolved oxygen dynamics in coastal habitats may be modified by climate-driven environmental change.
MF17130Examining trends in abundance of an overexploited elasmobranch species in a nursery area closure
This study compared recent and historic longline catch rates to determine whether juvenile school shark (Galeorhinus galeus) continue to use nursery areas closed to fishing in south-eastern Australia, following overfishing during the 1940s and 1950s. Our data suggest that abundances in the nursery areas may have increased, or at least remained stable, since the 1990s, which may be indicative of some stock recovery.
Thallium (Tl) is a highly toxic heavy metal, although the mechanisms underlying its toxicity are not completely understood. In this study we investigated the physiological responses of giant reed Arundo donax to Tl accumulation in a simulated wetland. The giant reed had strong tolerance to Tl pollution, and this can probably be attributed to its root rejection and amelioration of oxidative stress, which are involved in the mechanism of Tl toxicity.
MF17226Have droughts and increased water extraction from the Murray River (Australia) reduced coastal ocean productivity?
The study investigated the effect of Murray River outflows on the coastal ocean productivity beyond the Murray Mouth. Using historical flow records and satellite-imagery products, our findings suggested that declining river flows have greatly reduced coastal ocean primary productivity. There are likely to be negative consequences of this on coastal ecosystems and fisheries, and the effects of outflows warrant improved consideration in river-management plans.
Mangroves in Kakadu National Park in Australia’s Northern Territory have undergone significant changes, occupying much of the lowlands c. 6000 years ago, but are now confined to the river margins and islands. Recent observations from satellite and aircraft have indicated that fluctuations in sea level exert a significant effect on the distribution of mangroves, with a drop in the sea level from 2015 to 2016 contributing to unprecedented dieback on the landward margins.
MF17233Reef fish at a remote tropical island (Principe Island, Gulf of Guinea): disentangling taxonomic, functional and phylogenetic diversity patterns with depth
Biodiversity is a multifaceted concept. Patterns of the taxonomic, functional and phylogenetic diversity of fish were studied across a depth gradient from 3 to 31 m. The results demonstrated decays in biodiversity, from different perspectives, of reef fish with depth, which are connected with shifts in fish traits, in particular their shape and trophic mode.
MF17135Sex-specific differences in growth, mortality and migration support population resilience in the heavily exploited migratory marine teleost Mugil cephalus (Linnaeus 1758)
The sea mullet Mugil cephalus is a commercially important species globally and within Australia. The eastern Australian stock of sea mullet has a long history of heavy exploitation during its annual northerly spawning migration, yet the fishery is sustainable. Here we propose a model whereby sex-specific differences in life history and biological parameters contribute to population resilience and so support a sustainable commercial fishery.
MF17118Wetlands in the Jiuzhaigou World Natural Heritage site of south-west China: classification and recent changes
Identification and understanding of human-induced wetland changes is critical for wise wetland use. This study investigated wetland changes in a rare wetland system in a popular tourist destination visited by >5 million people per year. The high number of tourists and their movement in buses have probably caused water-related changes. Determining the appropriate number of visitors is crucial for the wise use of wetlands that are tourist destinations.
MF17177Interspecific correlation between exotic and native plants under artificial wetland forests on the Dianchi lakeside, south-west China
Interspecific relationships were analysed using the Chi-Square test, Spearman rank correlation coefficient and Ward’s method of hierarchical clustering on field data collected from 4 plots and 160 quadrats. The results imply that exotic species can coexist with native species and become a common species composition when they have existed for a sufficient period of time in artificial wetland forests.
Concentrations of rare earth elements (REEs) in freshwater environments are rising, but very little information is available regarding the accumulation and toxicity of REEs. Aquatic plants are known to accumulate and bioconcentrate metals. The aim of the present study was to explore the molecular distribution and assess the toxicity of yttrium in Elodea canadensis. The results indicate that Y accumulation occurred along a gradient, with the highest accumulation in cell walls, and that Y accumulation destroyed organelles and damaged the antioxidant system. This work suggests that metabolic parameters appear to be promising biomonitors of Y toxicity in aquatic plants.
