In this paper we propose eight principles that form a heuristic framework to navigate the interface between river science and river policy. These principles were qualitatively evaluated against the objectives of the Australian Water Act 2007 and specifically, the draft Murray–Darling Basin Plan; a component of the Act. We examine whether the eight principles of river science could be recognised in the design of the Water Act 2007 and the draft Basin Plan.
Marine and Freshwater Research
Volume 68 Number 3 2017
Rhodolith beds are major marine benthic algal communities, comparable in size and significance to kelp beds, seagrass meadows and coralline reefs. Our study indicated that rhodoliths (free-living coralline red algae) are common throughout 70% of Australia’s coastline, forming a vast natural resource in terms of area covered, biodiversity and carbonate production.
The zooplankton of lakes can consume basal carbon sources originated in aquatic and terrestrial habitats and, it plays an important link between these sources and organisms in higher trophic levels such as fish. Using stable isotopes analyses, we showed that in a productive tropical lake, the reliance of mesozooplankton on basal carbon sources seems to follow the seasonal dynamics of in-lake primary production (algae) and terrestrial carbon (plant) inputs.
MF15365Carbon sources for aquatic food webs of riverine and lacustrine tropical waterholes with variable groundwater influence
Food web studies help us understand how ecosystems work. In wetlands of the Kimberley region of north-west Australia we found that microscopic algae is a major source of food for aquatic animals. Groundwater inputs to some waterholes were enough to allow waterholes to persist throughout the dry season. Using groundwater for development may affect the ecological and cultural value of freshwater wetlands through reducing permanence and altering foodwebs.
MF15427Contrasting population structures of three Pristis sawfishes with different patterns of habitat use
The present research has demonstrated how population structure differs in elasmobranchs with different patterns of habitat use. The dwarf and green sawfishes, which spend their entire life in marine waters, were found to have restricted gene flow in Australian waters. In contrast, the largetooth sawfish, which uses freshwater rivers as juveniles and marine waters as adults, was found to have male-biased dispersal in these waters.
The present study provides the first length-at-age, growth and maturity estimates for the bronze whaler (Carcharhinus brachyurus) from Australian waters. Growth-model parameters combined with reproductive information identified C. brachyurus to be long-lived, slow growing and late maturing. These life-history characteristics highlight the potential vulnerability of C. brachyurus to anthropogenic impacts.
MF15326Difference in the trophic structure of fish communities between artificial and natural habitats in a tropical estuary
The present study demonstrated that fish abundance was up to threefold higher and species richness twofold higher on artificial structures compared with the natural habitat on a tropical estuary. In addition, fish trophic structure from an adjacent coral reef area showed more than 60% similarity with the fish community on the artificial structures surveyed.
The present study describes the food web and trophic relationships of a macroinvertebrate assemblage of a permanent Mediterranean river during the four seasons of the year. Moreover, a quantitative approach to estimate the link strength was developed and applied. Finally, relationships between diversity (biological and functional) and food-web complexity are then analysed with the distribution of strong and weak links, and their permanence over time, identified.
We tested the separate and combined effects of altered flow and fines on macroinvertebrates. Sedimentation and decreased flows individually decreased density and richness of macroinvertebrates and altered assemblage and trait structure. Higher flows did not ameliorate any effects of sedimentation. Further research is required to find the lowest thresholds of sedimentation that have ecological impacts and determine the flows required to ameliorate those impacts.
MF15291Effects of nutrient addition, recovery thereafter and the role of macrophytes in nutrient dynamics of a Mediterranean shallow lake: a mesocosm experiment
In Mediterranean shallow lakes, there is a primary effect of external nutrient loads and temperature on eutrophication. However, in these lakes, both senescence and the removal of aquatic plants strongly affects nutrient dynamics, and the amount of the external nutrient load determines the recovery of the lake once nutrient discharges cease.
MF15162Effects of small changes in riparian forest complexity on aquatic insect bioindicators in Brazilian subtropical streams
This study shows that small changes in riparian forest complexity affect the composition of Ephemeroptera, Plecoptera and Trichoptera insects across a small environmental gradient in subtropical streams. The genera Kempnyia (Plecoptera) and Zelusia (Ephemeroptera) were indicative of streams with greater forest complexity, whereas Farrodes (Ephemeroptera) was significant in streams of intermediate riparian forest complexity.
MF15249Seasonal and diel effects on acoustic fish biomass estimates: application to a shallow reservoir with untargeted common carp (Cyprinus carpio)
Acoustic methods were used to investigate diel and seasonal fish distributions and biomass in a shallow Tunisian reservoir. Gas bubbles confounded spring and summer surveys; bubbles were rare and fish were distributed in open water at night during autumn and winter. Introduced carp, not targeted by fishers, were predominant. Advice on controlling carp to promote a desired fishery is offered.
MF15408Alpha and beta diversity of freshwater meiofauna at different spatial scales in a Neotropical lotic system
Spatial and temporal patterns of meiofaunal diversity in a Neotropical lotic ecosystem were investigated. Local and among-areas scales were the highest contributors to overall richness, suggesting local species aggregation and environmental variability as drivers of meiofauna diversity. Temporal diversity was aggregated primarily at the monthly scale. The differences among areas contributed to changes in community composition. Degradation levels and precipitation affected meiofaunal abundance and structure.
Stable isotopes were used to investigate the role of submerged aquatic plants (macrophytes) in agricultural stream food webs. Macrophytes made moderate contribution to food webs, but the contribution of macrophytes and their epiphytes was higher where riparian zones were degraded. Many macroinvertebrates were generalist feeders, so these resources may compensate for lost riparian vegetation food inputs in degraded streams.
Two types of tags were evaluated in the holothuroid Holothuria grisea: an external T-bar and a passive integrated transponder (PIT) tag. Neither the T-bar nor the PIT tags fulfilled the requirements of high retention required for long-term studies. However, we do recommend the use of T-bars for short-term studies for H. grisea under low complexity conditions.
MF15165Efficacy of baited remote underwater video systems and bait type in the cool-temperature zone for monitoring ‘no-take’ marine reserves
The study used cameras dropped from boats to examine fish populations in and around a small marine reserve in Tasmania, to assess their potential as a monitoring tool. The study found that fish populations differed depending on location, depth and bait, with fish abundance increasing significantly with depth. The research validated the use of underwater cameras for monitoring deep reefs.
MF15207Does the relative value of submerged aquatic vegetation for penaeid shrimps vary with proximity to a tidal inlet? Preliminary evidence from a subtropical coastal lagoon
The importance of submerged aquatic vegetation (SAV) beds, dominated by seagrass, as a habitat for shrimp in relation to their distance to a tidal inlet was evaluated in a subtropical coastal lagoon (Laguna Madre of Tamaulipas, Mexico). The SAV bed located 1 km from the inlet had consistently higher shrimp abundance during the day and night, whereas the distant SAV bed (25 km from the inlet) was apparently limited by recruitment, resulting in low shrimp densities.
We interviewed local fishermen and conducted a fishing survey, so as to assess presence and abundance of bull sharks in the Navua River in Fiji. Both the interviews and the fishing survey confirmed the presence of young sharks. Our findings provide a preliminary characterisation of a potential shark parturition or nursery area from a data-poor region.
MF16236Retraction notice to ‘Overexploitation of a seagrass-dominated fishery by fish fences in the Pacific Coral Triangle, Indonesia.’ [Marine & Freshwater Research (2017) doi:10.1071/MF16236]
The peer-reviewed and edited version of record published online before inclusion in an issue
The presence and movement patterns of eastern fiddler rays (Trygonorrhina fasciata), Port Jackson sharks (Heterodontus portusjacksoni) and bluespotted flathead (Platycephalus caeruleopunctatus) were monitored using acoustic telemetry around an artificial reef (AR) to examine the degree of site attachment and the potential for fish production at this reef. All three species moved frequently between the AR and nearby natural reefs, and their moderate presence at the AR indicates that this reef has been incorporated by these species into their natural range.
