Great Barrier Reef Marine Park Authority Submission to The independent assessment of the sugar industry’s viability and restructuring needs 1. Introduction 1.1 The Great Barrier Reef (GBR) is situated adjacent to the Queensland (and northeastern Australian) coast, and is the largest reef system in the world. The Great Barrier Reef World Heritage Area (GBRWHA) contains more than just coral reefs. It also contains many different community types, plants, animals and their habitats including extensive seagrass beds, mangrove forests, sandbanks, sponge and soft coral gardens, and soft bottom and island communities (Wakenfeld et al 1998). The reef is not a continuous barrier, but a broken maze of coral reefs and coral cays. It includes some 2,900 individual reefs, of which 760 are nearshore fringing reefs and another 200 plus inshore reefs close to the coast. 1.2 The GBR was proclaimed a Marine Park in 1975 and listed on the World Heritage Register in 1981 in recognition of its outstanding universal value (GBRMPA 1981). The protection of the values of the GBRWHA is the primary responsibility of the GBRMPA with approximately 99% of the GBRWHA falling within the boundaries of the GBRMP and therefore under the jurisdiction of the Great Barrier Reef Marine Park Act 1975 and Regulations 1983. 1.3 The Great Barrier Reef Marine Park (GBRMP) and GBRWHA have an interdependent relationship with adjacent coastal river catchments. The GBR Catchment covers 22% of Queensland‟s land area (~370,000 square kilometres) and contains 23% of its population (~800,000 people). This region accounts for approximately 30% of the Gross State Product and around 60% of exports (Gilbert 2001). 1.4 The direct economic value of the GBR for marine tourism, commercial fishing and recreational use is now estimated at around $1 billion annually and growing (Driml 1994, KPMG Consulting 2000), suggesting that the flow-on effects of the use of the reef underpins a significant portion of Queensland‟s regional economy. Many of these uses can potentially conflict with each other and with the protection of the values of the GBRWHA. 1.5 The coastal region adjoining the GBRWHA is divided into a number of wet and dry tropical catchments, with twenty six major catchment areas draining directly into the GBR lagoon (Gilbert 2001, GBRMPA 2001)). The region is a focus of agricultural production, tourism, industry, shipping and urban centres (Lucas et al. 1997; Gilbert 2001), all of which present a range of risks to the GBR in terms of pollution inputs. 1.6 Most activities affecting water quality in the GBRWHA occur in the GBR Catchment and are the responsibility of other Queensland agencies. Most landbased activities that can affect water quality of the coastal zone of the GBRMP and GBRWHA fall outside the direct jurisdiction of the Great Barrier Reef Marine Park Authority (GBRMPA), except for point source discharges from coastal aquaculture facilities that are regulated under the Great Barrier Reef Marine Park (Aquaculture) Regulations 2000. 2. Environmental Issues Overview 2.1 Fifteen years of marine and land-based research on the GBR and the adjacent catchment have shown that the water quality and ecological integrity of the coastal area of GBRWHA are affected by material originating from a range of human activities on the land (summary by Williams 2002). 2.2 Protection of the ecological systems of the GBRWHA from these land-sourced pollutants is recognised as one of the most critical issues for the long-term viability of the World Heritage Area. 2.3 The major concerns with respect to adverse impacts on the GBR involve the loss of sediments, nutrients and pesticides from agricultural activities, as well as the loss of riparian and wetland vegetation which may reduce the transport of these pollutants to marine habitats. 2.4 Sugarcane is by far the largest crop on the GBR catchment, and has continued to increase in area over the last 50 years (Gilbert 2001). It is grown on the coastal floodplains of the rivers south of the Daintree River, with small but increasing areas also grown on the Atherton Tablelands, north Queensland. 2.5 The extent of the threats from these pollutants is enhanced by the ongoing expansion of area under cultivation. From 1990 to 1999, the area harvested for sugarcane increased by 26% in the Northern mill region, 65% in the HerbertBurdekin area, 22% in the Mackay region and 6% in the Bundaberg region (Australian Sugar Year Book, 2001) 2.6 These issues, and measures to address them, have been raised in the GBRMPA‟s recently released Great Barrier Reef Catchment Water Quality Action Plan (the Action Plan: GBRMPA 2001). The Action Plan suggests a number of water quality targets for 26 major catchment area (amalgamation of around 40 drainage basins) adjacent to the GBRWHA and measures to achieve them (GBRMPA 2001, Gilbert 2001). 