Reef fish

Get your optimism from the past

When we think about a “pristine” untouched ecosystem we often have a single, preconceived image in mind. It could be a grassland with thousands of bison, a thick tropical forest, or a coral reef teeming with fish and sharks. These places certainly existed, and in many cases are now lost or replaced by alternatives, but there has always been variation and that variation must have contributed to the rich mosaic of life.

It is this variation that we propose can help conservation, but first we need to describe it. If we can describe it we can do a better job of placing modern ecosystems into context. In this paper, published in Conservation Biology, BaselineCaribbean members discuss our ideas of how the fossil record can be used to redefine what should be considered “pristine” and the positive benefits of doing so for conservation.

Open Access available

O’Dea, A., M. Dillon, E., H. Altieri, A. and L. Lepore, M. (2017), Look to the past for an optimistic future. Conservation Biology. doi:10.1111/cobi.12997

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DCIM105GOPRO

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New expedition: Curaçao February 20th

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The Baseline Caribbean team is gearing up for another expedition, this time to the sparkling, cerulean seas of the Netherlands Antilles in the Southern Caribbean.

Reefs on these Dutch Islands are in relatively good shape when compared to the rest of the Caribbean. But what were they like in the past?

Anecdotal evidence suggests that sharks were once abundant around these islands, yet empirical data are desperately needed to guide management. Reef fish communities are overfished today, but by how much? When did coral communities begin to deteriorate, and did it depend on their proximity to historical settlements?

To get at these questions and more, we plan to collect nearly a ton of sediment from modern and fossil reefs along the southwest coast of Curaçao. We also hope to get the chance to explore Klein Curaçao — a 1.7-square-kilometer uninhabited island just southeast of its big sister and namesake.

Instead of reading about the results in a stale journal in two years’ time, experience science in action. Beginning February the 20th, join us with daily posts, photos, and short videos from the field on the Baseline Caribbean science blog.

This expedition builds on our previous exploits in Panama, Belize and the Dominican Republic. We see familiar faces return: Erin Dillon (who recently hightailed it to the McCauley Lab), faithful malacologist Felix Rodriguez and ring-leader Aaron O’Dea. We are also joined by some fresh blood in the form of fish ecologist and evolutionary biologist Michele Pierotti and STRI videographer extraordinaire  Ana Endara.

A huge Thank You to our supporters who will make it possible: The Caribbean Research and Management of Biodiversity field station (CARMABI) who kindly gave us a Research Prize, the Smithsonian Tropical Research Institute (STRI), and YOU! – the generous donors who contributed to our crowd-funding campaign. Stay tuned…!

 

 

 

 

When parrotfish abound the reef grows faster

 

Several years ago Katie Cramer, Dick Norris and I hatched a plan. We knew that the sediments on coral reefs preserved the robust teeth of fish and we guessed that the branching corals of the reef would hold it all in place. We just needed a way to extract the layers of reef sediments to reconstruct the history of fish communities on the reef.

Katie led the project with support from MarineGEO and Dick built a pushcore/vibracore hybrid, with which we managed to extract a good number of 3-4 metre long cores from coral reefs in Bocas del Toro, Panama.

Back at Scripps Katie led the troops to split the cores, take samples along them and extract the teeth from the matrix by acid digestion of the carbonate sediments. Sounds easy?

Then she had to identify what all these teeth were. Along with the team in Norris’ lab, and help from our lab in Panama, she built a reference collection of coral reef fish teeth, which turn out to be variable in shape, but on the whole extremely well-preserved over millennia.

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We needed to date the cores, that’s where Jian-xin Zhao at University of Queensland came in. There we were able to date small pieces of coral using the U-Th dating technique which gave really high-resolution dates, and more importantly showed that the chronology of the cores were intact – i.e. there had been no mixing up and down which would have ruined any attempt to explore changes through time.

Our cores from Bocas stretched back 3000 years or so, and one of the most abundant teeth that Katie found was the various teeth produced by parrotfish.

Using the dates of the samples to calculate reef accretion rates we discovered that as the reef was growing it did so at a faster rate when there were more parrotfishes. This results shows that the benefit of parrotfishes for the health of the reef is always high, not only in the degraded habitats of today but also on “near-pristine” reefs which were much less fished.

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The fossil record is a powerful tool to reveal ecological processes that have direct implications for conservation. And parrotfish conservation must be made a priority for the recovery and persistence of coral reefs.