Tropical seagrass meadows are commonly recognised as important habitats for juvenile fish, whereas tropical seaweed beds have rarely been investigated. The present study illustrates that the abundance of juvenile fish in seaweed beds can surpass that in seagrass meadows, also when it comes to coral reef-associated species and species used by fisheries, which underscores the need to widen the view of the tropical seascape.
MF16251Life history aspects of carp (Pisces:Cyprinidae) in a dam lake ecosystem: current status and future needs
Carp is the most common cyprinid species in Turkey and accounts for approximately one-fifth of total inland water aquaculture production. Carp production in Turkey has decreased in recent years. This article identifies population structure, growth and reproduction characteristics of carp in Hirfanli Dam. Changes in the carp population in this area are compared with those reported in previous studies worldwide.
MF16222Broad-scale coastal movements of white sharks off Western Australia described by passive acoustic telemetry data
This study monitored the movements of 89 acoustically tagged white sharks (Carcharodon carcharias) around southern and western Australia, using an extensive network of passive acoustic receivers. Results indicate little evidence of predictable or coordinated movements among individual sharks. Nevertheless, these data can inform initiatives to mitigate the risks associated with human encounters with white sharks.
MF16297Spatial variability of phytoplankton in the Pacific western boundary currents during summer 2014
The spatial distribution of phytoplankton was investigated in Pacific western boundary currents. Traditional approaches (size-fractionated chlorophyll-a and microscopic analyses) combined with single-cell analysis (using a flow cytometer) were used to analyse the whole range of phytoplankton community in the Pacific western boundary currents.
MF16278Depth-related composition and structuring of tropical riverine fish assemblages revealed by baited video
Deep sections of river channels present challenges for surveying riverine fish assemblages based on conventional techniques. Herein we demonstrate an application of underwater video for detecting multiple species of fish in shallow and deep sections of two tropical rivers and conclude that where water clarity is favourable, video provides one means by which assemblages can be investigated across the entire depth profile.
MF16331Responses of a phytoplankton community to seasonal and environmental changes in Lake Nansihu, China
We investigated phytoplankton community structure and environmental factors of Lake Nansihu, the largest freshwater lake in north China. Seasonal fluctuations in phytoplankton community composition were recorded and their driving environmental factors were identified based canonical correspondence analysis. The results of this study will be useful in guaranteeing the water quality and ecological security of lakes in temperate regions.
The study describes the first reported instance of severe, sudden and widespread dieback of mangrove vegetation associated with an extreme weather event. Although moisture stress is largely considered the cause, the combination of relevant likely stress factors, each linked to the same extreme fluctuation in the Southern Oscillation Index, elude to a plausible connection with global climate change.
MF16301Presence of invasive Gambusia alters ecological communities and the functions they perform in lentic ecosystems
Here, we show the effect of invasive species across whole ecological communities and the important functions they perform. By investigating sites with and without the invasive fish species Gambusia holbrooki, we found significant differences in pelagic and benthic community composition, and size distribution of zooplankton. Reductions in leaf-litter breakdown, an energy source for lake ecosystems, in invaded sites were also found.
MF16080Stable isotopes in biota reflect the graduated influence of sewage effluent along a tropical macro-tidal creek
Nitrogen and carbon isotope compositions in biological tissues are effective tracers of the source and fate of nutrients in coastal ecosystems. This study traced the time-integrated dispersion and biological uptake of sewage-derived nutrients along a tropical macro-tidal creek by measuring the isotope compositions in mangrove leaves and gastropod snail tissues.
MF16415Using telemetry data to develop conceptual models of movement to support the management of riverine fishes
Telemetry studies can provide valuable data to fill crucial gaps in our knowledge of the movement behaviours of fish. Herein we use four native Australian fish species as case studies to demonstrate how data derived from telemetry studies can be synthesised into conceptual diagrams to help scientists and managers develop targeted and effective conservation management strategies.
The first Australian workshop addressing climate concerns for fisheries was held in 1991. The nine workshop recommendations are still relevant today, and while monitoring efforts have been significant and knowledge has accumulated rapidly, implementation of management and policy responses have lagged. To successfully respond to the climate change challenges to Australian fisheries over the next decade increased support for climate-ready fishery policies and programs is needed.
MF16232Physiological and biochemical responses to elevated temperature in a threatened freshwater crayfish, Euastacus sulcatus (Decapoda: Parastacidae)
We sought to determine whether a montane freshwater crayfish limited to a southern Queensland (Australian) catchment experiences thermal stress under natural conditions. Laboratory-conditioned crayfish exhibited evidence of thermal stress at higher temperatures. When applied to field populations, crayfish at the lowest altitude of sampling exhibited evidence of a thermal stressor. It appears those crayfish at the lower altitude experience higher levels of environmental stress than those populating cooler, higher habitat.
We examined the implications of climate change for wetland policy and management with an emphasis on the Ramsar Convention. We considered wetland vulnerability to climate change, the setting of management objectives and targets, how management could be adapted, and how to monitor and evaluate wetland condition. In conclusion, we presented six principles to guide wetland policy for climate change.
MF16042Land use, soil properties and weather conditions influence nutrient fluxes into a deep oligotrophic lake
In southern New Zealand, in-stream nitrogen (N) and dissolved organic carbon (DOC) concentrations increased with increasing agricultural development in high-country grassland watersheds. Weather and soil conditions mediated the amount of DOC transferred from soils into streams, but did not influence the relationship between land use and N or phosphorus (P) when stream flow rates were low to moderate.
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%.
CO2 concentration in freshwater environments is rising, but is also poorly understood, particularly when compared to in marine environments. We sought to test predation success of a common freshwater fish in elevated CO2, and found that even very high concentrations of CO2 did not affect predation success. With little research having investigated biological and ecological outcomes of high CO2 in freshwater, our work suggests a difference in expectations from elevated CO2 marine biota and systems.
MF16252Determination of the physical drivers of Zostera seagrass distribution using a spatial autoregressive lag model
Physical processes that determine the spatial distribution of Zostera seagrass in Port Phillip Bay, Australia, were investigated by examining the links between seagrass abundance and broadscale hydrodynamic (waves, currents), physical (light, depth, salinity and temperature) and catchment (nutrient and suspended sediment concentrations) processes. The present study found that the distribution of seagrass meadows is principally constrained by two physical thresholds, namely, wave height or exposure and light. The former excludes seagrasses from colonising wave-exposed coastlines, whereas the latter directly determines the depth profile of seagrasses through its influence on light availability.
MF16076Temporal patterns of association between the jellyfish Catostylus mosaicus and a sphaeromatid isopod and parasitic anemone
Jellyfish often carry other animals with them as they swim through coastal waters, yet ecological data on these relationships are scarce. The relationship between a large jellyfish and an associated isopod and anemone was studied over 2 years. The isopod was prevalent on the jellyfish nearly year round, whereas the anemone occurred less often and only between autumn and spring.
MF16286Linking patterns of freshwater discharge and sources of organic matter within the Río de la Plata estuary and adjacent marshes
Sources of organic matter within the Río de la Plata estuary were investigated by stable isotopic analysis. Upper reaches were highly influenced by terrestrial and freshwater sources, lower reaches were mostly influenced by marine organic matter, and marsh habitats did not supply sediments into the estuary. El Niño events influenced the spatial dynamics of sources within the estuary.
