An international team of scientists has used the 23-million-year fossil record to calculate which marine animals and ecosystems are most at risk of extinction today.

In a paper published in the journal Science, the researchers found those animals and ecosystems most threatened are predominantly in the tropics.

“Marine species are under threat from human impact, but knowledge of their vulnerabilities is limited,” says study co-author, Professor John Pandolfi from the ARC Centre of Excellence for Coral Reef Studies at the University of Queensland.

The researchers found that the predictors of extinction vulnerability, geographic range size and the type of organism, have remained consistent over the past 23 million years.

As such, they were able to use fossil records to assess the baseline extinction risk for marine animals, including sharks, whales and dolphins, as well as small sedentary organisms such as snails, clams and corals.

They then mapped the regions where those species with a high intrinsic risk are most affected today by human impact and climate change.

“Our goal was to diagnose which species are vulnerable in the modern world, using the past as a guide” says study lead author, Assistant Professor Seth Finnegan from the University of California Berkeley.

“We used these estimates to map natural extinction risk in modern oceans, and compare it with recent human pressures on the ocean such as fishing, and climate change to identify the areas most at risk,” says Professor Pandolfi.

“These regions are disproportionately in the tropics, raising the possibility that these ecosystems may be particularly vulnerable to future extinctions.”

The scientists say that identifying the regions and species at greatest risk means conservation efforts can be better targeted.

“We believe the past can inform the way we plan our conservation efforts. However there is a lot more work that needs to be done to understand the causes underlying these patterns and their policy implications,” says Asst. Professor, Seth Finnegan

Co-author, Dr Sean Anderson from Simon Fraser University, British Columbia adds, “It’s very difficult to detect extinctions in the modern oceans but fossils can help fill in the gaps.”

“Our findings can help prioritize areas and species that might be at greater risk of extinction and that might require extra attention, conservation or management – protecting vulnerable species in vulnerable places.”

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Paper

The paper, Paleontological baselines for evaluating extinction risk in the modern oceans by Seth Finnegan, Sean C. Anderson, Paul G. Harnik, Carl Simpson, Derek P. Tittensor, Jarrett E. Byrnes, Zoe V. Finkel, David R. Lindberg,Lee Hsiang Liow, Rowan Lockwood, Heike K. Lotze, Craig M. McClain, Jenny L. McGuire, Aaron O’Dea, & John M. Pandolfi., is published in the journal Science

Copies of the paper can be accessed at: http://www.eurekalert.org/jrnls/sci/

 Contacts

John Pandolfi, j.pandolfi@uq.edu.au, +61 (0) 400 982 301

Seth Finnegan, sethf@berkeley.edu, +1 (951) 452-2759

Sean Anderson, sean_anderson@sfu.ca

Paul Harnik, paul.harnik@fandm.edu, +1 (717) 358-5946

Eleanor Gregory, (Communications), eleanor.gregory@jcu.edu.au, +61 (0) 428 785 895

Researchers in Queensland have found that where baby corals choose to settle is influenced by ocean temperature and the presence of their symbiotic algae in the water.

Warmer than normal maximum temperatures are known to have a negative impact on the reproduction and survival of some corals. The researchers wanted to find out how a cooler climate, similar to that found south of the Great Barrier Reef, would affect coral larvae settlement.

“We were interested to see how temperature influenced the selection of where corals chose to settle,” says Dr Eugenia Sampayo from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at the University of Queensland.

“At colder than average ambient temperatures we found that the larvae settled on more exposed surfaces where they were more likely to be damaged or removed entirely by fish.”

Coral larvae actively search out a place to settle using a range of sensory cues. Once in place they can’t move, so a poor choice of location increases the risk of death.

As part of the experiment researchers exposed larvae from coral commonly found on the Great Barrier Reef, Acropora millepora, to several different temperatures; including normal temperatures for the Great Barrier Reef and cooler temperatures similar to those experienced south of the Great Barrier Reef.

Coral Spawning. Image: Natalia Winkler

Under normal conditions, the larvae prefer to settle on surfaces covered in crustose coralline algae, but the researchers found larvae in the cooler water were less likely to choose such a surface, reducing their chance of a successful settlement.

