Fishing for Facts in Guyana

Listen to a TerraTalk podcast with Brian Sidlauskas at
Listen to a TerraTalk podcast with Brian Sidlauskas

For two weeks in 2011, dawn signaled the beginning of another day of fish sampling for Oregon State University professor Brian Sidlauskas and his small team of colleagues and graduate students. Their camp was wedged within a mountainous area of northern South America called the Guyana Shield, and they surveyed a 125 mile stretch of the Cuyuni River that had never before been sampled.

“A typical day we’d get up at first light or not much after it, make a fast breakfast in our camp, and we’d get out on the little boat we had commissioned, it was maybe 18 or 16 feet. We had our guide, and we would say, ‘this is the type of habitat we are looking for’ or ‘do you know a good place we can fish today?’ We’d go out with our scientific equipment and our nets and spend a couple of hours running nets through the water trying to see what fish were there.”

Brian Sidlauskas on the river
Sidlauskas (right) sorts through samples from the Cuyuni River. During the expedition, he spent two weeks sampling a 125 mile stretch of river that had never before been surveyed. (Photo by Whit Bronaugh)

This expedition, sponsored in part by the Smithsonian Research Institution, was an attempt to survey fish diversity within this unexplored portion of Guyana, a country Sidlauskas says is one of the most biodiverse places on the planet.

But compared to estimates for the river based on the rest of the country, Sidlauskas and his team found an astonishing lack of diversity present.

“All of the herbivores were either absent or rare. As far as I can tell, the reason for this is that there is so much sediment in the water that the plants are dying and there is not a lot of food for the fish that eat the plants or that live in the plants.”

Mining and dredging have consumed the area as they are a cornerstone for the local economy. One result of these activities is the dumping of sand, which causes immense buildups that are potentially making the river inhospitable to plants.

Following the survey, Sidlauskas found himself with a few thousand fish and a mandate from the Guyana EPA to identify them down to species before exporting them from the country for further study. Due to a sudden departure of one graduate student, Sidlauskas was short-staffed and with only eight days to identify the specimens and it would be social networking that would allow the research to continue.

Some of the 150 species of headstanding tetras (Family Anostomidae). These fish range from less than an inch to about a foot in length.

Rather than just trying to do this on his own, he said, “Well we have Facebook, we have the internet, we’ve got all these photos, what happens if we just stick all of these photos up on my Facebook page and send a bunch of messages to our friends saying, ‘Hey, you’re an expert on this particular group of fish, do you know what this is?’ We started tagging the fishes as different people who are experts on those fish,” Sidlauskas says. “We did this and within about 24 hours we had the vast majority of our photographs with an ID on them.”

After successfully importing the specimens back into the U.S., Sidlauskas has been busy assembling an official report for the Guyana EPA with the hope of seeing mining reform in the future to prevent further biodiversity loss.

For more information, listen to the Terra Talk Podcast with Brian Sidlauskas.


This was a very interesting column. I would like to know if there is a programme in place where you give your reports to the designated officials where they can make changes? Hopefully you guys can keep updates on their progress.

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