MF17120Carbon sequestration and its controlling factors in the temperate wetland communities along the Bohai Sea, China
Carbon sequestration rates (CSRs) and their controlling factors were determined in the Yellow River delta (YRD) and Liaohe delta (LHD) wetlands. Organic CSRs at sites above mean sea level were virtually identical in the two wetlands, but organic CSRs were much more sensitive to changes in sediment accumulation rates in the LHD wetlands than in the YRD wetlands.
MF17119Wetlands classification and assessment of Ramsar sites in China based on time series Moderate Resolution Imaging Spectroradiometer (MODIS) imagery
Satellite image time series (Moderate Resolution Imaging Spectroradiometer, MODIS) data collected in 2001 and 2013 were used to monitor the long-term environmental changes in 20 Ramsar sites in China. The tremendous efforts of the Chinese government contributed to effective protection for most reserves. However, unfavourable environmental conditions for some reserves still existed, primarily due to increasing water requirements outside the reserves. Therefore, a balance between economic development and ecological protection will be important in the future.
MF17079Variation in climate determines differences in the effects of abiotic variables on the phytoplankton community in tropical ecosystems
Experiments were conducted to evaluate the effects of abiotic variables on phytoplankton in tropical and semi-arid climates. Climate was found to determine the effects of abiotic variables on the phytoplankton community in both an independent and synergistic manner. Phytoplankton in tropical and semi-arid reservoirs are mostly regulated by nutrients, the effects of which vary according to climate.
MF17104Quantitative prediction and typical factor effects of phosphorus adsorption on the surface sediments from the intertidal zones of the Yellow River Delta, China
This study systematically investigated the characteristics of P adsorption on the sediments of the intertidal zones in the Yellow River Delta. Salinity, pH and oxidation–reduction potential significantly affected the adsorption rate and amount of P adsorbed on the sediments in these zones. In addition, a predictive model for the P-adsorption capacity of sediments was developed. Together, the results could contribute to the restoration and management of intertidal zones.
MF17140Reconstructing Western Australian white shark (Carcharodon carcharias) catches based on interviews with fishers
Historical and contemporary levels of white shark bycatch are unknown. Based on interviews with commercial fishers, the catch of white sharks off Western Australia was reconstructed, with the results suggesting that the catch peaked in the late 1980s. Fishers expressed doubts about the accuracy of self-reported white shark catch data, a requirement of current legislation. Efforts to accurately record this information should be improved.
MF17043An integrated risk-assessment framework for multiple threats to floodplain values in the Kakadu Region, Australia, under a changing climate
The floodplains of the Kakadu Region, world-renowned for their natural and cultural values, are threatened by invasive species and future sea-level rise. A risk assessment that integrates both threats to multiple values out to 2100 was undertaken, and suggested that floodplains will likely transform to marine-dominated ecosystems that cannot be managed back to previous conditions. The study highlighted the importance of freshwater refugia because both their value and vulnerability will increase over time.
MF17103Role of environmental and spatial processes structuring fish assemblages in streams of the eastern Amazon
The roles of environment and space in stream fish assemblages were evaluated in distinct hydrological periods in the eastern Amazon. The results indicate that spatial and environmental factors play complementary roles, and that diversity was affected by changes in the habitat connectivity experienced in different hydrological periods.
MF17096Response of demersal fish assemblages to an extreme flood event in a freshwater-deprived estuary in South Africa
A large flood (436.6 m3 s–1) that occurred in the freshwater-deprived Kariega Estuary resulted in a normal longitudinal salinity gradient being present throughout the study period (December 2013–November 2014). This resulted in an increase in the abundance of early juvenile estuarine-associated marine fish, particularly in the middle and upper reaches, which was linked to an increase in nutrients and food availability, as well as increased nursery habitats.
Eels have been remotely tracked in their freshwater, brackish and marine habitats for five decades to understand the extent of their migrations and to ensure the conservation of these enigmatic species. Herein we review 105 studies that tracked eels and summarise findings relative to the species, life history stages and habitats studied. In addition, we discuss the need for continued development of telemetry technology and future research directions in eel biology.
