How Healthy is Moreton Bay?

1. How Healthy is Moreton Bay? CRC for Coastal Zone Estuary & Waterway Management • Angela Grice, Ivan Holland, Francis Pantus, Andrew Watkinson, Dan Wruck & Bill Dennison Adrian Jones

2. EHMP Project Team CRC for Coastal Zone Estuary & Waterway Management Angela Grice Ivan Holland Paul Lutz Andrew Moss Mark Davidson John Ferris Michelle Leutton Myles Waller Ray Clark Darren Renouf Chris Ovenden Nathan Johnston Phil Thornton Nicola Udy Bill Dennison Adrian Jones Courtney Henderson Volunteers Francis Pantus Peter Toscas Tom Taranto Dan Wruck Gary Prove

3. Moreton Bay Bribie Island • Moreton region has 2 million people and is the fastest growing region in the country • Moreton Bay receives input from Brisbane, Logan, Caboolture and Pine Rivers • The Brisbane River has the • largest catchment of all regions • highest population density • highest sewage inputs Caboolture River Moreton Island Redcliffe Pine River Luggage Point Dunwich Brisbane River Logan River

4. Residence time affects the dilution of nutrients discharged into the waterways • Residence times are highly variable • Rivers have the longest residence time • Short residence times near inlets • Bramble Bay has the longest residence time within the bay

5. The river estuaries are BROWN iological diversity low esuspended Brown ver-loaded aste water utrient laden

6. Moreton Bay is BLUE iological diversity high Blue ow nutrients nimpacted nergetic

7. Historically, the rivers were cleaner Swimming enclosure at East Brisbane Aug 1918 July 1917 Oct 1997 Moreton Bay Colleges Crossing 250 Turbidity 200 150 0 10 20 30 40 100 50 0 Jewfish caught in Brisbane River • Historically, the rivers had: • much lower inputs ofsewage and catchment runoff • extensive vegetation on river banks • water clarity was much better • large fish such as cod, black swans and aquatic plants existed in Brisbane River

8. Historically the Western Bay was relatively pristine Within Moreton Bay, dugongs, sea turtles and extensive seagrass beds were once present on the urbanised western shores, but are now largely restricted to the well flushed eastern regions.

9. Population Growth is a major pressure • Population expansion in the region over the past half century is one of the most rapid in the world • Results in increased land-use and fertiliser application and sewage discharges

10. Sewage discharges concentrated in Brisbane River & Bramble Bay • Largest sewage discharge = Luggage Pt. at mouth of Brisbane R. • Oxley Creek = second largest • 3 significant discharges into Pine Rivers and Hayes Inlet from Pine Rivers, Redcliffe and Brisbane City • Multiple minor discharges scattered throughout tidal reaches

11. Multiple sewage discharges in region stimulated large regional study • Concern about expanding population and impacts of sewage discharges • 6 local councils formed regional study group, obtained commonwealth & state matching funds • 1997-1998 large intensive study conducted • Developed Vision & monitoring strategy

12. Monitoring is an essential tool for effective preservation & remediation of waterways • Research and monitoring provides the information to determine the most effective remediation options • It determines the ecological outcomes of nutrient removal from sewage, stormwater controls and other management actions

13. Monitoring Ecosystem Health • loss or recovery of seagrasses, mangroves and corals Indicators of Ecosystem Health

14. Monitoring Ecosystem Health Indicators of Ecosystem Health • loss or recovery of seagrasses, mangroves and corals • outbreaks of Lyngbya

15. Monitoring Ecosystem Health • Indicators of Ecosystem Health • loss or recovery of seagrasses, mangroves and corals • outbreaks of Lyngbya • the extent of sewage plumes

16. Monitoring Ecosystem Health • Indicators of Ecosystem Health • loss or recovery of seagrasses, mangroves and corals • outbreaks of Lyngbya • the extent of sewage plumes • nutrient responses of phytoplankton communities

17. Monitoring Ecosystem Health • Indicators of Ecosystem Health • loss or recovery of seagrasses, mangroves and corals • outbreaks of Lyngbya • the extent of sewage plumes • nutrient responses of phytoplankton communities • occurrence of nuisance macroalgae e.g. sea lettuce

18. Monitoring Ecosystem Health • Indicators of Ecosystem Health • loss or recovery of seagrasses, mangroves and corals • outbreaks of Lyngbya • the extent of sewage plumes • nutrient responses of phytoplankton communities • occurrence of nuisance macroalgae e.g. sea lettuce • status of turtles and dugongs

19. Monitoring Ecosystem Health • Indicators of Ecosystem Health • loss or recovery of seagrasses, mangroves and corals • outbreaks of Lyngbya • the extent of sewage plumes • nutrient responses of phytoplankton communities • occurrence of nuisance macroalgae e.g. sea lettuce • status of turtles and dugongs • water quality • phytoplankton biomass • nitrogen and phosphorus • turbidity

20. Sewage Plume Mapping identifies zones of human impact • Macroalgae takes up sewage nutrients • Chambers deployed around bay and rivers • Allows mapping of extent of sewage plume

21. Plume mapping technique identifies different nutrient sources • Highest sewage concentration is in middle reaches of the rivers due to inputs and lack of tidal flushing • Plume concentrated in western bay • Sewage plume from rivers is seasonally variable September 1997 March 1998 June 2000

