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SECTION 1 SEASCAPE
A Marine Account, analogous to the land use accounts, was developed using zoning data from the GBRMPA. The Great Barrier Reef Marine Park Zoning Plan 2003, which came into effect on 1 July 2004, was enacted to protect the biodiversity within the park better. The plan helps 'to ensure that a diverse range of other benefits and values of the Marine Park, including recreational, cultural, educational and scientific values are protected' (Zoning, Permits and Plans, GBRMPA).
Table 1.1 below sets out the area of each zone type before and after 1 July 2004 while Figure 1.1 displays the current zoning in a map. The 2004 re-zoning resulted in a large decline in the amount of area classified as 'General Use', with large increases in the area of 'Habitat Protection' and 'Marine National Park'.
TABLE 1.1: MARINE ZONING (USE) ACCOUNT, GREAT BARRIER REEF MARINE PARK, at 01 July 2004
FIGURE 1.1: MAP OF GREAT BARRIER REEF MARINE PARK ZONING, 2004 to Present
The presence of coral in the Great Barrier Reef Region is central to the areas identification as a World Heritage Area. It is critical to fish populations, to the provision of recreation opportunities (such as snorkelling), and to other ecosystem services.
TABLE 1.2: INSHORE CORAL CONDITION, BY SELECTED NRM REGIONS, GREAT BARRIER REEF REGION, 2007-08 to 2011-12, Index (2007-08 = 100)
The Fitzroy NRM Region recorded the biggest overall drop in coral condition over the period 2007-08 to 2012-13, with condition decreasing by 64 per cent. No regions recorded an increase in the overall condition of coral, and the GBR Region decreased by 28 per cent over the reference period.
Hard coral cover is a component of inshore coral condition and data on this characteristic is also available for offshore areas. Tables 1.3 and 1.4 below present hard coral cover as a measure of condition for coral across the marine area. Note that the data below is based on a sample of reefs, and not the total number in each region.
TABLE 1.3: NUMBER OF REEFS SAMPLED AND HARD CORAL COVER (AVERAGE PERCENTAGE OF TOTAL REEF AREA), BY NRM REGION (INCLUDING OFFSHORE), GREAT BARRIER REEF REGION, 2003 to 2013 (Calendar Years)
The Burnett Mary NRM Region reported the largest decline (95 per cent) in hard coral cover between 2003 and 2013. It is also the least sampled area, with sampling in some years reduced to two reefs. 'Lady Musgrave' and 'One Tree' are the two reefs that contributed to this area's scores in 2009, 2011 and 2013. The scores were at high levels in 2003, but the low cover levels seen in the later years of the time series are similar to those recorded by these reefs in the early 1990s. This is an example where users should be aware of the limitations of using a reference condition based on the beginning of time series, rather than that of the original or natural state.
Of the six NRM Marine Regions, the Mackay Whitsunday NRM Region and Wet Tropics NRM Regions are the only areas to record an increase in hard coral cover, with increases of 1 and 28 per cent respectively. The total marine area recorded an average decrease in hard coral cover of 20 per cent between 2003 to 2013.
TABLE 1.4: NUMBER OF REEFS SAMPLED AND HARD CORAL COVER (AVERAGE PERCENTAGE OF TOTAL REEF AREA), BY GREAT BARRIER REEF MARINE PARK AUTHORITY MANAGEMENT (GBRMPA), Sector, 2003 to 2013 (Calendar Years)
Table 1.4 shows that the inshore sectors recorded increases in hard coral cover as a percentage of total reef area between 2003 and 2013. The Northern Inshore sector increased by 5 per cent between 2003 and 2013, and the Southern Inshore sector by 15 per cent. These changes were more than offset by decreases in hard coral cover in the offshore sectors in the same period. The Northern Offshore sector decreased by 23 per cent between 2003 and 2013, and the Southern Offshore sector by 40 per cent.
The offshore sectors recorded significant falls in percentage cover in recent years. The Northern Offshore sector decreased by 17.1 per cent between 2011 and 2013, and the Southern Offshore sector by 25 per cent between 2009 and 2010. These changes can be attributed in large part to the Category 5 cyclones that impacted those management sectors. Cyclone Hamish progressed along the offshore portion of the marine area for five days in March 2009, while Cyclone Yasi crossed the northern area of the Great Barrier Reef Marine Park in February 2011.
These two cyclones are not the only two to inflict damage on the GBR Region. It has been estimated that 'between 1995 and 2009, approximately 34 per cent of all coral mortality recorded in the Great Barrier Reef Long Term Monitoring Program has been caused by storm damage' (Managing the Reef, GBRMPA).