MF17195Seasonality, sex ratio, spawning frequency and sexual maturity of the opakapaka Pristipomoides filamentosus (Perciformes: Lutjanidae) from the Main Hawaiian Islands: fundamental input to size-at-retention regulations
Pristipomoides filamentosus, a long-lived deep-water eteline snapper, is an economically important component of commercial and recreational fisheries throughout much of the Indo-Pacific region. This study provides the first sex-specific, histologically validated estimates of size at maturity for P. filamentosus in the Main Hawaiian Islands or elsewhere. Estimates are compared with those previously derived for the species using non-histological methods, and suggestions for re-evaluating minimum legal size regulations for fisheries of the species in Hawaii are included.
MF17016Sexual development and demography of the rock hind Epinephelus adscensionis, a protogynous grouper, in the south-west Atlantic
The rock hind is a medium-sized Atlantic reef grouper exploited by fisheries; it represents an important resource for small and medium-scale fisheries along the coast of Brazil. This study reports on the pattern of sexual development and demography of a protogynous species on the north-east coast of Brazil. A lack of fisheries management endangers the future sustainability of fisheries for this and other hermaphroditic species of groupers that otherwise may suffer declines similar to those observed for larger species.
Rezoning of Moreton Bay Marine Park increased the no-take area from 0.5 to 16%, incorporating 10% of each major habitat type. Displacement of fishing effort was 6.3%, demonstrating that science-based conservation and community consultation can protect biodiverse habitats, while maintaining existing uses of a marine park. However, achieving biodiversity conservation must rely on ensuring no-take zones adequately represent ecological processes.
MF17110Scale deformity descriptions for 23 species of fish, from various geographical areas and habitats
In this study, 63 cases of deformities were reported from 23 fish species collected from five countries. The observed abnormalities are discussed within the framework of contaminated aquatic environments, with a goal of recognising the cause of abnormality. There were 52 cases of slight and 9 of severe scale anomalies. The results of this study should assist in future work on the environmental condition.
MF16388Reproduction and embryo viability of a range-limited tropical freshwater fish exposed to fluctuating hypoxia
Hypoxia can profoundly affect fish reproduction and larval development, but its effects on fish from tropical Australia are not well understood. In the study, the effects of diel fluctuating hypoxia on reproduction were identified for a range-limited tropical freshwater fish. Utchee Creek rainbowfish appear to be more hypoxia tolerant than many temperate species, but are still susceptible to the increasing frequency and intensity of hypoxia that may occur as a result of climate change.
This study provides insights into nekton communities as possible indicators of habitat functionality in planted mangroves. The community structure of nekton was compared between planted and natural mangrove stands (as a reference trajectory). Nekton assemblage in general (especially fish species) is not a reliable restoration indicator because it is not entirely dependent on mangroves. Crustaceans demonstrated more dependency on habitat structural complexity and food offered by mangroves.
MF17102Importance of free-living and particle-associated bacteria for the growth of the harmful dinoflagellate Prorocentrum minimum: evidence in culture stages
The present study is the first to investigate the bacterial communities associated with the harmful dinoflagellate Prorocentrum minimum using a pyrosequencing assay. Throughout the study, particle-associated (PA) and free-living (FL) bacterial communities were significantly associated with the growth phases of P. minimum. Although the FL and PA bacterial communities differed significantly, Roseobacter and Marinobacter clades showed a close association with the growth of P. minimum in both communities.
MF16290Does the reintroduction of large wood in a large dryland river system benefit fish assemblages at the reach scale?
This study assesses the effect of reintroducing large wood on fish assemblages along the Barwon-Darling River, Australia. Results demonstrate that reintroducing large wood had limited influence on fish. It is hypothesised the lack of a detectable response by fish was because the physical character and position of the reintroduced wood pieces didn’t replicate ‘natural’ reference conditions.
MF17156Nitrogen removal during the cold season by constructed floating wetlands planted with Oenanthe javanica
The present study shows that a constructed floating wetlands (CFWs) system planted with Chinese celery (Oenanthe javanica) is a viable option for nitrogen removal from waste water during the low-temperature season (mean water temperature <10°C) and that nitrogen removal is better from CFW systems with vesuvianite as a substrate than from those without a substrate.
MF17133Water quality affects the structure of copepod assemblages along the Sfax southern coast (Tunisia, southern Mediterranean Sea)
Copepod species diversity along the southern coastline of Sfax, Tunisia, depends on anthropogenic inputs. Oithona nana, Paracalanus parvus, Harpacticus littoralis and Tisbe battagliai were spread along the coast and were more adapted to coastal anthropogenic inputs. The Shannon–Wiener index, H′, was higher in the southern, less affected, stations than in the northern stations, which were affected by sewage to a greater extent.
