6 Marine environment | Supplementary Material

State of the Environment 2011 Committee. Australia state of the environment 2011.
Independent report to the Australian Government Minister for Sustainability, Environment, Water, Population and Communities.
Canberra: DSEWPaC, 2011.

6 Marine environment

Supplementary Material

Australia's coral reefs in a changing ocean

In the past two decades severe coral bleaching on Australian reefs were mainly confined to the Great Barrier Reef and other reefs at low latitudes (e.g. Scott Reef), however, recently the first extensive bleaching events have occurred around Ningaloo, Lord Howe Island, Houtman Abrolhos and Rottnest Island. As Australia moves into a high-CO2 era, ocean warming and acidification are predicted to continue from low to high latitudes. The medium to long-term projections indicate that the frequency and severity of coral bleaching events will continue to increase, accompanied by progressive ocean acidification.

Factors potentially affecting the resilience of temperate marine populations

Six main categories of factors have the potential to influence population resilience of fish species; these are climate change, fishing, coastal development, introduced marine pests, infectious diseases and the socio-economic influences associated with fishery management. Four different case studies of Australian commercial fish stocks; western rock lobster, southern rock lobster, eastern gemfish and tiger flathead; are used to provide a contrast to marine population resilience.

SoE 2011 National marine condition assessment - decision model and workshops

In the absence of strong regional or national indicator datasets, and to limit the bias inherent in a narrow information base, the SoE 2011 process adopted an expert elicitation approach to assess the condition and trends of Australia's marine environment. A select representative group of marine experts from various disciplines were engaged for a series of assessment workshops. The decision model, grading system and procedures are described. The overview results of the six assessment parameters for the five marine bioregions are presented.

Phytoplankton dynamics in shelf waters around Australia

A comprehensive summary of phytoplankton bloom occurrences, both in-water and surface expressions, for five coastal sites around Australia based on earth observation data of up to eight years (2003-2010). Concentrations in chlorophyll-a (CHL), a widely-used measure of algal biomass, were estimated for each site from the NASA-MODIS (Aqua) ocean colour sensor. Surface algal bloom expressions, likely composed of different phytoplankton species than the in-water algal blooms, were mapped by the ESA-MERIS (Envisat) ocean colour sensor. Time-series of satellite-derived CHL and surface bloom expressions are presented and discussed for the five reporting regions. Results show that the phytoplankton biomass varies in its cycle and amplitude depending on the Australian continental shelf region considered.

Case study: the resilience of the nature-based tourism system on Australia's Great Barrier Reef

Factors that affect the resilience of the nature-based tourism system on Australia's Great Barrier Reef include climate change and the sediments, nutrients, and pesticides from agriculture and coastal development. The lifestyle values of enterprise owners and staff are significant predictors of enterprise resilience to crises and change. Higher lifestyle values are also associated with a higher level of enterprise support for reef conservation, and a greater level of participation in reef conservation activities.

Vulnerability and status of marine fishes for the Australian State of Environment report 2011 - temperate species

An assessment of vulnerability were conducted on two species in the south-east corner of Australia: the red Morwong (Cheilodactylus fuscus), and the southern Maori wrasse (Ophthalomolepis lineolata). The red morwong, although locally abundant with high numbers of reproductive individuals, was classed as 'Vulnerable' because of its restricted spatial distribution. It is sensitive to climate change and local recreational fishing. This species responded rapidly to closure to fishing. The southern Maori wrasse is locally abundant, with high numbers of reproductive individuals, and its range extends longitudinally to Western Australia. Despite being landed in commercial numbers as bycatch, as well as landed locally by recreational fishers its vulnerability is low.

Vulnerability and status of marine fishes for the Australian State of Environment report 2011 - tropical species

Assessments of vulnerability and population status were completed for two species of coral reef fishes: the redfin butterflyfish (Chaetodon lunulatus), and the leopard coral trout (Plectropomus leopardus). The inherent vulnerability to extinction for both species was considered Low, given their reasonably large geographic ranges and ability to utilise a wide range of different reef habitats. The current population status for both C. lunulatus and P. leopardus was considered Good, with no evidence of long-term, reef-wide declines in abundance. The two species (C. lunulatus and P. leopardus) are each facing distinct threats, due to habitat degradation (especially coral loss) and direct fisheries exploitation, respectively. Current fisheries for Plectropomus spp. on the Great Barrier Reef do appear to be sustainable, and populations exhibit considerable resilience. With the recent expansion of no-take marine reserves, populations on reefs closed to fishing have recovered very quickly. In contrast, C. lunulatus appears to have Poor population resilience, with no recovery observed >5 years after severe coral bleaching in the central Great Barrier Reef.