MF16208Forestry affects the abundance of Phormidium-dominated biofilms and the functioning of a New Zealand river ecosystem
We hypothesised that Phormidium biofilms better use sediments as a nutrient resource than diatoms, and thus Phormidium proliferations would increase with forestry cover in the catchment affecting river ecosystem functioning. Cover of Phormidium increased with the proportion of forestry in the catchment, and river ecosystem metabolism increased with this abundance, suggesting that pine forestry promotes ecological changes along the New Zealand rivers.
MF16132Physiological response and immediate mortality of gill-net-caught blacktip reef sharks (Carcharhinus melanopterus)
In this study the causes and rates of blacktip reef shark (Carcharhinus melanopterus) mortality during gill-net capture were assessed. The results demonstrated that juvenile blacktip reef sharks are more likely to die during capture than adults. If populations decrease in the future, fisheries regulations designed to conserve the species should focus on reducing juvenile encounters with gill-nets.
MF16124Using an acoustic telemetry array to assess fish volumetric space use: a case study on impoundments, hypoxia and an air-breathing species (Neoceratodus forsteri)
The behaviour of the air breathing Australian Lungfish was assessed in three dimensions within a large riverine impoundment using an acoustic array and depth sensors. We found that lake stratification constrained fish depth use, however the total volumetric activity space used remained similar between stratified and un-stratified periods. The use of a 3-D modelling approach to describe fish activity space use, revealed information that traditional 2-D fish tracking approaches would not have identified.
Microhabitat preferences of caddisfly species in four rivers in north-western Spain were analysed, namely, macrophytes, moss, pebbles and sand. Significant differences in the abundance of seven species (Drusus bolivari, Glossosoma privatum, Larcasia partita, Micrasema longulum, M. servatum, M. gr. moestum and Sericostoma sp.) were found among substrates, confirming that they have substrate preferences.
MF16227Cormorant predation overlaps with fish communities and commercial-fishery interest in a Swedish lake
Water quality in Lake Roxen, Sweden, is improving, but an expected development towards larger predatory fish is missing. Cormorant diet, recovery of tagged fish, gill-nets surveys and commercial-fishery catches were used to describe the potential effects of cormorant predation. Results indicated that cormorants and fisheries may both be responsible for the lack of recovery. Cormorant predation keeps recruitment high, but the number of fish that reach large sizes remains low.
MF16068Geographic distribution pattern of low and high nucleic acid content bacteria on a river-catchment scale
Bacteria with low (LNA) and high (HNA) nucleic acid content are widely distributed in aquatic environments. Their geographical distribution on a large river-catchment scale was investigated. The strong covariation of cytometric expressions between LNA and HNA indicated that they were intrinsically linked. The abundance and cytometric characteristics of LNA and HNA were regulated differently. The results suggest that they play different ecological roles in river ecosystems.
MF16296A preliminary study of the movement patterns of false killer whales (Pseudorca crassidens) in coastal and pelagic waters of the Northern Territory, Australia
This study presents the first detailed information on movement patterns in Australian waters for the poorly known false killer whale (Pseudorca crassidens). We satellite tracked four individuals over ~3–4 months, in coastal waters of the Northern Territory, finding total dispersal distances of ~5000–8000 km over that period. Prior to this study, information deficiencies meant that this species was largely unconsidered in conservation planning and management in Australian coastal waters; the information obtained in this study will allow this deficiency to be remedied.
MF16098Effects of forest width on fish use of fringing mangroves in a highly urbanised tropical estuary
This study used underwater cameras to examine how the width of fringing mangrove habitats affected the composition and use patterns of the fish assemblage using mangrove edge habitats in an urbanised estuary on the flooding tide. Both wide and narrow mangroves were found to be viable habitats for estuarine fish.
MF16194Environmental and individual effects on the behaviour and spawning movements of Lethrinus nebulosus on a coral reef
Acoustic tagging and tracking of spangled emperor (Lethrinus nebulosus) indicated that although home range locations of some individuals varied according diel and tidal signals, variation among individuals was generally greater than that related to environmental signals. Individual home range sizes were similar across diel and tidal cycles. Seasonal variation in habitat use included annual migrations, sometimes over 100 km, to potential spawning locations that coincided with particular lunar phases.
MF16217Groynes: a factor modifying the occurrence of dragonfly larvae (Odonata) on a large lowland river
Hydro-engineering constructions such as groynes change hydromorphology of rivers and affect their aquatic biota. Investigation of odonate fauna from the River Oder, Poland, revealed that groynes increased the abundances, species richness and diversity of dragonflies by creating the mosaics of heterogeneous habitats inhabited by species with particular preferences. The presence of groynes may be essential to the restoration or stabilisation of the populations of certain species and to renaturalisation processes in large rivers.
MF16085Interdisciplinary conservation; meeting the challenge for a better outcome: experiences from sturgeon conservation
Inclusion of a social perspective in conservation research in addition to the natural sciences can lead to a more holistic and far-reaching result. Yet, few studies cross borders to be truly multidisciplinary. This perspective addresses previous calls for collaborating authors to share their experiences and considers the existing limitations and ways forward to support multidisciplinary research in conservation science.
We evaluated the sensitivity of 12 ecological indicators that characterise fish abundance, body size and trophodynamics with respect to temporal scales. The study explicitly accounted for trophic interactions in the responsiveness and detectability of the indicators, by using a size-spectrum model. The results demonstrated the essential non-linear relationship between EIs and fishing pressures and highlighted potential misinterpretation of indicator temporal dynamics.
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.
MF16199Habitat effects on home range and schooling behaviour in a herbivorous fish (Kyphosus bigibbus) revealed by acoustic tracking
The herbivorous coral reef fish Kyphosus bigibbus was tagged with acoustic transmitters revealing that this species has a larger home range area than documented previously for any other coral reef herbivorous fish. The fish showed long-term fidelity (up to 20 months) to particular home reefs and within the school with which they were tagged. Patterns of habitat use varied substantially, despite the close proximity of these home reefs.
MF16206Differentiating the roles of shrimp and aquatic insects in leaf processing in a Neotropical stream
In many coastal tropical streams, omnivorous shrimp and aquatic insects cause the breakdown of leaf material that falls into the stream. To investigate the relationships between omnivorous shrimp, aquatic insects and leaf breakdown, we excluded either shrimp alone or shrimp and insects from leaf packs by creating electric fields. Leaves broke down fastest when shrimp, but not insects, were excluded, indicating that shrimp are potential predators of insects that are the principal processors of leaves in this stream ecosystem.
MF16267Rapid appraisal links feral buffalo with kunkod (Melaleuca spp.) decline in freshwater billabongs of tropical northern Australia
A rapid assessment of paperbark (Melaleuca spp.) decline in permanent freshwater wetlands of the Djelk Indigenous Protected Area, northern Australia, was conducted by scientists and local Aboriginal Rangers. The decline was significantly correlated with poor water quality (high electrical conductivity, turbidity, ammonium), which, in turn, was correlated with feral buffalo activity, suggesting an indirect effect of buffalo on paperbark health.
MF16073Tidal and diel movement patterns of the Atlantic stingray (Dasyatis sabina) along a stream-order gradient
Organisms such as stingrays may vary their habitat selection based on a variety of environmental factors, and their location can indirectly provide insight into the distribution of both their prey and their predators. The purpose of this study was to determine whether tidal stage and diel period affected the movements of Atlantic stingrays (Dasyatis sabina); and we found that they consistently used tidal currents to access their habitat, but only varied habitat selection with diel period in the winter. These movements may affect the probability of a stingray encountering predators, competitors and prey.
