SECTION 1 SEASCAPE


SEASCAPE

This section presents a marine ecosystem account for the GBR Region. It includes measures that provide a broad indication of the condition of the marine area, and is drawn from the detailed and extensive data presented in the Great Barrier Reef Outlook Report series, published every five years by the Great Barrier Reef Marine Park Authority (GBRMPA). Assessments of more marine ecosystem assets will be able to be added with time, resources and continued assessment of datasets feeding into the Outlook Report.

The scope of the marine section of the ecosystems account is the marine area within the Great Barrier Reef World Heritage Area. Note that an assessment of condition and extent of the islands within this area is not included.

The marine account used ABS experience in developing land accounts to build a remotely sensed asset account, describing the extent of each class of marine ecosystem and corresponding changes in extent over time, as well as measures of use, condition and where possible, value of those assets. However, annual consistent time series of remotely sensed data on marine ecosystems for the region were not available. This is in contrast to the well-established remotely sensed datasets on land cover and condition as reported in the Landscape section of this publication. Consequently, an asset account was not able to be constructed and this release focuses on condition measures and use.

While an asset account is not presented for the marine area, the following areas were reported by GBRMPA in 2013 for the extent of marine assets within the Great Barrier Reef Marine Park:

• Mangroves 2,070km²
• Seagrass meadows - shallow (<15m from surface) 5,700km², - deep (>15m from surface) 40,000km²
• Coral reefs - 26,000km²
• Lagoon floor 210,000km²
• Shoals 278km²

MARINE USE

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'.

	Opening Area	Net Change in Area	Closing Area
	pre 2004 Rezoning		post 2004 Rezoning
Zone Type	sq km	sq km	sq km
Preservation Zone	344	344	688
Marine National Park	15 842	98 843	114 685
Scientific Research	34	310	344
Buffer	344	9 643	9 988
Conservation Park	2 066	3 100	5 166
Habitat Protection	52 349	44 771	97 120
General Use	268 288	-157 012	111 276
Total GBR Marine Park	339 268	0	339 268
sq km - square kilometres
Source: Table 6.4 Changes in Zone Area following 2004 Rezoning, GBRMPA, 2009, p.126.

Coral

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.

NRM Region	2007-08	2008-09	2009-10	2010-11	2011-12	2012-13
Burdekin	100	110	95	88	70	78
Fitzroy	100	89	100	82	42	37
Mackay Whitsunday	100	107	87	84	82	95
Wet Tropics	100	108	109	77	68	70
Total GBR Region	100	102	96	81	67	73
Source: Reef Water Quality Protection Plan, Report Card series, Commonwealth and Queensland governments (various issues)

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.

		2003	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013
NRM Region	Indicator
Burdekin	average %	20.8	19.6	20.9	13.9	21.8	11.9	22.1	14.2	16.0	7.3	19.3
	no. reefs	9	9	15	18	14	16	14	16	15	16	14
Burnett Mary	average %	75.4	73.6	66.1	74.1	70.4	64.8	15.6	10.5	1.6	9.4	3.8
	no. reefs	2	2	2	4	2	4	2	4	2	4	2
Cape York	average %	37.0	37.8	33.1	na	29.4	na	32.2	na	36.3	na	30.3
	no. reefs	8	8	8	0	8	0	8	0	8	0	8
Fitzroy	average %	35.3	33.8	38.9	31.4	34.4	31.2	32.1	22.4	19.2	20.8	21.9
	no. reefs	9	9	15	31	12	30	13	30	14	30	13
Mackay Whitsunday	average %	29.5	31.3	34.0	35.4	37.0	35.9	32.0	28.8	26.8	29.2	29.8
	no. reefs	9	9	16	10	14	8	14	8	14	8	14
Wet Tropics	average %	17.8	18.4	26.9	24.0	26.1	26.7	30.9	32.2	24.7	20.7	22.8
	no. reefs	10	10	26	28	20	22	19	22	21	22	19
Total GBR Region	average %	29.7	29.7	31.0	28.0	30.5	28.2	29.3	23.5	22.9	18.3	23.6
	no. reefs	47	47	82	91	70	80	70	80	74	80	70
na - not available
Source: Long-Term Monitoring Program (LTMP), Australian Institute of Marine Science (AIMS)

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.

		2003	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013
GBRMPA Management Sector	Indicator
Northern Inshore	average %	26	27	29	33	32	38	36	42	35	30	28
	no. reefs	7	7	11	6	9	4	9	4	9	4	9
Northern Offshore	average %	38	38	31	na	26	na	30	na	35	na	29
	no. reefs	6	6	6	0	6	0	6	0	6	0	6
Southern Inshore	average %	21	22	30	26	30	28	31	29	23	22	24
	no. reefs	11	11	41	41	33	33	32	33	36	33	32
Southern Offshore	average %	32	32	32	29	32	28	25	18	16	15	20
	no. reefs	23	23	23	43	22	43	23	43	23	43	23
Total GBR Region	average %	30	30	31	28	31	28	29	24	23	18	24
	no. reefs	47	47	82	91	70	80	70	80	74	80	70
na - not available
Source: Long-Term Monitoring Program (LTMP), Australian Institute of Marine Science (AIMS)

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 QUALITY

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).

	2005-06	2006-07	2007-08	2008-09	2009-10	2010-11
NRM Marine Region
Burdekin	100	106	121	121	146	121
Burnett Mary	100	99	84	95	72	57
Cape York	100	74	121	87	128	90
Fitzroy	100	98	91	100	100	59
Mackay Whitsunday	100	86	88	98	116	54
Wet Tropics	100	78	136	106	133	108
Total GBR Region	100	95	100	102	115	73
Source: Reef Water Quality Protection Plan, Report Card series, Commonwealth and Queensland governments (various issues)

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.


SEAGRASS

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.

	2005-06	2006-07	2007-08	2008-09	2009-10	2010-11	2011-12	2012-13
NRM Marine Region
Burdekin	100	92	67	67	53	22	29	62
Burnett Mary	100	94	69	97	60	34	50	33
Cape York	100	34	65	66	111	69	34	45
Fitzroy	100	70	61	54	69	58	42	38
Mackay Whitsunday	100	128	77	54	62	15	21	38
Wet Tropics	100	145	140	175	170	115	108	115
Total GBR Region	100	107	82	80	77	43	44	64
Source: Reef Water Quality Protection Plan, Report Card series, Commonwealth and Queensland governments (various issues)

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.


FISH

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.

	2001	2002	2003	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013
NRM Marine Region
Burdekin	100	112	107	119	117	134	102	132	107	136	102	139	102
Burnett Mary	100	105	122	112	120	140	119	130	109	126	64	122	58
Cape York	100	100	100	102	103	na	104	na	107	na	101	na	106
Fitzroy	100	102	101	103	115	107	106	105	106	107	96	104	92
Mackay Whitsunday	100	100	105	107	104	100	109	95	113	105	106	102	111
Wet Tropics	100	102	104	104	103	111	103	115	103	114	101	116	103
na - not available
Source: Long-Term Monitoring Program (LTMP), Australian Institute of Marine Science (AIMS)

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.

	2001	2002	2003	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013
GBRMPA Management Sector
Northern Inshore	100	102	101	104	100	110	100	110	101	110	99	115	101
Northern Offshore	100	101	100	103	104	na	104	na	108	na	102	na	107
Southern Inshore	100	114	109	118	118	146	109	151	109	150	105	149	109
Southern Offshore	100	101	106	106	110	109	108	106	109	108	98	108	98
na - not available
Source: Long-Term Monitoring Program (LTMP), Australian Institute of Marine Science (AIMS)

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