3. Sources and impacts of nutrient runoff and eutrophication 3.1 Sugarcane, as it has been cultivated since the 1950s, requires substantial use of inorganic fertiliser, particularly nitrogen. Current fertilizer usage recommendations for cane cultivation in Queensland are about 150 to 200 kg/ha/year of nitrogen fertiliser (as N). As a consequence, approximately 65,000 tonnes of nitrogen are applied to cane production areas on the GBR catchment per year (refs. in Haynes 2001). 3.2 Of the 200 kg/ha of fertiliser N applied annually to sugar cane crops, about 70 kg is taken up by the crop (Reganzani and Armour 2000). The remaining 130 kg/ha/year are lost to a number of environmental compartments including the atmosphere (volatilization and denitrification) (Freney et al. 1994; Weier et al. 1996), groundwater (Bohl et al. 2000), surface run-off (Reganzani and Armour 2000) and soil storage (including trash storage) (Robertson and Thornburn 2000). A large fraction of this lost nitrogen reaches adjacent streams and rivers (as shown e.g. for the Johnstone River, Hunter et al. 1996; Hunter 1997; Herbert River, Mitchell et al. 1997; Burdekin River irrigation area, Congdon and Lukacs 1996; and the Atherton Tablelands, Hunter et al. 1999), and ultimately the GBR (Devlin et al. 2001) 3.3 For example, the upper Tully River catchment, with largely undisturbed rainforest catchment has maximum dissolved inorganic nitrogen (DIN) concentrations of 1-12µM (Faithful and Brodie 1990, Mitchell et al. 2000). However, the lower Tully River catchment, dominated by sugarcane, horticulture, grazing and urban land uses, has DIN concentrations of 40 µM (Mitchell and Furnas 1997). Analysis of a long-term sampling program in the Tully River has demonstrated an increasing trend in nitrate and particulate nitrogen concentrations over a 13-year period (Mitchell et al. 2000). These trends have occurred at the same time as a substantial expansion of intensive agricultural activity within the Tully area and a large increase in fertiliser use associated with increased cane area and increased banana cultivation. From 1990 to 1999, the combined usage of nitrogenous-fertiliser for both sugarcane and bananas is estimated to have increased by 55% in the Johnstone River catchment and 118% in the Tully - Murray River catchments. 3.4 Significant proportions of these nutrients reach the waters of the GBR, especially during the intense flood events that dominate North Queensland rainfall and river flows. For example, dissolved inorganic nitrogen (DIN) concentrations in flood plumes range between 10 to 100 times ambient concentrations, as well as high levels of particulate nitrogen (Devlin et al. 2001). Sugarcane runoff thus constitutes a major contribution to the overall increase in nutrient inputs to the waters of the GBR. 3.5 Increased inputs of nutrients ("eutrophication") often have critical impacts on marine ecosystems, especially tropical systems such as coral reefs. There is now a considerable body of evidence demonstrating these impacts, including: Examples of ecosystem degradation due to eutrophication: (e.g. Hawaii: Smith et al. 1981; Reunion Island: Naim 1993; Red Sea: Walker and Ormond 1982, Genin et al. 1995; S.E. Asia (Wilkinson and Rahman 1994; and the Caribbean (Lapointe et al 1994, Lapointe 1997). In general, the impacts noted include major declines in abundance and diversity of corals and fishes, and replacement of corals by a range of algae (seaweeds). Importantly, reef decline often involves a failure of community recovery from other disturbances at impacted sites; - Evidence for reef decline on GBR in wet tropics (CRC) and Whitsundays (van Woesik et al 1999) Experimental evidence demonstrating nutrients as the cause of changes: (e.g. enhanced algal growth and coral overgrowth: Schaffelke and Klumpp 1997; Jompa and McCook 2002; phytoplankton blooms: Smith et al. 1981; reduced coral viability: Ferrier Pages et al. 2000, 2001; Harrison and Ward 2001; Koop et al. 2001). Increases in nutrient availability may promote seagrass growth in ecosystems that are generally nutrient-limited, such as coral reef environments (Carruthers et al. in press). In sheltered environments, epiphytic macroalgae respond quickly to water-column enrichment and may outgrow grazing pressure, leading to a decline of the underlying seagrass (Orth & Moore 1983, Bulthuis 1983, Cambridge & McComb 1984, Neverauskas 1987, Walker & McComb 1992, Burkholder et al. 1992, Short et al., 1996). Recent seagrass fertilisation experiments in Morton Bay, Weipa, and Rottnest Island indicate that