Monster fish surgery in the wilds of Guyana

As the sun rises on the Rewa River, I wake to the sounds of howler monkeys rambling in the trees and a cacophony of tropical birds with their joyful noises. I pause for a moment and ponder the drastic difference between this and the wake-up calls of the bustling city of Chicago, where I live: police and fire truck sirens blaring in the streets, buses making their daily routes and anxious drivers blowing their horns as they navigate traffic. I welcome the change and feel a stream of excitement, as these are the sounds of my new home here.

After coffee overlooking the river, my field assistant Liz Smith and I walk to the home of the village leader, or Toshao, to discuss the details of the research. Welcoming us under a mango tree, the Toshao expresses his excitement at our being the first researchers to base out of Rewa Village for an extended project like this. Likewise, it is difficult to conceal my excitement for the opportunity to work on the river, where villagers have been on the forefront of conservation efforts for arapaima and other local wildlife.
Our conversation leads into a discussion of the unknown in pioneering something in research. To my or the Toshao’s knowledge, no study has ever implanted arapaima with radio transmitters for telemetry. I find myself anxious and excited, but mostly encouraged by the Toshao’s support of my research.
In the afternoon I receive word from Georgetown that the net I need to continue my project is stuck in customs. My net was custom-made for arapaima; it is 250 feet long and weighs more than 200 pounds, and has apparently raised some eyebrows in the customs office. The net is critical to the success of the project, and I shipped it several weeks in advance to ensure it would be here upon my arrival. My experience from prior expeditions is that logistical challenges are an expected companion on every trip. I remain optimistic that it is a minor issue and talk to villagers to orchestrate a different method for catching arapaima, which can reach lengths of nearly 10 feet and weigh more than 440 pounds, in the meantime. What we couldn’t catch with an impounded net, we would try with an available rod.
The next morning, Liz and I join Rovin Alvin, one of Rewa’s best fishermen, and two other fishermen for a trip to a nearby pond to find arapaima. The sun has barely illuminated the sky as we paddle the short narrow stretch that opens into a large pond. I gaze across the glassy surface as it mirrors a perfect reflection of the shoreline and the sky. An arapaima rolls, disturbing the perfect stillness and the normal pace of my heart. The angler’s cast has an immediate effect. The line buzzes furiously out of the reel as the fish bolts across the pond. The arapaima leaps into the air, and I see for the first time the magnitude of the fish I will somehow have to handle.
The angler continues working and my mind begins to race. I realize just how enormous this fish really is.
Amerindian guides instruct the angler to get the arapaima closer to the boat so it can be handled and I can insert a radio transmitter. As the fisherman draws the arapaima closer, Liz prepares the surgical equipment. With a deep breath, I force myself to rise above my nervous energy and jump into the water. Despite being tired, the arapaima releases a thunderous kick creating a wave underwater with enough force that I stop to secure my footing. Rovin and two other strong Amerindian men jump into the water and hold the arapaima.
They turn its belly upward so I can perform the surgery. To begin, I remove several scales. Quickly, I make an incision, insert the radio transmitter and begin suturing. As I finish the suture, the arapaima releases one last kick. I secure the incision with tissue glue and we take final measurements. The arapaima gulps air as Rovin and I gently release it back into the pond.
Completely exhausted by the intensity of what just happened, I submerse myself underwater for a few long seconds. This is certainly one of the more surreal moments of my life. Handling one of these creatures is like stepping back in time to swim amongst dinosaurs. (By Dr. Lesley de Souza. First published in New York Times under ‘Science at Work’ blog)
Dr. Lesley de Souza, a research biologist at the John G. Shedd Aquarium, writes from Guyana, where she studies the region’s rich aquatic wildlife, including the arapaima, one of the largest freshwater fishes in the world.