If you're looking for some peaceful reflection, I've got 40 seconds of looped fish swimming through one of my study reserves to help chill you out. These mahseer definitely enjoy the protection offered by the local communities throughout the Mae Ngao River basin.
I just got back from a brief trip to Thailand. The trip was a success in that I was able to collect the last few fish samples for a migration study I'm working on, purchase 220 lbs of fish from 8 different markets around the country for a project on mercury contamination (and successfully get them through customs), visit my host family up in Mae Hong Son with a couple of Berkeley School of Journalism students who are doing a story on community conservation in my research area, and get a duffel bag full of human hair home for my wife's research on stress in women and children using hair cortisol. Not bad for 7 days of work. It did, however, require driving 3,000+ km and more than 44 hours in a car (map of route below).
I definitely enjoyed scoping out the fish markets throughout the northeast of Thailand. Livelihoods and local culture in this region is so strongly connected to the Mekong, it's fun to talk with local fish sellers and to see what that catch of the day is.
I also saw the largest Pangasius catfish I've seen in Thailand in Khon Kaen, a 26+ kg individual. Sounds big, but if the saleswoman was telling the truth, this species gets well over 100 kg.
For the last five years, I’ve been working on research related to the conservation of aquatic ecosystems in Southeast Asia, and I'm happy to announce that the first chapter of my dissertation has recently been published. While it's only available online at the moment, it should be making its way onto a printing press at Ecosystems in the coming months. A big thank you to my collaborators Joel Moore (Towson U.), Naparat Suttidate (formerly at UW-Madison now in Thailand), Robyn Hannigan (U. Mass-Boston) and my advisor Pete McIntyre (UW-Madison), my field assistant, Jack Siddoway, and the International Sustainable Development Studies Institute for logistical support.
Much of the work of conservation is figuring out how to balance human needs for resources like food, water, and timber with the need to maintain the organisms and ecosystems that produce these goods. There have been a lot of studies that have specifically looked at how to meet the future food demand of humans while maintaining sufficient areas for wildlife. Many scientists argue that the best way to do this is to maximize the amount of food produced from the minimum amount of land. By doing this, there will be more land with high-quality habitats for wildlife. Achieving this goal would require substantial centralization of agriculture as well as substantial fertilization and irrigation effort in most places. Other researchers have suggested that we should mix agricultural landscapes with conserved areas, because these sorts of arrangements can be better for both wildlife and for the farmers. This may just sound like an academic argument, but land managers from all over the world have to deal with these types of questions.
The question that I and my collaborators were interested in trying to answer was, What happens to the aquatic ecosystems when you try to intensify agricultural production and maximize forest cover? This scenario is currently playing out in much of Southeast Asia as the historical swidden farming system common in northern Thailand and throughout Southeast Asia is being converted to more industrialized corn and soybean farming. Swidden is a long-standing process of cultivating plots of land that depends on forest regeneration to maintain the fertility of soils. Swidden is sometimes referred to as rotational farming because farmers rotate their cultivation among 5-20 different patches of forest, one of which is cut and burned each year to provide a pulse of nutrients at the beginning of the growing season before laying fallow for several years.
There are lots of forms of swidden, but they all typically don't require the use of commercial fertilizers like more conventional, or modern, farming techniques. Because of the increased pressure on many regional governments to increase agricultural production while also increasing forest cover, people practicing swidden have often been incentivized, or in some cases forced, to adopt conventional farming practices. While this might have benefits for increasing the extent of forest cover, which in turn may help conserve terrestrial biodiversity, the necessity of using commercial fertilizers may result in losses of water quality in these areas, and thereby negatively impact freshwater biodiversity.
Our results strongly suggest that areas with low swidden coverage and high levels of commercial farming have higher nutrient concentrations in the rivers that drain those landscapes. More importantly they have potentially altered ratios of nutrients like nitrogen and phosphorus, which have been shown to affect the production of algae, the bottom of the food web in these tropical aquatic systems. At low concentrations, these nutrients might actually increase the food resources available to the rest of the organisms in the rivers, but, in most aquatic systems around the world, having too much nutrient availability often results in hazardous algal blooms. So, while curtailing swidden and concentrating agriculture production on smaller patches of land might provide more forest habitat for things like birds and mammals, the impact may actually be negative on all freshwater organisms both in the immediate area and downstream of farmed areas. Unfortunately, the ongoing debates regarding terrestrial management that either favors swidden or alternatively intensive forms of farming have rarely considered the effects of these transitions on aquatic systems.
