Castello, L. et al. 2014. Low and declining mercury in Arctic Russian Rivers. Environmental Science & Technology 48, 747−752
Impacts of dams on the integrity of Amazonian ecosystems
NEW PROJECT: Freshwater ecosystems in the Amazon are among the most biological diverse and productive in the world. Current infrastructure development (e.g., hydroelectric dams) is altering the structure and function of these ecosystems. However, detailed ecological assessments of the impacts created by such dams on the integrity of these freshwater ecosystems are lacking. With funding from WWF-Brasil, the project will assess the potential impacts of hydroelectric dams on the lateral and longitudinal connectivity of Amazon freshwater ecosystems. Participants include Marcia N. Macedo (Woods Hole Research Center).
Integrating fishers’ knowledge in management promotes sustainability
Castello, L. et al. 2009. Lessons from integrating fishers of arapaima in small-scale fisheries management at the Mamirauá Reserve, Amazon. Environmental Management 43:197-209.
Study shows dependence of floodplain fishes on complex habitat structure
Castello, L. 2008. Lateral migration of Arapaima gigas in floodplains of the Amazon. Ecology of Freshwater Fish 17:38-46.
Muskellunge population dynamics in the New River
NEW PROJECT: A project in the New River of Virginia to reassess the potential of muskellunge (Esox masquiongy) to impact the smallmouth bass (Micropterus dolomieu) population through predation. With funding from the Virginia Department of Game and Inland Fisheries, the project will assess current population dynamics and life history of muskellunge, and model musky growth dynamics and effects of musky predation on smallmouth bass. Participants include Brian Murphy (Virginia Tech).
Land and resource use on the Amazon floodplain under evolving management systems and environmental change
NEW PROJECT: An interdisciplinary project aiming to:
(i) measure historical human impacts on river-floodplains of the Amazon
(ii) quantify relations among fish, forests, grasslands, and human welfare, and
(iii) identify expected outcomes under simulated conditions of increased resource demand and climate change.
The project is funded by the National Aeronautics and Space Administration (NASA). Participants include Laura L. Hess (University of California, Santa Barbara), David G. McGrath and Michael T. Coe (The Woods Hole Research Center), Victoria J. Isaac (the Universidade Federal do Pará, Brazil), and Frank Merry and Greg Amacher (Virginia Tech). Our lab contributes to this project by quantifying and modeling the influences of hydrological alteration and floodplain vegetation cover on fisheries productivity.
Read more about this project.
Community-based management of arapaima in river-floodplains of the Lower Amazon
This is a long-term research and extension program aiming to promote sustainable arapaima fisheries through
(i) increased understanding of the biology, ecology, and status of arapaima populations
(ii) capacity building of fishers and their communities, and
(iii) development of community-based management plans.
Funding comes from Conselho Nacional de Pesquisa (CNPq), Brazil, and Mamirauá Sustainable Development Institute, Brazil). Participants include Fabio Sarmento (Instituto de Pesquisa Ambiental da Amazônia), Caroline C. Arantes (Texas A&M University), and David G. McGrath (The Woods Hole Research Center). Our lab contributes by providing stock assessments and investigating the requirements necessary for sustainable resource governance. Read more.
Mercury levels declining in Arctic Rivers
NEW PUBLICATION: A recent paper* published in Environmental Science and Technology suggests that mercury levels are declining in some Arctic rivers.
- This study was featured in various news media outlets, including
Abstract (2014)
Mercury (Hg) dynamics in the Arctic is receiving increasing attention, but further understanding is limited by a lack of studies in Russia, which encompasses the majority of the pan-Arctic watershed.
This study reports Hg concentrations and trends in burbot (Lota lota) from the Lena and Mezen Rivers in the Russian Arctic, and assesses the extent to which they differ from those found in burbot in arctic rivers elsewhere. Mercury concentrations in burbot in the Lena and Mezen Rivers were found to be generally lower than in 23 other locations, most of which are in the Mackenzie River Basin (Canada). Mercury concentrations in burbot in the Lena and Mezen Rivers also were found to have been declining at an annual rate of 2.3% while they have been increasing in the Mackenzie River Basin at annual rates between 2.2 and 5.1% during roughly the same time period. These contrasting patterns in Hg in burbot across the pan-Arctic may be explained by geographic heterogeneity in controlling processes, including riverine particulate material loads, historically changing atmospheric inputs, postdepositional processes, and climate change impacts.
*Castello, L., Zhulidov, A.V., Gurtovaya, T.Yu., Robarts, R.D., Lysenko, V.S., Holmes, R.M., Zhulidov, D.A., Spencer, R.G.M. 2014. Low and declining mercury in Arctic Russian Rivers. Environmental Science & Technology 48: 747−752. pdf
M.S. Assistantship in Fisheries Ecology & Conservation
LAB NEWS: A qualified and motivated candidate is sought to investigate hydrological influences on the dynamics of commercially important fish populations in the Amazon Basin. The selected candidate will design and conduct a catch data analysis plan to investigate the following two main research questions: (1) how natural fluctuations in river water levels affect the population dynamics and associated fishery yields of a chosen species (e.g., Prochilodus nigricans, Colossoma macropomum); and (2) how water level fluctuations altered by climate change and construction of dams impact fishery yields and associated food security. The candidate will collaborate with project participants in Brazil, and prepare scientific reports for publication in peer-reviewed journals. This project is part of a multidisciplinary research grant awarded by NASA.
Anticipated start date is August 2014.
Click here for the complete position announcement.
Amazon freshwater ecosystems vulnerable, despite protected areas
NEW PUBLICATION:
The hydrological connectivity of freshwater ecosystems in the Amazon basin makes them highly sensitive to a broad range of anthropogenic activities occurring in aquatic and terrestrial systems at local and distant locations. Amazon freshwater ecosystems are suffering escalating impacts caused by expansions in deforestation, pollution, construction of dams and waterways, and over-harvesting of animal and plant species. The natural functions of these ecosystems are changing, and their capacity to provide historically important goods and services is declining.
Existing management policies–including national water resources legislation, community-based natural resource management schemes, and the protected area network that now epitomizes the Amazon conservation paradigm–cannot adequately curb most impacts. Such management strategies are intended to conserve terrestrial ecosystems, have design and implementation deficiencies, or fail to account for the hydrologic connectivity of freshwater ecosystems. There is an urgent need to shift the Amazon conservation paradigm, broadening its current forest-centric focus to encompass the freshwater ecosystems that are vital components of the basin. This is possible by developing a river catchment-based conservation framework for the whole basin that protects both aquatic and terrestrial ecosystems.
Castello, L., McGrath, D.G., Hess, L.L., Coe, M.T., Lefebvre, P.A., Petry, P., Macedo, M.N., Reno, V., Arantes, C.C. 2013. The vulnerability of Amazon freshwater ecosystems. Conservation Letters 6: 217–229. pdf