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 fiance! :-).

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 in 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 other loud people. 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.

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.
The Dakar to Ziguinchor ferry... a really nice boat!

Mangroves viewed from the ferry

Bottlenose dolphins leaping everywhere!!

My first view of Ziguinchor. It's 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 bizarrest things I've ever seen). We gave the staff manatee educational posters and they told us there were many more manatees in the past, but since no studies have been done in this region, it's impossible to quantify.

The mummified manatee head.
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. Pt. 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 visit 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 Pt. 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 (infact, 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 6-8 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!

Our host Oussman's house in Pt. St. George.

Pt. St. George already attracts a few tourists who come to see the manatees. This sign (Manatee ecology path) was in the center of the village.

The manatee viewing tower seen from the Pt St George beach.

Closeup of the tower. At high tide the water comes up past the base of the tower. At low tide it sits at the shoreline and the spring is about 50 meters offshore, within the river.

View of the beach from the top of the tower.

View of the main river from the tower, with the approximate location of the spring shown by the red arrow.
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.
Manatee tail fluke diving back down to the spring.

This manatee's tail is covered with both barnacles and mud. 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 very warm- 26 degrees Celcius.

Mother and calf manatees diving. This was my first verified sighting of a West African manatee calf!
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 Pt St George El Hadj and Oussman took us on boat excursions along the mangroves to look for manatee feeding sign, 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).

El Hadj (with his niece) points out manatee feeding sign in the mangroves.

Mangrove branch with cropped leaves eaten by manatees. This is the species of clam manatees eat in Casamance (Adrana senilis).

El Hadj and Oussman's father was a manatee hunter and they still had an old skull, which they gave me for my genetics research.

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 luckily he doesn't use them!

Tomas checks out a very old manatee rib that El Hadj also gave me.

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 Pt. St George community to develop a long-term conservation and research project there!

African Manatee Work Goes Regional!!

As many of you know, it has been my hope for the past several years to create a regional network of African manatee researchers to increase communication, data collection efforts and collaboration between people working in different countries. Manatee research in Africa is still in its infancy and many people who are trying to get started have told me they feel isolated because they are the only person or organization working on manatees in their country. Additionally, people are looking for guidance on how to develop studies and begin fieldwork. And often, they don't have even basic field equipment such as binoculars, GPS units or environmental sampling tools.

For the past two years I have co-taught training workshops in Ghana for African researchers from 12 different countries, but funding for those workshops is now finished. So I am very excited to report that I have recently received my biggest grant to date from the U.S. Marine Mammal Commission to continue training and building the regional network! This will allow me to both bring researchers to active study sites in Africa to get practical experience in manatee surveys, tagging and tracking, necropsies, genetics sampling, and for me to go to some other sites to work with researchers in their home countries. It will also allow me to get some basic equipment to collaborators in need so they can get accurate manatee data in their countries. There are still alot of challenges to overcome, but I'm really looking forward to helping train and expand manatee research throughout the range of the species. So thanks very much to the Commssion for giving me this opportunity!

10 days in eastern Senegal

On February 9th we headed east from Dakar towards Matam, a town on the Senegal River. This is where we rescued manatees trapped behind a dam in January 2009, and it's the place where manatees migrate in the rainy season onto a huge floodplain to feed on submerged grasses and plants in this otherwise extremely dry region. It's a 12 hour drive through dust and many small villages to get to this part of the world, so this time we split the drive up by spending a night at Lac de Guiers and arrived in Matam on the 10th.

It's hard to describe how completely the dust pervades every pore of your body in this place. This is Aziz, our driver, doing his best to fight off the dust from getting in his eyes, ears, nose and mouth (he failed, he was as red as the rest of use when we arrived).
Our first task in Matam was to recover and clean three manatee skeletons that were buried to decompose last November. Unfortunately these three manatees likely died while trying to exit the Navel dam as the waters receded after the rainy season last Fall. Unfortunately grates on the dam doors were not lifted, so they probably drowned trapped up against the grates. Some interested kids watched Tomas and I cleaning skulls. We hope at least the bones of this rare species will be useful for science and educational purposes in Senegal.
This is the burial site, in view of the dam that unfortunately killed them.
After the skulls, we checked on the rest of the bones, but found that due to the extremely dry soil (it hasn't rained here since August) they haven't finished decomposing. So we collected a few more, but we'll have to wait for the rest.

Next we checked the water level at the Navel tributary. The dam doors are now closed and this water is being used for crops, but there are still some manatees trapped inside (no one knows how many since this tributary, full of chocolate milk water, runs for miles). We scouted for them but didn't see any, and I also listened for the radio-tagged manatee (the only one still tagged from January 2009), but I didn't hear her signal at this location.

The water is slowly receding, but it's still alot higher than it was in January 2009. Unfortunately for the trapped manatees, the water needs to be lower in order for captures to occur. All the captures are done by hand nets, so the water can't be over people's heads, and we need to limit the manatees to a smaller area to catch them. But I did see several places where plants were in reach of the water, so they may still be able to find food.

Next we traveled about 35 kilometers south down the road to the town of Kanel, another part of the huge floodplain. Here the water has always formed large pools (really lakes several miles long) as the tributary dries up. So this is an area where manatees become trapped in pools, but it's not because of a dam. I learned that the first manatee captures here were in 1964, so the people here have a long history of returning the manatees to the Senegal River. We went out on the Wendou Kanel lake in a boat with a fisherman named Moutar, who took me out tracking last Fall. I was happy to see a huge area of flooded grasses and waterlilies (both known manatee food plants) along one side of the lake.

