Flexibility for fuelling reproduction in a pelagic ray (Mobula eregoodoo) suggested by bioenergetic modelling.

This study investigated the measurements of energy density and bioenergetic modelling for a pelagic ray, Mobula eregoodoo, to estimate its relative allocation to various bodily processes and especially reproduction. The data revealed M. eregoodoo uses up to 21.

Evaluating the effectiveness of drones for quantifying invasive upside-down jellyfish (Cassiopea sp.) in Lake Macquarie, Australia.

Upside-down jellyfish (Cassiopea sp.) are mostly sedentary, benthic jellyfish that have invaded estuarine ecosystems around the world. Monitoring the spread of this invasive jellyfish must contend with high spatial and temporal variability in abundance of individuals, especially around their invasion front.

Signatures of selection underpinning rapid coral adaptation to the world's warmest reefs.

Coral populations in the world’s warmest reefs, the Persian/Arabian Gulf (PAG), represent an ideal model system to understand the evolutionary response of coral populations to past and present environmental change and to identify genomic loci that contribute to elevated thermal tolerance. Here, we use population genomics of the brain coral to show that corals in the PAG represent a distinct subpopulation that was established during the Holocene marine transgression, and identify selective sweeps in their genomes associated with thermal adaptation. We demonstrate the presence of positive and disruptive selection and provide evidence for selection of differentially methylated haplotypes.

Foraging plasticity diversifies mercury exposure sources and bioaccumulation patterns in the world's largest predatory fish.

Large marine predators exhibit high concentrations of mercury (Hg) as neurotoxic methylmercury, and the potential impacts of global change on Hg contamination in these species remain highly debated. Current contaminant model predictions do not account for intraspecific variability in Hg exposure and may fail to reflect the diversity of future Hg levels among conspecific populations or individuals, especially for top predators displaying a wide range of ecological traits. Here, we used Hg isotopic compositions to show that Hg exposure sources varied significantly between and within three populations of white sharks (Carcharodon carcharias) with contrasting ecology: the north-eastern Pacific, eastern Australasian, and south-western Australasian populations.

Assessment of the temporal retention of mercury and nutrient records within the mangrove sediments of a highly impacted estuary.

Mangrove ecosystems are dynamic and biodiverse environments with the capacity to sequester more organic carbon per unit area, per time, than terrestrial forests, yet are among one of the most heavily degraded ecosystems on Earth. Here, we quantify trace metal, nutrient and carbon accumulation rates in a tropical mangrove environment in northeast Brazil, a region that has been rapidly developed over the past seven decades. Carbon accumulation rate results show modest or no increase since the 1950's, when major development occurred in the region.

Assessment of acetylcholinesterase, catalase, and glutathione S-transferase as biomarkers for imidacloprid exposure in penaeid shrimp.

Shrimp aquaculture is a valuable source of quality seafood that can be impacted by exposure to insecticides, such as imidacloprid. Here, adult black tiger shrimp (Penaeus monodon) were used to evaluate the activity of acetylcholinesterase (AChE), catalase (CAT), and glutathione S-transferase (GST) in abdominal, head, gill, and hepatopancreas tissue as biomarkers for imidacloprid exposure. Adult P.

Persistence of seaweed forests in the anthropocene will depend on warming and marine heatwave profiles.

Marine heatwaves (MHWs), discrete periods of extreme warm water temperatures superimposed onto persistent ocean warming, have increased in frequency and significantly disrupted marine ecosystems. While field observations on the ecological consequences of MHWs are growing, a mechanistic understanding of their direct effects is rare. We conducted an outdoor tank experiment testing how different thermal stressor profiles impacted the ecophysiological performance of three dominant forest-forming seaweeds.

Forecasting intraspecific changes in distribution of a wide-ranging marine predator under climate change.

Globally, marine animal distributions are shifting in response to a changing climate. These shifts are usually considered at the species level, but individuals are likely to differ in how they respond to the changing conditions. Here, we investigate how movement behaviour and, therefore, redistribution, would differ by sex and maturation class in a wide-ranging marine predator.

Mollusc-Derived Brominated Indoles for the Selective Inhibition of Cyclooxygenase: A Computational Expedition.

Inflammation plays an important role in different chronic diseases. Brominated indoles derived from the Australian marine mollusk () are of interest for their anti-inflammatory properties. This study evaluates the binding mechanism and potentiality of several brominated indoles (tyrindoxyl sulfate, tyrindoleninone, 6-bromoisatin, and 6,6'-dibromoindirubin) against inflammatory mediators cyclooxygenases-1/2 (COX-1/2) using molecular docking, followed by molecular dynamics simulation, along with physicochemical, drug-likeness, pharmacokinetic (pk), and toxicokinetic (tk) properties.

Oxic and Anoxic Organic Polymer Degradation Potential of Endophytic Fungi From the Marine Macroalga, .

Cellulose and chitin are the most abundant polymeric, organic carbon source globally. Thus, microbes degrading these polymers significantly influence global carbon cycling and greenhouse gas production. Fungi are recognized as important for cellulose decomposition in terrestrial environments, but are far less studied in marine environments, where bacterial organic matter degradation pathways tend to receive more attention.

Global blue carbon accumulation in tidal wetlands increases with climate change.

Coastal tidal wetlands produce and accumulate significant amounts of organic carbon (C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation.

