Este artículo contiene 13 páginas, 6 figuras, 3 tablas. ; Seagrass meadows are highly productive ecosystems that provide ecosystem services to the coastal zone but are declining globally, particularly due to anthropogenic activities that reduce the quantity of light reaching seagrasses, such as dredging, river discharge and eutrophication. Light quality (the spectral composition of the light) is also altered by these anthropogenic stressors as the differential attenuation of wavelengths of light is caused by materials within the water column. This study addressed the effect of altered light quality on different life-history stages of the seagrass Posidonia australis, a persistent, habitat-forming species in Australia. Aquarium-based experiments were conducted to determine how adult shoots and seedlings respond to blue (peak λ = 451 nm); green (peak λ = 522 nm); yellow (peak λ = 596 nm) and red (peak λ = 673 nm) wavelengths with a control of full-spectrum light (λ = 400 – 700 nm, at 200 µmol photons m−2 s −1 ). Posidonia australis adults did not respond to changes in light quality relative to full-spectrum light, demonstrating a capacity to obtain enough photons from a range of wavelengths across the visible spectrum to maintain shortterm growth at high irradiances. Posidonia australis seedlings (<4 months old) grown in blue light showed a significant increase in xanthophyll concentrations when compared to plants grown in full-spectrum, demonstrating a pigment acclimation response to blue light. These results differed significantly from negative responses to changes in light quality recently described for Halophila ovalis, a colonizing seagrass species. Persistent seagrasses such as P. australis, appear to be better at tolerating short-term changes in light quality compared to colonizing species when sufficient PPFD is present. ; Funding from the Western Australian Marine Science Institution (WAMSI, Dredging Science Node), Woodside Energy, Chevron Australia, and BHP Billiton as environmental offsets and by coinvestment from the WAMSI Joint Venture partners provided crucial funds that were used to build, maintain and run all aquarium experiments throughout this document. This research was also partially funded through the Australian Commonwealth Government's Collaborative Research networks scheme (Grant CRN2011:05) and the School of Science, Edith Cowan University. ; Peer reviewed
Healthy coastal habitats like seagrass meadows, coastal saltmarsh, kelp forests, coral and shellfish reefs, and mangrove forests ('blue infrastructure') are essential to the economic and social well-being of coastal communities. These habitats drive coastal productivity supporting our fisheries and other industries associated with recreation in marine environments, improve water quality, sequester carbon, protect shorelines from erosion, and support thriving biodiversity, including threatened species. These habitats are under pressure from coastal development, climate change, pollution, invasive species and other anthropogenic pressures, which have led to drastic declines in many of our important marine and coastal habitats. Under the division of powers between the Australian Government and the states under the Australian Constitution, states and territories have the primary responsibility for environmental protection of coastal habitats within three nautical miles of the coastline. The Environment Protection and Biodiversity Conservation Act 1999 (C'th) (the EPBC Act) enables the Australian Federal Government to join with the states and territories in providing a national scheme of environment and heritage protection and biodiversity conservation. The EPBC Act focuses Australian Government interests on the protection of nine Matters of National Environmental Significance (MNES). These include World Heritage Areas and Ramsar wetlands, threatened and endangered species and habitats, and migratory species protected through international agreements, and Commonwealth Marine Areas. Given the current state of decline in natural ecosystems, there is a general consensus that there are two paths to conserve critical habitats; habitats can either be protected from extractive or destructive human influences (e.g. through national parks, marine reserves, fishery closures, gear restrictions or riparian conservation), and/or actively rehabilitated towards a preferred healthy state (i.e. restoration). Early environmental conservation was primarily focused on the former of these methods, with the establishment of national parks and conservation areas globally, and sector-based management of remaining pressures. However, despite these intensive interventions, many habitats have continued to decline over the past half century. There is increasing recognition that protection by itself is no longer sufficient and interest and demand for rehabilitation