As always, I listened for the tagged manatee. Here I heard the signal a few times, but extremely faint and off to the south. It's very hard to get around this area (no roads) and even though we went to the south end of this lake, she could be in a different area.

(Photo T. Diagne) Coming in from tracking (photo T. Diagne)
The last site we visited was Patowel, another part of the tribuary cut off from the main Senegal River, approximately 7km long. The water here never completely dries up and it's an important fishing spot for the local people (the fish are refreshed during the rainy season overflow from the main river). Manatees get trapped in here every year and there are almost no plants during the dry season, so they eat fish from the fishermen's nets. This occurs in other countries as well, and African manatees are reported to eat not only fish but several species of clams throughout Africa, so they are more omnivorous than their Floirida cousins!

Patowel fisherman cast netting. They also use large nets across the entire river, which manatees break through. It's challenging to explain to the fishermen that if they don't want their nets broken, they are going to have to alter their fishing practices and leave an open space for manatees to pass by... they would not welcome hearing this from an outsider, so I discussed this with the local fisheries representative, a very enthisiastic guy who is very interested to try to find good solutions for both fishermen and manatees.
Catfish heads found in fishermen's nets after the rest of the fish were eaten by manatees.
At the end of our tip, Tomas and I attended a 2 day long multi-agency meeting hosted by Wetlands International in Matam. The meeting brought together all the interested parties in manatee issues on the Senegal River- government agencies (manatees are a protected species under the Water and Forestry Ministry, but the water bodies are overseen by the Senegal River Development Authority, and there are also local fisheries departments), NGOs (Wetlands and Oceanium Dakar, both of whom I collaborate with), and local elders from the various villages. There were also several journalists there.

The meeting was held at a hotel, but the entire group also took field trips to Navel, Wendou Kanel and Patowel. Here a fisherman in Patowel explains their concerns about the manatees. (Photo T. Diagne)
An engineer with the Senegal River Authority discussed the Navel dam... at the Navel dam. I learned alot at this meeting and it was impressive to see all the interest in finding solutions from all the different attendees. (Photo T. Diagne)

Last but not least, Tomas had learned of some old photos of manatee captures in Matam, and we tracked them down. Unfortunately they had not been well-preserved, but it was still neat to see them. Oceanium began working on manatee rescues here in 1986.

I always enjoy the trips to eastern Senegal, but it's also good to get back to Dakar and wash off the dust! I'm now planning my next field trip to southern Senegal....

Onward to Senegal...

I haven't been blogging this past month because I've been working on lots of annual reports, grant applications and export permits, which are all necessary and important, but definitely not thrilling enough for commentary! I'm happy to report that I've cleared quite alot of office work off my plate now and am heading back to fieldwork. I fly to Senegal tomorrow night and am in the process of getting ready for manatee work in several parts of the country... stay tuned!

Gabon: Manatee Capture!

The frustration had definitely been building. Eight days and nights around the clock setting nets and waiting, having manatees punch holes through the nets every night, second guessing our decisions about where nets should be set, and seeing manatees near the nets everyday, was making us all crazy. Not to mention the heat/humidity, the bugs and the dwindling food supply. Two team members had already had to leave and on the ninth day we knew it was our last day before the rest of the team would start having to depart back to their other lives. So we set out at our usual 5:30am a bit disheartened to say the least.

We checked the first three nets and they were empty as usual. But as we approached the fourth and last net across a small open mangrove lagoon, I noticed that it was bowed at an odd angle, no longer straight into the channel as we had left it. As we came close, stopped the boat engine and began to lift the net to check it, suddenly a manatee nose surfaced right next to one of the buoys! I think we were all in a state of shock, and that shock grew as we saw the manatee and realized it was only caught by its tail, not wrapped around the front part of its body the way they usually get caught. Luckily for us the net was wrapped in a tight knot around the tail and he could not escape. We moved him to shore alongside the boat, moving very slowly so he could breathe. The closest land we could find was an opening in the forest at the edge of the lagoon about a quarter mile away.

The manatee caught by his tail as we first found him in the quiet lagoon. Through the water you can see the net wrapped around his tail.

The manatee was given a complete health assessment including taking morphometrics (standard length and girth measurements), standard photograph views (left side, right side, dorsal, ventral, etc.), body temperature, collection of blood, genetics, fecal, urine, tear, hair and skin lesion biopsy samples. Unfortunately though, the manatee was too small to tag. He was a subadult and the smallest manatee I have recorded in Gabon so far. Manatees need to be a certain size to safely carry the GPS tags, because we don’t want do anything that could cause difficulty for the animal to live its normal life. The point of tagging is not only to track where the manatee moves, but to study behavior. The tags are built with several “weak links” that will break it off the manatee if it gets caught on anything, and they are neutrally bouyant, but they’re still built for adult manatees and this one was just too small. However, the team was excited since this is the first time many of these biological samples have been collected for the species, and this is the first live-captured manatee ever for Gabon.

As usual, a genetics sample was taken by punching a notch in the manatee's tail with a cattle ear notcher. Aside from the valuable information genetics analysis provides about the species, the resulting notch can help identify a manatee that has been peviously captured (if it is caught again in the future).
Standard length and width measurements were also taken, which means we can start to build a database for Gabon's manatees and also compare these measurements to manatees in other parts of Africa. .
I taught Ken how to draw a blood sample from a manatee...

Ken and I posing with the manatee just before we released itReleasing the manatee back into the lagoon

Although time and funding were finished for this round of captures, we were lucky to get one manatee at least, and I hope to be able to try again to tag here in the future.