The impact of turbidity on seagrass and other marine life

Historically, dugongs and turtles grazed on seagrass beds within Bramble Bay, but high turbidity and nutrients eliminated these beds at least 30 years ago. Current water quality conditions of Bramble Bay are unsuitable for the re-establishment of seagrass meadows. Nitrogen in the Bramble Bay zone has been decreasing since the upgrade of the Luggage Point Waste Water Treatment Plant (WWTP) in 2001. However, poor flushing continues to contribute to the poor condition of this catchment, the area possessing the longest residence time of Moreton Bay (59 to 62 days).

Deception Bay is situated at the northern section of Moreton Bay from Newport up to the south of Bribie Island and receives input from the Caboolture River, Pumicestone Passage and several other streams including Burpengary Creek.

Extensive seagrass meadows are present in the northern part of the bay but have been threatened by toxic Lyngbya blooms. Lack of seagrass recovery is likely due to discharge of poor quality water from the Caboolture River which remains a pressure on Deception Bay’s overall ecosystem health. Poor flushing resulting in turbidity in that area of Deception Bay compounds the impact of this discharge.   Since 2002 Healthy Waterways has monitored 9 sites within the Deception Bay reporting zone.


Seagrass Monitoring data from Wildlife Queensland Coastal Citizen Science has enabled the processing of Landsat imagery (USGS product) to understand the impact of Turbidity upon seagrass in Deception Bay. The negative impact is quite clearly seen in Sheet 10 of!/vizhome/mbay-sgw/Dashboard1  

A recent seagrass survey at Ormiston (Moreton Bay) noted turbidity impacting upon the coral reef located adjacent to the monitoring site.   This area supports coral gardens but they are under threat from too much turbidity. If we want to protect these amazing coral gardens we need to improve our land management within the catchment, starting with protecting natural vegetation.



Fish habitat for Moreton Bay or views for a few?

Fish habitat for Moreton Bay or views for a few?

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As the world celebrates World Wetlands Day with the 2017 theme “Wetlands for Disaster Risk Reduction” the BCC is considering whether views of the water are more important than the retention of mangroves.
Mangroves are protected plants under the Fisheries Act regulated by the State Government but following a petition received recently, Brisbane City Council (BCC) is soon to vote on whether they support the views of petitioners who want mangroves between Lota and Wynnum removed. Peter Cumming has stated that he recognizes the value of mangroves and only supports maintaining a gap of 125 metres along the Lota Camping Reserve Park.
This is welcome news to Citizen Scientists, the people who volunteer their time to be trained in and undertake monitoring for scientific purposes according to Debra Henry, Coordinator of Wildlife Queensland’s Coastal Citizen Science Program.  In 2016 Citizen Scientists consisting of college students, corporate teams, indigenous and conservation groups volunteered 300 hours to monitor Moreton Bay’s mangroves using the Shoreline Video Assessment Methodology devised by MangroveWatch Scientists from James Cook University.
“Cr Cumming’s fellow Councillors would be shrewd to realise that mangroves are ‘Mother Nature’s all-rounders’.   Amongst their benefits to fisheries as nurseries and climate change mitigation through absorption of carbon, they are also our insurance against the wrath of nature. You just need to reflect on the 2004 tsunami where thirty mangroves per 100 square meters reduced the maximum flow to villages on India’s east coast by more than 90 percent. Closer to home, when ex-Tropical Cyclone Oswald battered the south-east Queensland coast, the value of mangroves for shoreline protection was evident” Debra said.
Wynnum resident Rensche Schep says that mangroves provide recreational, tourism and artistic opportunities. “A painting titled ‘High Tide, Wynnum’ beat 100 finalists in the 2014 Waterhouse Natural Science Art Prize winning the artist Carol King $50,000 and accolades, while giving posterity a fine piece of art” said Rensche who is both a Citizen Scientist and an artist. “People may think we’ve got plenty of mangroves but it’s important that the mangroves are resilient as there’s lots of pressure on them”.
According to MangroveWatch Scientist Jock MackenzieThis need not be a situation where it’s either mangroves or no mangroves. We advocate a ‘mangrove garden’ approach which integrates the needs of local residents while recognising the important ecosystem services that mangroves provide.  This can be achieved through slope and substrate modification, trimming, thinning, windowing etc and managing the shoreline in much the same way we manage many of our other urban spaces to maximise value for all residents”.
Lota resident and Citizen Scientist Ian who has travelled far and wide along Moreton Bay’s rivers, creeks and foreshores believes the status quo should remain. “The legislation protecting mangroves should be supported and removal of any mangroves should only be sanctioned after strenuous consideration and proof of overwhelming community benefit and support”.
Simon Baltais, Manager of Wildlife Queensland’s Coastal Citizen Science project said we as a community need to be clear about the ecosystem services we value from our coastal environments and what we’re willing to give up for a view of the water. Mangroves are protected plants under the Fisheries Act and regulated by the State, not BCC. And, they’re protected for a reason. We trust Cr Cummings gets the understanding and support of his colleagues”.


Logan River mangroves under the spotlight

Logan River mangroves under the spotlight

Mangroves are great fish habitat, help keep Moreton Bay clean and protect our shorelines from erosion.

But, are mangroves in the Logan River healthy and doing their job?  What can you do to help them?  To find out, come along to Kimberley College, Carbrook on 19th August when scientists and citizen scientists will be “Putting a spotlight on mangroves”.

Trained, equipped and keen to gather data on riverine mangrove condition the citizen scientists, which included students from Logan schools and members of Wildlife Queensland Logan Branch, filmed 65 kilometres of the Logan and Albert Rivers.  The scientific analysis of this baseline data will be presented by JCU TropWater MangroveWatch scientists Jock Mackenzie and Dr Norm Duke who will enthuse you with a visually-compelling and information-packed presentation featuring imagery and other data captured by the crews.

Data will cover Logan and Redland Council areas, Moreton Bay Marine Park and the Jumpinpin Fish Habitat Area (FHA). The presentation will also include a historical perspective of Logan River mangroves, an update on current mangrove condition and options for shoreline rehabilitation.

The project received EnviroGrant funds from the Logan City Council and the Scientific Report will be shared with Council to inform their natural resource management.  Other project partners were the Jacobs Well Environmental Education Centre who liaised with schools and provided vessels for the monitoring.

“Putting a spotlight on mangroves” will be held at Kimberley College, Krueger Road Carbrook.  Doors open at 5.30pm 19th August for networking with presentations commencing at 6.30pm and concluding by 9pm.

Come along for a scientific analysis presented in an easy-to-understand format, to learn of the multiple benefits provided by mangroves and to experience a blend of science and art from a diverse group of people with a similar interest.

“Putting a spotlight on mangroves” is part of activities for National Science Week, Australia’s annual opportunity to meet scientists, discuss the hot topics, do science and celebrate its cultural and economic impact on society.  Now in its eighteenth year, National Science Week is one of Australia’s largest festivals, with last year’s programme offering over 1000 events throughout Australia, reaching an audience of over a million people.

National Science Week event details for 2015 can be found at
More information or to connect with other Logan River MangroveWatch Project partners:  Debra Henry, WPSQ CCS   0439 914 631