in the form of interventions and restoration has been growing. Restoration is now seen as a key element in achieving conservation and environmental management goals internationally. In recent decades, nations such as the United States, Canada and the United Kingdom have embraced the need for large-scale marine and coastal restoration. Further, restoration also produces economic benefits. For example, restoration activities were recently estimated to contribute almost US$25 billion and 221,000 jobs annually to the United States economy. In this report we review the state of four ecologically critical coastal marine habitats in Australia; seagrass meadows, kelp forests, shellfish reefs, and coastal saltmarsh wetlands, and evaluate (1) the Commonwealth responsibility for the habitat under the EPBC Act, (2) capacity of habitat restoration to insulate against loss and degradation of MNES, through restoration of key habitats and the species they support, (3) recent advances in restoration with the potential to improve outcomes associated with MNES. This report demonstrates that each of the four habitats fall under up to six of the nine MNES, by being directly listed as or supporting threatened species or ecosystems, providing habitat for listed migratory species, and being important components of World Heritage Areas, Commonwealth waters, the Great Barrier Reef Marine Park, and Ramsar wetlands. For example, giant kelp (Macrocystis pyrifera) forests are listed as an endangered ecological community; temperate and subtropical saltmarshes are listed as a vulnerable ecological community and three saltmarsh species are listed as vulnerable. In addition, the habitats formed by the two primary reef-forming oyster species are under consideration for listing as endangered ecological communities under the EPBC Act. Coastal saltmarshes provide critical habitat for listed threatened species, such as the green and golden bell frog (Litoria aurea) and the orange-bellied parrot (Neophema chrysogaster), and migratory species such as the eastern curlew (Numenius madagascariensis), the Pacific golden plover (Pluvialis fulva), the sharp-tailed sandpiper (Calidris acuminata), and the red-necked stint (Calidris ruficollis). Seagrass habitats make up a large proportion of the Great Barrier Reef Marine Park and World Heritage Area and support listed turtle species and dugong. Similarly, kelp forests support a disproportionately high number of endemic species, including several listed under the EPBC At, including the spotted handfish (Brachionichthys hirsutus, critically endangered), red handfish (Thymichthys politus, critically endangered), Ziebell's handfish (Brachiopsilus ziebelli, vulnerable), black rockcod (Epinephelus daemelii, vulnerable) and members of the Syngnathidae family (seadragons, seahorses and pipefish).
Este artículo contiene 10 páginas, 3 tablas, 2 figuras. ; Policies aiming to preserve vegetated coastal ecosystems (VCE; tidal marshes, mangroves and seagrasses) to mitigate greenhouse gas emissions require national assessments of blue carbon resources. Here, we present organic carbon (C) storage in VCE across Australian climate regions and estimate potential annual CO2 emission benefits of VCE conservation and restoration. Australia contributes 5–11% of the C stored in VCE globally (70–185 Tg C in aboveground biomass, and 1,055–1,540 Tg C in the upper 1m of soils). Potential CO2 emissions from current VCE losses are estimated at 2.1–3.1 Tg CO2-e yr-1, increasing annual CO2 emissions from land use change in Australia by 12–21%. This assessment, the most comprehensive for any nation to-date, demonstrates the potential of conservation and restoration of VCE to underpin national policy development for reducing greenhouse gas emissions. ; This project was supported by the CSIRO Marine and Coastal Carbon Biogeochemical Cluster, CSIRO Oceans and Atmosphere, the ECU Faculty Research Grant Scheme and Early Career Research Grant Schemes, UTS Plant Functional Biology and Climate Change Cluster, NSW Southeast Local Land Services, Department of Environment, Land, Water and Planning (DELWP), Parks Victoria, Victorian Coastal Catchment Management Authorities (GHCMA, CCMA, PPWCMA, WGCMA, EGCMA), University of Queensland Centennial Scholarship, Hodgkin Trust Scholarship, Australian Institute of Nuclear Science and Engineering, Northern Territory Government Innovation Grant, Australian Research Council (DE130101084, DE140101733, DE150100581, DE160100443, DE170101524, DP150103286, DP150102092, DP160100248, DP160100248, DP180101285, LE140100083, LE170100219, LP150100519, LP160100242 and LP110200975), the Generalitat de Catalunya (MERS 2014 SGR-1356), the ICTA 'Unit of Excellence' (MinECo, MDM2015-0552), Obra Social "LaCaixa", SUMILEN, CTM 2013-47728-R, Ministry of Economy and Competitiveness and UKM-DIP-2017- 005. ; Peer reviewed