Conservation planners face the continual challenge of maintaining biodiversity and important ecosystem functions, while also ensuring there is enough land for producing the food our growing human population needs. However, our research suggests that there may be costs to aquatic systems if we just try to maximize our agricultural production on less land in order to increase the amount of land for conservation. With additional consideration of aquatic ecosystems in our land management strategies we can make sure we aren't just saving our forests at the expense of our rivers.
My advisor, Pete McIntyre, along with co-authors Cathy Reidy Liermann and Carmen Revenga, published an important paper in the Proceedings of the National Academy of Sciences today. The paper is a first look at the importance of freshwater fisheries for food security at the global scale, an issue that motivates my research in Southeast Asia. Due to the importance of Pete's research, the University of Wisconsin has published a press release featuring some of my photos from Thailand. You can check it out the press release, and my photos, here.
The Bangkok Post just published a nice video about current efforts to describe the entire list of species present in the Salween River. As there are plans to put large dams of the Salween, getting this basic, but incredibly important, information into the hands of fisheries officials will help in understanding how such development projects might affect the river's biodiversity.
The initial image shows Mr. Dee, the man on the right in the Post's photo below, who was invaluable as a guide and Karen translator during my first field season in 2013. Great to see him getting this sort of recognition for his conservation work!
This week I'm off to Ubon Ratchathani, Thailand's eastern-most province bordering both Laos and Cambodia. The purpose of the trip is to pick up fish from colleagues at Ubon Ratchathani University which were collected for an ongoing project on fish migration in the Mun River.
While in Ubon I had the chance to visit Pha Taem National Park, where a series of 3,000 year old cliff paintings show just how important the Mekong River, and the fish therein, have been to local cultures throughout the region's history.
I also had the chance to revisit Pak Mun Dam, this time in rainy season, when the flood gates are opened to allow fish migrating upstream to spawn to move into the Mun River. The dam, completed in 1996, dramatically affected upstream fish stocks and sparked strong protests both during and after its construction. To appease affected fishermen and those concerned about the environmental impacts of the project, the government has compromised by opening the flood gates during four months of each year to allow fish migration and reproduction and improve upstream fish catches. In a global review of the impacts of dams around the world published in 2000, the World Commission on Dams named the Pak Mun Dam the worst dam constructed at the time due to the myriad social, economic, and environmental impacts associated with the project. Our research is aiming to look at the current state of fish movement within the Mun River basin as well as the size and composition of catches by villagers in the region. For more photos from Ubon and the surrounding area, check out the gallery below.
I had the privilege of working with three of my academic advisors (along with many other collaborators) Kirk Winemiller of Texas A&M, and U. Wisconsin professors Pete McIntyre and Ian Baird on a piece published in Science's Perspectives section back in January. Briefly, we highlight in the article that the three most biodiverse rivers on earth, the Amazon, Congo, and Mekong, are all slated for significant hydropower development, which will have major effects on the connectivity within each basin as well as potentially inundate many critical habitats for fast-water specialist (rheophilic) species. Therefore, it is crucial that hydropower projects are developed with thought to the cumulative basin-scale impacts of each potential project. Also, shout out to my McIntyre lab-mate Etienne Fluet-Chouinard who made the beautiful maps. If you want to read the whole article, there's a link here.
For the last 5 months I have had the privilege of having Vera Swanson, a UW-Madison undergraduate, assisting me in the field. While in Thailand Vera has been participating in an internship program with the UW, which recently ended. As part of this project Vera was tasked with creating a multimedia project describing her time abroad, as well as what she has learned from the experience. She did a stellar job. Check it out below!
This week I, along with two field assistants, Vera and Hannah, set up the second round of my exclosure experiments. This entailed scouting potential sites in the river, getting village approval from the headman, a lot of rebar pounding and a lot of plastic. But, after several days of work, the first half of the experiment is up and running! On Monday we'll deploy the second experimental treatment and then it will be time count fish, collect macroinvertebrates, scrub algae off of rocks all in order to measure the effect of maintaining high levels of fish diversity and biomass in tropical rivers by means of setting aside protected areas within the system.
Recently, our research lab at the University of Wisconsin-Madison's Center for Limnology, headed by Pete McIntyre, launched a new website! This goal of this website is to serve as an outlet for the numerous research and outreach activities pertaining to migratory fishes that go on within our group. The majority of the projects that the McIntyre lab is involved with are related to the Laurentian (American) Great Lakes, but also documents work from the Great Lakes of Africa (Lake Tanganyika in particular) and my work in Southeast Asia.
You can visit the new website here. I'm sure I'll be linking to updates on the site periodically, but check it out for yourself!