MF17018Feeding ecology of the piked spurdog Squalus megalops (Chondrichthyes: Squalidae) in the Gulf of Gabès (central Mediterranean Sea)
Analysis of the stomach contents of the 630 Squalus megalops examined in the Gulf of Gabès (Tunisia) showed that the species consumed teleosts, cephalopods and crustaceans. Significant differences in the diet related to size, season and sex were noted. Trophic position and quantitative analysis revealed that the species is a secondary consumer and a generalist feeder.
This paper provides a description and evaluation of a retrieval pod that can be attached to remote release underwater telemetric or oceanographic devices to facilitate the retrieval of moorings. The system was successfully tested in an estuary after consecutive 6-month deployments. The pods are a convenient and low-cost option for the retrieval of moorings deployed with remote release systems.
MF17030Characterisation and monitoring of one of the world's most valuable ecotourism animals, the southern stingray at Stingray City, Grand Cayman
Over 30 years of provisioning has led to a predictable aggregation of southern stingrays in Grand Cayman, which is visited by over one million people annually. Despite the economic importance of this aggregation, there had never been a formal assessment of the aggregation. Using previous tagging data and structured censuses, we describe the dynamics of this popular wildlife tourism destination.
MF17173Is climate change driving recruitment failure in Australian bass Macquaria novemaculeata in southern latitudes of the species range?
The Australian bass is a long-lived native fish. Little is known of the timing of flows important for recruitment of the species in the south of its range. We found recruitment was related to high flows in spring and increasing water temperatures at the time. Lower rainfall and higher temperatures in the region may result in prolonged periods of recruitment failure over the medium to longer term.
MF17139Successful mangrove establishment along an artificially created tidal creek at Port Hedland, Western Australia
Mangrove seedlings planted along an artificial tidal creek at Port Hedland, Australia, showed 18% survival after 3 years. Large numbers of seedlings had recruited naturally into the site. Seedling survival was affected by tidal elevation, but not by creek bank design or erosion protection. Given the right environmental conditions, mangroves will re-establish naturally, although recovery may take >10 years in this semi-arid region.
Because predation risk and food quality are crucial in ecological communities, it is important to understand their combined effects to freshwater invertebrates, namely aquatic insect larvae, which are considered important links in freshwater food webs. Leaf decomposition decreased under predator presence, impairing insect larvae growth, this effect being exacerbated when Eucalyptus globulus, a widespread invasive species, was given as a food source.
During a routine environmental monitoring in the Bahía Blanca Estuary, a temperate and eutrophic ecosystem on the Argentine coast, a parasitic infection was documented on phytoplankton. The host-specific infection on diatoms co-occurred with an extreme precipitation period in the region. Afterwards, the phytoplankton composition and size structure shifted towards dominance of smaller species.
MF16166Understanding climate-change adaptation on Kakadu National Park, using a combined diagnostic and modelling framework: a case study at Yellow Water wetland
We have developed an approach to assess sea-level rise effects on socio-ecological systems, using Yellow Water wetland on Kakadu National Park as a case study. Sea-level rise will cause profound changes in the Park, but it may also provide an opportunity to bring together Indigenous and non-Indigenous knowledge towards a commonly perceived threat. Strategies that facilitate Indigenous people’s participation in research and monitoring programs are needed to improve understanding of impacts and enhance adaptive capacity.
Distance decay was used as a descriptor of the compositional variation in diatom community similarity over six reservoirs (São Paulo, Brazil). Similarity decreased with distance between habitats and seasons, but the results were not statistically significant for surface sediment assemblages. Diatom communities were controlled more by limited dispersal, probably as a result of the water quality and scale of the study area.
MF16360Muscle and carapace tissue–diet isotope discrimination factors for the freshwater crayfish Cherax destructor
This study has increased our understanding of how isotopes of carbon and nitrogen are incorporated into different tissues of consumers within a freshwater food chain. The study identified that isotopic ratios of these elements vary significantly between tissues, but strong correlations between muscle and shell suggest that the shell can be used as an alternative for muscle in certain circumstances.
