BRI’s Tropical Program is engaged in a wide variety of research and conservation initiatives that will expand our understanding of how environmental contaminants impact ecosystems and human health in tropical regions. These interdisciplinary studies include collaborators from national agencies within tropical countries as well as local and international conservation organizations.
Current projects range from studying the biomagnification and bioaccumulation of mercury in aquatic ecosystems and how mercury-contaminated fish potentially pose human health threats, to identifying species that indicate contamination in terrestrial ecosystems, to assisting with the establishment of a region-wide tropical bat monitoring network.
Understanding the potential impact of climate change on mercury biogeochemistry in the tropics
Climate change, environmental contaminants, and ecosystem health in the Maya Forest region of Mesoamerica—This region contains the most extensive track of continuous tropical forest in the Americas outside of Amazonia and is considered a biodiversity hotspot. A pronounced rainfall gradient across the region allows us to examine potential relationships between rainfall and the bioavailability of mercury in select indicator species sampled across that gradient.
Promoting tropical bat conservation through research, local capacity building, and long-term monitoring
Bats as indicators of metal contamination in tropical ecosystems—Bats represent a significant component of mammalian diversity in the tropics, with approximately 1200 species currently known. BRI coordinates a region-wide network of bat researchers with the goal of investigating mercury exposure in bats and identifying superior indicator species for heavy metal contamination in tropical ecosystems.
Bats of the Maya Mountains, Belize - The Maya Mountains of Belize are considered a core conservation area within the Maya Forest region of northern Mesoamerica. Much of the area’s rugged terrain is inaccessible and little is known about the abundance and diversity of bat species in the region. BRI has initiated a series of studies that examine the migration patterns of apparent disjunct bat populations, as well as their roosting and foraging behavior.
Studying mercury biomagnification in aquatic ecosystems
Mercury bioaccumulation in fishes of the Mesoamerican Barrier Reef and its adjacent watersheds—The Mesoamerican Reef is the largest coral reef in the Western Hemisphere and extends more than 1000 km along the coastlines of Mexico’s Yucatán Peninsula, Belize, Guatemala, and Honduras. In previous research, BRI and collaborating scientists documented high mercury concentrations in marine fishes. Current research focuses on measuring fish mercury concentrations sampled from the region’s major watersheds in an effort to identify potential terrestrial sources of mercury that are delivered to the coastal zone and out onto the reef.
Trophic transfer of mercury in the food web of Lago Yojoa, Honduras—Lago Yojoa is a large, natural lake located in northeastern Honduras. BRI is collaborating with researchers at Dartmouth College to investigate the movement of mercury through the aquatic food web and to identify potential human health risks associated with fish consumption.
Global Fish and Community Mercury Monitoring Project—BRI’s Tropical Program and Center for Mercury Studies are collaborating with the International Persistent Organic Pollutants Elimination Network (IPEN) to help raise awareness about global mercury pollution and to identify biological mercury hotspots in remote and understudied regions of the world.
Identifying indicator species of heavy metal contamination within tropical terrestrial ecosystems
Heavy metal cycling within a lowland tropical forest—There is a lack of information about how mercury accumulates and biomagnifies in tropical food web ecosystems. BRI biologists have been conducting research at our tropical field station in Belize to examine the linkages between lower trophic level organisms such as snails and spiders and to learn how they mediate the transfer of heavy metals up the food chain to higher trophic level organisms such as birds and bats.
- Maya Forest region of Mexico, Guatemala, and Belize
- Costa Rica
- Buck, D.G., P.C. Esselman, and J. Villafranco. (In Press). Monitoring land use changes along riparian corridors in lowland tropical watersheds: application of human impact mapping and estimation of local stress intensity. Mesoamericana 16(2).
- Divoll, T. and D.G. Buck. (In Review). Caves and mines as bat roosting sites in Honduras, with ecological notes on Sturnira ludovici, Balantiopteryx io, and Phyllostomus hastatus. Mastazoología Neotropical.
- Evers, D.C., R.T. Graham, C.R. Perkins, R. Michener, and T. Divoll. 2009. Mercury concentrations in the goliath grouper of Belize: an anthropogenic stressor of concern. Endangered Species Research 7: 249-256.
- Buck, D.G., D.C. Evers, T. Divoll, R. Graham, D. Castellanos, C. Barrientos, D. Medina, C. Chen, and F. Elvir. Distribución de mercurio en las cuencas hidrográficas que desembocan al arrecife mesoamericano. Presented at the 15th Congress of the Mesoamerican Society for Biology and Conservation, 24-28 October 2011, Mérida, Mexico.
- Divoll, T., D.G. Buck, D.C. Evers, and D. Yates. Murciélagos como indicadores de contaminación ambiental en Mesoamerica. Presented at the 15th Congress of the Mesoamerican Society for Biology and Conservation, 24-28 October 2011, Mérida, Mexico.
- Divoll, T., D.G. Buck, D.C. Evers, and D. Yates. Murciélagos como indicadores de contaminación ambiental en Mesoamerica. Presented at the Simposia Peruano de Murcielagos, 13-14 January 2012, Lima, Peru.
- Buck, D.G., Timothy Divoll and D.C. Evers. La bioacumulación de mercurio en redes tróficas de embalses hidroeléctricos. Presented at the 14th Congress of the Mesoamerican Society for Biology and Conservation, 8-12 November 2010, San Jose, Costa Rica.
- Buck, D.G., M. Brenner and M.J. Cohen. Temporal and spatial variability of in-stream nutrients in a small tropical watershed dominated by shifting cultivation. Presented at the annual American Society for Limnology and Oceanography Aquatic Sciences meeting, 6-11 June 2010, Santa Fe, New Mexico.
- Divoll, T., R. T. Graham, N. Hammerschlagg, C. Hammerschmidt, D.C. Evers. Bioaccumulation of methylmercury in sharks from Florida and Belize: an international comparison of marine apex predators. Presented at the International Conference on Mercury as a Global Pollutant, 24-29 July, 2011, Halifax, Nova Scotia.
- Divoll, Timothy, D.C. Evers, R. Graham, D.W. Castellanos, and D.G. Buck. Mercury level exploration in marine food fish species in Belize. Presented at the 13th Congress of the Mesoamerican Society for Biology and Conservation, 26-30 October 2009, Belize City, Belize.
- Buck, D.G., T. Divoll and D.C. Evers. Identifying potential mercury hotspots in the watersheds of the Mesoamerican Barrier Reef: Phase One – watersheds of Belize. Presented at the 13th Congress of the Mesoamerican Society for Biology and Conservation, 26-30 October 2009, Belize City, Belize.
- Buck, D.G., T. Divoll and D.C. Evers. 2011. Preliminary report: Mercury contamination in the Gulf of Honduras and its adjacent watersheds. Submitted to the Ocean Foundation. Biodiversity Research Institute, Gorham, Maine.
- Buck, David G., Timothy Divoll, and David C. Evers. 2011. Pilot assessment of mercury concentrations in the freshwater fishes of Belize, Central America. Report BRI 2011-18 submitted to the Belize Fisheries Department. Biodiversity Research Institute, Gorham, ME.
- Evers, D.C. 2008. Mercury in terrestrial birds of Belize. Report BRI 2008-05. Biodiversity Research Institute, Gorham, Maine.