Keyword

EARTH SCIENCE | BIOLOGICAL CLASSIFICATION | PLANTS | MACROALGAE (SEAWEEDS)

28 record(s)
 
Type of resources
Topics
Keywords
Contact for the resource
Provided by
Years
From 1 - 10 / 28
  • Most research investigating how ocean warming and acidification will impact marine species has focused on visually dominant species, such as kelps and corals, while ignoring visually cryptic species such as crustose coralline algae (CCA). CCA are important keystone species that provide settlement cues for invertebrate larvae and can be highly sensitive to global ocean change. However, few studies have assessed how CCA respond to low emission scenarios or conditions. In a laboratory experiment, we examined the responses of temperate CCA assemblages to combined warming and acidification projected under low, medium, and high emissions. Net calcification and net photosynthesis significantly declined in all emissions scenarios, while significant reductions in relative growth rates and increases in percentage bleaching were observed in the highest emission scenario. The negative responses of CCA to both low and medium emissions suggest that they may be adversely impacted by combined warming and acidification by 2030 if current emissions are sustained. This will have far reaching consequences for commercially important invertebrates that rely on them to induce settlement of larvae. These findings highlight the need to take rapid action to preserve these critical keystone species and the valuable services they provide.

  • Categories  

    An aerial survey was conducted for giant kelp (Macrocystis pyrifera) on the east coast of Tasmania from Eddystone Point to Southeast Cape. This survey represents part of a series of similar surveys, with historic aerial surveys having been conducted in 1986 and 1999. The survey was conducted via light aircraft. Areas of visable Macrocystis pyrifera beds were marked on topographical land tenure maps using landmarks as references, and complimentary photo footage was collected.

  • In coastal ecosystems, seaweeds provide habitat and a food source for a variety of species including herbivores of commercial importance. In these systems seaweeds are the ultimate source of energy with any changes in the seaweeds invariably affecting species of higher trophic levels. Seaweeds are rich sources of nutritionally important compounds such as polyunsaturated fatty acids (PUFA) and are particularly rich in long-chain (≥ C20) PUFA (LC-PUFA). In southern Australia, the ‘Great Southern Reef’ has one of the most diverse assemblages of seaweeds in the world, which support highly productive fisheries and have been recognised as a promising resource of omega-3 LC-PUFA. Despite this, there is little information on the biochemical composition of most species and how it varies between sites and seasons. To address this knowledge gap, we undertook a survey to assess seasonal variability in the biochemical composition (fatty acids and nitrogen content) of abundant understory seaweeds across three sites in eastern Tasmania. The availability of nutritional compounds differed between sites and was primarily driven by differences in the biomass and the biochemical composition of the nutritious red seaweeds at each site. This variability may explain regional differences in the productivity of commercial fisheries. At the species level, seasonal changes in fatty acid composition were highly variable between species and sites, indicating that multiple environmental drivers influence fatty acid composition of seaweeds in this system. This finding suggests that commercial harvest of seaweeds from eastern Tasmania will need to consider species and site-specific variability in fatty acid composition.

  • Categories  

    Annotations of Centrostephanus rogersii sea urchin barrens derived from towed video at selected key abalone blocks along the east coast of Tasmania. The purpose of the study was to examine the patch dynamics of urchin barrens and to provide validation for the identification of urchin barrens from multibeam surveys.

  • The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including Rottnest Island, a popular family holiday destination just 20 km off the Perth coast. One of the main drawcards of the island is the diverse marine life inhabiting the surounding waters, which Western Australian locals and tourists can experience by snorkelling, diving, boating and fishing. The marine environment around Rottnest includes seagrass meadows, kelp-covered reef tops, coral patches, and sponge gardens in deeper water. As a result of the warm, southward flowing Leeuwin Current, the island represents the southern limit of the distributions of many tropical corals and fish. The marine life around Rottnest therefore represents a unique mix of tropical and temperate species and habitats.

  • The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including Jurien Bay. The Jurien Bay marine environment is highly diverse, and is home to a wide variety of species, including sea lions and sea birds on the many offshore islands. Limestone reef and seagrass habitats in the area support a diverse fish and invertebrate fauna, and a local crayfishing industry is based around the Western Rock Lobster (Panulirus cygnus).

  • The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including Broke Inlet, a relatively remote area 400km south of Perth, between the towns of Augusta and Albany. The nearest major town, Manjimup, is situated 100km north and the small coastal settlement Windy Harbour approximately 30km west of Broke Inlet. The Inlet is entirely surrounded by the D’Entrecasteaux National Park, which is accessible via a sealed road and attracts limited ‘through-traffic’ to the area. The marine environment off Broke is one fairly untouched by major tourism pressures and thus this location was selected due to its relative inaccessibility.

  • The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including Point Ann, a site which lies within the Fitzgerald Biosphere, a UNESCO designated International Biosphere Reserve and one of the largest and biologically significant National Parks in Australia (DEC) on West Australia’s south coast, approximately 180km east of Albany.

  • Categories    

    Annotations of canopy forming seaweed derived from towed video at selected key abalone blocks along the east coast of Tasmania. The purpose of the study was to examine the patch dynamics of seaweeds and urchin barrens and to provide validation for the identification of urchin barrens from multibeam surveys.

  • The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including the Capes region of southwest Western Australia. The area is one of the most diverse temperate marine environments in Australia. Warm, tropical waters of the Leeuwin Current mingle with the cool waters of the Capes Current, resulting in high finfish diversity, including tropical and temperate species, as well as internationally significant seagrass diversity with meadows occurring at depths greater than 40 metres. The region's geomorphology is complex with an array of intertidal and subtidal reef environments. Many marine plants and animals are endemic to the southern coast of Australia due to its long geographical isolation, with seagrass, algae and estuarine habitats functioning as spawning, nursery and feeding grounds for a wide range of invertebrates and fish. Significant numbers of marine mammals also frequent the area, including the blue whale, the largest of all marine creatures.