Group items tagged

The productivity and sustainability of coastal, marine, and estuarine ecosystems are heavily reliant on the quality of coastal waters (JHA et al., 2013; JHA et al., 2015; DHEENAN et al., 2016). These locations are thought to have greater biodiversity than open ocean zones (GRAY, 1997). Among the biological components of soft bottom sediments, macrobenthic organisms are essential for ecosystem functioning (Pandey et al., 2022). They play a vital role in secondary production and nutrient exchange between the pelagic and benthic realms and therefore constitute essential elements of estuarine and coastal habitats (SNELGROVE, 1998) and are a reliable indicator for assessing the biotic integrity of the coastal ecosystem (RYU et al., 2011; Pandey et al., 2021). Due to their sedentary lifestyle, long life cycle, and differential response against the perturbation, they also serve as useful bio-indicator (GESTEIRA-GOMEZet al., 2003) for health monitoring and assessment of coastal ecosystems (GANESH et al., 2014) and evaluating the success of conservation efforts (WINBERGT et al., 2007). Identification of factors responsible for spatiotemporal patterns in macrofaunal assemblages is the primary goal amongst many marine benthic ecological studies (BOLAM et al., 2008; DUTERTRE et al., 2013; PANDEY and GANESH , 2019b). However, such pattern in the benthic community is often hard to predict due to the complex interplay between environmental parameters and biological interactions (ELLIS et al., 2006). The relationship between natural environmental factors and macrobenthos is reported to help delineate faunal distribution patterns, characterising benthic habitats, establish baseline knowledge, and enabling the detection of spatial and temporal variations (BOLAM et al., 2008; SHUMCHENIA and King, 2010; Dutertre et al., 2013). Numerous studies (Van Hoey et al., 2004; Hily et al., 2008; DUTERTRE et al., 2013; Pandey and Ganesh, 2019b) have identified sediment properties as a significan

Repeat multibeam mapping of two slope-confined canyons on the northwest Australian margin provides new understanding of the processes that are active in shaping these environments. The Cape Range and Cloates canyons initiate on the mid to lower continental slope but are now known to be connected to the shelf via small channels and gullies. Both canyons have areas of steep walls, with evidence of slides, and large depressions on the canyon floors. These canyons were first mapped systematically with multibeam sonar in 2008 and were remapped in 2020 during a biodiversity survey that also collected high-resolution imagery and biological samples. Comparison of seabed features between these two time periods indicates active sliding, minor headwall retreat and continued excavation of deep depressions on the canyon floor. Significantly, intact blades of displaced seagrass imaged at various depths up to 4200 m throughout both canyons indicates that material sourced from the adjacent continental shelf is being transported through these canyon systems. Turbidity currents are actively modifying canyon walls and floor depressions, while also providing a sediment source that has resulted in minor accretion on the canyon floor. Sedimentation likely regulates benthic communities in these canyons, with imagery showing highest densities of sessile invertebrates in habitats protected from sedimentation (e.g. rock overhangs, cliff edges). Since steep canyon habitats are rare within these canyons, and support high benthic abundance, they likely represent biologically significant areas of the Gascoyne Marine Park. Repeat mapping provides an understanding of the dynamics of these canyons and a context for assessing and monitoring the stability of the seabed habitats within this marine reserve.

En avril 2017, une équipe internationale de scientifiques part étudier les écosystèmes inconnus d'un mont sous-marin reculé du sud-ouest de l'océan Indien à bord du MARION-DUFRESNE, navire océanographique français opéré par l'Institut polaire français IPEV. Le Banc WALTERS, une montagne submergée située au-delà des juridictions nationales, est étudié par les scientifiques du Muséum National d'Histoire Naturelle et de l'IRD (Institut de Recherche pour le Développement) pendant l'expédition de 26 jours. 'La Dernière Frontière' est un documentaire produit par l'UICN en partenariat avec et grâce au soutien financier du Fonds Français pour l'Environnement Mondial (FFEM) qui relate cette expédition et ses enjeux. Il appelle à plus de science pour la haute mer, et une meilleure gouvernance des eaux internationales. Ecrit par James NIKITINE, il est réalisé par James NIKITINE et Fabiano D'AMATO, avec une narration d'Alain GHAZAL et une musique de Woodkid. La haute mer constitue #LaDernièreFrontière à nos connaissances. Pour plus d'informations rendez-vous sur le site: https://www.iucn.org/science4highseas

Scientists circumnavigate and map the seafloor of the entire mesophotic (deep water) zone in ASHMORE Reef Marine Park.

