Group items tagged

The sea turtles at Ningaloo Reef love to cruise the waters of this heritage-listed area in Western Australia to munch on green delights, like seagrass. But what happens if they leave their safe haven of the Reef, and where do they go? We are conducting research to better understand their behaviour, where they travel to, what they eat, and importantly, where they go to nest, to ensure their conservation.

There's no 'garbage patch' in the Southern Indian Ocean, so where does all the rubbish go?

In recent years, attaining gonadal maturation in smaller Hilsa (Tenualosa ilisha) has become a burning issue for Hilsa fishery of Bangladesh. Causes of early maturation are not yet clearly understood. Along with environmental parameters, genetic differentiation within the population was hypothesized as the main driver, and therefore, assessing the correlation between gonadosomatic index (GSI) and environmental factors and analyzing genetic diversity were set as objectives of the present study. To address these complex issues, six diverse habitats across Bangladesh were chosen for Hilsa sample collection. For GSI, gonad was dissected from fresh fish and preserved in Bouin's fluid for histological observation. Water quality parameters such as temperature, dissolved oxygen, pH, and salinity were also assessed. 35 fish from each habitat were used to extract and amplify DNA through the PCR technique, and genetic diversity was examined. Further, to draw a firm conclusion, the phylogenetic tree of the Hilsa population was developed by the unweighted pair-group method of arithmetic mean method based on the Cyt b gene of mitochondrial DNA. Results of GSI studies revealed that peak spawning months of T. ilisha were in October and February, where October showed the highest values in all six habitats. Histological examination showed different stages of gonadal development in different sizes and ages of Hilsa. Among all sampling sites, no statistical difference was observed for GSI value; however, smaller sized and aged Hilsa being ripped were evident in Gaglajur Haor and Kali River. Among the observed water quality parameters, temperature correlated with GSI strongly. Increased GSI was observed with temperature augmentation from downstream to upper stream, irrespective of body size and age. A perplex correlation between dissolved oxygen of observed habitats and GSI was executed. Other physico-chemical parameters viz. pH and salinity exhibited weak and moderate positive associ

Iodine affects the radiative budget and the oxidative capacity of the atmosphere and is consequently involved in important climate feedbacks. A fraction of the iodine emitted by oceans ends up in aerosols, where complex halogen chemistry regulates the recycling of iodine to the gas-phase where it effectively destroys ozone. The iodine speciation and major ion composition of aerosol samples collected during four cruises in the East and West Pacific and Indian Oceans was studied to understand the influences on iodine's gas-aerosol phase recycling. A significant inverse relationship exists between iodide (I-) and iodate (IO3-) proportions in both fine and coarse mode aerosols, with a relatively constant soluble organic iodine (SOI) fraction of 19.8% (median) for fine and coarse mode samples of all cruises combined. Consistent with previous work on the Atlantic Ocean, this work further provides observational support that IO3- reduction is attributed to aerosol acidity, which is associated to smaller aerosol particles and air masses that have been influenced by anthropogenic emissions. Significant correlations are found between SOI and I-, which supports hypotheses that SOI may be a source for I-. This data contributes to a growing observational dataset on aerosol iodine speciation and provides evidence for relatively constant proportions of iodine species in unpolluted marine aerosols. Future development in our understanding of iodine speciation depends on aerosol pH measurements and unravelling the complex composition of SOI in aerosols.