MF16355Use of epidermal mucus in elasmobranch stable isotope studies: a pilot study using the giant manta ray (Manta birostris)
This is the first study to investigate mucus as a potential new and useful material in elasmobranch dietary studies using stable isotope analysis. Mucus collected from giant manta rays was indicative of a broader short-term diet during aggregation periods in Ecuador, in comparison to muscle, which suggested long-term diet is more conservative. Both mucus and muscle support that giant manta rays predominately feed on zooplankton at a secondary consumer trophic level.
MF17126Cold fins, murky waters and the moon: what affects shark catches in the bather-protection program of KwaZulu–Natal, South Africa?
The influence of environmental variables on shark catch in the bather-protection program along the South African East Coast was investigated for 11 species. Results suggested that measurable, predictable relationships exist between environmental conditions and presence and, consequently, catch of shark species in this program. Understanding these relationships could be useful to mitigate against unwanted catch and to further reduce risk for bathers.
MF17020Influence of the water quality on the occurrence of the Neotropical otter (Lontra longicaudis) (Olfers, 1818) in a human-altered river basin
The degradation of freshwater ecosystems is a threat to biodiversity. We evaluated the influence of water quality on the occurrence of a threatened mammal, the Neotropical otter in a river basin under different degradation levels. We found the Neotropical otter to be tolerant to human-altered environments; however, beyond a certain threshold of water-quality degradation, its persistence is at risk.
MF17005Diversity patterns of subterranean invertebrate fauna in calcretes of the Yilgarn Region, Western Australia
Invertebrate diversity in subterranean groundwater calcretes of central Western Australia is influenced by periodic rainfall events. After rainfall, taxonomic richness in boreholes increased, as shown by an 11-year survey. Taxonomic groups such as small crustaceans (copepods, amphipods) and dytiscid beetles were the common groups, increasing in numbers during these rainfall periods. An understanding of invertebrate diversity patterns and how they vary temporally will provide information for the management of these groundwater ecosystems.
MF16329Are Pacific spiny dogfish lying about their age? A comparison of ageing structures for Squalus suckleyi
This study examined two approaches to ageing Pacific spiny dogfish and inter-laboratory variability. Age estimates from dorsal fin spines (historical method) did not agree with age estimates from vertebrae (new method) for older fish, suggesting the new method is not appropriate for fish aged over 10 years. However, inter-laboratory variability was improved using the new method. Results suggest further investigation of the new method is warranted.
MF17059Effect of the invasive New Zealand mud snail (Potamopyrgus antipodarum) on the littoral macroinvertebrate community in a temperate mesotrophic lake
The analyses performed showed the following effects of the P. antipodarum invasion on the macroinvertebrate community of a temperate mesotrophic lake: a definite increase in the total macroinvertebrate biomass, a significant increase in the local macroinvertebrate family richness and diversity, a shift in the community composition from crustacean- to gastropod-dominated.
The present study examined the effects of nudibranch predation on behaviour of the geographically restricted and potentially threatened soft coral species Dendronephthya australis. Observations clearly demonstrated the negative impact of predation on feeding ability of this soft coral and suggested that interactions with additional anthropogenic stressors may increase mortality risk for this important habitat-forming species.
MF16417Environmental dissimilarity over time in a large subtropical shallow lake is differently represented by phytoplankton functional approaches
The response of different phytoplankton functional approaches to environmental variability over time was evaluated in a large subtropical shallow lake. Dissimilarity in phytoplankton functional composition was related to nutrient and light conditions, even though the sensitivity of the approaches seemed to differ with regard to environmental variability. The functional group composition of phytoplankton sensu Reynolds et al. (https://doi.org/10.1093/plankt/24.5.417) seemed to be the most effective system in describing environmental variability in Lake Mangueira, in southern Brazil, over the long term.
MF17007Ecology, adaptation and acclimatisation mechanisms of Bythograeidae Williams, 1980, a unique endemic hydrothermal vent crabs family: current state of knowledge
This review is the first on Bythograeidae, documenting the state of our knowledge regarding their taxonomy, evolution, ecology, morphology and physiology (i.e. osmoregulation, oxygen consumption, sulfide and metal detoxification, temperature tolerance). We also report on recent progress in maintaining bythograeids in an artificial ex situ environment.
