Leandro Castello

Slowing Amazon deforestation through public policy and interventions in beef and soy supply chains.

The recent 70% decline in deforestation in the Brazilian Amazon suggests that it is possible to manage the advance of a vast agricultural frontier. Enforcement of laws, interventions in soy and beef supply chains, restrictions on access to credit, and expansion of protected areas appear to have contributed to this decline, as did a decline in the demand for new deforestation. The supply chain interventions that fed into this deceleration are precariously dependent on corporate risk management, and public policies have relied excessively on punitive measures. Systems for delivering positive incentives for farmers to forgo deforestation have been designed but not fully implemented. Territorial approaches to deforestation have been effective and could consolidate progress in slowing deforestation while providing a framework for addressing other important dimensions of sustainable development.

Balancing hydropower and biodiversity in the Amazon, Congo, and Mekong

Basin-scale planning is needed to minimize impacts in mega-diverse rivers The worlds most biodiverse river basins—the Amazon, Congo, and Mekong—are experiencing an unprecedented boom in construction of hydropower dams. These projects address important energy needs, but advocates often overestimate economic benefits and underestimate far-reaching effects on biodiversity and critically important fisheries. Powerful new analytical tools and high-resolution environmental data can clarify trade-offs between engineering and environmental goals and can enable governments and funding institutions to compare alternative sites for dam building. Current site-specific assessment protocols largely ignore cumulative impacts on hydrology and ecosystem services as ever more dams are constructed within a watershed (1). To achieve true sustainability, assessments of new projects must go beyond local impacts by accounting for synergies with existing dams, as well as land cover changes and likely climatic shifts (2, 3). We call for more sophisticated and holistic hydropower planning, including validation of technologies intended to mitigate environmental impacts. Should anything less be required when tampering with the worlds great river ecosystems?

A Method to Count Pirarucu Arapaima gigas: Fishers, Assessment, and Management

Abstract The giant and obligate air-breathing fish pirarucu Arapaima gigas (also known as arapaima) is a species endemic to the Amazon Basin that is increasingly managed by artisanal fishers because of government failure to control the fishery. In this study the ability of experienced artisanal fishers to count the number of pirarucu at the moment of aerial breathing was assessed. Counts were strongly correlated (r = 0.98) with mark–recapture abundance estimates calculated for the same populations. The potential for trained fishers to train other fishers to count pirarucu without slow and expensive mark–recapture work was also assessed and confirmed. Not only are the counts a cost-effective method for assessing pirarucu populations, they also allow fisher participation in decision making and contribute to effective management. The increasing number of community-based management schemes can now be matched with the training of fishers to count pirarucu.

Large‐scale degradation of Amazonian freshwater ecosystems

Hydrological connectivity regulates the structure and function of Amazonian freshwater ecosystems and the provisioning of services that sustain local populations. This connectivity is increasingly being disrupted by the construction of dams, mining, land-cover changes, and global climate change. This review analyzes these drivers of degradation, evaluates their impacts on hydrological connectivity, and identifies policy deficiencies that hinder freshwater ecosystem protection. There are 154 large hydroelectric dams in operation today, and 21 dams under construction. The current trajectory of dam construction will leave only three free-flowing tributaries in the next few decades if all 277 planned dams are completed. Land-cover changes driven by mining, dam and road construction, agriculture and cattle ranching have already affected ~20% of the Basin and up to ~50% of riparian forests in some regions. Global climate change will likely exacerbate these impacts by creating warmer and dryer conditions, with less predictable rainfall and more extreme events (e.g., droughts and floods). The resulting hydrological alterations are rapidly degrading freshwater ecosystems, both independently and via complex feedbacks and synergistic interactions. The ecosystem impacts include biodiversity loss, warmer stream temperatures, stronger and more frequent floodplain fires, and changes to biogeochemical cycles, transport of organic and inorganic materials, and freshwater community structure and function. The impacts also include reductions in water quality, fish yields, and availability of water for navigation, power generation, and human use. This degradation of Amazonian freshwater ecosystems cannot be curbed presently because existing policies are inconsistent across the Basin, ignore cumulative effects, and overlook the hydrological connectivity of freshwater ecosystems. Maintaining the integrity of these freshwater ecosystems requires a basinwide research and policy framework to understand and manage hydrological connectivity across multiple spatial scales and jurisdictional boundaries.

Anchovy stocks (Engraulis anchoita) and larval growth in the SW Atlantic

Abstract Growth rates of anchovy larvae were estimated from samples collected in the Brazilian Southeastern Bight (BSEB) in June/July and November/December, 1995. Horizontal distribution and abundance of the larvae were determined. The rate of ring formation on the otolith was related to the marginal increments and time of day. The Laird–Gompertz growth model was adjusted to the data and instantaneous growth rates were compared for anchovy larvae of other habitats in the SW Atlantic. Larval growth rates for several stocks were shown to be dependent on environmental conditions and the calculated size at first feeding on the temperature, producing geographical variation of larval growth rate throughout the distribution range of the species. The results suggest that E. anchoita from the BSEB may form a population distinct from stocks already known in more southerly regions.