mainly nitrogen rather than phosphorus stimulates seagrass growth, however, the addition of both nitrogen and phosphorus lead to the strongest response (Udy & Dennison 1997a, b). Seagrass meadows around Green Island near Cairns, reportedly enhanced by primary treated effluent runoff from the resort between 1972 and 1992 still persist despite treatment system being upgraded to tertiary treatment with a high level of effluent recycling in the early 1990s. Udy et al. (1999) attributes this to either increased nutrient availability from mainland runoff, or a long-term increase in sediment nutrient stocks (as occurred in Kaneohe Bay). - - 4. Sources and impacts of sediment runoff 4.1 Soil erosion from cane land was recognised as a major sediment source to river systems when the predominant cultivation technique was burnt cane harvesting („conventional cultivation‟) (Prove and Hicks 1991). In contrast, green cane harvesting/trash blanketing (GCTB) using minimum tillage, can result in dramatically lower soil erosion rates (average losses of 10 tonnes/ha/year Prove and Hicks 1991; Rayment and Neil 1997). Thus there is an urgent need for industry-wide adoption (and auditing) of these practices. 4.2 Soil loss in newly developed cane lands can be particularly severe, as observed in the expansion areas of the Tully/Murray floodplain during the 1990s. Such losses may, in part, explain the major rise in particulate nitrogen concentrations in the Tully River during the 1990s (Mitchell et al. 2000). This is of particular concern given the major increases in area cultivated over the last decade, already noted. 4.3 There is unequivocal evidence that high, chronic input of terrestrial sediment and organic matter will lead to the destruction of reefs through direct burial, increased turbidity, disruption of recruitment or deleterious community shifts (detailed review in Haynes et al. 2001). For example, both detailed, organismlevel experiments and population-ecosystem level evidence have demonstrated: Increased coral mortality (Dollar and Grigg 1981; Rogers 1990; Hodgson 1990a; Hodgson 1990b; Stafford-Smith 1992; Stafford-Smith and Ormond 1992; Stafford-Smith 1993); Reduced coral photosynthesis: (Philipp and Fabricius in review); Reduced removal of competing algae by herbivorous fishes (Purcell 2000); Reduced recruitment and growth of important reef seaweeds (Umar et al. 1998; Fabricius and De'ath 2001) Reduced coral recruitment (Fabricius et al. in review; Babcock and Davies 1991), which is likely to be particularly critical, in terms of population recovery after disturbances. - 4.4 There is some evidence that the quantity of suspended sediments delivered to nearshore reefs has not changed as a result of human landuse, but it is probably that the quality (i.e. size composition, and sediment bound nutrient and pesticide levels) have. Nearshore and coastal reef systems have evolved in relatively turbid environments where suspended sediment and turbidity are influenced by local wind and wave regimes rather than by sediment supply (Larcombe and Woolfe 1999). Despite high turbidity levels and sedimentation rates, a number of inshore reefs sustain high and healthy coral cover and diversity, suggesting local adaptation to intense sedimentation regimes (Ayling and Ayling 1998). However, changes in the nutrient and pesticide levels associated with these sediments are likely to cause a number of significant stresses to reef organisms, such as increased phytoplankton blooms, increased algal trapping of sediments resulting in decreased coral recruitment, and the formation of marine snow (discussed below). 5. Sources and impacts of Pesticides 5.1 A number of new generation insecticides and herbicides are used by the Queensland sugarcane industry. Insecticides in use include chlorpyrifos and herbicides in use include atrazine, diuron, 2,4-D, glyphosate and paraquat (Hamilton and Haydon 1996). Other pesticides in use include rodenticides such as thallium sulphate, and the mercury based compound, methylethoxymercuric chloride (MEMC) used to treat sugar cane fungal disease (Hamilton and Haydon 1996). 5.2 Broadscale surveys of sediment herbicide concentrations in nearshore GBR waters during 1998 and 1999 have detected both atrazine and diuron (Haynes et al. 2000a). Low concentrations of diuron (0.2-10.1 µg kg-1) were found to be widely distributed in marine sediments along the wet tropics coastline between Port Douglas and Lucinda. The herbicide was detected in both subtidal and intertidal samples. Highest concentrations of diuron were detected adjacent to the mouths of the Herbert and Johnstone Rivers. Highest northern Queensland agricultural usage of the herbicide occurs in these two river catchments (Hamilton and Haydon 1996). 