MF17077Spawning area and season of butterfly kingfish (Gasterochisma melampus), a large scombrid adapted to cooler temperate southern water
Butterfly kingfish (Gasterochisma melampus) is a large Scombridae species distributed in circumpolar temperate waters of the Southern Hemisphere whose ecological characteristics were unknown. Observation of gonads collected by longline operations revealed that spawning took place in the south-east Pacific Ocean from mid-April to mid-July. The present study promotes an understanding of the life history and stock structure of this species.
MF16317Coral bleaching in the southern inshore Great Barrier Reef: a case study from the Keppel Islands
Warm sea temperatures affected the Great Barrier Reef in the summer of 2016, causing severe coral bleaching in northern and central reef regions. Southern reef areas were thought to escape bleaching; however, herein we report minor coral bleaching around the Keppel Islands (14 sites). Approximately 21% of corals were mildly affected, with Pocillopora and some Acropora appearing sensitive. No mortality was observed. This study contributes to the long-term records of disturbance and recovery dynamics in the Keppel Islands.
Streams under reference conditions are necessary for the evaluation and monitoring of the conservation status of aquatic ecosystems of a region. In this study we demonstrated that a hydrological unit does not constitute a homogeneous entity in terms of environmental variables and biological composition. The results of the study will improve and facilitate the selection of reference sites for biomonitoring programs and for managing Neotropical savanna streams.
Although mailing of live or dead organisms is forbidden in Brazil, smugglers use the postal service to transport aquarium species throughout the country. To assess this illegal practice, confiscations comprising native (including species threatened with extinction) and non-native organisms were performed. Brazilian authorities must intensify package inspections, especially in the south-eastern region, because seizures seem to mitigate the illicit transportation of aquarium species to some extent.
MF16403Age and growth of the banded guitarfish Zapteryx exasperata (Chondrichthyes: Trygonorrhinidae)
The age and growth of the banded guitarfish (Zapteryx exasperata) from Baja California Sur, Mexico, was estimated for the first time based on growth band counts in its vertebrae. Larger sizes than those reported in the literature were observed for both females (103-cm total length, TL) and males (92 cm TL). Similarly, females lived longer than males (22.6 v. 19.6 years respectively).
MF16118Seasonal habitats, decadal trends in abundance and cultural values of magpie geese (Anseranus semipalmata) on coastal floodplains in the Kakadu Region, northern Australia
The magpie goose is an iconic tropical species highly valued as a conservation asset and by Aboriginal people as a cultural resource. Their spatial and temporal dynamics in the Kakadu Region of Northern Australia are characterised at seasonal and decadal time scales using long-term aerial survey data. The customary harvesting practices of geese and their eggs in the region show that their cultural value extends beyond consumption of bush-food.
Sediment fluxes and sinks based on total sediment load for Magela Creek in the Australian wet–dry tropics have been constructed from detailed measurements of turbidity, suspended sand and bedload for the 10-year period from 2001–2002 to 2010–2011. The present work showed that the sediment-trap efficiency of the vegetated wetlands on lower Magela is high at ~89.5%.
MF16175Vulnerability of fish and macroinvertebrates to key threats in streams of the Kakadu region, northern Australia: assemblage dynamics, existing assessments and knowledge needs
Key stream fauna in Kakadu National Park face severe threats in 100+ years associated with climate change, invasive species, and mine-site rehabilitation. Sea level rise will salt the coastal floodplains and the fauna must then rely on reduced upstream refuges vulnerable to strong swings between more intense El Niños and La Niñas. Rates and extremes of future climate change appear unprecedented, making predictions associated with past climate change unreliable.
MF16148Dynamics of plant communities and the impact of saltwater intrusion on the floodplains of Kakadu National Park
On the Kakadu floodplains, the distribution of different plant communities varies yearly, related to flooding duration and water depth. Because these floodplains are close to the coast, they are vulnerable to saltwater intrusion as the sea levels rise. The most obvious effect of this will be the transformation from freshwater vegetation to salt-tolerant plants in susceptible areas.
Sea-level rise associated with global warming will increase across Kakadu causing widespread saltwater intrusion. We aimed to understand how soil bacteria might respond to these impacts, by sampling transects in different river zones. We found diverse bacterial communities that were sensitive to soil variables, suggesting that saltwater intrusion may affect bacterial contributions to the dynamic floodplain ecosystems of Kakadu.