MF16219Baseline biogeochemical data from Australia's continental margin links seabed sediments to water column characteristics
The biogeochemistry of surficial marine sediments is poorly known in Australia. The aim of the present study was to summarise a large suite of seabed biogeochemical ‘baseline’ data and to make inferences about the processes that govern the concentrations. The datasets have redressed some regional and global data gaps and led to improved knowledge about processes that support benthic diversity in Australia’s marine jurisdiction.
MF16121Insights into movement behaviour of snapper (Chrysophrys auratus, Sparidae) from a large acoustic array
The patterns of distribution and abundance of snapper in South Australia changed throughout the 2000s, subsequently affecting the best approach for managing snapper fisheries. The aim of the present study was to investigate snapper movement behaviour, revealing aspects of its spatial scope, seasonal variation and systematic nature. The findings revealed the complexity of snapper movement, which is beneficial for developing appropriate fishery and spatial ecosystem management approaches.
MF16102Assessment of the physicochemical characteristics of surface waterbodies in a region earmarked for shale gas exploration (Eastern Cape Karoo, South Africa)
This study provides important limnological data collected in the semi-arid Eastern Cape Karoo region of South Africa before hydraulic fracturing impacts. It was found that depression wetlands and rivers had distinct physicochemical signatures, whereas dams exhibited variable characteristics that were similar to those of either rivers or depression wetlands. These data are important as baseline for long-term monitoring of freshwater ecosystems in the region.
MF16125Migration patterns and estuarine aggregations of a catadromous fish, Australian bass (Percalates novemaculeata) in a regulated river system
We investigated the effects of oocyte development, flow magnitude and artificial barriers on migration behaviour in Australian bass (Percalates novemaculeata). Bass spawning migrations occurred only when gonads were mature and on large flows. Connectivity to estuarine spawning habitats was reduced by instream weirs. Our findings are relevant to water resource managers formulating environmental flow rules for regulated river systems.
MF16274Inferring trends and linkages between shark abundance and shark bites on humans for shark-hazard mitigation
The recent popularisation of water-based activities is expectedly responsible to increase the odds towards the occurrence of shark bites. Our investigation about the factors underlying shark hazard indicated that shark abundance and shark-bite frequency followed compatible trends off Recife. This study has provided an important insight into the possible biological drivers that regulate the distribution of shark hazard.
MF16211Age and growth, reproductive biology, and histology in Atlantic needlefish (Strongylura marina) in a coastal freshwater lake
The Atlantic needlefish (Strongylura marina) is a coastal epipelagic species inhabiting shallow coastal waters along the western Atlantic coast from Maine to Brazil. We studied the anadromy hypothesis for this species by examining the aggregation of Atlantic needlefish entering and living in Lake Mattamuskeet, the largest natural lake in North Carolina. Although we found no direct evidence of spawning, data compilation suggests that Atlantic needlefish could be using this coastal lake for reproduction.
Elasmobranch species (juveniles and adults) are distributed in medium and high trophic levels, preying on numerous fish and invertebrates. These species had roles as both predator and prey in four trophic levels of the web, participating in most of the identified roles, and are highly redundant in their functions as prey and mesopredators, but not in their role as top predators.
Reproduction is a key biological process that underpins the persistence and maintenance of populations. The present study assessed reproduction in two species of Great Barrier Reef (GBR) sponges: one a brooder and the other a spawner. Temperature was significant in affecting reproduction in these two sponge species. These two species were comparatively more fecund than other sponge species in the region, which may explain their apparent abundance on the GBR.
MF16260Inorganic nitrogen release from sediment slurry of riverine and estuarine ecosystems located at different river regimes
We have compared dissolved inorganic nitrogen (DIN) release from sediments of rivers and estuaries located at two different hydrologic flow regimes. The DIN releases in the sediment slurry were measured for 48 h at variable salinities, and with constant agitation. Hydrologic forcing on organic matter deposition and salinities had an important role in the sediment slurry release of inorganic nitrogen.
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.
MF16051The East Australian Current, upwellings and downwellings off eastern-most Australia in summer
Instruments on a ship, a satellite, moorings and drifters gave 50 data streams that helped us describe upwellings of cold, nutrient-rich waters that move across the seafloor into the northern New South Wales–southern Queensland coast. The East Australian Current drives the upwellings, with northerly winds providing extra impetus. Conversely, southerlies move warm surface waters coastward and switch off the upwellings. Sunlight shining on upwelled water promotes the growth of phytoplankton that are the base of the food chain.
MF16177Use of otolith chemistry and acoustic telemetry to elucidate migratory contingents in barramundi Lates calcarifer
Migration is a fundamental aspect of the life history of many fish. This study used acoustic telemetry and analysis of strontium isotopes in otoliths (fish ear stones) to study intraspecific variation in the migrations of barramundi in the Northern Territory, Australia. A revised life history model identifying three migratory contingents is presented to support future management of the species.
MF16294Accurate systematic frameworks are vital to advance ecological and evolutionary studies, with an example from Australian freshwater fish (Hypseleotris)
Carp gudgeons are the focus of a theory to explain their biodiversity and life histories, based on developmental plasticity. However, basic data relating to their species boundaries, phylogenetic relationships, life histories and species distributions are not yet clear, have often been misinterpreted and are still in the process of being assembled, making it premature to apply more advanced evolutionary theories to this group.
MF15420Range extensions in anemonefishes and host sea anemones in eastern Australia: potential constraints to tropicalisation
High-latitude regions are likely to be sensitive to ocean warming, and anemonefishes and their host sea anemones may be a useful indicator group for identifying associated changes. We found that the southern range limits and overwintering of these iconic inhabitants are changing along the eastern coast of Australia. However, the paucity of islands and rocky islets south of our surveys, and host-usage patterns, could constrain future range extensions.
MF16233Biogenic processes or terrigenous inputs? Permanent water bodies of the Northern Ponds in the Lake MacLeod basin of Western Australia
Lake MacLeod contains permanently inundated ponds, despite its arid location, because of a subterranean marine link. The present study investigated the effect of biogenic and terrigenous inputs on the physical, sediment and chemical characteristics of these ponds, where the smaller ponds were found to have a persistent marine signature because of their size and faster flushing times. These results have shown that, under certain circumstances, a ‘marine-like’ state can override the typical characteristics of inland water bodies.
MF16022Investigating ecosystem processes using targeted fisheries closures: can small-bodied invertivore fish be used as indicators for the effects of western rock lobster fishing?
Summary. Ecosystem modelling has predicted that fishing for western rock lobster in deep water (50–80 m) habitats results in greater production of small-bodied invertivore fish species. To investigate this prediction, a targeted fisheries closure was proposed along the coast of Western Australia. We demonstrate that any changes in fish species are most likely to be detected in the western king wrasse (Coris auricularis), which was found to be abundant across all habitats and sites.
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.
This study assessed the efficiency of a national acoustic telemetry network to detect passing animals. The aim was to determine how many receivers could be decommissioned from each of the eight curtains while maintaining its integrity. Applying predefined criteria, we were able to improve the network significantly, reducing the number of stations by 36%, yet still retaining 84% of total detections, 86% of transmitters and 100% of detected species. This study provides a useful framework for refining acoustic telemetry networks.
MF16316Spatial and temporal dynamics of suspended sediment causing persistent turbidity in a large reservoir: Lake Dalrymple, Queensland, Australia
MF16069A risk assessment for the introduction of invasive fish for Kejimkujik National Park and National Historic Site, Canada
Risk analyses and management techniques are presented for the establishment and effects of two invasive species, smallmouth bass and chain pickerel. With their encroachment on the boundary of Kejimkujik National Park and National Historic Site, there is concern about potential ecological effects. Similar challenges for assessment and mitigation exist elsewhere, and our methods may prove illustrative for researchers and managers working under similar conditions.
