February 1, 2009

Today I was able to get in the water for a dive. I went out with my friend Jean, the owner of one of the local resorts, and a proucer, Mark, from the BBC Natural History unit. We first stopped for a little snorkelling off of some unual rock structures near the mouth of Chole Bay. They have some shallow coral an sea grass beds around them, and even have some swim throughs when the tide is right. We then headed out to a location called Kinasi Pass. There was a gentle current and excellent visibility, and it was a beautiful, relaxing dive. The reef structure is healthy and impressive, with lots of hard corals. The main attraction is the large amounts of fish. This dive site is within the boundaries of the Mafia Island Marine Park and the success of MIMP's protective measures is easy to see here. I saw several large potato bass - a species of grouper. We also encountered a large napolean wrasse - over a meter in length. The existence of large fish coupled with schools of smaller fish numbering in the hundreds is a welcoming sight. This area is still mostly natural, and thanks to the marine park, it has been protected. Nothing I have seen in the Caribbean can compare to this little slice of Indian Ocean paradise.

February 4, 2009

I went on a whale shark survey today with some visiting Swedish scientists as my guests. They are studying a species of mud crab, the crabs' habitats in mangrove and sea grass beds, and the potential for development of aquaculture of the species locally. In essence, they tramp through the mangroves in the middle of the night being harassed by mosquitos while hunched over an looking for crabs. Haha. The glamorous life of a marine biologist...Anyway - I had to take them out to see my sampling regime - quite posh in comparison to theirs. We rode around on a boat in the sun looking for whale sharks and slipping into the water to snorkel with them. It was actually a very productive day - I put out three more identification tags on new individuals today. This means that to date I have deployed 13 of the 21 tags I brought with me this year. I also resighted three sharks that had been previously tagged. This has been a particularly good year, with a large amount of sharks. The tagging is going well and I am starting to see more tagged than untagged sharks. I go out on surveys twice a week to do tagging. I usually go out an additional couple times a week on the tourist boats to do observations. I have an unerstanding with the local resorts so that I can go out on one of their trips and then talk to the guests about the sharks and my research and answer any questions they have. It works well, as I get extra days in the field, and get to educate many of the guests that come here to see the whale sharks.

February 12, 2009

Sometimes when you are in exotic locale you have the opportunity for completely chance experiences that can surprise you. I recently had one such experience in Mafia Island. Two dugongs, a mother and calf were drowned in fishing nets in the Rufiji River delta across on the mainland. Dugongs are marine mammals related to manatees, and like their cousins these “sea cows” are placid herbivores content to munch sea grasses and keep to themselves. Dugongs are also highly endangered and have not been reported in Tanzania for approximately two years. I had never seen a dugong before, and was pretty disappointed that the first one I would see was dead. The bodies were shipped over to Mafia Island as there is a conservation organization – Sea Sense, which works to save sea turtles and dugongs, here on the island. Sea Sense also supports the work of the Mafia Island Whale Shark Conservation Society, and I personally know some of the people in the organization. The baby was put in a small freezer at a local fish factory, while the mother was buried. I was contacted by Sea Sense to photograph and measure the baby and get skin samples from both dugongs for DNA analysis. I have not done any marine mammal work before, but I was keen to help, especially since most of their personnel were away in Dar es Salaam. I arrived in Kilindoni to see a large crowd gathered near the fisheries building. The baby dugong was splayed out on a tarp. It was much darker than I thought it would be. It was about four feet long, and looked extremely pitiful with its dead eyes bulged out of its stiff body. I pulled out a measuring tape and started to take every measurement I could think of. I measured the length, width, tail, flippers, and mouth in detail. We then flipped it over and took some ventral measurements. I proceeded to take a slew of images, trying to get the animal from every angle, and get close-up detail shots of its skin and various cuts and lacerations. Finally, I used alcohol to clear off my knife and set about the task of cutting into the tough skin to get a sample for DNA analysis. I was able to finally wrestle a small square from the baby’s back and jam it into a vial of preservative. It was grim work, but at least we may be able to extract some information from this animal, and derive some small compensation for its tragic death. The next task was to be an ordeal. The baby dugong had been frozen, and had barely thawed out. The mother had been buried for a few days and I am sure had already started to decompose. The African sun was beating down as we dug into the earth to find the body. We finally found the mother and were promptly hit with a wave of noxious aroma. Marine mammals usually have large fat layers, and when they decompose they give off a strong rotting smell. So even though I am in Mafia to study whale sharks, on this day I found myself squatting in a hole, sweat running from every pore in my body and bearing the obscene smell while I cut and tug and strain to get a tiny piece of dugong tissue. So much for the glamorous life of a marine biologist! It took about 15 minutes, but I was able to secure a sample. At the end of the day we had measurement data, photographs, DNA samples, and the smell of rotting dugong that lingered on my hands for days despite repeated hand washing. I would like to point out that despite the unpleasantness, I would do it again in a second. The pictures I took were to be run in local newspapers to raise awareness. The DNA from the animals can be compared to a population in Mozambique, to see if they are from that population or if there is still a small secret refuge where the dugongs reside here in Tanzania. I do not study dugongs, and the work was not particularly pleasant. However, as a marine biologist, and someone who believes in the conservation of all marine creatures, I am excited that I was able to do this work and hopefully contribute in a small way towards preventing this event from repeating itself. The marine ecosystem needs the full scope of its animal diversity to function healthily. The ocean and its inhabitants are threatened from many directions, and when the need to fight for them presents itself, I am happy that I can answer that call. Although it came as a surprise, after the day I could not imagine myself anywhere but squatting in that hole to get the DNA that may eventually aid us in dugong conservation.

