CANEGROWERS Reef Science discussion 24 July 2018 QCGO Reef science - - PowerPoint PPT Presentation

CANEGROWERS

Reef Science discussion

24 July 2018

QCGO Reef science discussion – What do we know?

What do we know?

• 1. Sugarcane is the dominant contributor to dissolved inorganic

nitrogen and pesticides delivered to the GBR.

• 2. Management priorities are established at a basin scale.
• 3. Social factors have a major influence on management practice

adoption.

Jane Waterhouse, C2O Consulting and TropWATER JCU Mobile: 0409 053 367 Email: j.waterhouse@c2o.net.au

Sugarcane, 78% Sewage Treatment Plants, 5% Urban and other intensive uses, 4%

• 100

200 300 400 500 600 700 800 900 1,000 Herbert Haughton Johnstone Russell-Mulgrave Plane Tully Murray Mary O'Connell Pioneer Burdekin Burrum Proserpine Burnett Mossman Daintree Don Kolan Barron Black Baffle Fitzroy Jacky Jacky Olive-Pascoe Lockhart Stewart Jeannie Normanby Endeavour Ross Styx Shoalwater Water Park Calliope Boyne

Annual average total DIN load from sugarcane (t/yr)

QCGO Reef science discussion – what don’t we (yet) know?

What don’t we (yet) know?

• 1. The best ways to incorporate science into delivery and learning

from the past.

• 2. How to prioritise beyond the catchment scale – using adoption,

social and economic factors

• 3. The quantified benefits of a range of alternative management
• ptions including ‘system repair’ that might complement BMP.

QCGO Reef science discussion – What do we know?

Russell Reichelt, Chairman, Great Barrier Reef Marine Park Authority

Observations & assumptions (unconscious bias?) & what’s missing?

1. Reef water quality along much of the GBR coast south of Cape Tribulation has declined

• ver the past 50 years and probably longer

i. Based on the progressive loss of large mainland-attached reefs that required clear water over centuries to have formed where they were.

2. Water quality & the Reef: It would be useful for farmers [& other community] and scientists to share a common understanding of the issues & agree some priorities for actions and key indicators that are meaningful for everyone (not just scientists)

i. This is different from a scientific consensus statement. It would require trusted knowledge brokers on all sides ii. It is done in other sectors like fisheries where the two sectors get together & develop a narrative that works for both groups. Where it is done well, the limits of ‘use’ of the resource is jointly agreed or at least jointly understood iii. The outcome is increased mutual respect & stronger commitment to address the issues for both the industry & the ecosystems under pressure from human use & other natural pressures

QCGO Reef science discussion – What do we know?

Russell Reichelt, Chairman, Great Barrier Reef Marine Park Authority

What are the water quality concerns for Reef protection?

1. GBRMPA’s interests are to protect the Great Barrier Reef – which means sustaining areas that are coral dominated in a healthy state; enable natural cycles of loss & recovery for corals, Seagrass, mangroves, island vegetation 2. Fertiliser & sediments [nutrients & fine soil particles in elevated amounts] kills coral reefs & sea grass [turtle & dugong food; prawn & fish habitat]; loss of coastal wetlands enhances impacts in the ocean & reduces fish nursery areas

i. causes water to lose its clarity and prevents plant and coral growth; ii. causes blooms of marine plants/algae that smother reefs and block light iii. Coral areas turn into rubble with murkier water, no 3-dimensional structure, so fewer fish and lobster

3. GBRMPA would like the science to be more specific. Identify areas where changes in land use would create improvements in water quality & would lead to measurable change for the better in the GBR World Heritage Area – not just in the water indicators but across all the themes in the Reef 2050 Plan: biodiversity, water quality, benefits to society, cultural heritage, etc.

QCGO Reef science discussion – What do we know?

What do we know?

• 1. Increasing sea temperatures have a

major impact on the health of the GBR.

• 2. Increased inputs of terrestrial

sediments, nutrients and pesticides have wide-ranging impacts on health and recovery of corals and seagrasses.

Britta Schaffelke, Research Program Director- Great Barrier Reef , Australian Institute of Marine Science Mobile: 0427 029 464: Email: b.schaffelke@aims.gov.au

Source: ARC Centre of Excellence for Coral Reef Studies

QCGO Reef science discussion – what don’t we (yet) know?