During feeding and burrowing, many epibenthic and infaunal animals bioturbate sediments and form a range of traces called lebensspuren (German for 'life traces'), defined as any type of sedimentary structure produced by a living organism. During a 2020 survey along western Australia in the Gascoyne Marine Park, a distinct trace was observed several times, identical to the 'spider trace' observed in a 2007 survey along eastern Australia, over 4000 km away. The purpose of this brief note is to document and describe the occurrence of this unique and distinctive type of lebensspuren and to discuss ways in which similar observations may be effectively shared to increase our understanding of deep-sea biology.

India Secures Seabed Mining Rights.

India Secures Seabed Mining Rights.

India makes its claim for sulphide mining from the Indian Ocean.

Surprising Christmas Island Seamounts Mystery Solved.

Still no success as deep-sea drone searches for MH370.

Around 60 years ago, marine scientists on an armada of ships from 14 countries combined their efforts to explore the largest unknown area of earth, the deep waters and seafloor of the Indian Ocean.

Geological Insights from Malaysia Airlines Flight MH370 Search.

A small, motorised fishing boat heads out to sea from the port of Sinabang, leaving behind the remote island of Simeulue, off the coast of western Sumatra. Noticeable on the deck is a tangle of plastic tubes, linked up to a roaring, spluttering engine. The on-board fishers are going 'compressor fishing', a practice that involves divers searching the seabed for lucrative octopus, grouper and sea cucumber, all the while relying on air supplied by a single plastic lifeline, snaking precariously up to the surface. The rewards can be great - fishers are able to stay deep underwater for long periods, harvesting catches that would be inaccessible to those using other fishing techniques. However, this method is fraught with dangers, as local Simeulue fisher, Anhar, can testify.

There is growing awareness of the need for greater acknowledgement of underwater prehistoric cultural resources as part of management and regulation of the seabed around many maritime countries, especially those with large indigenous populations and history such as Australia. Prehistoric cultural places and landscapes inundated by Post-glacial sea-level rise on Australia's continental shelf remain largely out-of-sight and out-of-mind, hence awareness and hence legal protection of this resource is lacking. There is a clear need for greater integration of archaeology and cultural heritage management within the marine sciences as well as a greater awareness of this resource as part of a common heritage more generally. This paper explores some of the dichotomies between Western and Indigenous cultures in valuing and managing the seabed. We argue that in developing science-policy, an attempt at least needs to be made to bridge both the gap between the nature and culture perspectives, and the jurisdictional divide between land and sea. Part of the answer lies in a convergence of Indigenous knowledge with Western science approaches, focused around our understanding of physical processes impacting past and present coastal landscapes and on the seabed itself. We explore several case studies from northern and Western Australia that are trying to do this, and which are helping to provide a greater appreciation of the inundated landscapes of the inner shelf as part of a common heritage.

A group of female dolphins has been learning from their mothers to use sponges to help catch fish for at least 180 years, a UNSW study has found.

Sentinel-2A is demonstrating how it can be used to help forecast ocean waves around our coasts: sunlight reflected from the water surface reveals complex waves as they encounter the coastline and seafloor off the tip of Dorre Island, Western Australia.

Sentinel-2A is demonstrating how it can be used to help forecast ocean waves around our coasts: sunlight reflected from the water surface reveals complex waves as they encounter the coastline and seafloor off the tip of Dorre Island, Western Australia.

Voici le ver Bobbit, l'un des plus terrifiants prédateurs des océans.

Voici le ver Bobbit, l'un des plus terrifiants prédateurs des océans.

Disrupting just one process in the important relationship between microbes and bigger plants and animals that live in ocean floor sediment may have knock-on effects that could reduce the productivity of coastal ecosystems, according to international research published online yesterday in Philosophical Transactions of the Royal Society B.

Mini-sub dives again after aborting first MH370 search.