Managing agricultural & port derived pollution in the Great - PowerPoint PPT Presentation

Managing agricultural & port derived pollution in the Great Barrier Reef – success and failure R. Kelley Jon Brodie Chief Research Scientist Science leader, Catchment to Reef Research Group, TropWATER, James Cook University, Townsville, Australia. 7 th GEOSS Asia-Pacific Symposium Asia-Pacific Biodiversity Observation Network Tokyo, Japan, 2014 catchment to reef

The Great Barrier Reef (GBR) The “Reef” 350,000 km 2 3000 coral reefs Large seagrass meadows Dugongs, turtles, whales, fisheries 2000 km N to S Cairns GBR Catchment Townsville 400,000 km 2 Abbot Point Sugarcane, beef grazing, urban, mining, grains, cotton, horticulture Hay Point Ports Gladstone Major – Cairns, Townsville, Abbot Point, Hay Point, Gladstone Marine Park – 1975 World Heritage - 1981

GBR catchment scale Cape York Wet Tropics Burdekin Mackay-Whitsunday Fitzroy Burnett-Mary

Catchment landuses Sugarcane Beef grazing Large scale coal mining Large and expanding ports Urban

Sediment, nutrient and pesticide loads to the GBR • Sediment – 5 times increase since 1850 – sourced mainly from erosion in grazing lands. • Total Nitrogen – 6 times increase since 1850 – Particulate N loads mainly from erosion in grazing lands, nitrate from fertiliser use in sugarcane, cotton, horticulture, grains. • Total Phosphorus – 9 times increase since 1850 – Particulate P loads also from grazing lands. • PSII herbicides (atrazine, diuron, tebuthiuron and others) – 28 tonnes ( no natural load) – from sugarcane, grains cropping and weed control in grazing lands. Loads from Kroon et al 2012; source information from Waterhouse et al. 2012

River discharge MODIS Image Pollutants discharged in large river flow events in wet season producing huge flood plumes Direct effects Keppel Reefs (Alison Jones)

Flood plumes Plumes studied using MODIS, Landsat and other RS platforms plus sampling in the plume

History of management • Marine Park Act – 1975 • Great Barrier Reef Marine Park Authority – established 1975 • World Heritage listing 1981 • Zoning complete by about 1990 • More than $A 1 billion spent on management, research, monitoring since 1975 However management over the first 20 years focussed largely on tourism and exclusion of fishing only in the small area of no-take zones. Traditional fisheries management prevailed as well by the Qld. Gov.

Terrestrial runoff management • Scientific consensus – 2001 (after 20 years of research and monitoring) (Williams et al. 2001) • Reef Plan 2003 • Reef Rescue program funded 2008 - $A200 million over 5 years • Scientific Consensus Statement 2 – 2008 (Brodie et al. 2008 • Reef Plan 2009, 2013 • Scientific Consensus Statement 3 – 2013 (Brodie et al. 2013) • Reef Rescue 2 funded 2013 – 2018 - A$200 million • Queensland Gov. actions (> A$200 million)

Some success under Reef Plan Reef Rescue and Qld. Gov. investment 2009 – 2011 with farmer and grazier cooperation and financial support. • Nitrogen discharges down by 7% (2013 target 50%)(new 2018 target at about 36%) • Suspended Sediments down by 6% (~ 360,000 tonnes) (2013 target 20%)( new 2018 target 20%) • Herbicides (PS II) down by 15% (2013 target 50%)(new 2018 target 60%)

HOWEVER Coral reef degradation Dugong loss Seagrass loss

Coral cover decline (mid-shelf reefs mainly) Coral Coral cover in Coral cover in ~1960 = Coral cover in 1986 = 40 – 55% cover in 2004 = 28% (Bruno and Selig 2012 = 2007; Bellwood et al. 22% (Sweatman et al. 2004; Hughes et al. 2011) 14% (De’ath et 2011) (Sweatman et al. 2011) al. 2012) (note 11% south of Cooktown) Coral cover in 2020? – see Inner-shelf reefs also in De’ath et al. decline (Thompson et al. 2012 – 5%? 2013)

Declining seagrass cover Abundance decreased significantly since 2009 in all habitats • 2010/11 abundances lowest on monitoring record • 2011/12 abundances improving but remain low • McKenzie LJ, Collier C, Waycott M (2012) Reef Rescue Marine Monitoring Program: Nearshore Seagrass, Annual Report for 2010–2011. Fisheries Queensland, Cairns. www.seagrasswatch.org

