Senegal: Casamance Was Worth the Wait!
I've been wanting to get to the Casamance River, the southern boundary of Senegal and Guinea-Bissau, for about a year. It's been difficult because there have been a few rebel uprisings from separatists who want to break away from Senegal, so there have been a couple military interventions (not exactly a good time to go there!) and also logistically it requires a few weeks of time to plan and travel there. But finally, last week, we pulled it off thanks to great logistical help from Tomas, my Senegalese manatee colleague extraordinaire (and my fiancé)! We took an overnight ferry from Dakar to Ziguinchor, the largest city on the Casamance River. The ferry took 14 hours and was the hardest part of the trip, because we had some hassles with checking my equipment, and since we booked the ferry the morning we left, we couldn't get a cabin, so instead we sat in airplane-style seats for 14 hours in a room with about 50 others. But it was worth it, in the morning when we went up to the top deck at sunrise, just as we entered the river from the ocean. Bottlenose dolphins leapt all around the boat in the waves, and the shoreline was pristine mangroves dotted with a few small fishing villages.
Here's a map of the lower Casamance River showing all the mangrove tributaries. Ziguinchor is on the lower right side of the map, and our final destination, Point St. George, is at the upward bend of the river in the middle of the map.
Ziguinchor is a pretty and sleepy fishing town, and it would be hard to believe there's recently been trouble there, except that we saw lots of military everywhere in town.
Once we arrived in Ziguinchor, we headed to the local fisheries office to say hello. They had a mummified manatee head that apparently had been in their office since before 1975 (originally preserved in formalin and then allowed to dry, it was rock hard and one of the most bizarre things I've ever seen). We gave the staff manatee educational posters and they told us that there were many more manatees in the past, but since no studies have been done in this region, it's impossible to quantify.
The next morning we arranged a car to take us back downriver to the fishing town of Elinkine, where we met El Hadj, who, with his brother Oussman, works for Oceanium Dakar and is working to establish a protected area for manatees in Point St George on the Casamance River. El Hadj took us by boat to Point St. George, a trip of about 2 hours through the mangroves. Point St. George is of particular interest for manatees, because there's a small freshwater spring just offshore and manatees come there to drink everyday. Sometimes up to 30 manatees a day visiting the spring, the largest gathering spot I've heard of in Africa (which is why I'd been trying to get here for a year!). The Casamance River is extremely salty, infact the salinity is higher than the ocean. Manatees don't get all the freshwater they need from the food they eat, so they need to drink freshwater periodically. Studies of Florida manatees indicate that manatees living in saltwater usually travel to a freshwater source to drink approximately once a week.
After walking around the village of Point St. George, I went up the manatee viewing tower and waited for the manatees to show up. Like clockwork, as soon as the tide began to fall, they appeared. The water is not very clear (in fact, when I snorkeled out to the spring, the visibility was about 6 inches...not great when there are big jellyfish everywhere!). So mostly what I could see of the manatees were their noses poking up at the water's surface for a breath, then their backs and tails as they dove back down to the spring. The first day there were about 6 to 8 manatees there, and later I saw at least 10 around the spring. Very neat and definitely a good place for me to set up a longer-term study. There is almost nowhere in Africa where manatees come with this kind of predictability, I was ecstatic!
Lots of manatee noses popped up at the spring during low tides. An Oceanium student intern who worked here started a rudimentary photo ID catalog for individual manatees based on scar patterns on their tails. He identified about 15 different individuals. I plan to train Senegalese biologists to continue and expand this work in order to get a better idea of the population.
Manatees get barnacles all over their bodies if the spend alot of time in saltwater. The mud is likely from the manatee rolling on the bottom. In Florida we see this behavior during the winter, when the manatees "burrow" their heads into the warmer mud at the bottom of warm water locations, but I'm not sure why these manatees are rolling. Maybe they're trying to rub off the barnacles. The water here was a very warm 26 degrees Celcius.
As I mentioned, there were LOTS of big jellyfish in the river and many others dead on the beach. I'm not sure if this was normal or not, but they were beautiful although it was eerie swimming in the murky water knowing they were there.
I snorkeled out to the manatee spring to check the depth and salinity at low tide. I also listened for manatee vocalizations, but didn't hear any, even though I'm pretty sure there were a few in the area.
The village has buoys provided by Oceanium to mark the spring as a protected area, but they weren't in the water while we were there, and we watched several boats go right over the manatees. I will be providing recommendations to Oceanium for future conservation activities, and the first will be to put the buoys back in the water and connect them with cords so that boats can't enter the spring area.
While in Point St. George El Hadj and Oussman took us on boat excursions along the mangroves to look for manatees feeding, and to clam flats where manatees feed (yes, here as in several other places in Africa, manatees are known to eat clams - the proof has been found in stomach samples from dead manatees).
On our return trip to Elinkine, El Hadj showed me his father's old manatee harpoons. Culturally, manatee hunters are well-respected in Africa, and the tradition is often passed from father to son, so El Hadj is proud to own these, although happily he doesn't use them!
At the end of our trip we returned to Ziguinchor and boarded the ferry for another overnight trip to Dakar, although this time we had cabins which made the journey much more enjoyable! We sailed out of the Casamance River into the Atlantic Ocean at sunset. In Diogue, the village at the river mouth, people say they see manatees swimming in the ocean. This isn't surpising given the large number of mangrove channels in the area. El Hadj also volunteered that there are aquatic plants in the sea that manatees like to eat. You can bet I'll check that out next time!
This is definitely not the last I will see of the Casamance manatees, I'm looking forward to working with Oceanium Dakar and the Point St. George community to develop a long-term conservation and research project there!
Reporting from West Africa, EcoHealth Alliance research scientist Lucy Keith is working on an extensive collaborative project to study West African manatees.