MF16120Measuring niche overlap between co-occurring Plectropomus spp. using acoustic telemetry and stable isotopes
Movement and dietary patterns of two co-occurring predatory reef fish were examined at Orpheus Island, Australia, respectively using acoustic telemetry and stable isotopes. The findings show low spatial overlap, but high dietary overlap between Plectropomus leopardus and P. maculatus, which may be a product of competition for resources. This research provides new species-specific information about resource use within a genus commonly reported as a single entity.
MF16184Use of stereo baited remote underwater video systems to estimate the presence and size of white sharks (Carcharodon carcharias)
Stereo baited remote underwater video systems (stereo-BRUVs) were used in this study to investigate the occurrence and size of white sharks (Carcharodon carcharias) in the near-shore environment off Bennett’s Beach, in central New South Wales, Australia. Stereo-BRUVs successfully recorded 34 separate sightings of 22 individual white sharks. This study demonstrates that stereo-BRUVs are a viable, non-destructive method to obtain estimates of the size and presence of white sharks.
In this study we investigated how diet composition and intestinal length of the generalist and omnivorous characid fish Bryconamericus iheringii respond to riparian degradation in Brazilian subtropical streams. Open canopies were related to longer intestines and to decreased ingestion of terrestrial plants and invertebrates, concomitant with increased ingestion of filamentous algae, macrophytes and detritus. Riparian degradation may trigger increased intestinal length of generalist fish populations by driving higher relative consumption of indigestible and low-protein food resources.
MF16001Factors affecting the survival of Indus River dolphin and species tolerance towards anthropogenic pressures
Range-wide marked declines in population over the past two decades has necessitated a clear strategy for conserving Indus dolphins. Thus, the present study reports a species tolerance threshold towards anthropogenic disturbances and suggests management interventions to conserve the identified havens of dolphins. Ecological constraint of Indus dolphins is considered to be linked to rich biodiversity, therefore assessing the anthropogenic pressure on dolphins may be a surrogate for other threatened components of sympatric freshwater biodiversity.
MF16071Community structure of reef fishes in shallow waters of the Fernando de Noronha archipelago: effects of different levels of environmental protection
Shallow reef-area fish communities of Fernando de Noronha archipelago (north-eastern Brazil) with different levels of environmental protection (no-take MPA and MPA) were compared. Differences in benthic composition, abiotic data and fish-community structure were observed in the comparison between no-take MPA and MPA. A higher diversity, richness, biomass and density of larger fishes were observed for the no-take MPA.
MF16015The effect of ramp slope and surface type on the climbing success of shortfin eel (Anguilla australis) elvers
To help juvenile shortfin eels negotiate instream obstacles (e.g. dams), more information is required on ramp angle and what material to line fish ramps with. We found that climbing success decreased with steeper ramps and that climbing success differed between material types. Optimal juvenile shortfin eel ramps would be lined with Miradrain (plastic drainage product) and be set at an angle close to 30°.
MF16269Food chain length in a large floodplain river: planktonic or benthic reliance as a limiting factor
The aim of the present study was to test the hypothesis that food chain length (FCL) in floodplain systems depends on the planktonic or benthic reliance of predators. Stable isotope analysis was used in eight waterbodies of the Middle Paraná River. The results supported the hypothesis because the planktonic reliance of predators and the relative availability of planktonic resources were correlated with FCL.
MF16174Body size at sexual maturity in the eteline snappers Etelis carbunculus and Pristipomoides sieboldii: subregional comparisons between the main and north-western Hawaiian Islands
This laboratory study identified body size at sexual maturity, across the Hawaiian Archipelago, for two species of deep-reef snappers, fish of great economic importance across the Indo-Pacific region. Females of both species matured at similar body length, but were ~5 cm smaller in the waters of the fished main v. unfished north-western Hawaiian Islands. Such information helps fisheries managers better specify minimum size regulations.
MF16032Connecting the litterfall temporal dynamics and processing of coarse particulate organic matter in a tropical stream
Litterfall and leaf decomposition represent important functional processes in small streams. We investigated how monthly variation in litterfall influences the aquatic community associated with the decomposition of leaf mixtures during 1 year in a tropical stream. We found that litterfall decreased in the period of higher rainfall intensity, and that the litter-breakdown rate was considerably higher in the warmest months.
MF15240Challenges faced by shorebird species using the inland wetlands of the East Asian–Australasian Flyway: the little curlew example
This review of the status of the little curlew draws attention to the challenges faced by migratory shorebirds using grasslands and inland freshwater wetlands along the East Asian–Australasian Flyway (EAAF). Knowledge gaps about the physiology and functional ecology of different species and a lack of survey data from inland wetlands along the EAAF limit our ability to assess the status and population trends of most species.
MF16031Evidence for a single panmictic and genetically diverse population of the coconut crab Birgus latro (Decapoda: Anomura: Coenobitidae) on Christmas Island in the Indian Ocean
Coconut crabs Birgus latro on Christmas Island in the Indian Ocean may be the only population of this declining species not threatened by overharvesting. To assess the population’s diversity and identify the number of conservation units, we conducted a combined morphometric and population genetic analysis. The findings suggest that the population is genetically diverse and panmictic, and may therefore be considered as a single conservation management unit.
In the Australian subtropics, seasonal changes to flow regimens can affect the conditions of freshwaters and their biological communities. In the ephemeral streams of central Queensland, the macroinvertebrate communities did not change in response to changing flow. Mostly tolerant taxa were found, with sensitive taxa most abundant during high-flow periods. This study provides novel information on the flow-linked succession of macroinvertebrate communities and is important for developing environmental management tools.
MF16200The diet of the coffin ray, Hypnos monopterygius (Shaw, 1795), and predation mode inferred from jaw, dentition and electric organ morphology
The coffin ray is an electric ray endemic to Australia. The combination of the species’ teleost fish diet coupled with its poor swimming ability, very small teeth supported on slender jaws and its large electric organs strongly suggests that this ray uses powerful electric discharges to stun or kill prey before engulfing them whole.
The movements of Port Jackson sharks captured in Jervis Bay on the NSW south coast were tracked, finding that sharks migrate thousands of kilometres each year to their feeding sites in Bass Strait. Males and females return to the same breeding reef each year. Males migrate more quickly than females and the trip south is faster than the trip north.
The purpose of the present study was to validate vertebral band-deposition rates of blue sharks tagged and recaptured in the eastern Pacific Ocean by using oxytetracycline (OTC). Results from band counts distal to the OTC mark on each vertebra indicated that a single band pair (one translucent and one opaque) is formed per year for blue sharks ranging from 1 to 8 years of age.
MF16275Rockpool ichthyofauna of Amazon coastal zone: spatial and environmental effects on species distribution
This research covers aspects of rockpool fish in the Amazonian estuary, assessing how the distribution and occupation patterns are affected by abiotic characteristics. The results show that species occurrence and abundance respond to local environmental and spatial variations, highlighting the role of extreme dynamics conditions in governing this ecosystem.
MF16165Age, growth and maturity of oceanic whitetip shark (Carcharhinus longimanus) from Papua New Guinea
Oceanic whitetip sharks (Carcharhinus longimanus) are overfished in the Western Central Pacific and require regional biological information to improve assessment and management. Age, growth and maturity parameters estimated using vertebral analysis indicated that individuals from this region have substantially slower growth and mature at an older age than other populations. This highlights an increased vulnerability to fishing pressure and provides an important step to understanding the population status of C. longimanus in the Western Central Pacific.
