Background

The landscape and oceanic processes of the Burnett Mary region have produced a dynamic and diverse coastal and marine environment.  The waters of the Burnett Mary region lie within the Tweed-Moreton marine bioregion, incorporating the landmark Fraser Island.  Fraser Island traps warm waters in Hervey Bay and creates the Great Sandy Strait, as well as marking the southern boundary of the Great Barrier Reef (GBR) lagoon – the world’s largest and most diverse coral reef system.  The region’s coast and waters are characterised by the interface of tropical and subtropical zones, producing some of Australia’s highest coastal and marine biodiversity.  This biodiversity underpins environmental, commercial and recreational pursuits in the region.

The diverse range of coastal, estuarine and marine habitats includes some that are conserved and protected under World Heritage or Ramsar listing and Queensland legislation. These habitats include:

  • the deep continental shelf located just off Fraser Island, influenced by the East Australian Current
  • rocky shores, dunes, coastal and tidal wetlands – mangrove forests, coastal she-oak stands and saltmarsh backed by peat swamps
  • seagrass meadows
  • coral and other reefs, including GBR’s southernmost reefs
  • soft-bottom habitats.

This mosaic of habitats encompasses critical connections that enable the movement of water, sediment, plants and animals – connections essential for marine life processes.  As well as supporting marine life, coastal habitats play a vital role in addressing atmospheric levels of greenhouse gases.  They can capture and store carbon at up to forty times the rate of carbon capture by tropical rainforests.

The region’s coastal plants and animals include iconic and migratory species, such as shorebirds, grey nurse sharks, humpback whales, dugong and Indo-Pacific humpback dolphins.  All rely on healthy and available habitat.  The region hosts the east coast’s largest dugong population south of Torres Strait and six of the world’s seven species of endangered and vulnerable marine turtles.  Of these, loggerhead, green and flat-back turtles regularly nest along the region’s foreshores.  Other species have iconic or economic value and sustain our tourist and fishing industries.

Coastal, estuarine and marine habitats are often disturbed by natural events such as tides, floods and severe storms. This disturbance is normal, natural and essential for ecosystem health.  On the other hand, human-induced pressures can often “tip the balance”, reducing resilience and contributing to major biodiversity loss.  Pressures on coastal, estuarine and marine environments include coastal development, recreational and commercial fishing, public access, pests and weeds, and upstream land management with associated run-off.  Runoff management to minimise sediment, nutrient and pesticide pollution of waterways and marine and coastal environments is critical.

Balancing natural resource use, both on land and in the coastal and marine sphere, with healthy ecosystem function is central to the maintenance of these assets for use and enjoyment by future generations.

Asset Description

Coastal, estuarine and marine habitats of the region are identified as either benthic – those related to “the bottom” – or water types – subsets of the region’s oceanic waters classified on the basis of a range of characteristics.  Classification of the benthic habitats follows the classes adopted by the Queensland Wetlands Program:

  • Aquatic Zones
  • Dominant Energy Regimes
  • Dominant Biotic Structure
  • Consolidation Type.

Benthic habitats of the region are captured in Table 1.  Although classified, these habitats are yet to be comprehensively mapped.

The region’s water types, along with two important adjacent types, are identified in the second table.  They reflect differences in (1) wave energy regimes and (2) freshwater influence i.e. surface water runoff from land; collectively these determine the turbidity and temperature of each water type.  Some of the water types are further sub-divided into seascapes.  The extent of the water types and associated seascapes is captured in the map of coastal, estuarine and marine habitats.

A complete description of the delineation of this asset and the characteristics of each benthic habitat and water type is contained in the assets background report.

Table 1. Benthic habitats of the Burnett Mary region

Asset Code Description Aquatic Zone Dominant Energy Regime Dominant Biotic Structure Consolidation
ME 1 Intertidal Rock Platform Intertidal Low Bare Consolidated
ME 2 Sandy Beach Intertidal Undifferentiated Bare Sand
ME 3 Mud Flat / Sand Flat Intertidal Low Bare Mud
ME 4 Basalt Boulder Beach / Cobble Intertidal (HAT to MSL) Undifferentiated Bare Boulders
ME 5 Tidal Salt Pan Intertidal Low Encrusting Unknown
ME 6 Intertidal Seagrass Intertidal Low Low Veg Unknown
ME 7 Tidal Salt Marsh Intertidal Low Low Veg Unknown
ME 8 Mangrove Intertidal Low Med-High Veg Unknown
ME 9 Intertidal Sessile (Corals and Sponges) Intertidal Low Sessile Fauna Unknown
ME 10 Subtidal Platform Subtidal Low Bare Consolidated
ME 11 Sandy Bottom Subtidal High/Low* Bare Sand
ME 12 Muddy Bottom Subtidal Low Bare Mud
ME 13 Pebbly Bottom (includes gravel) Subtidal/Intertidal Undifferentiated Bare Unconsolidated
ME 14a Seagrass Subtidal – Baffle Subtidal High Low-Med Veg Mud /Sand
ME 14b Seagrass Subtidal – Coastal Catchments Subtidal Low Low-Med Veg Mud /Sand
ME 15 Algae Subtidal High Low-Med Veg Mud /Sand
ME 16 Sessile (Corals, Sponges & Coralline Crustose Algae) fauna Inshore Consolidated (GSS & 2km along Coast) Subtidal Low Sessile Fauna Consolidated
ME 17 Sessile (Corals, Sponges & Rhodoliths) fauna Inshore Unconsolidated (GSS & 2km along Coast) Subtidal Low Sessile Fauna Unconsolidated
ME 18 Sessile (Corals and Sponges) fauna Offshore Subtidal High Sessile Fauna Unknown