The power of national acoustic tracking networks to assess the impacts of human activity on marine organisms during the COVID-19 pandemic.

COVID-19 restrictions have led to an unprecedented global hiatus in anthropogenic activities, providing a unique opportunity to assess human impact on biological systems. Here, we describe how a national network of acoustic tracking receivers can be leveraged to assess the effects of human activity on animal movement and space use during such global disruptions. We outline variation in restrictions on human activity across Australian states and describe four mechanisms affecting human interactions with the marine environment: 1) reduction in economy and trade changing shipping traffic; 2) changes in export markets affecting commercial fisheries; 3) alterations in recreational activities; and 4) decline in tourism.

Mapping the future for coral reefs.

The ability of corals to adapt to global warming may involve trade-offs among the traits that influence their success as the foundational species of coral reefs.

Secondary predation constrains DNA-based diet reconstruction in two threatened shark species.

Increasing fishing effort, including bycatch and discard practices, are impacting marine biodiversity, particularly among slow-to-reproduce taxa such as elasmobranchs, and specifically sharks. While some fisheries involving sharks are sustainably managed, collateral mortalities continue, contributing towards > 35% of species being threatened with extinction. To effectively manage shark stocks, life-history information, including resource use and feeding ecologies is pivotal, especially among those species with wide-ranging distributions.

Enhancing the heat tolerance of reef-building corals to future warming.

Reef-building corals thriving in extreme thermal environments may provide genetic variation that can assist the evolution of populations to rapid climate warming. However, the feasibility and scale of genetic improvements remain untested despite ongoing population declines from recurrent thermal stress events. Here, we show that corals from the hottest reefs in the world transfer sufficient heat tolerance to a naïve population sufficient to withstand end-of-century warming projections.

Impact of marine protected areas on temporal stability of fish species diversity.

Preserving biodiversity over time is a pressing challenge for conservation science. A key goal of marine protected areas (MPAs) is to maintain stability in species composition, via reduced turnover, to support ecosystem function. Yet, this stability is rarely measured directly under different levels of protection.

Ecosystem carbon losses following a climate-induced mangrove mortality in Brazil.

Drought events may induce mangrove mortality and dieback events worldwide as a result of climate extremes. As mangroves sequester large quantities of carbon, quantifying the losses of these stocks following climate disturbances may guide wetland governance strategies globally. In Southeast Brazil, we determined the total ecosystem carbon stocks (TECS) of pristine mangroves that were up to 1851 Mg of carbon per hectare (Mg C ha), which are the highest stocks measured from South American and raising estimates of Brazil's mangrove TECS to 0.

Where three snail species attach while emersed in relation to heterogenous substrate temperatures underneath intertidal boulders.

Mobile intertidal gastropods can employ behavioural thermoregulation to mitigate thermal stress, which may include retreating under boulders when emersed. However, little is known about how gastropod occupancy of under-boulder habitats is associated with any variations in substrate temperature that exist under boulders. Thermal imagery was used to measure the temperature of boulder lower surfaces and investigate how three snail species were associated at low tide with the maximum and average temperatures underneath grey siltstone and quartzite.

Marine heatwaves have minimal influence on the quality of adult Sydney rock oyster flesh.

Marine heatwaves (MHWs) are impacting marine biodiversity, including fisheries and aquaculture. However, it is largely unknown which species will be able to endure MHWs and at what price. Here, we applied elevated temperature (2 °C above ambient) and two different heatwave scenarios to adults of the economically important Sydney rock oyster (SRO, Saccostrea glomerata), and evaluated the impact on nutritional properties, gene expression profiles and immune health indicators.

Charting a course for genetic diversity in the UN Decade of Ocean Science.

The health of the world's oceans is intrinsically linked to the biodiversity of the ecosystems they sustain. The importance of protecting and maintaining ocean biodiversity has been affirmed through the setting of the UN Sustainable Development Goal 14 to conserve and sustainably use the ocean for society's continuing needs. The decade beginning 2021-2030 has additionally been declared as the UN Decade of Ocean Science for Sustainable Development.

Selectivity of marine-debris ingestion by juvenile green turtles (Chelonia mydas) at a South American World Heritage Listed area.

Beaches in southern Brazil have substantial marine debris and strandings of dead juvenile green turtles (Chelonia mydas). This study investigates associations by quantifying marine debris (1) ingested among new (<40 cm curved carapace length; CCL) and older (≥40 cm CCL) juvenile C. mydas recruits; (2) concentrations on beach transects; and then (3) selective ingestion by C.

Tropical Beaches Attenuate Groundwater Nitrogen Pollution Flowing to the Ocean.

Tropical urbanized coastal regions are hotspots for the discharge of nutrient-enriched groundwater, which can affect sensitive coastal ecosystems. Here, we investigated how a beach modifies groundwater nutrient loads in southern India (Varkala Beach), using flux measurements and stable isotopes. Fresh groundwater was highly enriched in NO from sewage or manure.

Genotype-Environment mismatch of kelp forests under climate change.

Climate change is increasingly impacting ecosystems globally. Understanding adaptive genetic diversity and whether it will keep pace with projected climatic change is necessary to assess species' vulnerability and design efficient mitigation strategies such as assisted adaptation. Kelp forests are the foundations of temperate reefs globally but are declining in many regions due to climate stress.