An understanding of processes such as diel vertical migration of fish at reservoirs, and the major factors driving it, is needed to provide information for the implementation of management and mitigation measures for the effects of hydroelectric plants. Using hydroacoustics, this study evaluated the occurrence and some characteristics of this process in a Neotropical reservoir.
MF16104Discriminating populations of medusae (Chironex fleckeri, Cubozoa) using statolith microchemistry
This study revealed that deadly ‘stinger’ jellyfish (Chironex fleckeri) have localised populations separated by tens to hundreds of kilometres. This was demonstrated by examining the chemistry of their tiny bony structures, called statoliths. Unique location-dependent chemical ‘fingerprints’ represent the whole life of the jellyfish from the time they metamorphose from benthic polyps.
MF16078DNA barcoding of fish larvae reveals uncharacterised biodiversity in tropical peat swamps of New Guinea, Indonesia
The Indonesian archipelago hosts a significant proportion of the biodiversity on Earth, but several species groups, such as freshwater fish, remain poorly described. In this study we characterised larval and juvenile fish biodiversity, as well as spatial and temporal variability, in a pristine peat swamp environment of the River Kumbe in West New Guinea, Indonesia, based on mitochondrial DNA sequence analysis.
MF16035‘La Niña’ phenomenon and the relationship between decapod populations and fishes in temporarily isolated shallow lakes
Freshwater prawns and fishes coexist in environments of Paraná. The interaction between species of prawns and fishes during ‘La Niña’ phenomenon was studied. Population densities varied in both prawns and fishes. These changes have not been simultaneous. These variations might be associated with predation, aggressive behaviour and micro-migrations. La Niña effect creates additional stress when water inflow is delayed.
Monitoring size can provide an alternative to monitoring population abundance when assessing fishing impacts. In the present study, temporal patterns in the mean size of the four main commercial shark species of Western Australia were evaluated. Unlike commonly reported for other shark populations, the mean size of these species showed fairly stable patterns or slight increases.
MF16169Age, growth, reproductive biology and spawning periodicity of the forktail rabbitfish (Siganus argenteus) from the Mariana Islands
Rabbitfish are an esteemed food resource in the Mariana Islands and their seasonal recruitment events represent culturally important harvest periods. In the present study we used a 2-year market sampling strategy to determine life-history traits of the forktail rabbitfish in Saipan, including lifespan, growth and reproduction. Results suggest the species has a rapid life history and considerable variability in reproductive output from year to year, which may help explain yearly variability in recruitment.
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.
MF15393Effects of zooplankton and nutrients on phytoplankton: an experimental analysis in a eutrophic tropical reservoir
Experiments were conducted to evaluate the effects of the N : P ratio, as well as the effects of the interaction between the N : P ratio and zooplankton, on phytoplankton. We found that the typical zooplankton of tropical reservoirs may interfere with phytoplankton responses to the effects of nutrients. The zooplankton can also stimulate the growth of ‘less palatable’ algae.
MF15469Ecological singularity of temperate mesopredatory myliobatoid rays (Chondrichthyes: Myliobatiformes)
In tropical and subtropical ecosystems with high diversity and low amounts of nutrients, benthic-feeding stingrays and eagle rays partition their trophic resources, resulting in high ecological singularity. However, it is unknown whether this is true for temperate low-diversity nutrient-rich ecosystems. In the present study we compared the diet of three temperate co-occurring species. The three species had a markedly different diet composition, indicative of high ecological singularity.
MF16070Latitudinal change in the distribution of luderick Girella tricuspidata (Pisces: Girellidae) associated with increasing coastal water temperature in eastern Australia
A research study by Sunfish Queensland, a peak body for recreational fishing in Queensland, shows a major decline in the population and fishery for luderick (blackfish), an important species in coastal fisheries in eastern Australia. Southern Queensland is the northern range limit of this species, and the population decline in this region is significantly correlated with increasing coastal water temperature over the period 1976–2015. The increasing water temperature over the past two decades has caused a southward shift in the luderick population.
MF15435Contrasting intra-annual patterns of six biotic groups with different dispersal mode and ability in Mediterranean temporary ponds
The temporal patterns of six biotic groups (from phytoplankton to amphibians) and their responses to environmental variation were studied in a set of Mediterranean temporary ponds. Different temporal patterns were observed among the biotic groups studied, and in some (but not all) cases these differences were explained by their dispersal ability. Similarly, we observed that environmental control was group specific.
MF15445Opening the floodgates to the recovery of nektonic assemblages in a temperate coastal wetland
Floodgates that restrict tidal flow can reduce the diversity and abundance of fish and crustaceans (e.g. prawns) in coastal wetlands. This study illustrates that these impacts can be overcome by opening floodgates to restore tidal flushing and reinstating biotic passage and the habitat conditions (e.g. pH, salinity) most suitable for the juveniles of estuarine and marine dwelling species. This has implications for improving the nursery value of estuaries to support fisheries productivity.
MF15454Interactions between bivalves and zooplankton: competition or intraguild predation? Implications for biomanipulation in subtropical shallow lakes
Trophic interactions between two different filter-feeding communities in subtropical shallow lakes were investigated experimentally. Bivalves consumed small-sized zooplankton, but no consumption of medium-sized individuals was registered, favouring an average larger-sized community. Bivalves consumption of phytoplankton was higher than that of zooplankton and bivalves were also able to reduce cyanobacteria. Together, the results suggest that the introduction of bivalves can have positive effects in eutrophic systems mitigating the excessive growth of phytoplankton.
MF16020Environmental factors influencing the distribution and abundance of the introduced signal crayfish in the north of Iberian Peninsula
We studied the distribution and abundance of the invasive signal crayfish in northern Spain and analysed the relationships with several abiotic and biotic parameters of the aquatic ecosystems. Our analysis indicated that the habitat of signal crayfish is among salmonid (headwaters) and cyprinid (low waters) stretches. The existence of a natural environmental limiting factor in upstream reaches facilitates the conservation of aquatic ecosystems and native fauna.
The approach used in this study indicated a match between fishers’ and scientific histories with regard to the richness and composition of catches, as well as relative trends in abundance. Histories diverge when fishers were asked to recall their largest catch and the largest fish caught. This study provides a roadmap of what information can and cannot be considered reliable when recalled by fishers.
We examined fish recruitment patterns in 10 permanent lagoons on the Tully–Murray floodplain in the Queensland Wet Tropics bioregion, Australia. Lagoon connectivity to the rivers, distance from the coast and flood dynamics influenced temporal variation in fish abundance, population size structures and recruitment patterns. Maintenance of natural seasonal patterns of flow and connectivity, and active protection of permanent floodplain lagoons from riparian and land-use disturbance, will be essential if their roles in fish recruitment are to be sustained.
MF16067Dormant propagule banks of aquatic invertebrates in ponds invaded by exotic pine species in southern Brazil
Dormant stages of aquatic invertebrates are vital to identify the resilience of communities in ponds invaded by exotic pine species. Pine invasion decreased the richness and affected the composition and β diversity of drought-resistant aquatic invertebrates in ponds in southern Brazil. Effectively dealing with invasive pine should become a priority for wetland conservation.
This research has used a mechanistic approach combining field, laboratory and modelling components to determine the importance of hydrological connectivity in the early life history of the freshwater shrimp (Macrobrachium spinipes) in northern Australia. It has confirmed that larvae are produced over 400 km from the estuary and despite this, the species is obligate amphidromous and larvae must travel this distance within 7 days of hatching. Large flood events were critical in connecting these upstream habitats to the estuary.
MF16046A historical and contemporary consideration of the diet of the reef manta ray (Manta alfredi) from the Great Barrier Reef, Australia
The reef manta ray, one of the largest fishes in the world, is known as a filter-feeding planktivore, although its diet is basically unknown. By looking at stomach contents, we show that large copepods dominate the diet. The results may indicate limitations of the filter mechanism or may mean that the manta ray preferentially targeted large copepod prey.