Table 2. Water types of the Burnett Mary region

SR Subregion (description)
A Fitzroy-Keppels-Corio (located outside the regional boundary)
B Gladstone Harbour (located outside the regional boundary)
C Colosseum-Rodds-Bustard Head-south to Roundhill Head
D Capricorn Channel inter-reefal area, east side of Port Clinton
E Capricorn Bunker group including Lady Musgrave Island Islands
F Round Hill Head to Elliott Heads
G Hervey Bay (Elliott Heads-Breaksea Spit to Wide Bay Bar), consisting of (a) Platypus Bay ciguatera (b) Hervey Bay & northern Great Sandy Strait and (c) Remainder of Great Sandy Strait.
H Breaksea Spit to NSW Border and beyond – the Tweed

Potential Climate Futures

The CSIRO and Bureau of Meteorology have used sophisticated models to project potential future climates based, broadly, on levels of greenhouse gas emissions.  The vulnerability of the region’s coastal, estuarine and marine assets was considered under 2030 and 2090 scenarios, considering both a high emissions state (RCP 8.5) and an intermediate state (RCP 4.5).  See the Climate Change in Australia website for additional information about climate scenarios or Background Paper – Coastal and Marine.

Coastal & Marine systems of the region were assessed by an “expert panel” of marine scientists; the systems are considered to be sensitive to the following climate change exposure indicators:

  • air temperature increases
  • increasing lengths of dry periods
  • increased frequency of intense rainfall events
  • extreme coastal sea levels
  • ocean temperature increase
  • ocean acidification.
Emission Scenario Potential Climate Future 2030 Potential Climate Future 2090
Intermediate
(RCP 4.5)
Air temp increase – 0.9°C
Time in drought – increase (medium confidence)
Extreme rainfall – increase (high confidence)
Sea level increase (Gladstone) – 0.13m
Ocean temp increase (Gladstone) – 0.7°C
Ocean acidification, pH decrease – 0.07
Air temp increase – 1.9°C
Time in drought – increase (medium confidence)
Extreme rainfall – increase (high confidence)
Sea level increase (Gladstone) – 0.47m
Ocean temp increase (Gladstone) – 1.5°C
Ocean acidification, pH decrease – -0.10
High
(RCP 8.5)
Air temp increase – 1.0°C
Time in drought – increase (medium confidence)
Extreme rainfall – increase (high confidence)
Sea level increase (Gladstone) – 0.13m
Ocean temp increase (Gladstone) – 0.8°C
Ocean acidification, pH decrease – -0.08
Air temp increase – 3.6°C
Time in drought – increase (medium confidence)
Extreme rainfall – increase (high confidence)
Sea level increase (Gladstone) – 0.64m
Ocean temp increase (Gladstone) – 2.9°C
Ocean acidification, pH decrease –  -0.14

Strategic Direction

Coastal, estuarine and marine resources and their processes:
•    are healthy and resilient
•    are appreciated for their value and vulnerability to changes in climate and human activity
•    underpin our community’s industries and lifestyles.

2020 Target (Physical and biological processes)

CM1. Critical ecological connections (interactions) and processes are identified.
CM2. Surface water and groundwater flows are measured and maintain ecological connections that underpin coastal values.
CM3. Geomorphological processes (including riverine and shoreline) maintain or restore sediment transport that sustains beaches and coastal dunes.

2020 Target (Coastal, estuarine and marine habitats)

CM4. The extent of all coastal, estuarine and marine benthic habitats will be known and a baseline created.
CM5. The function and value of all coastal, estuarine and marine benthic habitats are improved or maintained.
CM6. There is no net loss of the extent of natural wetlands.
CM7. There is an improvement in the ecological processes and environmental values of natural wetlands.

2020 Target (Coastal, estuarine and marine plants & animals)

CM8. There is no adverse change in biological diversity in coastal, estuarine and marine species.
CM9. Actions identified in the Burnett Mary Water Quality Improvement Plan are implemented to achieve water quality targets to maintain coastal, estuarine and marine ecosystem health.

2020 Target (Water Quality)

CM9. Actions identified in the Burnett Mary Water Quality Improvement Plan are implemented to achieve water quality targets to maintain coastal, estuarine and marine ecosystem health.