Water, both fresh and sea water, links inland and offshore activities and ecosystems. A measurement of water quality for both inland and marine areas are an important part of this account. See River Loads in the Landscape Section for a discussion of inland areas.
Reef Plan indicators of water quality (sourced from the Report Card series) have been used due to their close description of the assets ability to contribute to the health and ongoing function of the marine ecosystem. For example, suspended solids impact on the amount of sunlight reaching seagrasses, and chlorophyll is a measure of eutrophication. Note that the methods used to derive Water Quality indicators changed for the 2011-12 reporting year and are not presented in this time series(footnote 1).
TABLE 1.5: WATER QUALITY SCORES, BY NRM MARINE REGION, GREAT BARRIER REEF REGION, 2005-06 to 2010-11, Index (2005-06 = 100)
The Wet Tropics and Burdekin NRM Regions were the only NRM Regions with an increase in water quality from 2005-06 to 2010-11 with all other NRM Regions showing a drop in water quality, most notably between 2009-10 and 2010-11. The Mackay Whitsunday NRM Region fell more than 50 per cent from an index score of 116 in 2009-10 to 53 in 2010-11, while the Fitzroy NRM Region was relatively stable through the first five years of the reference period before falling 41 per cent in 2010-11 to a closing condition index of 59.
More than half of the seagrass species found in Australia are present in the marine area of the GBR Region. Seagrasses vary from small and short-lived to large and long-lived structures. They are not true grasses but are an ecological group that arose through convergent evolution. All except one of the fifteen seagrass species found in the area can survive totally submerged in salt water. Seagrasses provide habitat for diverse marine communities, are primary producers and storers of carbon and help to stabilise the sediments at the floor of the marine environment.
TABLE 1.6: SEAGRASS CONDITION SCORES, BY NRM MARINE REGION, GREAT BARRIER REEF REGION, 2005-06 to 2012-13, Index (2005-06 = 100)
A large decrease in seagrass condition followed the significant flooding event in Queensland at the end of 2010 and beginning of 2011. Rivers such as the Fitzroy and Burnett reached heights not recorded for over fifty years. The weighted seagrass condition for the total marine area decreased by 34 percentage points (or 44 per cent) between 2009-10 and 2010-11. The Mackay Whitsunday NRM Region dropped 46 percentage points (or 75 per cent) in the same period, achieving a low index score of 15.
The Wet Tropics NRM Region, while variable over the time period presented here, has continuously been above the condition score of 100 in the reporting period. It is the only NRM Marine Region to be in better condition in 2012-13 than in 2005-06.
The diversity of fish species in the marine area is recognised in the World Heritage listing of the GBR Region. There are 1,625 species in the area, of which 1,400 are coral reef species. The presence and abundance of selected fish is considered an ecosystem condition measure. Tables 1.7 and 1.8 below present fish abundance scores for NRM Marine Regions and Management Sectors in the Great Barrier Reef Marine Park.
Data in both tables were sourced from the Long-Term Monitoring Program (LTMP) produced by the Australian Institute of Marine Science (AIMS). Data are collected across sites designed to monitor the impact of the 2004 re-zoning. The numbers of fish sighted in each sample area are averaged per reef and are referenced against a list of 'easy-to-identify' species.
Data for the first year of the time series are indexed at 100. For context, Tables 1.7 and 1.8 also include the average number of fish recorded per region in the reference year.
TABLE 1.7: FISH ABUNDANCE SCORES, BY NRM MARINE REGION, GREAT BARRIER REEF REGION, 2001 to 2013 (Calendar Years), Index (2001 = 100)
Table 1.7 above shows that the abundance of selected fish species has remained relatively stable across the majority of NRM Marine Regions. The exception is the Burnett Mary NRM Region, which saw a decrease of 42 per cent in the number of fish recorded between 2001 and 2013. The Mackay Whitsunday NRM Region recorded an increase of 11 percent in fish numbers over the same period, the largest increase among NRM Regions.
TABLE 1.8: FISH ABUNDANCE SCORES, BY GREAT BARRIER REEF MARINE PARK AUTHORITY (GBRMPA) MANAGEMENT SECTORS, 2001 to 2013 (Calendar Years), Index (2001 = 100)
Table 1.8 above shows the abundance of selected fish species has remained relatively stable across the majority of management sectors. Three sectors recorded an increase in fish numbers over the reference period with the largest being 9 per cent in the Southern Inshore sector. The only area to record a decrease was the Southern Offshore sector, which saw a fall of 2 per cent in the number of fish recorded between 2001 and 2013.
1. Reef Water Quality Protection Plan, Report Card series, Commonwealth and Queensland governments. <back
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