McKenna, S.A., and Rasheed, M.A. (2014) Port of Abbot Point long-term seagrass monitoring: annual report 2012-2013. Report. TropWATER, James Cook University, Cairns, QLD, Australia.

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Abstract

Key Findings:

1. Seagrasses have been monitored quarterly at Abbot Point since 2008 with additional broader regional seagrass surveys conducted in 2008 and 2013.

2. After 18 months of recovery deep water seagrass underwent declines through 2013 following Tropical Cyclone Oswald and associated rainfall, high winds and flooding.

3. Inshore monitoring meadows have yet to show substantial recovery but in 2013 there were some initial signs of recovery with small amounts of Halodule uninervis present at two of the inshore meadows.

4. The density of deep water seagrass in the broader port limits dramatically declined in the 2013 baseline surveys compared with the last regional baseline surveys conducted in 2008. Similarly the density of seagrass at inshore meadows in the broader region declined from dry season 2008 to dry season 2013.

5. The total extent of all seagrass meadows in the broader Abbot Point area declined by 60% between the 2008 and 2013 wet season surveys. However by the 2013 dry season survey, total meadow area had increased again to be similar to the 2008 dry season.

6. The first ever recorded occurrence of Halophila tricostata in the Abbot Bay/Bowen area was made in the September 2013 baseline survey.

7. The broader scale baselines in 2013 have found meadows of the key inshore species Halodule uninervis and Zostera muelleri near to Abbot Point that could provide a means of recovery for Abbot Point meadows through dispersal of seeds and other propagules.

8. Light (Photosynthetically Active Radiation) monitoring indicated that during the seagrass growing season in the second half of 2013, the amount of light available was favourable for seagrass growth at both inshore and offshore sites. While some seagrass recovery was observed the lack of recovery at other meadows was likely due to a lack of available propagules (seeds, fragments, adult plants).

9. The declines in Abbot Point seagrasses over recent years mean that they likely have a reduced resilience to further impacts and stressors. The cumulative impacts of natural stressors need to be considered in conjunction with future developments associated with port expansions in formulating management strategies to protect seagrasses.

10. Assessments of seagrass seed banks and their viability will be a key addition to the monitoring program in 2014 to understand their resilience to impacts and potential for recovery.

Item ID:	39634
Item Type:	Report (Report)
Keywords:	seagrass, dredging, resilience, recovery, monitoring, water quality, light thresholds, photosynthetic active radiation, climate impacts
Additional Information:	Access: This report is openly accessible from the link to TropWATER's Technical Reports web page above. Copyright: Please refer to the copyright statement in the report.
Funders:	North Queensland Bulk Ports Corporation (NQBP)
Date Deposited:	25 Aug 2015 06:12
FoR Codes:	05 ENVIRONMENTAL SCIENCES > 0502 Environmental Science and Management > 050205 Environmental Management @ 50% 05 ENVIRONMENTAL SCIENCES > 0502 Environmental Science and Management > 050206 Environmental Monitoring @ 50%
SEO Codes:	96 ENVIRONMENT > 9605 Ecosystem Assessment and Management > 960503 Ecosystem Assessment and Management of Coastal and Estuarine Environments @ 50% 96 ENVIRONMENT > 9605 Ecosystem Assessment and Management > 960507 Ecosystem Assessment and Management of Marine Environments @ 50%
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