MF15409Estuarine characteristics, water quality and heavy metal contamination as determinants of fish species composition in intermittently open estuaries
Intermittently open estuaries are important fish nursery habitats and are common along microtidal coasts. The present study demonstrated that fish assemblages in these estuaries can be used as indicators of estuary condition, and that estuarine resident species are particularly tolerant to contamination and poor water quality. These findings suggest that anthropogenic activity has a negative effect on estuarine biodiversity and highlights the importance of improving management strategies and environmental monitoring of these key habitats.
MF16058Nursery areas and connectivity of the adults anadromous catfish (Genidens barbus) revealed by otolith-core microchemistry in the south-western Atlantic Ocean
The aim was to clarify different aspects of the population structure of Genidens barbus, such as connectivity among nursery areas and homing behaviour. For this purpose, otolith-core chemical signatures were compared among different estuaries from south-western Atlantic Ocean. These results suggested that a high level of spatial segregation exists in adult catfish life, and that catfish tend not to mix among estuaries, supporting the homing hypothesis.
MF15285Evaluation of a floating fish guidance structure at a hydrodynamically complex river junction in the Sacramento–San Joaquin River Delta, California, USA
In this study we used two dimensional acoustic telemetry to evaluate a floating fish guidance structure designed to deter imperilled juvenile salmonids from a high mortality emigration route in the Sacramento–San Joaquin River Delta. Results suggested that the structure was successful at guiding fish away from the high mortality route under certain conditions.
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.
MF15354An analysis of recent saltwater crocodile (Crocodylus porosus) attacks in Timor-Leste and consequences for management and conservation
Saltwater crocodiles (Crocodylus porosus) have strong cultural value in Timor-Leste, yet attacks on people show the highest fatality rate of any country within the crocodile’s range (82.2%). Attack statistics are made worse by poor food security, and the demographic at highest risk is male teenagers involved in subsistence fishing. Developing a management plan is strongly recommended to reduce attacks without affecting wild crocodile populations.
MF16026Bioaccumulation, oxidative stress and cellular damage in the intertidal gastropod Bembicium nanum exposed to a metal contamination gradient
In situ organisms as bioindicators are essential in assessing the effects of contamination on the environment. The present study, on the intertidal gastropod Bembicium nanum, demonstrated a link between the accumulation of metals at a contaminated site and reduced health of the organisms, measured by increased lysosomal destabilisation. These results show that B. nanum has potential for use as a bioindicator of metal contamination.
The dietary composition (including temporal and spatial variations) of the seahorse Hippocampus guttulatus from the north-western Iberian Peninsula was assessed using Bayesian stable isotope mixing models and revealed that Caprellidea were the primary source, followed by Gammaridea and Caridea. Mysidae and Annelida represented the less dominant prey. These findings improve knowledge of feeding patterns of this endangered species, providing relevant data for its conservation management.
MF15478Biology and ecology of Zearaja maugeana, an Endangered skate restricted to two south-western Tasmanian estuaries
The Maugean skate is a listed threatened species restricted to two estuaries in Tasmania, Australia. The present study provides preliminary knowledge of life history traits essential for conservation management of this species, including movement patterns, population status, habitat use, diet, size structure and reproduction. Survival of this unique species depends on appropriate management of human impacts and environmental pressures within Macquarie Harbour, the sole stronghold of this species.
MF15457Crustacean assemblages of coastal wetlands from fragmented and scarcely isolated islands compared with the mainland
Few studies have been performed in fragment (continental) islands compared with Darwinian (oceanic) islands, probably due to the expected similarity between the fragment island and landmass. However, fragment islands can develop their own assemblages through biological and biogeographical processes, and thus differentiate themselves from their continental sources, becoming important contributors to global biodiversity.
MF15388How do abiotic environmental variables shape benthic diatom assemblages in subtropical streams?
We investigated spatial variation of benthic diatom assemblages in reasonably undisturbed subtropical streams. The results demonstrated that diatom growth form, cell size and attachment mode can be used to create a more quantitative and predictive approach to establishing relationships between diatoms and environmental gradients. This study is a stepping stone towards further understanding of diatom ecology and the development of a diatom biological monitoring protocol that is suitable for subtropical regions.
In this paper, we tested the influence of species–area relationship and species–energy association on taxonomic richness and functional richness of fish assemblages of tropical streams. Using data of two distinct basins, we demonstrated that the influence of area and energy varies for each basin, a possible response to local conditions of the environment.
The present study describes the river microbial communities upstream and 3.3 km downstream of a small rural town. We report three patterns in microbial community composition, namely, persistence, loss and appearance. Sample dissimilarity, present as microscale hotspots of discrete species, indicated higher heterogeneity downstream, and therefore increased patchiness from downstream transport and inputs of bacterial species. These findings suggest three fates for bacterial species of fluvial systems, namely, persistence, loss and appearance, with each having different effects on system dynamics.
MF16114Is the Kuroshio Current a strong barrier for the dispersal of the gizzard shad (Konosirus punctatus) in the East China Sea?
The mitochondrial DNA marker was employed to analyse phylogeographical patterns of 10 populations of K. punctatus. The results showed that the climate of Pleistocene periods had played an important role in phylogeographical patterns of K. punctatus and the dispersal strategy of coastal species may be the major current physical barrier for the gene flow among populations from Chinese and Japanese coastal waters.
MF15436Assimilation of organic matter by two benthic consumers across gradients of latitude and nutrient enrichment
Estuarine invertebrates may consume carbon originating from a variety of sources, including mangroves, seagrass, microphytobenthos and phytoplankton. Using stable isotope analyses, we found that the relative importance of carbon sources to a polychaete varied with latitude along the east Australian coast, following spatial variation in the nitrogen content of seagrass. Latitude may influence carbon sources of consumers by modifying producer traits.
MF15134Susceptibility of coral assemblages to successive bleaching events at Moorea, French Polynesia
We examine the impacts of consecutive bleaching events in 2002 and 2003 on coral susceptibility across various habitats and depths at Moorea, French Polynesia. Bleaching effects were genus specific and highly variable at small spatial scales. This variability has important implications for assessing changes to coral community structure over time and for estimating coral-reef resistance and resilience to future bleaching disturbance.
MF15304Carrion consumption and its importance in a freshwater trophic generalist: the invasive apple snail Pomacea canaliculata
The invasive apple snail Pomacea canaliculata feeds primarily on aquatic plants, but some anecdotal reports indicate that it also consumes carrion. Herein, we studied carrion ingestion and its effects on growth, concluding that carrion may be important as an alternative resource when aquatic plants are absent. This feeding flexibility helps explain the potential of P. canaliculata to establish in new wetlands and, paradoxically, its persistent effects on aquatic vegetation.
MF15468A comparison of temperature regimes in dry-season waterholes in the Flinders and Gilbert catchments in northern Australia
Ephemeral rivers in northern Australia break up into a series of waterholes during the dry season, within which fish have to survive. This depends on the waterholes lasting throughout the dry season and with temperatures that are not lethal. Using comprehensive waterhole temperature data, we found that fish could survive in waterholes that remained deeper than 0.5 m, especially if they were turbid.
MF16029First report of Aphanizomenon favaloroi occurrence in Europe associated with saxitoxins and a massive fish kill in Lake Vistonis, Greece
The cyanobacterium Aphanizomenon favaloroi was identified for the first time in Europe in the Mediterranean brackish Lake Vistonis during July–August 2014. During its occurrence, the cyanotoxins saxitoxin and neo-saxitoxin were detected in the lake, coinciding with a massive fish kill. This saxitoxin-producing species may pose a health risk to animals and humans and have adverse effects on water quality.