5.3 Based on observed sediment concentrations, partitioning models predicted that chronic water column diuron concentrations near the mouths of most wet tropics rivers are likely to range from 0.1 to 1.0 µg L-1 (Table 1). Concentrations are likely to be higher during monsoon rainfall periods that occur over the summer months as first rainfalls of the wet season flush herbicides from the catchments (November to April). Detection of these levels of diuron contamination are of concern as laboratory trials have indicated that diuron concentrations of less than 1 µg L-1 significantly reduce photosynthetic rates in seagrass commonly found along the Queensland coast (Haynes et al. 2000b). Diuron has also been found in mangrove communities on the central Queensland coast (Duke et al. 2001). 5.4 Broadscale surveys have also detected the pesticides lindane, dieldrin and DDT (and its breakdown product DDE) in nearshore marine samples collected along the Queensland coast in 1998 and 1999 (Haynes et al. 2000a). Dieldrin was detected in sediments collected from the mouth of both the Barron and Johnstone Rivers (0.09-0.37 µg kg-1) and in sediments from Halifax Bay (0.05 µg kg-1). 5.5 A range of organochlorine pesticides have been detected in catchments and subtidal sediments in the GBRWHA (Clegg 1974, Cavanagh et al. 2000; Kannan et al. 1995; Russell et al. 1996c; Rayment et al. 1997) and in fauna in marine environment adjacent to agricultural activity (Mortimer 2000, Russell et al. 1996c, von Westernhagen and Klumpp 1995). As a consequence, organochlorine pesticide residues may present a localised threat to nearshore marine organisms along the wet tropics Queensland coast (Haynes et al. 2000a). 5.6 Lindane was only detected in sediments from the vicinity of the mouth of the Johnstone River. Lindane has not been detected in water or riverine sediment samples collected in the Johnstone catchment in the 1990s (Hunter et al. 1999). However, the pesticide is still detectable in northern Queensland agricultural soils and in sediments from irrigation drains (Cavanagh et al. 1999; Müller et al. 2000). 5.7 It has been assumed that no significant sources of dioxins exist in Australia‟s northeast tropical region as it has a relatively low population density with little industrial activity. However, high concentrations of octachlorinated dibenzodioxin (OCDD) and a relatively unusual PCDD/F congener profile have been found in topsoil samples from a sugar cane field in northern Queensland (Müller et al. 1996a; Müller et al. 1996b). Concentrations of octachlorinated dioxin were found to be high in dugong fat tissue compared with concentrations detected in marine mammals elsewhere (Haynes et al. 1999). Polychlorinated dibenzodioxins (PCDDs) appear to be the most significant organochlorine pollutant bioaccumulated in dugong, however, the most important consequences of coastal contamination for GBR dugong populations are likely to be indirect through herbicide impacts to their nearshore seagrass food resource (Haynes et al. 2001). [Dioxins are a group of 210 chlorinated compounds consisting of chlorinated dibenzo-para-dioxins (PCDDs) and chlorinated dibenzofurans (PCDFs). They are formed during various chemical and industrial manufacturing processes, by combustion of organic material (Kjeller et al. 1991), and also via lesser known natural processes (Hashimoto et al. 1995; Alcock et al. 1998). They are known to display a diverse and complex array of toxicological properties (Buckland et al. 1990) and have been detected in a variety of marine mammals (Buckland et al. 1990; Norstrom et al. 1990; Oehme et al. 1995; Jarman et al. 1996; Muir et al. 1996; Tarasova et al. 1997)]. Table 1. Potential Great Barrier Reef diuron water column concentrations (Haynes et al. 2000a). Location Organic Carbon (%) Diuron (µg kg-1) Csoc 0.4 1.6 10.1 1.4 0.8 2.8 1.6 0.9 44 133 404 117 47 82 107 129 Diuron (µg L-1) Koc 398 398 398 398 398 398 398 398 Cw* 0.1 0.3 1.0 0.3 0.1 0.2 0.3 0.3 Barron River Russell River Johnstone River Tully River Cardwell Herbert River Lucinda Fitzroy River 0.9 1.2 2.5 1.2 1.7 3.4 1.5 0.7 * Cw = Csoc (Koc) –1 (Connell 1990) Csoc Concentration in sediments expressed in terms of organic carbon Koc Partitioning coefficient between organic carbon and water Cw Water concentration 6. Combined effects of runoff pollutants: 6.1 The impacts of sediment, nutrient and pesticide pollutants will be significantly increased because they generally occur in combination. There is evidence, for example, that the combination of fine sediments and high nutrient conditions causes the formation of sticky marine mucous-like material (marine snow), which is highly detrimental to coral reef organisms (Fabricius and Wolanski 2000; Fabricius et al. in review). 