I traveled to Tanzania this August to collect fishes for the
Museum of Natural Science, and to help
|A beautiful seine pull in low tide.|
I must admit to being a bit nervous before the trip, there were a lot more unknowns than I am used to. It has been a long time since I went on a collecting trip where I wasn’t the lead, and where I was without other members of my own lab. I wanted to be sure not to get in the way of the research being conducting by Mike and his colleagues. I had also never collected in mainland Africa before; the closest I had ever been was Madagascar (which although close is very different). Perhaps the strangest thing about me going to this trip was the location within Tanzania. Most people interested in the fishes of the region would be headed straight to the famous East African Great Lakes – 85% of the fish landings from Tanzania are still from Lake Victoria. Ichthyologists interested in the marine fauna are more likely to go to Zanzibar (an island off the coast) – but since the Oceanography team was interested in studying mangroves, I would be studying the fishes of the mangroves. Knowing how few ichthyologists had ever collected in the area gave me high hopes that we might have the opportunity to discover new records and perhaps even new species.
|The striking difference between low tide and high.|
|Beautiful shrimpfish collected by Mike Polito.|
The original plan was to collect in a region called Rufiji – an area with high tides in a very remote area where we would be camping with little access to infrastructure. Unfortunately, some politically motivated problems arose: people were protesting police corruption resulting in some folks being killed. Even if we would likely be safe as foreigners, it would be impossible to get the boats and local help that we needed. The Oceanography team decided instead that they would return to an area they sampled previously: Pangani.
Pangani (specifically Kjongo Bay near the town of Kipumbwe) is a region across from the island of Zanzibar, and about seven hours north by car from the capital Dar es Salaam. Despite being remote as well, this area has quite a bit more infrastructure and creature comforts than Rufiji. In the end we were safe and had very agreeable accommodations, included three square meals a day. More importantly our hosts allowed us to spread dead fish specimens all over the place while we all took samples of otoliths, isotopes, DNA samples, and cores of mangrove mud.
We were traveling to Tanzania to allow the Oceanography team to better understand how the mangroves functioned in the larger ecosystem. Besides Mike and Mario there was Steve Midway and his student Matt Roberts filling out Team Samaki (‘samaki’ is Swahili for fish). There was also Team Mangrove led by Victor Rivera-Monroy and his lab who were taking core samples and other data to better understand the role of mangroves in general. Team Mangrove spent many hours a day out deep in the mangrove forest being tortured by insects and being cut by razor clams and other protruding organic weaponry. When they returned they spent many hours that could have been used for drinking cocktails to clean their equipment and organize their samples.
The mangroves in Kjongo Bay have a tide that rises and sinks about three meters twice a day. Our boats could only go out while the tides were high enough to allow the boats in and out of the mangroves. Unfortunately, the best collecting time was near the lowest points of the tide when the boats would be stranded. There was always a race against the clock, and we were nearly always stuck somehow – either stuck waiting for the tide (to go up or down), or literally stuck in the mud. Our boats were often stranded when the tide went out. Sometimes we would chant, ‘samaki, samaki’ while rocking our vessel from side to side, trying to steer it into deeper waters.
At one site we suddenly hit a sand bank and the boat was stranded in a few inches of water, while we figured out what to do next I got stung in the temple by a bee, and then stung again on the face, as I swatting furiously Mario yelled out “bees!” and then another person yelled out while pushing us, “jump into the water!” We all dove into the shallow water but the bees kept stinging the back of our heads and necks – we swam to the other side of the riverbank to escape. When we looked back at the boat we could see hundreds of bees swarming it. We were each stung about a half dozen times. As we licked our wounds we decided to walk downriver to join another team while we waited for the tide to rise, and to free our boat to drift down river away from the bees.
As luck would have it that other ‘bee-free site’ was remarkably diverse. We were seining different spots getting lots of different species. These included young grouper, snappers, but also species of a group I know well – the Leiognathidae (or ponyfishes). I had noticed that Mario had seen some of these ponyfishes in markets the previous year but I was still surprised to see ponyfishes in nearly every seine haul we made. I was surprised because adult ponyfishes can be collected nearly anywhere throughout the enormous Indian and Pacific oceans – but adults are bioluminescent and typically found at depths several hundred meters deep – what on Earth are juveniles doing in mangroves alongside mosquitofish and gobies? Part of what I hypothesize is happening is that ponyfishes spawn in shallow waters near the mangroves. Coastal Tanzania is known for its bioluminescencent bays; the light is caused by high concentrations of small glowing organisms. Perhaps ponyfishes ‘gets their glow’ from a bacterium that may be in high concentrations here? Only time, and a $500,000 grant from the National Science Foundation, will tell.
Some of my days were spent sorting the fishes others were collecting. My job those days were to help with IDs for the project goals of the Oceanography team. It was sometimes hard not to think of the fish collections I curate whenever we got something new. It caused me physical pain and mental anguish to see some rare specimens being torn up for isotope analysis rather than being preserved as pristine specimen for our museum. I had to remember that these specimens may help the Oceanography team better understand how to save these mangroves – and who would want to get in the way of that? In the end I still brought back nearly 500 samples from about 50 species, most new to the collection, and perhaps new to any collections – stay tuned for more on that.
It was certainly an interesting time to be in Tanzania – a new leader is pushing out
foreign interests, trying to cut down on corruption (which also is cutting into the shadow
economy that benefits many impoverished people). Tourism to Tanzania has also gone down
dramatically because of increased violence. Despite our efforts to stay safe by choosing Pangani
over Rafiji we sometimes found ourselves just at the periphery of deadly violence. We began and
ended our trip in the capital city of Dar es Salaam. And although Dar has traditionally been rather
safe we heard of several reports of gun violence. Near the end of our trip, a noted elephant
conservation biologist Wayne Lotter was murdered just a few blocks from a place we were
visiting. We learned of how he was killed (followed in his taxi from the airport, shot while he sat
beside his wife) from reading the cover of the New York Times the next day, and not from the local
news. The news shocked our colleague Lindsey West who runs a local NGO called Seasense.
Lindsey, who is British, has lived in Tanzania for many years and has been dealing with the
increase in violence daily. She is extremely efficient and she masterfully arranged for local help
for us from her many Tanzanian contacts and colleagues. Less shocking to Lindsey was our
report that a corpse had washed up on the beach in Kijongo with its hands and feet cut off
and a plastic bag around the head. ‘Oh that’s just witchcraft stuff’ nothing we needed to worry
about. We learned to listen carefully to Lindsey, if she said not to worry, we did not.
She was ‘dada mkubwa’ big sister, after all.