February 17, 2009

The whale shark action continues to be hot and heavy. Today I wnet for another whale shark survey. There were sharks everywhere. I attached four more ID tags to sharks and recorded five sharks that had been tagged previously. I also encountered one untagged shark that was only 2.5 meters (about 7-8 feet long). This shark was one of the smallest I have ever seen in Mafia and may be indicative of recruitment to the population. I do not tag any sharks less than 4 meters in total length. Their skin is not as thick and tough as sharks that are aboput 4 meters or more. I am down to only two ID tags left, having marked nineteen sharks this year. I will have to go through the spot-pattern pictures but I think most of these sharks were not previously tagged. I am sure I re-tagged a shark from year 1. It has a very distinctive spot pattern with very large and bright white spots which curve in a sort of wave pattern. I have also been able to identify approximately 6 individuals by distictive fin scars, and these six sharks have been observed all three years of the study. Finally, a shark that was tagged in Kenya and observed last year (#K001) is swimming around Mafia again this year. I will be heading up to Kenya the first week of March to visit the whale shark researchers there on a good will trip. It seems we have some overlap in our shark populations and I am interested in opening communication with them in anticipation of future cooperation.

February 22-23, 2009

From time to time I enjoy being involved with education. After all - what good is research unless you go out and disseminate your findings? An opportunity to work with a class of kids from Cyprus fell into my lap and I jumped on the opportunity. The class was a diverse group, with teens from 13-18. They were all from British RAF (military) families, and although they lived on an island, many had barely swam before in their lives. They had come to Tanzania for safari and some time on Mafia to learn about the marine environment. I went to Chole Mjini (one of the resorts), to meet the class and set up a presentation. I had made a powerpoint talk covering whale shark biology and the research here in Mafia with small tangents into general shark research and conservation applications. I had 65 slides an was a bit nervous about holding the attention of a group of teens. My fears proved grounless, as no one fell asleep during my talk, and there were a few good questions at the end. We enjoyed a good dinner and went to bed, hoping for a day full of sharks to dawn upon us. In the morning we grabbed our equipment and headed across the bumpy, muddy road to the west side of the island. We got to the harbor and climbed into our boats. It was a drizzly but calm day. We drove around for hours, finding nothing but a few floating palm fronds. The water was very clear and I had a couple kids jump in with me on snorkel. I freedove about 40 feet down to the bottom and picked up some of the various species of sea stars that dot the area. The kids really liked the small break - and a distraction from driving around in a boat staring at the water. We sailed to a beach for a picnic barbeque lunch. The rain stopped and the sun began to weakly shine through the thinning clouds. There was barely a breath of wind, and the seas were flat calm. We drove around for another few hours but again to no avail. Finally, we decided to hea back to the harbor. I was in a conversation about shark finning, when to my surprise I spotted an elusive fin breaking the surface halfway between our boat and the harbor. Suddenly there seemed to be fins on all sides as we observed five different whale sharks.Three of them were small and swimming mostly just below the surface. We found two sharks I recognized and took turns getting everyone in with them. Some of the kids showed considerable trepidation about gettin in with the large fish. I coerced two of them to get in, though I had to hold their hand. After getting over their initial fear, they started swimming off in pursuit of the sharks. Their smiles confirmed that they were full converts. the sharks chose to be a bit dramatic, but the hours of searching pai off in the end. The kids were thrilled and their excited chatter on the boat was music to my ears. Working with whale sharks can be a humbling experience. their size, beauty, and surprising grace have a strong emotional effect on people. To see and approach such an animal with a sense of security and awe elicits a fervent response. I could see in the eyes of everyone in the class that they had been touched by this experience. Hopefully, the experience will help imprint on them some of the information I shared with them, as well as the desperate need for shark conservation.

"Tell me and I will forget, show me and I will remember, involve me and I will understand..." - Tennyson

February 24, 2009

It finally happened. Up until this point I was rocking a perfect record for seeing sharks. Went out on a survey today and drove around for a few hours but didn't see a single fin. I knew I would eventually get skunked, but it is still dissappointing. The sharks have been so good this year I was becoming really spoiled. You need a day like today every now and then so you can appreciate the fact that they are wild animals. That is actually part of the beauty of studying sharks. As opposed to terrestrial predators, which man has mostly caged, diminshed, or otherwise subjugated, sharks are still the masters of their envionment. I appreciate every time I see one in the water because that shark is there before me of its own volition, a true masterpiece of nature which allows me the privilege of glipsing it. I have a pretty goo idea why the whale sharks are not here. The water off the west side of Mafia is crystal clear right now. For some reason there appears to be an eddy or small chgange in currents which is bringing the clear ocean water from the channel south of Mafia up along the west coast. The clear water means great visibility, but also no food for the sharks. It has also rained a fair amount recently so there appears to be a small fresh water layer being trapped on the surface, which may force any plankton in the area down and therefore giving the sharks little reason to come to the surface where we can spot them. Hopefully, these strange conditions will pass soon and I can get back to observing sharks. I need some nutrient-rich water from the Rufiji River delta to flow back down here and return the west side to the green soup that attracts the whale sharks.