Ocean alkalinity enhancement (OAE) is an emerging carbon dioxide removal (CDR) strategy that leverages the natural processes of weathering and acid neutralisation to durably store atmospheric CO2 in seawater. OAE can be achieved with a variety of methods, all of which have different environmental implications. One widely considered method utilizes electrochemistry to remove strong acid from seawater, leaving sodium hydroxide (NaOH) behind. This study evaluates the impacts of OAE via NaOH (NaOH-OAE) on a coastal plankton bloom, with particular focus on how macronutrient regeneration in the aftermath of the bloom responds to the perturbation. To investigate this, we enclosed a natural coastal phytoplankton community, including coccolithophores, in nine microcosms. The microcosms were divided into three groups: control, unequilibrated (512.1 ± 2.5 µmol kg-1 alkalinity increase) and equilibrated (499.3 ±5.65 µmol kg-1 alkalinity increase). Light was provided for 11 days to stimulate a bloom (light phase) and lights were turned off thereafter to investigate alkalinity and nutrient changes for 21 days (dark phase). We found no detectable effect of equilibrated NaOH-OAE on phytoplankton community and bacteria abundances determined with flow cytometry but observed a small yet detectable restructuring of phytoplankton communities under unequilibrated conditions. NaOH-OAE had no significant effect on alkalinity, NOx- and phosphate regeneration, but increased silicate regeneration by 64% over 21 days under darkness in the unequilibrated treatments where seawater pH was highest (8.65 relative to 7.92 in the control). Additional dissolution experiments with two diatom species supported this outcome on silicate regeneration for one of the two species, thereby suggesting that the effect is species specific. Our results point towards the potential of NaOH-OAE to influence regeneration of silicate in the surface ocean and thus the growth of diatoms, at least under the very extreme NaOH-OAE conditions simulated here.

These files contain the data recorded from a mesocosm experiment conducted in Bergen, Norway 2022 which assessed the effect of simualted mineral-based (silicate or calcium) ocean alkalinity enhancement (OAE) on diatom silicification. Ten mesocosms were used in total, divided into two groups either the silicate- or calcium based group and alkalinity was increased by either 0, 150, 300, 450 or 600 µmol L-1 above natrually occuring levels. The PDMPO-fluorescence (an appropriate proxy for silicification) of diatoms was recorded on eight seperate days during the experiment. Accompanying data includes measured; macronutrients (nitrate, nitrite, phophate, silicate), total alkalinity, biogenic silica in the water column and sediment trap.

Physical and chemical parameters at five Pacific oyster (Crassostrea gigas) growing areas in Tasmania - Pittwater, Pipeclay Lagoon, Little Swanport, Georges Bay and Simpsons Bay - were measured as part of a study to determine the carrying capacity of the areas for oyster farming. The data represented by this record, was collected in Pipeclay Lagoon. This has provided valuable environmental data for these areas. The hydrodynamic regimes at each area except Simpsons Bay were studied, including high and low water volumes, flushing rates, flow rates and depth contours. Temperature, salinity and concentrations of nitrates, phosphates, silicates and chlorophyll a were measured monthly at several sites in each area. The change in these parameters over different time scales also was examined at two sites in Pittwater and indicated temporal and spatial variability in the environmental parameters measured.

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).

Quantitative surveys were undertaken at five sites in the Kent Group, north eastern Tasmania (Murray Pass, Winter Cove, Little Squally Cove,and southern end of Erith Island) by divers using underwater visual census methods to survey the reef habitat. Additional spot dive surveys were undertaken at northern side of East Cove, Garden Cove, Winter Cove, Squally Cove (Deal Island), northern and southern sides of West Cove (Erith Island) and north east and north west coasts of Dover Island. Divers recorded numbers of sea urchins (Centrostephanus rodgersii and Heliocidaris erythrogramma), as well as extent of urchin barrens, size of algal patches, and measured boundaries of macroalgal patches of Macrocystis angustifolia, Phyllospora comosa and Ecklonia radiata-fucoid communities. Spot dives detailed additional qualitative observations of C. rodgersii.

This record provides an overview of the scope and research output of NESP Marine Biodiversity Hub Project B3 - "Enhancing access to relevant marine information –developing a service for searching, aggregating and filtering collections of linked open marine data". For specific data outputs from this project, please see child records associated with this metadata. -------------------- This project aims to improve the searchability and delivery of sources of linked open data, and to provide the ability to forward collections of discovered data to web services for subsequent processing through the development of a linked open data search tool. This work will improve access to existing data collections, and facilitate the development of new applications by acting as an aggregator of links to streams of marine data. The work will benefit managers (i.e. Department of the Environment staff) by providing fast and simple access to a wide range of marine information products, and offering a means of quickly synthesizing and aggregating multiple sources of information. Planned Outputs • Delivery of open source code to perform the search functions described above. • A simple initial web interface for performing the search and retrieval of results. • Expanded collections of data holdings available in linked open format, including the use of semantic mark-up to enable fully-automated data aggregation and web services. In particular, addition of linked-open data capability to a pilot collection of existing data sets (GA, CERF and NERP data sets).