The researchers also examined the influence of dinoflagellates (Symbiodinium), microscopic single celled organisms that live inside coral tissue once it has settled. This so-called symbiotic relationship is essential to the survival of corals in tropical oceans.

“Perhaps the most surprising result is that the presence of these symbionts in the water also influenced whether the coral larvae settled on the algae encrusted surfaces or not,” says study lead author, Natalia Winkler from the Coral CoE.

“The fact that the symbionts can influence larval settlement without actually being inside the coral tissue highlights just how important the symbionts are for corals,” Ms Winkler says

Dr Sampayo adds the results suggest a link between crustose coralline algae and the symbionts.

“If symbionts cluster near favorable locations, the coral larvae kill two birds with one stone by finding a good spot to settle and a concentrated source of symbionts, which are normally sparse in the water,” Dr Sampayo says.

“We have discovered a previously unknown biological control over coral settlement, one that is likely to be influenced by warming oceans and that can change how corals select their life-long position on the reef.”

Paper

Symbiodinium identity alters the temperature-dependent settlement behaviour in Acropora millepora coral larvae before onset of symbiosis by Winkler NS, Pandolfi JM, Sampayo EM is published in the journal, Proceedings of the Royal Society London B. http://dx.doi.org/10.1098/rspb.2014.2260

Contacts

Dr Eugenia Sampayo, Coral CoE, +61 (0) 7 3365 2729, e.sampayo@uq.edu.au

Natalia Winkler, Coral CoE, natalia.s.winkler@gmail.com

Eleanor Gregory, Communications Manager, +61 (0) 428 785 895,

eleanor.gregory@jcu.edu.au

Scientists in Queensland have used historic media to measure the decline in Queensland’s pink snapper fishery, highlighting a drop of almost 90 per cent in catch rates since the 19^th Century.

Researchers from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at the University of Queensland and the Department of Agriculture Fisheries and Forestry examined thousands of newspaper articles dating back to1870 to reveal the historic catch rates for the iconic Queensland fishery.

“We found that 19^th century recreational fishers would regularly catch hundreds of fish off the coast of Queensland, often in just a few hours of fishing,” says Dr Ruth Thurstan, a Research Fellow from the Coral CoE.

Combining historical data with statistical analyses allowed the researchers to calculate catch rates, which are the number of fish caught per hour fishing per day, for nearly 300 fishing trips between 1871 and 1939.

When the researchers compared the findings to contemporary fishing trips, they found that recent catch rates averaged just one-ninth of historical levels.

The old news articles have given researchers unparalleled insights into the history of the Queensland snapper fishery.

“When we searched through these old newspapers we were amazed by the level of detail they provided,” Dr Thurstan says.

“They give us a much better understanding of just how rich and productive this fishery used to be, as well as providing us with some fascinating insights into the development of offshore recreational fishing in Queensland.”

“Crucially, these newspaper articles place the modern day fishery into a longer-term perspective that isn’t available using only official records. This helps us understand the changes that have occurred in the fishery over time, and provides an additional piece of the puzzle for those managing this fishery today,” Dr Thurstan says.

Study co-author, Professor John Pandolfi, also from Coral CoE agrees.

“This is one of the most comprehensive perspectives on historical trends in catch rates for Australian fisheries ever compiled,” Professor Pandolfi says.

“We expect similar trends to be uncovered for other Australian fisheries.”

Paper

‘Nineteenth century narratives reveal historic catch rates for Australian snapper (Pagrus auratus)’ by Ruth H Thurstan, Alexander B Campbell and John M Pandolfi is published in the journal Fish and Fisheries.

http://onlinelibrary.wiley.com/doi/10.1111/faf.12103/abstract

 Contacts

Dr Ruth Thurstan: +61 (0) 450 586 263 or r.thurstan@uq.edu.au;

Professor John Pandolfi: + 61 (0)7 3365 3050 or j.pandolfi@uq.edu.au

Eleanor Gregory, Communications Manager: +61 (0)7 47816067, +61 (0)428 785 895 or eleanor.gregory@jcu.edu.au