Hydrothermal vent areas have drawn increasing interest since they were discovered in 1977. Because of chemoautotrophic bacteria, they possess high abundances of vent endemic species as well as many non-vent species around the fields. During the survey conducted by the Bundesanstalt für Geowissenschaften und Rohstoffe (Federal Institute for Geosciences and Natural Resources, BGR) to identify inactive polymetallic sulfide deposits along Central and Southeast Indian Ridges, the INDEX project studied the scavenging amphipod community at three newly discovered hydrothermal fields. A sample consisting of 463 representatives of Amphipoda (Malacostraca: Crustacea) was collected by means of baited traps in active and inactive vents of three different sites and subsequently studied by both morphological and genetic methods. Molecular methods included the analysis of two mitochondrial (cytochrome c oxidase subunit I [COI] and 16S rRNA) and one nuclear (18S rRNA) genes. By six delimitation methods, 22 molecular operational taxonomic units (MOTUs) belonging to 12 genera and 10 families were defined. The existence of potential species complexes was noted for the representatives of the genus Paralicella. The inactive site, where 19 species were found, showed higher species richness than did the active one, where only 10 taxa were recorded. Seven genera, Ambasiopsis, Cleonardo, Eurythenes, Parandania, Pseudonesimus, Tectovalopsis, and Valettiopsis, were observed only at inactive sites, whereas Haptocallisoma, was collected exclusively at active ones. The species Abyssorchomene distinctus (BIRSTEIN and VINOGRADOV, 1960), Hirondellea brevicaudata Chevreux, 1910, and Hirondellea guyoti (BARNARD and INGRAM, 1990), have been previously reported from vent sites in the Atlantic or Pacific oceans. The present study provides the first report of Eurythenes magellanicus (H. Milne Edwards, 1848) and five other already described species in the Indian Ocean. The addition of 356 sequences strong

Manta ray populations worldwide are vulnerable to sublethal injuries resulting from human activities, e.g., entanglement in fishing line and boat strikes, which have the potential to impact an individual's health, fitness, and behaviour. Sublethal injuries and physical abnormalities also occur naturally from predation events, deformity, parasites, and disease. To determine the type and frequency of anthropogenic and natural originated injury events affecting Mobula alfredi and M. birostris in the Maldives, we examined data from the Manta Trust's Maldivian Manta Ray Project (MMRP) database, which contains 73,638 photo-identification (photo-ID) sightings of the two manta ray species from 1987 to 2019. The likely origin of each injury or physical abnormality was determined based on visual assessment of the photo-ID images. Multiple injuries to an individual originating from the same event were grouped for analysis. Generalised linear mixed models (GLMM) were used to investigate the relationship between the occurrence of injury events and the explanatory variables sex and maturity status for both species, with the additional variable site function (cleaning, feeding, cruising) investigated for M. alfredi. Spatial and temporal variations in M. alfredi injury events, and their origin and type, were investigated by calculating the percentage of injury events per sighted individual at each Maldivian atoll, and per re-sighted individual in each year from 2005 to 2019. For both species, injury events were predominantly of natural origin, with predatory bites being the most frequent type. The most common anthropogenic injury type was entanglement in fishing line. Injuries to M. alfredi were significantly more likely to be observed on juveniles than adults, males than females, and at cleaning stations as opposed to feeding or cruising sites. Neither sex nor maturity status were significant explanatory variables for the occurrence of injuries to M. birostris. Highest percentages

Introduction: Ocean fronts are moving ephemeral biological hotspots forming at the interface of cooler and warmer waters. In the open ocean, this is where marine organisms, ranging from plankton to mesopelagic fish up to megafauna, gather and where most fishing activities concentrate. Fronts are critical ecosystems so that understanding their spatio-temporal variability is essential not only for conservation goals but also to ensure sustainable fisheries. The Mozambique Channel (MC) is an ideal laboratory to study ocean front variability due to its energetic flow at sub-to-mesoscales, its high biodiversity and the currently debated conservation initiatives. Meanwhile, fronts detection relying solely on remotely-sensed Sea Surface Temperature (SST) cannot access aspects of the subsurface frontal activity that may be relevant for understanding ecosystem dynamics.

Kuala Lumpur has asked for more help in the search for a Malaysia Airlines plane missing for more than a year, with France to send planes, boats and helicopters to scour the coast of a remote Indian Ocean island where debris washed up.

Kuala Lumpur has asked for more help in the search for a Malaysia Airlines plane missing for more than a year, with France to send planes, boats and helicopters to scour the coast of a remote Indian Ocean island where debris washed up.