Dams, weirs and other barriers disrupt river connectivity and degrade fish communities worldwide. Fishways are in place at few sites relative to the numbers of barriers, and very few effectively mitigate barrier effects. Herein we review migratory behaviour among Australian fish and the effects of fish passage barriers. Australia’s highly variable hydrology challenges mitigation programs; options include basin-scale approaches; improved management of barriers, environmental flows and water quality; barrier removal; and development of improved fishway designs.
MF16062Comparable cross-taxa risk perception by means of chemical cues in marine and freshwater crustaceans
In aquatic systems, odour cues can be used to quickly identify predation risk. Here, we show temperate marine and tropical freshwater shrimp avoid predator odours but not those of non-predators or conspecifics. Cues also alter habitat selection, with structurally complex habitats favoured when predator odour is present. Rapidly altering behaviour in response to perceived risk could reduce predation while increasing time available for tasks such as foraging.
MF15325Nocturnal sampling reveals usage patterns of intertidal marsh and subtidal creeks by penaeid shrimp and other nekton in south-eastern Australia
Juvenile penaeid prawns were sampled from temperate intertidal marsh and subtidal creeks. Very few prawns were sampled within the intertidal marsh, suggesting these habitats may generally not be directly utilised by juvenile penaeids in temperate Australia. Larger school prawns (M. macleayi) sampled from the middle of subtidal creeks compared to edge habitat. Although juvenile penaeids may not directly utilise intertidal marshes, they may still export important resources for prawns in subtidal creeks.
Incorporating species trait information may provide insight into complex trophic interactions. In this study, we evaluated the effect of the common carp, Cyprinus carpio, on aquatic ecosystems, focusing particularly on middle-out-mediated effects. Common carp foraging activities and abiotic effects caused a shift in ecosystem structure and function. Specific autecology information will be critical for understanding the effects of ecosystem engineers and invasive species.
MF15350Multiple stressors associated with acid sulfate soil effluent influence mud crab Scylla serrata predation on Sydney rock oysters Saccostrea glomerata
Multi-generational exposure of oysters Saccostrea glomerata to acid sulfate soil runoff altered predator–prey interactions between the oysters and mud crabs Scylla serrata. Mud crab predation was greater on oysters from reference sites than affected sites, and the time mud crabs spent foraging was positively correlated with oyster mortality, providing a potential mechanism for observed trends in oyster mortality.
MF15253Aggregations and reproductive events of the narrownose smooth-hound shark (Mustelus schmitti) in relation to temperature and depth in coastal waters of the south-western Atlantic Ocean (38–42°S)
The present study provided evidence of interannual changes in the M. schmitti reproductive aggregation patterns in coastal waters of the south-western Atlantic Ocean, associated with different bottom-temperature regimens, depending on depth. The M. schmitti reproductive aggregations, observed during spring, were associated with temperatures above 16–17°C, which occurred mainly in shallow waters. The results suggested that changes in depth-dependent bottom-temperature patterns may be important drivers of the reproductive dynamics of this species.
Rivers often span administrative boundaries, and their condition may be best protected and managed under national policies, supported by coordinated national bioassessment. To improve bioassessment practice in Australia we recommend: (1) convene a summit of policy makers and key scientists; (2) develop strategies and priorities to protect rivers and meet emerging challenges; (3) identify key biological indicators; (4) establish measures of success; and (5) develop plans for both ‘bottom-up’ community-driven bioassessment and ‘top-down’ government-led programs.
MF15345Spatiotemporal variation among demersal ichthyofauna in a subtropical estuary bordering World Heritage-listed and marine protected areas: implications for resource management
Teleost spatiotemporal distributions and key abiotic associations were quantified throughout an important estuary within Brazil’s Atlantic Forest biosphere. As in other subtropical estuaries around the world, assemblages mostly comprised juveniles. Five species dominated samples, and their distributions were either negatively affected by salinity or positively affected by temperature or depth. These patterns were attributed to species-specific life stage requirements, and ultimately support clear conservation strategies.
MF16024Abundance patterns at the invasion front: the case of Siganus luridus in Linosa (Strait of Sicily, Central Mediterranean Sea)
The dusky spinefoot (Siganus luridus) entered the Mediterranean through the Suez Canal, conquering the eastern sectors of the basin, with marked effects on both natural habitats and native communities. In this study we monitored a recent population of this tropical invader, which settled around the island of Linosa in 2003. The results show how the invasion had expanded to the west, with increasing abundance at the invasion front.
MF15183The effect of survey method on the detection probabilities of frogs and tadpoles in large wetland complexes
The choice of survey method can influence both the effectiveness and efficiency of monitoring programs. The present paper compares six commonly employed survey methods for six species of frogs and their tadpoles. Each survey method differed with respect to the probability of detection and the number of surveys required to determine the species.
Data from the Murray–Darling Basin Authority’s Sustainable Rivers Audit were used to classify the Murray–Darling Basin into nine regions with similar historical fish assemblages. We demonstrate how a regionalisation framework can be useful for characterising fish communities and providing a baseline for assessing change in species assemblages.
Deep pools of intermittent rivers in semi-arid regions provide refuge for aquatic biota during no flow periods. Pool depth is critical because it controls how long pools persist between flows. This study examines sedimentation rates in deep pools of intermittent rivers in eastern Australia to determine if rates have increased since European settlement and if depth reductions arising from higher rates reduce pool persistence times. Results show sedimentation has increased substantially and reduced persistence times by several months.
The effects of ash from controlled fires on macroinvertebrate communities in UK headwater streams were investigated experimentally by depositing ash onto natural stream substrata in trays placed on streambeds. Ash deposition together with stream depth altered macroinvertebrate community composition. However, changes in species composition caused by ash deposition were smaller than differences among streams, suggesting that effects of ash may be small in these streams.
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.
Drivers of sulfide intrusion in Zostera muelleri in a moderately impacted estuary in south-eastern Australia
Does water-depth influence size composition of estuary-associated fish? Distributions revealed using mobile acoustic camera transects along the channel of a small shallow estuary
An inter-dependence of flood and drought: disentangling amphibian beta diversity in seasonal floodplains
Influence of Environmental Conditions on Cetacean Entanglements â A case study from the Gold Coast, Australia
Benthic trophic status of aquatic transitional environments with distinct morphological and dynamic characteristics on the South-western Atlantic coast
Residency and movement patterns of yellowfin bream (Acanthopagrus australis) released at natural and artificial reef
Evaluation of growth-dependent survival during early stages of Pacific bluefin tuna using otolith microstructure analysis
Nitrogen nutrients in a subtropical river: Temporal variation and analysis at different spatial scales
Elucidation of fine-scale genetic structure of Sandfish (Holothuria scabra) populations in Papua New Guinea and northern Australia
The use of epidermal mucus in elasmobranch stable isotope studies: a pilot study using the giant manta ray Manta birostris
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Marine and Freshwater Research 50 (8)Ove Hoegh-Guldberg
Retraction notice to ‘Overexploitation of a seagrass-dominated fishery by fish fences in the Pacific Coral Triangle, Indonesia.’ [Marine & Freshwater Research (2017) doi:10.1071/MF16236]Marine and Freshwater Research 68 (3)Ashley J. Endacott, Bruce Carlisle
Marine and Freshwater Research 62 (9)Ned W. Pankhurst, Philip L. Munday
The importance of research and public opinion to conservation management of sharks and rays: a synthesisMarine and Freshwater Research 62 (6)C. A. Simpfendorfer, M. R. Heupel, W. T. White, N. K. Dulvy
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