6.2 Elevated sediment and nutrient concentrations can also be deleterious to seagrass beds. Australian seagrass communities are generally characterised by low ambient nutrient loadings and increased nutrients and water turbidity can adversely affect seagrasses by lowering ambient light levels and increasing epiphyte loads (Haynes et al. 2001). Extensive loss of seagrass beds were reported in Hervey Bay, Qld, as a result of high inputs of sediments and nutrients (McKenzie et al. 2000). Similar damage, including blue-green algal blooms, resulted from increased human-derived inputs of sediments and nutrients in Moreton Bay (Dennison and Abal 1999). 7. Wetland Clearing and Acid Sulphate Soils 7.1 Vegetation clearing associated with sugarcane expansion has led to major losses and alteration of wetland habitat in catchments adjacent to the GBR (Russell and Hales 1994; Russell et al. 1996a&b, Skull 1996; Johnson et al. 1998; Johnson et al. 2000). 7.2 Earth and drainage works are also considered to have the potential to change the hydrology of waterways leading to increased erosion potential and an increase in the sediment load and associated contaminants entering waterways that may then drain into the adjacent marine environment of the GBRWHA. Diversion of streams and drainage channels may directly impact on coastal mangroves, associated fringing vegetation, salt flats and salt marshes. The modification of the hydrological regimes may result in a reduction of suitable habitat for seagrass, mangroves, birds and juvenile fish. 7.3 In coastal areas where wetlands are disturbed, potential acid sulphate soils (PASS) can occur. Queensland has extensive areas (an estimated 2.3 million ha) of potential acid sulphate soils located in low lying areas near the coast (Sammut and Lines-Kelly 1996; White et al. 1997). Acid production can persist for years following PASS exposure, rendering surrounding soil toxic and barren, and killing fish and aquatic plants and invertebrates in adjacent waterways (White et al. 1996; White et al. 1997). 7.4 Thirty-five confirmed fish kills from acid sulphate soil disturbance have been documented along the north Queensland coast between 1997 and 1998. Nine of these were major events that are expected to have a lasting impact on local regional fishery resources. A majority of these have been attributed to agricultural developments, however, in some incidences urban development may be the primary cause. Low water column dissolved oxygen concentrations were cited as the cause of all incidents (Anon 1999). 7.5 Protection of remaining wetland and riparian vegetation should be seen as a priority for the agricultural industry, with an immediate halt to all further clearing of these vegetation remnants being enacted. 8. Protection of Great Barrier Reef Water Quality 8.1 A number of land management strategies have been initiated over the last 10 years. These include: An Integrated Catchment Management (ICM) program, which is based on the premise that decision making processes in management of land and water resources must be coordinated at a catchment level to achieve sustainability (Johnson and Bramley 1996). The recognition of economically sustainable development principles at the farm level through the use of property management plans and development of industry codes of practice is now also emerging (Johnson et al. 1998b). - Whilst some notable achievements have been made by Queensland agricultural industries and communities (eg. widespread adoption of sugar cane trash blanketing to minimise exposure of unvegetated soil to rainfall), appropriate land management in Queensland remains a great challenge (ANAO 1997; Boully 2000; Toyne and Farley 2000). Uptake of ICM and industry codes of practice has been limited, and is not currently subject to effective auditing. 8.2 Early approaches to catchment management involved a large number of independent projects under the Federally funded Landcare program. There is a need for a more strategic approach, integrated over larger scales, and backed by adequate resources, to achieve effective catchment management (ANAO 1997, Bellamy et al. 1999, Boulty 2000, Toyne and Farley 2000). 8.3 In 1994, the Queensland and Commonwealth governments agreed to the water quality strategies detailed in the 25 Year Strategic Plan for the Great Barrier Reef World Heritage Area. However, to date the delivery of outcomes against these strategies has been retarded by a lack of resources and commitment. 8.4 The Queensland Government announced in February 2001, as part of its election committment, the development of a Reef Protection Plan. This policy was to be developed in recognition that the level of pollution entering the Reef from its Catchment was significant and must be addressed. 