In a world where fish biodiversity is on the decline, highly vulnerable species are given a major boost today after scientists identified why some species are absent from reefs in the Indian and Pacific oceans. Incorporating this knowledge into conservation strategies will help to reduce human impact on species loss.

In a world where fish biodiversity is on the decline, highly vulnerable species are given a major boost today after scientists identified why some species are absent from reefs in the Indian and Pacific oceans. Incorporating this knowledge into conservation strategies will help to reduce human impact on species loss.

Leonardo DiCARPIO has made it clear that he is concerned about the environment and climate change, and now he's putting his money where his mouth is.

Leonardo DiCARPIO has made it clear that he is concerned about the environment and climate change, and now he's putting his money where his mouth is.

Where fresh is cool in Bay of Bengal.

For years, Kenya and Somalia have argued over where their maritime boundary in the Indian Ocean runs. The International Court of Justice in The Hague could now decide who owns the sea, a decision that will only suit one.

Researchers are planning to tag two of Ningaloo Reef's most famous whale sharks - Stumpy and Zorro - in a bid to discover where the ocean giants go to mate.

Seabirds have distinct individual personalities that affect where they feed and how likely they are to prosper, a pair of recent studies suggests.

Researchers from The University of Western Australia and the Australian Institute of Marine Science (AIMS) have raised concerns about the whereabouts of the world's biggest whale sharks after finding that the largest sharks observed in recent years were smaller than those recorded more than a decade ago.

Researchers from The University of Western Australia and the Australian Institute of Marine Science (AIMS) have raised concerns about the whereabouts of the world's biggest whale sharks after finding that the largest sharks observed in recent years were smaller than those recorded more than a decade ago.

Every one of India's 1.3 billion people uses an average 11kg of plastic each year. After being used, much of this plastic finds its way to the Arabian Sea and Indian Ocean, where it can maim and kill fish, birds and other marine wildlife.

The adaptation of tropical coral communities to the world's hottest sea, the Persian/Arabian Gulf (PAG), has recently been associated with ecological selection acting on a group of coral-associated algal symbionts, the Symbiodinium thermophilum group. Previous studies have shown that considerable genetic diversity exists within the group and that group members found within the PAG are significantly differentiated from those found externally, in the Gulf of Oman and wider waters. However, little is known about this genetic diversity. As an initial step towards understanding whether this diversity could represent niche adapted, selectable populations within the S. thermophilum group that may act as natural sources of stress tolerant associations to Indo-Pacific reefs, we investigate whether the diversity is structured between populations and where the location of the internal-external genetic partition lies. We use regions of the nuclear ribosomal DNA (ITS1-5.8S-ITS2) and chloroplastic psbA gene (non-coding region) from >100 S. thermophilum group-harbouring Porites spp. (P. lobata, P. lutea, and P. harrisoni) sampled across steep temperature and salinity gradients to conduct analyses of variance and create maximum parsimony networks to assess genetic structure and (dis)similarity within and between populations of S. thermophilum found within the PAG and externally in the Gulf of Oman. Our analyses resolve a sharp genetic boundary between Symbiodinium populations in the western Strait of Hormuz and identify significant genetic structure between populations with as little as 20 km between them demonstrating that differentiation between populations is likely due to factors other than limited connectivity. Further, we hypothesize that genotypes identified outside of the PAG in the Gulf of Oman existing in near-oceanic salinities, yet thermally challenging waters, putatively represent candidates for stress-tolerant symbionts that could act as natural seed populations of st

Whale sharks are the largest fish in the sea but much of their behaviour is still unknown. In a world-first, we'll be attempting to hit the marine jackpot and determine how old whale sharks are using DNA samples. We're also placing trackers on them to discover where in the ocean they travel and how deep below the surface they go from one of their favourite hangouts - Ningaloo Reef in Western Australia.

Whale shark researchers have marked International Whale Shark Day by solving a long-standing mystery about where the world's largest fish go during the Australian spring and summer.