The frog extinctions were starting to generate professional and public interest. Matt published results from his Panama studies done on the trips before ours in a very high profile, non-technical, ecological journal (the publicity magazine for the Ecological Society of America) and other more specialized papers from the group were coming out in the peer reviewed literature. Meanwhile Karen and Matt were receiving numerous invitations to speak at universities across the country where they would tell the story of the disappearing frogs of Panama and how the effects of these extinctions were reverberating through the ecosystems.
The research group also continued to make presentations at scientific meetings. Such meetings are great places to share scientific ideas and results with hundreds of others who are working on related issues. They provide the one time where scientific specialists are not the oddballs; nerd talk is the norm.
Matt and I attend a meeting of stream scientists every year and room together. Rooming with me may not be the most pleasant experience, but it is one way we could both use our grant money more efficiently. The day starts at 8:00 with scientific presentations till 5:00. Dinner is followed by a boisterous mixer in the meeting hall with hundreds of people discussing and arguing science. As with any large group of talking people, the volume increases to a roar. This makes for a long day, and after this Matt and I would lie in our beds and talk about science, our colleagues, and the state of the world.
Often our conversations would turn to the frogs in Panama. We kept trying to think of ways to strengthen the research. As in all science, every experiment leads to more experiments. In addition, the impending extinction of the frogs was something to worry about, even if we could do nothing to stop it. One thing we learned early on from rooming together at meetings, earplugs are essential.
One of the gaps in our research after our trip to Panama, and an issue Matt and the rest of us worried about for the next proposal, was measuring how much nitrogen is excreted by tadpoles. The tadpoles could be what we refer to as “ecosystem engineers”. Ecosystem engineers are organisms that have a disproportionately large effect on the environment and this effect cascades to the other species. Beavers that fill valleys with their dams, hippopotami grazing in fields and bringing nutrients they excrete back to the water, alligators digging water holes in the Everglades that last through the dry season, and bison eating dead grass and recycling the nutrients locked up in the grass available for the new growth of grass, are all examples of ecosystem engineers.
The tadpoles at El Valle were abundant and active enough that they could be major nutrient contributors to their streams. We were concerned with what happens when these potential ecosystem engineers in streams are lost. Some species of the tadpoles break down the organic material that falls into the stream in the form of leaves, and others clean the algae off the rocks. An interesting feedback is that the leaves become better to eat and the algae grow better when supplied with nitrogen. The tadpoles excrete nitrogen, and it actually stimulates production of their food. This excretion may also stimulate the microbes that serve as the food source for many of the tadpoles, insect larvae, shrimps, and fish in the stream. There were so many tadpoles in the streams that their effect had to be large, but how large was what we wanted to know.
Nitrogen excretion measurements were made while we were in the field with live tadpoles collected directly from the stream. The animals were placed in test tubes and then removed and released back into the stream. The amount of ammonia (the form of nitrogen excreted by the tadpoles) left after the tadpoles were removed was used to estimate the rate of their excretion. We did quite a few of these experiments streamside on the first trip with the samples returned to our rooms in Hotel Campestre for late night analyses. Our initial experiments indicated the rates of excretion were very high over the first few minutes and then decreased over time.
Bob argued that the tadpoles quit eating when they were placed in the experimental tubes and their excretion rates were slowing after a few minutes because of that. Alex and I thought that maybe stress was causing them to excrete more at the beginning of the experiment. Matt, being the diplomatic group leader, and a fine scientist to boot, suggested experiments were needed to settle the argument. This is the scientific processes. Our speculations formed hypotheses and now we needed the experiments to test them.
These discussions led Matt and Alex to run a series of experiments on tadpoles from the Midwestern US that are taxonomically-related to the tadpoles dominant at Rio Maria. These experiments proved that the higher excretion rates at the beginning were from the stress of being handled and put into a tube. Excretion rates from later in the experiment were more applicable to what the tadpoles were doing in the stream. Matt and Alex proved that handling tadpoles and putting them in large test tubes literally scared the piss out of them. These results were written up and submitted for publication in the scientific literature. They also strengthened the next proposal and would guide our experiments if we got funded to go back to Panama.
Another five months went by and the proposal was rejected again. This was extremely disheartening because once again, the reviews were fabulous. Matt called the program officers at the National Science Foundation to try to figure out how to get the proposal funded. The funding situation was getting dire because Piet’s and several graduate students’ salary depended upon continued funding.
We had agreed to fund the follow-up experiments in Panama out of our own pockets if need be, but we could not expect post-doctoral researchers or graduate students already living on poverty-level salaries to do the same. Luckily the program directors at the National Science Foundation agreed to some stop-gap funding to keep the project going and allow Matt time to apply for funding in the next round. One of the investigators on the grant actually paid Piet’s salary out of her personal funds for awhile. Scientists generally don’t enter the field of ecology to get rich, and many are quite generous with their time and resources, but this was exceptional. There is a long tradition of using personal funds for research; Charles Darwin had to pay his own way as naturalist on the Beagle.
Scientists through the years have had to scrape for external funding and we were no exception. Matt and the rest of us had to strategize on how to make the proposal sexy, compelling, and stress how imperative it was to fund the research immediately. We needed to write the proposal so well that the agency simply could not justify declining to fund it. Matt worked with the group on the best way to sell the research, and the proposal was submitted yet again.
The third time was a charm. I received an email from Matt telling me to plan to travel to Panama the following February. This was very good news and just in the nick of time. Matt had scouted out one site not far from the other side of Panama City where there were still frogs and additional experiments could be conducted as part of this new grant. If the disease spread much further into Panama the work would be finished for good. The remote Darien rainforest between Panama City and Columbia presumably contains the last areas the disease has not reached, but the eastern part of it is inhabited by drug runners and rebels and is not a safe place to work without an entire protective army. Going to the Darien was out of the question; we had a hard enough time getting funding, but getting support for a private protective army was out of the realm of possibility.
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