We evaluate the status of shellfish reef ecosystems in Australia including their historical distribution and loss, regulation and management and identify current research priorities, policies and conservation mechanisms that can enable their future protection and repair. Eight species of shellfish were identified as developing complex, three-dimensional reef systems over large scales in intertidal and subtidal areas across tropical, subtropical and temperate Australia. A dramatic decline in the extent and condition of Australia’s shellfish reef ecosystems occurred during the mid-1800s to early 1900s in concurrence with extensive harvesting for food and lime production, habitat modification, disease outbreaks and a decline in water quality. Despite early attempts during the late 1800s to curb over exploitation and repair degraded reefs through protection, primitive aquaculture and enhancement, living examples of shellfish reefs are now rare. Only one Ostrea angasi reef is known to exist that is comparable in size to reefs historically commercially fished, compared to at least 118 previously known locations. Out of the 60 historically fished locations identified for Saccostrea glomerata, only five are known to still contain commercially harvestable sized reefs. The introduced oyster Crasostrea gigas is increasing in reef extent, whilst data on the remaining five reef-building species is limited, preventing a detailed assessment of their current status. Our knowledge of the extent, physical characteristics, biodiversity and ecosystem services of natural shellfish reefs in Australia is extremely limited. Australia is well equipped to reverse the decline of shellfish reef ecosystems with a number of state and federal protection laws, international conventions and management mechanisms already in place, all of which can be used to help protect remaining reefs and aid in future recovery. Several restoration projects have recently begun as awareness of historical loss grows amongst the community and groups become motivated to implement repair. As momentum continues to grow, Australia could serve as a long-term model for other regions that may currently have limited understanding of their shellfish reefs ecosystems but wish to work towards their future conservation. Data to be made publicly available with publication of manuscript by end 2018.

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 Mount Gardner, a site located just off Two People’s Bay, 30km east of the town of Albany. The area is host to a number of human uses, including recreational and commercial fishing, diving, surfing, recreational boat use and shipping and mining. The marine environment at this location is different to the other three study locations on the south coast, in that it encompasses the protected Two Peoples Bay with seagrass and invertebrate communities and the more exposed rocky and macroalgal reefs around the Mt Gardner peninsula itself.

Redmap is a primarily a website that invites the community to spot, log and map marine species that are uncommon in their region, or along particular parts of their coast. The information collected is mapped and displayed on the site, demonstrating, in time, how species distributions may be changing. Sightings are divided into two categories – those with a photo that can be ‘verified’ by a marine biologist, and sightings without photos that we call community sightings (anecdotal). All the information collected, with and without photos, is mapped and will be used in the following years to map out a ‘story’ of changes occurring in our marine environment. The main data collected includes the species sighted (normally selected from a list comprising preselected species of interest), the location, date/time and activity being undertaken. Other optional information gathered include biological data such as sex, size and weight and environmental data such as water depth and temperature and habitat. This record is associated with live data (and will subsequently change over time) and spatial elements have reduced accuracy. It is also subject to a three year embargo (ie. does not contain data less than three years old). If you wish to discuss obtaining a citable, static dataset, that is current and/or contains accurate spatial elements, please see Point of Contact.

Redmap is a primarily a website that invites the community to spot, log and map marine species that are uncommon in their region, or along particular parts of their coast. The information collected is mapped and displayed on the site, demonstrating, in time, how species distributions may be changing. Sightings are divided into two categories – those with a photo that can be ‘verified’ by a marine biologist, and sightings without photos that we call community sightings (anecdotal). All the information collected, with and without photos, is mapped and will be used in the following years to map out a ‘story’ of changes occurring in our marine environment. The main data collected includes the species sighted (normally selected from a list comprising preselected species of interest), the location, date/time and activity being undertaken. Other optional information gathered include biological data such as sex, size and weight and environmental data such as water depth and temperature and habitat. This record is associated with live data (and will subsequently change over time) and spatial elements have reduced accuracy. It is also subject to a three year embargo (ie. does not contain data less than three years old). If you wish to discuss obtaining a citable, static dataset, that is current and/or contains accurate spatial elements, please see Point of Contact.