Productivity

Description

Benthic primary producers survive and often thrive in the Kimberley despite the extreme conditions. Benthic primary producers, such as coral, seagrass and macroalgae, play important roles in a variety of coastal processes. They provide habitats for marine organisms, stabilise sediments, attenuate water motion, and support coastal food webs.

Our present understanding of environmental controls on reef productivity is based primarily on studies from reefs of the Caribbean, Hawaii, southern Great Barrier Reef and other Indo-Pacific regions.

Reefs where tides primarily control water motion (such as those in the Kimberley region, where tidal range can reach 12 metres) can be considered ‘tide-dominated’ and comprise approximately 30 per cent of tropical reefs worldwide. Tide-dominated reefs can experience much greater ranges in environmental conditions than wave-dominated reefs, yet have been largely unstudied.

This project has quantified the environmental variability across a macrotidal reef system in the Kimberley and assessed how benthic primary producers generally respond to extremes in water motion, light and temperature.

Aims

• Understand the productivity and growth rates of communities of organisms on fringing reefs in the west Kimberley.
• Investigate the influence that ocean conditions (such as large tides) and seasonal changes (such as the monsoon) play on reef productivity rates.
• Trace the sources of material feeding reefs to their ocean or land origins.

Methods

• Record water motion and water quality on a fringing reef for short periods by deploying small, non-invasive oceanographic instruments.
• Collect water samples from atop fringing reefs and the surrounding ocean to test for nutrient and oxygen levels.
• Use small benthic chambers at some sites to directly measure production and respiration rates to compare with the water quality measurements.
• Conduct surveys of King Sound to monitor water quality throughout the year.
• Use computer simulations to understand water motion around reefs and the delivery of material from land.

Outcomes

• Demonstration of the uniqueness of Kimberley fringing reefs and comparison to other Australian reef systems.
• Key baseline information to support longer-term reef monitoring or management plans.
• Build capacity amongst Indigenous ranger groups through training of the key methodologies used in the research as well as knowledge transfer of the key results.

 

Project News

• Oxygen and temperature levels examined in Kimberley reef
• Study confirms the ‘uniqueness’ of Kimberley reefs (WAMSI Bulletin June 2017)
• Rising sea levels could benefit some reef systems (UWA News)
• Rising seas may help some coral reefs (Cosmos Magazine)
• All that melting ice could actually be good for some coral reefs, study finds (Science Alert)
• Rising sea levels could benefit some reef systems (Phys.Org)
• Rise In Sea Levels Caused By Global Warming May Save Coral Reefs (Science World Report)
• Rising sea levels could be good news for over-heated corals reefs (Australian Geographic)
• Kimberley tides for National Science Week (Science Network WA)
• Rising Sea Levels Could Actually Benefit Coral Reefs, Scientists Say (Nature World News)

Reports

Gruber R, Lowe R, Falter J (2018) Benthic uptake of phytoplankton and ocean-reef exchange of particulate nutrients on a tide-dominated reef. Limnology and Oceanography doi: 10.1002/lno.10790

Lowe R.J., Pivan X, Falter J, Symonds G, Gruber R (August 2016) Rising sea levels will reduce extreme temperature variations in tide-dominated reef habitats Science Advances DOI: 10.1126/sciadv.1600825

Jiangtao Xua, Ryan J. Lowe, Gregory N. Ivey, Nicole L. Jones and Richard Brinkman Observations of the shelf circulation dynamics along Ningaloo Reef, Western Australia during the austral spring and summer. Continental Shelf Research Volume 95, 1 March 2015, Pages 54–73 doi:10.1016/j.csr.2014.12.013

Jones N, Patten N, Krikke D, Lowe R, Waite A, Ivey G. Biophysical characteristics of a morphologically-complex macrotidal tropical coastal system during a dry season Estuarine, Coastal and Shelf Science Volume 149, 5 August 2014, Pages 96–108 doi:10.1016/j.ecss.2014.07.01

Ryan J. Lowe, Arturo S. Leon, Graham Symonds, James L. Falter, and Renee Gruber The intertidal hydraulics of tide-dominated reef platforms Journal of Geophysical Research: Oceans Volume 120, Issue 7 July 2015 Pages 4845–4868 DOI: 10.1002/2015JC010701

Ryan J. Lowe and James L. Falter Oceanic Forcing of Coral Reefs  Annual Review of Marine Science 2015. 7:43–66 doi: 10.1146/annurev-marine-010814-015834 view on the website

S. S. Dandan , J. L. Falter, R. J. Lowe, M. T. McCulloch Resilience of coral calcification to extreme temperature variations in the Kimberley region, northwest Australia Coral Reefs ISSN: 0722-4028 (Print) 1432-0975 (Online) pp 1-13 First online: 09 August 2015 DOI 10.1007/s00338-015-1335-6

 

Media

Presentations

Physical drivers of reefs in the Kimberley (2017 WAMSI Research Conference)

Reef production and nutrient uptake (2017 WAMSI Research Conference)

Environmental forcing of benthic community productivity within the Kimberley’s macrotidal reefs (Parks and Wildlife Lunch and Learn session)

Environmental forcing of benthic community productivity within the Kimberley’s macrotidal reefs (2015 Research Conference)