What don’t we (yet) know?

• 1. How do the pressures from climate

change and water quality interact?

• 2. How to forecast possible future reef

condition at a regional level to support planning and decision making from catchment-to-reef.

Source: Wolff et al. (2018) Global Change Biology 24

QCGO Reef science discussion – What do we know?

What do we know?

• 1. Since the start of marine monitoring in 2005, inshore water

quality (nutrients/turbidity) has generally shown no improvement.

• 2. When catchment loads reach the lagoon, they are transformed,

with much of the dissolved nutrients being used by

• phytoplankton. These nutrients re-enter the water when

phytoplankton die.

Renee Gruber, Biological-Chemical Oceanographer, AIMS Mobile: 0416 863 262 Email: r.gruber@aims.gov.au

QCGO Reef science discussion – what don’t we (yet) know?

What don’t we (yet) know?

• 1. How long do catchment sediment, nutrient, and pesticide inputs

remain in the GBR lagoon?

• 2. How much turbidity is due to catchment inputs versus

resuspension?

QCGO Reef science discussion – What do we know?

What do we know?

• 1. Increased nutrient availability is associated with outbreaks of the

coral-eating crown-of-thorns starfish, a native pest linked to significant declines in hard coral cover.

• 2. Increased sediment and pesticide concentrations can affect coral

reef organisms other than hard corals and seagrass, including the behaviour and physiology of coral reef fish.

Dr Frederieke Kroon, Principal Research Scientist / Team Leader ‘Tropical Marine Water Quality and Impacts, AIMS Mobile: 0427 775 180 Email: f.kroon@aims.gov.au

QCGO Reef science discussion – what don’t we (yet) know?

What don’t we (yet) know?

• 1. Science: The role of nutrient transformation and availability in

promoting crown-of-thorns starfish outbreaks (link to catchment management).

• 2. Science: The potential effects of contaminants other than

sediment / nutrients / pesticides on reef health.

• 3. Overall: Why have Reef Plan’s 2018 water quality targets not

been achieved, and has inshore water quality not improved since 2005, despite ~AUS$ 1 Billion Governments’ investment in catchment management since 2009?

QCGO Reef science discussion – What do we know?

What do we know?

• 1. Loads of sediments, nitrogen, phosphorus and pesticides

delivered to the Great Barrier Reef have increased over the past 50 years. Water quality issues specific to each land use (nitrogen and pesticides most relevant for sugarcane industry).

• 2. Sediment loads reduced from sugarcane land use in past 25 years

due to trash blanketing practices.

• 3. Current BMP for herbicides when implemented will greatly

reduce offsite risk

Stephen Lewis, Principal Research Officer, James Cook University Mobile: 0423942894 Email: Stephen.lewis@jcu.edu.au

QCGO Reef science discussion – what don’t we (yet) know?

What don’t we (yet) know?

• 1. How we can effectively reduce nitrogen losses from paddocks in

the face of climate uncertainty

• 2. Better quantification of ‘water quality benefits’ from farm trials.
• 3. How science and industry can better engage to achieve desirable

environmental and economic outcomes.

QCGO Reef science discussion – What do we know?

What do we know?

• 1. Growers are receptive to science – and want it to be precise

John Pickering (Behaviour Innovation) john@behaviourinnovation.com

QCGO Reef science discussion – what don’t we (yet) know?

What don’t we (yet) know?

• 1. How to manage the “evidence paradox”

John Pickering (Behaviour Innovation) john@behaviourinnovation.com

QCGO Reef science discussion – What do we know?

What do we know? 1.

Agricultural impacts on water quality are a global challenge.

• 2. Losses of nutrients and pesticides well-documented from sugarcane

cultivation (but also other land uses)!

• 3. Australian canegrowers face a challenging management environment

(climate, harvesting-milling operations, sugar price)

Dr Aaron Davis, Principal Research Officer, TropWATER-JCU, Mobile:0457300195 Email: aaron.davis@jcu.edu.au

QCGO Reef science discussion – what don’t we (yet) know?

What don’t we (yet) know?

• 1. What are the specific environmental impacts of water quality relative to
• ther factors (climate, weeds, changes to hydrology etc.)

2. On-farm practices to improve water quality? Not too many ‘silver bullets’?

• 3. How do scientists make their work more relevant to industry?