MF16049Assessing sea level-rise risks to coastal floodplains in the Kakadu Region, northern Australia, using a tidally driven hydrodynamic model
The coastal floodplains of the Kakadu Region of northern Australia are highly vulnerable to future sea level rise (SLR) and extreme weather events. A hydrodynamic model was developed to simulate the frequency and extent of saltwater inundation of future SLR scenarios from 2013 to 2100 (1.1 m above mean sea level), and was used to assess potential risk to freshwater floodplains.
These articles have been peer reviewed and accepted for publication. They are still in production and have not been edited, so may differ from the final published form.
Inter-population variability in growth and reproduction of invasive bleak Alburnus alburnus (Linnaeus, 1758) across the Iberian Peninsula
More (or less?) bounce for the ounce: a comparison of eDNA and classical approaches for bioassessment
Population genetics of Pampus echinogaster along the Pacific coastline of China: Insights from CR and microsatellite molecular markers
Mangrove response to sea-level rise: paleo-ecological insights from macrotidal systems in northern Australia
Effects of herbivores, wave exposure, and depth on benthic coral communities of the Easter Island Ecoregion
BIOLOGICAL ASPECTS OF THE ASSOCIATIONS OF BITING MIDGES (DIPTERA: CERATOPOGONIDAE) IN TWO SALINE RIVERS OF THE ELTON LAKE BASIN, RUSSIA
Horseshoe crabs as potential sentinel species for coastal health: juvenile hemolymph quality and relationship to habitat conditions
A sponge of the Cliona viridis complex invades and excavates corals of Gulf of Mannar, southeast India
Elevated salinity inhibits nitrogen removal by changing the microbial community composition in constructed wetlands during the cold season
Post-release survival of two elasmobranchs, the eastern shovelnose ray (Aptychotrema rostrata) and the common stingaree (Trygonoptera testacea), discarded from a prawn trawl fishery in southern Queensland, Australia
Relative importance of environmental variables for the distribution of an invasive marsh species Spartina alterniflora across different spatial scales
Embryos of eastern rainbowfish Melanotaenia splendida splendida (Peters 1866) tolerate fluctuating hypoxia
Life history characteristics of the silky shark, Carcharhinus falciformis, from the central west Pacific
Headwater-River Gradient: Trait-Based Approaches Reveal Functional Dissimilarities Among Tropical Fish Assemblages
Spatiotemporal variation in the structure of reef fish and macroalgal assemblages in a NE Atlantic kelp forest ecosystem: implications for the management of temperate rocky reefs
Can bioturbation be responsible for thicker freshwater lenses than expected in littoral environments?
Visual cues from an underwater illusion increase relative abundance of highly reef-associated fishes on an artificial reef
Stock structure of Lethrinus laticaudis (Lethrinidae) across northern Australia determined using genetics, otolith microchemistry and parasite assemblage composition.
Ontogenetic changes in DNA and RNA contents of laboratory-reared Prochilodus lineatus larvae: use of RNA/DNA ratios as nutritional condition indicator.
Inter and intra-regional patterns of stable isotopes in D. gigas beak: Biological, geographical and environmental effects
Effects of Pleistocene glaciation on the phylogeographic and demographic histories of chub mackerel Scomber japonicus in the Northwestern Pacific
The community structure and distribution patterns of stream macroinvertebrates in the Huai River Basin in China
Combined effects of light reduction and ammonia-nitrogen enrichment on submerged macrophyte Vallisneria natans
Patterns of infaunal macro-mollusc assemblages in a subtropical marine park: implications for management
Experimental evaluation for predation of stocked salmon by riparian wildlife: the effects of prey size and predator behaviors
Seasonal and Diurnal Methane and Carbon Dioxide Emissions from the Littoral Area of the Miyun Reservoir in Beijing, China
A multi-scale, hierarchical, ecoregional and floristic classification of arid and semi arid ephemeral wetlands in New South Wales, Australia
Assessing the hazards of trace metals in different land use types around a coastal wetland nature reserve in China
An Assessment of Water Quality from the Normanby River Catchment to Coastal Flood Plumes on the Northern Great Barrier Reef, Australia
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