22. Monitoring affects management decisions

23. River estuaries: moderately to highly degraded Pine River Moderate degradation • Nutrients & sediments from forestry, agricultural and urban areas • Algal booms, high nutrients • Nutrient uptake means no sewage nitrogen impact on Deception Bay • Urbanised & industrial catchment • High turbidity & nutrients High degradation Caboolture River • High sediment & nutrient loads • Extensive vegetation cleared • Low plankton species diversity • Extremely degraded • Very high nutrient loadings • High bacterial productivity • Long residence time • Urbanised & agricultural catchment • Aquaculture prominent Logan River Bremer River Brisbane River

24. Rivers receive inputs from a variety of point and non point sources Abatoir Outfall Sewage Treatment Plant Sewage Outfall Grazing - manure Golf course fertiliser runoff and gravel extraction plant Aquaculture • Primary inputs are nutrients (nitrogen & phosphorus) and suspended solids

25. Rivers are nutrient over-enriched Phytoplankton bloom in Caboolture River Aquatic weed bloom in upper Brisbane River Jellyfish bloom in response to high plankton biomass in Pine River Benthic microalgal bloom on Brisbane River sediment • High concentrations of nutrients often results in blooms of single species – reducing diversity

26. Rivers used for commercial and recreational purposes Trawling in Brisbane R Port of Brisbane Skiing in rivers Swimming in rivers Fishing at Luggage Pt Outfall

27. River Estuaries Report Card 2000 Bribie Island Caboolture River Moreton Island C Caboolture River Redcliffe D Pine Rivers Pine River Luggage Point D Brisbane River Dunwich Brisbane River F Bremer River D Logan River Logan River Worsened Unchanged Improved A excellent B good C fair D poor F fail

28. River estuaries Moreton Bay Highly impacted river estuaries Pristine and diverse marine environments

29. What are the impacts on Moreton Bay? • Sediments • 50,000 truck loads of mud into Brisbane River every year • Nutrients • 500 olympic swimming pools of treated sewage effluent every day • 1/3 Brisbane River flow is sewage effluent • Lyngbya • 3000 football fields of seagrass covered by Lyngbya in Moreton Bay

30. Sediments impact West Moreton Bay Total N (mg L-1) • With sediments come nutrients

31. Waters in Western Bay are Turbid • Reduced water clarity in Waterloo Bay due to river inputs and resuspension • Last remaining healthy seagrass beds in Western Moreton Bay • Sensitive region with variable water quality

32. Sediments affect seagrass distribution Suspended solids Seagrass distribution

33. Are sediments affecting corals too? • Scoping surveys shown dramatic shift from dead to live coral cover with distance from mainland in Waterloo Bay • Intensive survey will be conducted each winter Favia speciosa. Waterloo Bay

34. Lyngbya majuscula • Toxic marine cyanobacterium • Naturally occurring but proliferated in N. Deception Bay • Bulldozers needed to remove rotting, stinking mass • Human health problems • Ecosystem health problems – seagrass loss, repels fish

35. Lyngbya has rapid growth

36. Soils samples collected from various sites in the Pumicestone Passage and Deception Bay region Mangrove Cleared pine forest Intact pine forest Shirley Creek Melaleuca Canal development Sandstone Point Coffeerock

37. Lyngbyaat Amity & Moreton Banks • Occurs naturally on reefs and seagrass beds • Large amounts at Moreton / Amity Banks last summer • Potential threat to main dugong & turtle grazing areas • Less toxic than in Deception Bay, oyster impact unknown

38. Eastern & Northern Moreton Bay Best in the Bay No algal blooms Clean, clear water

39. Eastern & Northern Moreton Bay B-/A • Most pristine area of Moreton Bay • extensive seagrass beds, mangroves, & coral reefs supporting huge diversity of marine life • dugongs, turtles, whales, dolphins, fish • Excellent water quality • Tidal flushing – 1 day

40. Turtles and dugongs • Dugongs and turtles now concentrated on Eastern side • Dugongs • Population ~ 900 • 7 deaths since Jun 99 • Turtles • Population > 10,000 • Green Turtle Fibropapilloma Disease • 70% affected in S. Bay • 40% affected in Peel Is. & reefs • 20% affected at Moreton Banks

41. Northern Bay • Well-flushed by oceanic waters • Intact denitrification Worsened Unchanged Improved A • Eastern Banks • Well-flushed • Extensive seagrass beds supporting dugongs & turtles • Lyngbya B- • Northern Deception • Bay • No improvement • Declining seagrass • Lyngbya outbreak D- B • Central Bay • High sediment nutrients • Muddy sediments • Relatively good water quality D • Southern Deception • Bay • No seagrass recovery • High turbidity C- F • Southern Bay • Extensive mangrove forests • Sewage inputs • Seagrasslosses • Lack of mangrove recovery from hail damage • Bramble Bay • Sewage inputs • High nutrients and turbidity • Ulva blooms • Historical seagrass loss • High sediment nutrient fluxes C+ • Waterloo Bay • Some coral • Stable seagrass beds • Stormwater control Moreton Bay Report Card 2000 A excellent B good C fair D poor F fail

42. Communication • Quarterly newsletters • Annual report card • Healthy Waterways website • Coastal CRC website • Scientific papers • Scientific reports • Monitoring Technique Video www.botany.uq.edu.au/marbot/ (research) www.healthywaterways.qld.gov.au(management) www.coastal.crc.org.au/ehmp (monitoring)