Guinea-Bissau: Orango

My three Spanish colleagues from CBD-Habitat arrived in Bissau late night on May 20. Pablo and Mercedes work primarily with Mediterranean Monk seals in Mauritania, and they were joined by Victor, an “animal capture specialist” from the Spanish Ministry of the Environment who primarily works with birds of prey. The next day we took the capture nets they had brought from Spain to be fitted with buoys and lead lines so they would float correctly in the water. They had bought nets used by soccer goalies in Europe, so the mesh was not as thick as what we usually use for manatee captures, but it seemed durable enough. We searched out a local fisherman who told us he could have the nets ready the next morning.  

On May 22 I left Bissau in a car with Mercedes, Aissa, and most of our gear, while the guys went back to the fisherman to pick up the nets. We drove for about an hour and met our boat at a small coastal hotel southwest of Bissau. Unfortunately the guys were held up for several hours because when they went to get the nets, they weren’t done yet, even though the fisherman had told them over the phone they were. Classic Africa. In the early afternoon we finally left in our boat loaded down with gear and supplies, headed down a small river and out into the ocean to the Bijagos. I was surprised that as soon as we came out of the river, we could see islands stretched out before us. I had thought the Bijagos would be farther offshore. There are countless tiny islands with only a few trees and rocky shorelines, then a few huge ones with mangroves, palms, baobabs and white sand beaches. We saw lots of pelicans, egrets, herons, Palm Nut Vultures and a few African Fish Eagles along the way, and very few signs of humans.  

 

Loading the boat

 

It took us 6 hours to reach Meneque Island, which is part of the larger Orango Island group. We arrived after dark and then carried all our luggage about 10 minutes up a dirt path to the tiny village of Amupa. Originally we were planning to camp near the spring where we planned to capture manatees, but the local guys from CBD-Habitat (who had come ahead of us from their ecotourism hotel on Orango) had decided they preferred to set up camp in the village. This made life easier for them, but it meant a 45 minute walk to and from the capture site each day with all of our gear, not to mention being awakened at night by loud villagers, grunting pigs walking through camp, and by numerous crowing roosters starting each morning at 4am.

 

Our tent camp in the village

The next morning we headed up to the capture site. To get there we walked through the village, a grove of cashew trees, along the edge of mangroves, across salt flats and small areas of savannah, and finally through tropical palm woods. The walk was beautiful, and every day I saw something new- hippo or monkey tracks, a snake skin, lots of interesting birds.

Mercedes and Aissa getting ready to leave camp with capture gear

 

 

When the tide was high we walked through knee-deep water in many places, but it was cool and refreshing in the intense heat. Photo by M. Munoz

 We got to the spring just before low tide in order to assess how to place the nets. The spring sits in a small cove with only one entrance out to a larger mangrove channel, and the entire cove drains completely empty at each low tide. The single entrance makes it an ideal place to catch manatees, because if we block off the entrance/exit after they swim in to drink (they come most days as the tide is rising), they’ll be trapped. However, a couple things quickly became obvious the first day: although the bottom sediment around the spring itself was hard-packed sand, the edges the cove were extremely deep, thick mud banks. Additionally, despite being told that the water that the water was only waist high at high tide, we discovered that it was much higher. Deep mud coupled with high water meant our plan of having nets around the outer edge of the cove that could be brought in around trapped manatees was simply not going to work, because we would sink in mud in water that was about 9 feet deep. So a new plan was devised to affix nets around the edge to trees and poles, which would remove any possibility of manatees escaping through the mangroves, then continue with our plan to have someone at the entrance hiding in a tree to pull the net closed after manatees swam in. Once trapped, we would use a smaller net to surround the manatees inside the cove and bring them to shore (which was actually a 7 foot high embankment, so Victor set up a ratchet system to pull them up a ramp to the cleared area where we could do health assessments and attach tags).

 

Getting ready to set poles for nets on the first day

The blind and embankment as seen from inside the cove, low tide. Photo by P. de Larrinoa

 We set to work, but attaching the nets around the edge was an arduous task in all that deep mud, and it took 12 of us 4 full days of work. We went back to camp every day covered in mud and completely exhausted. The tide rose so much that it went over the tops of our nets, so we had to add a second tier in some places. And since we realized the water would be too deep for people to stand in, Victor decided to bury the smaller net around the spring itself (a net within a net), with lines to shore so that we could hopefully pull the manatee in. We also got kayaks from the ecotourism lodge to use to help handle the smaller net and to spook any manatees that didn’t swim near the spring towards it to be caught.

 

Setting up nets was a muddy business!

 

Pablo up to his thighs in mud! Photo by M. Munoz.

Placing a second tier of net above the high tide line. Photo by A. Regalla.

The cove at low tide with nets finally set up, day 4. Photo by P. de Larrinoa

High tide in the cove, checking nets by kayak. Photo by M. Munoz.

We set up the tags and I readied all the biomedical sampling supplies. 

The group watches a video of manatee captures in Senegal.

 Discussion of capture and sample collection protocols. Photo by M. Munoz.

Finally on the 5^thday we started quietly waiting at the site for manatees to come into the spring. Previous observations by the two local guys who have been documenting manatee use of the spring every day for the past few weeks showed that they come in as much as 2 hours before high tide, or three hours after. So we got there bright and early, and put Camino, our strongest guy, in the tree at the cove entrance, ready to pull the net shut after manatees swam in. Unfortunately, he never got the chance. After all the time we had to spend readying the site, we only had 4 days left to try to catch manatees, and they never came in the spring. We waited and waited, sitting quietly in the intense heat and humidity each day, getting bitten by bugs and biding the time taking turns watching for manatees from the blind at the edge of the cove, reading, sleeping, and playing cards.

Setting a camera trap to record if manatees enter the spring. CBD-Habitat set up camera traps all around the cove.

 View of the cove from inside the blind. Photo by P. de Larrinoa.

But I think all of our disturbance in the area spooked them, and they just went to another place to drink. There seem to be countless springs in this part of Africa, from central Senegal all the way to Guinea. In some places in Senegal there are over 20 known springs in close proximity, so it’s easy to imagine manatees going elsewhere. I wish more preparation could’ve been done by my colleagues before our trip to understand the capture site and prepare- we had discussed via email that they should out up nets a week in advance of our arrival to give the manatees time to adjust to the changes, but everything was very last minute, and it just didn’t happen. I still believe it’s a good place to try to capture manatees because there are very few places where one can enclose them in a natural cove.       

We had to give up because the Spaniards had booked flights home, so we had to return to Bissau. The final day we went over to Orango Parque Hotel, the eco-lodge run by CBD-Habitat, to drop off gear for next time and to spend the night. On the way in the boat, I saw a big manatee surface and dive (sorry, no photo, it happened too quickly for me to grab my camera). The eco-lodge is beautiful and we discussed my doing a manatee training workshop there in the future for IBAP field staff.

Even though we didn’t catch any manatees on this trip, it was good to finally see the site after 3 years of trying to get here, and to meet so many enthusiastic people. We hope to try again next year, and we know this kind of work takes a lot of time and patience- only in Florida is it more or less guaranteed to catch manatees when research teams to go out. In Cuba they recently finally tagged their first manatees after 10 years of trying, and in Costa Rica no manatees have ever been captured, despite 3 years of attempts, so we’ll just have to keep at it. And I’m not leaving empty-handed, because Aissa gave me a manatee sample from a carcass they found several years ago, which I’ll use for genetics analysis to add to my growing population database for the species.