8.5 The Commonwealth Government made a commitment, as part of the November 2001 election platform, to the achievement of end-of-river pollution targets for catchments adjacent to the GBR. This commitment would be promoted through intergovernmental agreements for the National Action Plan for Salinity and Water Quality (NAP) and the Natural Heritage Trust (NHT), in cooperation with the Queensland Government. 8.6 In accordance with the 25 Year Strategic Plan for the Great Barrier Reef World Heritage Area, the GBRMPA has adopted strategies to …“Encourage the development of methods of reducing undesirable land-based inputs and other pollutants to the Area” by: The GBRMPA prepared its Action Plan to suggest end of catchment water quality targets for all catchments adjacent to the GBRWHA following direction from the Great Barrier Reef Ministerial Council meeting in June 2001. The GBRMPA is working with other Commonwealth Agencies and Queensland Government agencies to develop an agreed approach to water quality issues, especially the setting of water quality targets or standards, in the GBR Catchment. An agreement on the need for water quality targets in the GBR Catchment has been achieved, in part, with the signing of the bilateral agreement between the two governments for the implementation of the NAP. This program aims to address water quality matters in the Burdekin, Fitzroy and Burnett River catchments. The GBRMPA is participating in the Queensland government facilitated preparation of natural resource management plans for other GBR catchments. The proposed funding for these plans includes Commonwealth NHT II funds, and the plans should address water quality issues if they are to achieve accreditation by the Commonwealth. The GBRMPA was invited as a stakeholder to participate on the Queensland Government‟s Reef Protection Taskforce. The Taskforce prepared a report that was considered by Queensland Cabinet in December 2001. Actions for reduction of sugar industy impacts on water quality: There are a number of actions that are recommended for consideration for implementation to achieve the water quality targets including: Reforms to ensure that all environmentally significant activities (including significant new agricultural activities or the significant intensification of existing activities) in catchments adjacent to the Reef are subject to proper environmental impact assessment and approval processes. Environmental assessments should specifically address potential impacts on water quality. Appropriate conditions should be attached to approvals to ensure that agricultural activities are carried out in a manner that protects and, as necessary, improves water quality. Constraint mapping for current and future agricultural development in the GBR catchment that identifies protection of catchment habitats and features at risk, including in particular documentation of freshwater wetlands and riparian vegetation that should be protected and rehabilitated; Standards for water quality discharge from coastal developments to watercourses should be established and enforced; Environmental management plans should be promoted for agricultural activities. These plans should promote farming practices that minimise downstream impacts, such as: - minimising erosion through conservation cropping techniques and pasture management; - minimising nutrient loss by aligning fertiliser amount, type and application methodology to the measured physiological requirements of the crop; and - implementing integrated pest management techniques (i.e. careful targeting and monitoring of pesticide needs and applications). Promotion of full compliance to Industry Codes of Practice; and Initiate public and catchment specific education programs about the connectivity between land use and the impacts on the Reef. Education and extension programs have an important role to play in ensuring the effectiveness of specific management practices. The physical separation between sources and impacts of land-based runoff represents a significant impediment to the recognition and acceptance of responsibility for the implementation of solutions. While significant progress has been made by some sectors of the community in recognising and addressing water quality problems, this effort is recoomended to be urgently accelerated. Voluntary approaches (e.g. industry codes of practice) that presently guide many relevant activities have not been adopted by agricultural industries broadly enough to bring about fundamental change. 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