Status of the GBR (from Brodie and Waterhouse 2012) Coral cover from about 50% fifty years ago to less than 14% • currently (11% south of Cooktown) and predicted to decline further (Hughes et al. 2011; De’ath et al. 2012) Dugong populations continue to decline • Seagrass in trouble especially associated with both chronic • stress and extreme events (Devlin et al. 2012; Petus et al. 2014). Shark populations declining (Robins et al. 2006) • Crown of thorns starfish outbreaks started again in 2009 for the • 4 th ‘wave’ (Fabricius et al. in prep.) Increasing inshore turbidity (Fabricius et al. 2013, 2014) • Increasing incidence of coral diseases • Increasing water temperatures • Declining calcification (e.g. Cooper et al. 2009) •

Status of GBRWHA and water quality Scientific consensus statement on water quality in the Great Barrier Reef (Brodie et al 2013) The overarching consensus is that key GBR ecosystems are showing declining trends in condition due • to continuing poor water quality, cumulative impacts of climate change and increasing intensity of extreme events. The decline of marine water quality associated with terrestrial runoff from the adjacent catchment is a • major cause of the current poor state of many of the key marine ecosystems of the GBR. The greatest water quality risks to the GBR are from nitrogen discharge, associated with crown of • thorns starfish outbreaks and their destructive effects on coral reefs, and fine sediment discharge which drives light reduction for seagrass ecosystems and inshore coral reefs. Pesticide inputs pose a risk to freshwater and some inshore and coastal habitats. Recent extreme weather– heavy rainfall, floods and tropical cyclones – have had severe impacts on • marine water quality and GBR ecosystems. Climate change is predicted to increase the intensity of extreme weather events. The main source of excess nutrients, fine sediments and pesticides from GBR catchments is from • diffuse source pollution from agriculture. The use of improved land and agricultural management practices is proven to reduce the runoff of • suspended sediment, nutrients and pesticides at the paddock scale .

Crown of thorns starfish again Three waves of outbreaks 1962 – 1975; 1978 – • 1990; 1993 – 2005; 2009 - ? Now well understood to be linked to increased • nutrient discharge from the land (Brodie et al. 2005; Fabricius et al. 2010) Removal of fish predators may also be linked. • No-fishing zones have less COTS? (Sweatman et al 2009) Largest cause of coral mortality on the GBR • (Osborn et al. 2011; Hughes et al. 2011; De’ath et al. 2012) Fourth wave of outbreaks now started off Cairns • north region (where all the other waves began) (Fabricius et al. in prep.) in 2009 We can now expect high coral mortality from • COTS in the central GBR over the next 10 years.

Why has management failed Early emphasis on tourism management – which was not • the main issue. Fishing only comprehensively managed by 2005 • Terrestrial runoff only started to be managed by 2009 • Pesticide management still an issue due to ineffectiveness • of Australian Government pesticide regulator Climate change not managed at all • Port development poorly managed and in contrast to other • issues management seems to be getting worse e.g. Gladstone Port, Abbot Point Difficulties of getting scientific consensus, political • agreement , organizational structure and a funded management response.

Port dredging and spoil dumping • Average annual suspended sediment discharge to GBR = about 9 million tonnes • Anthropogenic contribution = 6 million tonnes (agriculture) • Amount reduced by Reef Rescue so far (2011) = about 360,000 tonnes • Dredge spoil amount to be dumped over next decade = ~ 100 million tonnes – about 10 million tonnes per year • i.e. twice the total anthropogenic river discharge per year • Governance arrangements currently very poor (Grech et al. 2013; Brodie 2014), could be improved but little willingness to do so. • UNESCO concerns

Gladstone • Large scale dredging for CSG terminals on Curtis Island. • Coincident fish, sharks, crabs, prawns disease outbreaks. • Compliances monitoring and environmental oversight not adequate to determine causation. • Recent Australian Gov. review finds numerous flaws in environmental management system, both in design and implementation, including poor cooperation between Queensland and Australian Government 2011 2005

Abbot Point spoil dumping Dumping area to be Planned to determined dredge 3 million cubic metres and dump spoil in GBR Marine Park (5 million tonnes)

What were the options • Long jetty (trestle) and no dredging • Medium length jetty and dredge < 500,000 m3 • Dredge 3 million m3 and dump in GBRMP • Dredge 3 million m3 and dump behind bund wall reclamation • Dredge 3 million m3 and dispose of spoil on land