Sunday, April 20, 2008

The Sirenian Population Genetics Workshop

Last Sunday and Monday I attended a sirenian genetics conference in Orlando put on by Bob Bonde and others from USGS Sirenia Project and University of Florida. It was a very successful meeting, not only to hear about ongoing work from around the world for both manatees and dugongs, but also because it wasn't too technical for those of us who are just getting involved with genetics. It is really impressive how far genetics work for manatees has come in the past few years. I gave a presentation on the collaborative effort I'm trying to set up for West African manatee genetics with folks from 11 countries in Africa (so far) and it was well-received.

Most of the conference group assembled for a photo. Hopefully another workshop will be convened in a couple years. (Photo courtesy of USGS)

Bonde was awarded a lifetime manatee conservation award which was really nice considering everything he's done for sirenians throughout his career. I don't have a picture of him receiving the award, so I'm posting this older photo taken a few years ago, which will give you an idea of his flair for fashion. Congratulations Bob!

Saturday, April 19, 2008

Angola Manatee Trip 1 Completed

I'm pleased with all the interviews and surveys we've accomplished in just under 2 weeks. I leave Soyo with a good undersatanding of the area, the excitement of seeing and photographing a manatee, great information from all the villages I visited, and good ideas for work to accomplish next time. I'm planning to return next summer, dates to be determined soon.
Thanks so much to everyone at Angola LNG for all the help (and quite a few laughs); Sheryl, Brian, Joao, Mike, Burt, Keren, Karen, Dave and the boat drivers in particular! And as always, thanks to Tim for providing good advice, constant humor and enthusiasm.

Here are a few more pictures, to give you a feeling for this place:

Huge container ships wait at the mouth of the Congo River because dock space at their destination ports is limited. The Congo River submarine canyon comes quite close to shore, allowing enormous ships to get very close to shore.

A boatload of empty gas drums on it's way downriver from Boma, DRC. The driver can't see where he's going, so another man is posted on the bow to help guide the boat.

Most local people still travel in canoes hand carved from a single tree
A few boats had homemade sails added

Boys playing
Kids loved my camera and begged me to take pictures continuously. Joao printed out copies to give to them on his next visit.

Palm Nut Vultures are common here and much more handsome than their American cousins.

And lastly, a gorgeous Baobab tree on the lagoon!

Tuesday, April 15, 2008

Sereia Peninsula

So far I've mostly been writing about my trips up the Congo River, and from the interviews I’ve done, manatees do seem to be sighted most often in the deep tributaries off the main river. However, at the mouth of the Congo is the Sereia Peninsula (sereia means mermaid in Portuguese!), which is made up of sandy beach, a few fishing villages and mangrove habitat criss-crossed with channels. I spent parts three days visiting villages and touring the mangrove waterways last week. The habitat is good for manatees and there are several stunning areas where huge mangroves overhang the waterway, creating sunlit tunnels.
The Sereia Peninsula juts northward at the southern mouth of the Congo River in the lower left of this Google Earth photo.

Mangrove cathedral
Atlantic Ocean view at a village called Etuba

Most villagers we talked to say that although they remember manatees being common here in the past, they are now rarely seen here. Several people told us that they knew of manatees found dead in fishing nets about 2 years ago, and another man reported finding a fresh dead manatee with a large propeller cut when he went out to check his nets early one morning just over a year ago. Apparently there was an old manatee hunter here, but he died last year. And one man told me he has seen more manatees this year than in the past few. Infact, he claims he sees them fairly often and told me a place to go to watch for them during low tides. In the same area I suspect there may be some aquatic plants- it’s an open shallow section of one of the larger waterways (it resembles a lagoon more than a channel), so I hope to spend more time there during my next trip.

A village called Moita Seca I on the eastern side of the peninsula

An open shallow area where aquatic plants may grow and manatees are reported more recently

A Day of Drifting and the Manatee Hunter

On Sunday I went back up the Congo River, once again hoping to see manatees. By now I’ve started to get a pretty good sense of the area. We go up the main river for about an hour before turning off into a tributary.

Heading up the Congo River from the mouth, in the early morning calm

At the mouth of the tributary is an Angolan navy outpost where we check in. On Sunday a navy guy came over and excitedly told us they had just seen a manatee go by, heading up the tributary. So we motored up a short distance, turned off the engine and drifted, but we never saw it. The river was very deep, 17-22m. We headed upriver past Kibaka and returned to a village called Nzadi Caca. There are actually two villages across the river from each other, all built on large mounds of clam shells. Not surprisingly, the large freshwater clams are the main food and livelihood of the villages in this area. The men free dive as deep as 16m in the river to get the clams, which they tell me the manatees eat as well (they specified that manatees only eat rotten or baby clams, presumably because they can actually get them out of their shells). Clams have been found in manatee stomach samples from northern Africa, so it was interesting to hear it described here as well. Joao bought some clams from the village and I tried one… unfortunately the kindest way to describe the taste was salted sediment.

A village across from Nzadi Caca built on millions of clam shells
Skewers of clams being smoked at Nzadi Caca
Villagers at Nzadi Caca frequently see manatees and were very helpful in describing behaviors they observe. My fantastic translator Joao and I are on the back left, and Mike Carpenter from Angola LNG is also in back (photo credit goes to Mike!).

After leaving Nzadi Caca we drifted downstream for awhile, once again hoping to catch a glimpse of a manatee. But this day was a reminder that we had been incredibly lucky last Thursday, because we didn’t see any all day. However, today there were also a lot more motorized boats heading upstream, all filled with gas drums headed for the Congo.

