Coral resilience

Description

The Kimberley region is a naturally extreme environment that features abundant and highly diverse coral reefs. However, it is currently unknown how Kimberley corals can survive within these extreme conditions and whether this affects their calcification rates and resilience in the face of climate and environmental change.

The overall objectives of this project were to understand how corals, the key ecosystem engineers on tropical reefs, have adapted and will respond in the future to the extreme variations in physical (e.g., light, temperature, water motion) and chemical (e.g., pCO2, oxygen, and nutrients) conditions characteristic of the Kimberley coastal region.

Aims

• Assess seasonal variation in nutrient and carbonate chemistry around King Sound
• Measure organism and community scale rates of calcification.
• Assess the functional response of reef calcifiers to changes in light, temperature, salinity and elevated pCO2.
• Assess historical rates of calcification and environmental change using Porites coral cores from the Kimberley.

Methods

• Measure in situ growth and calcification rates of key reef calcifiers including coral and crustose coralline algae.
• Measure community scale rates of net calcification along intertidal reef communities throughout King Sound.
• Conduct manipulative experiments on coral and crustose coralline algae in flow-through mesocosms at the Kimberley Marine Research Station at Cygnet Bay to assess thermal tolerance and bleaching thresholds.
• Recover cores from massive coral to determine past records of environmental change and coral growth. Methods that will be employed include measurements of Sr/Ca (temperature proxy), 18O (salinity proxy), Ba/Ca (river sediment proxy) and boron isotopes (pH proxy).

Outcomes

• Better understanding of coral thermal tolerance and resilience to heatwave events that can be used to inform management strategies for future events.
• Documented seasonal and spatial variation in nutrient and carbonate chemistry and coral and coralline algae calcification rates.
• Better understanding of overall sensitivity of Kimberley reef calcifiers to past, present, and future environmental change.

Project News

The ocean heatwave that killed a WA reef (Perth Now 3 Nov 2017)

Coral bleaching badly affected reefs of Kimberley, study finds (The Guardian 4 Nov 2017)

Research examines impact of coral bleaching on WA coastline (UWA News 3 Nov 2017)

Naturally resilient Kimberley coral reefs vulnerable to climate extremes (WAMSI Bulletin May 2017)

The third global bleaching event took its toll on Western Australia’s super-corals (The Conversation)

Super-coral may take heat off Great Barrier Reef bleaching (The Age)

Thermally tolerant Kimberley corals are not immune to bleaching (WAMSI)

Even the super-corals of Australia’s Kimberley are not immune to climate change (The Conversation)

WA ‘super coral’ more resistant to bleaching, but still hit by rising sea temperatures (ABC News)

Thermally tolerant Kimberley corals are not immune to bleaching (The Conversation)

Reports

Le Nohaïc M, Ross C, Cornwall C, Comeau S, Lowe R, McCulloch M, Schoepf V (2017) Marine heatwave causes unprecedented regional mass bleaching of thermally resistant corals in northwestern Australia. Scientific Reports doi:10.1038/s41598-017-14794-y

Schoepf V, Carrion SA, Pfeifer SM, Naugle M, Dugal L, Bruyn J, McCulloch MT. (2019) Stress-resistant corals may not acclimatize to ocean warming but maintain heat tolerance under cooler temperatures. Nature Communications 4031  doi.org/10.1038/s41467-019-12065-0

Schoepf V, Stat M, Falter JL, McCulloch MT (December 2015) Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment. Nature Scientific Reports doi:10.1038/srep17639

Media

Presentations

Resilience of Kimberley Corals to Climate and Environmental Extremes: past, present and future (2017 WAMSI Research Conference)

Heat tolerance of Kimberley corals and impacts of the 2016 marine heatwave on coral reefs in the inshore Kimberley region (2017 WAMSI Research Conference)

The long-term drivers of environmental change in King Sound, Kimberley: the coral records (Parks and Wildlife Lunch and Learn session)

Impact of the 2015/16 marine heatwave and unprecedented mass bleaching in Kimberley corals (Parks and Wildlife Lunch and Learn session)

Resilience of Kimberley coral reefs to climate and environmental extremes: past, present and future (2015 WAMSI Research Conference)