On our way back down the main river to base, we passed the town where the manatee hunter lives. There were several fishing boats out in front, so we asked a fisherman if the manatee hunter was there. He said yes, he was a short distance away on another boat. He paddled over to us and we were able to interview him (with Joao translating). The manatee hunter is named Sebastian and he has lived in this village his entire life except from 1955-1958, when he was sent to India with the Angolan army. He is an old man now but still hunts both manatees and crocodiles. He showed us his harpoons and net and gave a lot of good information about manatees. Although it is depressing that he is killing manatees, these interviews have to remain completely non-judgmental if I’m going to gain trust and get good information. He does have some bones in his village and hopefully next time I will be able to convince him to let me take samples for genetics.

Sebastian and one of his harpoons. He uses one (with bouy attached) to initially harpoon and then follow the manatee, and he has another 2 harpoons to finish the job.
Fishermen display the manatee capture net.
Joao and I interviewing the manatee hunter (photo: Mike Carpenter)
Manatee Sighted!

Sorry for the silence, the wireless internet has been down here for several days and there was no other way for me to get online.

On Thursday we headed back up the Congo River to Kibaka, one of the first villages we visited on Tuesday. Two men there told us more about the local manatee hunter (luckily there is apparently only one in the region) and also that they had seen a manatee in front of the village just a few minutes before we arrived. I have to admit to being skeptical about the sighting, because I was a bit worried they were just telling us what they thought we wanted to hear. But just a few minutes later Tim spotted a manatee across the river! So we motored up a little way, stopped the engine and drifted with the current. Amazingly, the manatee surfaced 6 more times over about the next hour. This is the first time I’ve actually seen a West African manatee stay in the vicinity of a boat; in Gabon they take off as soon as we see them. So I was able to get a few photos, which will look pathetic if you aren’t a manatee biologist or someone who studies extremely elusive animals. One of the guys here said it looks like a pregnant woman bathing. But there are so few photos of manatees in all of Africa, that being able to get some the first time I see a manatee in Angola is exciting.
Brian & Tim looking for manatees, just a few minutes before Tim spotted one.
Manatee back / dorsal as it makes a deep dive in the river.
Manatee peduncle and tail as it dives (heading left). You can see the distinct outline of the tail vertebrae in the center of the fluke.
I hope the facts that villagers here see manatees everyday, and that our first sighting was such a good one, will mean that manatees are easier to observe and study here, but it also worries me that their visibility makes them easier targets for the hunter.

Wednesday, April 09, 2008

Greetings from Angola

At long last, I am here in northern Angola at the mouth of the Congo River. This study has been two years in the making and is a survey effort for manatees, cetaceans (mostly humpback whales and humpback dolphins) and sea turtles. I am working with WCS colleagues who I also collaborate with for work in Gabon, and I’m very happy to be a part of the team here. We are contracted by Angola Liquid Natural Gas for this project, and this is the first study to integrate sighting, acoustic (for cetaceans) and nesting (for turtles) surveys to assess marine mammal and sea turtle diversity and habitat use in northern Angola.

After a long flight from Houston directly to Luanda (the capital of Angola), I took another flight up to Soyo in the northern part of the country and arrived here Tuesday afternoon. I’m staying at the Angola LNG base, which is staffed by Brits, South Africans, Americans and of course Angolans (I’m sure I’m leaving out a few other nationalities). After briefings about safety and life at the base, and meetings with colleagues (several of whom had finished their work for now and were departing just hours after I arrived), I ate an early dinner at the mess hall and passed out from jet lag.

This morning I headed out onto the Congo River with colleague Tim, Brian and Joao from Angola LNG and two boat drivers. Brian is helping to coordinate all our logistics here (which takes a lot considering the varied needs of a group of people who work offshore, nearshore, in rivers and on the beach with all kinds of equipment). Joao is Angolan and is helping by translating for me when I interview people in villages (because there’s no way I’m going to learn Portuguese! Struggling with French in Gabon is about all my poor brain can handle). It’s the end of the rainy season here, and the heat and humidity are intense, but not unlike Florida in mid-summer. The mouth of the river is 15km wide and has a very strong current that flows at 7-8 knots. As the Safety Officer said yesterday, “Fall in and your next stop will be Rio de Janeiro”. It is muddy brown and has lots of floating vegetation, most of which are favored manatee food plants such as water hyacinth and grasses. We traveled up the south side of the river (the north side is Democratic Republic of the Congo), wound through several smaller tributaries and stopped at a Navy outpost and six villages over the course of the day. Everyone was very friendly and readily volunteered information about manatees. I was surprised to find that almost everyone said they are commonly seen, people in two villages described mating herds, others have seen manatees feeding, and no villages had hunters, although several people knew of manatee hunters that came from further upriver. We also found manatee feeding sign at a couple locations. The upshot is that I’m encouraged that there may be more animals here than I predicted to myself before coming (because of Angola's long war). Hopefully we’ll be able to see some!

Tim and Joao (front), Brian (in back in the tan cap) enjoying a really nice day on the river.
This is an example of a grassy area along a tributary off the main Congo River. Even though the current was strong, it looked like a good place for manatees to feed and had types of plants they are known to eat. About 5 minutes after examining this area, two men living across the river told us they see manatees here almost everyday.
A man at the last village we stopped at, Luamba, drew a manatee in the sand to describe what he has seen.