Environmental influences on the distribution of arapaima in Amazon floodplains

This study investigated the environmental factors influencing the distribution of the endangered arapaima (Arapaima spp.) in floodplains of the Amazon. The abundance of arapaima was found to be positively related to the area and depth of the water column, and hence volume of lakes. Greater depth of water column also was related positively with the abundance and presence of arapaima in connecting channels. The abundance of arapaima was positively related to the connectivity of the lake with other water bodies. The principal reason for arapaima to prefer habitats that are deep, large, and connected to other water bodies appears to be increased survival through lower susceptibility to extreme drought events and increased mobility and availability of food resources. Deeper, larger, and more connected lakes and connecting channels sustain greater arapaima populations; they can now be used to prioritize conservation efforts.

Flood pulse effects on multispecies fishery yields in the Lower Amazon

Seasonally fluctuating water levels, known as ‘flood pulses’, control the productivity of large river fisheries, but the extent and mechanisms through which flood pulses affect fishery yields are poorly understood. To quantify and better understand flood pulse effects on fishery yields, this study applied regression techniques to a hydrological and fishery record (years 1993–2004) for 42 species of the Amazon River floodplains. Models based on indices of fishing effort, high waters and low waters explained most of the interannual variability in yields (R2=0.8). The results indicated that high and low waters in any given year affected fishery yields two and three years later through changes in fish biomass available for harvesting, contributing 18% of the explained variability in yields. Fishing effort appeared to amplify high and low water effects by changing in direct proportion to changes in fish biomass available for harvesting, contributing 62% of the explained variability in yields. Although high waters are generally expected to have greater relative influence on fishery yields than low waters, high and low waters exerted equal forcing on these Amazonian river-floodplain fishery yields. These findings highlight the complex dynamics of river-floodplain fisheries in relation to interannual variability in flood pulses.

Participatory Conservation and Local Knowledge in the Amazon Várzea : The Pirarucu Management Scheme in Mamirauá

Participatory natural resource management has become the most used approach to the conservation of the Amazonian varzea. But poor understanding of the process of integration of local knowledge in such conservation schemes impedes further progress. We contribute to this subject by analyzing some of the challenges of one of the most significant schemes of participatory conservation based on local knowledge in the varzea. The scheme relies largely on the knowledge and skills of local fishers, and it has been shown to be very effective at promoting the recovery of previously overexploited populations of the fish pirarucu (Arapaima spp). Our analysis shows that the prevailing practice of simply including local communities in the management process is not sufficient to promote resource conservation. It also is necessary to (i) identify individuals of the communities that possess acute knowledge of natural resources, (ii) develop cost-effective approaches to assess local knowledge in a systematic fashion, and (iii) monitor the effectiveness of participatory schemes at promoting resource conservation. We suggest that conservation and development organizations need to develop further their current practices with the knowledge of local inhabitants, if that knowledge is to contribute further to the conservation of the varzea.

Market Formalization, Governance, and the Integration of Community Fisheries in the Brazilian Amazon

A major trend in global trade in forest, animal, and agricultural products is the implementation of importation policies and development of private sector standards and certification mechanisms to promote the sustainable management of natural resources in the countries of origin. In many cases, ensuring sustainable origins involves requirements that small-scale rural producers and fishers cannot meet. This article investigates the formalization of community-based floodplain fisheries in the Brazilian Amazon, including (a) the development of federal and state fisheries management policies, (b) the parallel development of community management systems, and (c) the role of these processes in the evolution of fisheries management in the Lower Amazon region. We argue here that market-oriented solutions, such as third-party certification, are insufficient. Government support for and collaboration with producers and industry are essential to creating conditions that enable fishing communities to sustainably manage their fisheries.

Unravelling the life history of Amazonian fishes through otolith microchemistry

Amazonian fishes employ diverse migratory strategies, but the details of these behaviours remain poorly studied despite numerous environmental threats and heavy commercial exploitation of many species. Otolith microchemistry offers a practical, cost-effective means of studying fish life history in such a system. This study employed a multi-method, multi-elemental approach to elucidate the migrations of five Amazonian fishes: two ‘sedentary’ species (Arapaima sp. and Plagioscion squamosissimus), one ‘floodplain migrant’ (Prochilodus nigricans) and two long-distance migratory catfishes (Brachyplatystoma rousseauxii and B. filamentosum). The Sr : Ca and Zn : Ca patterns in Arapaima were consistent with its previously observed sedentary life history, whereas Sr : Ca and Mn : Ca indicated that Plagioscion may migrate among multiple, chemically distinct environments during different life-history stages. Mn : Ca was found to be potentially useful as a marker for identifying Prochiloduss transition from its nursery habitats into black water. Sr : Ca and Ba : Ca suggested that B. rousseauxii resided in the Amazon estuary for the first 1.5–2 years of life, shown by the simultaneous increase/decrease of otolith Sr : Ca/Ba : Ca, respectively. Our results further suggested that B. filamentosum did not enter the estuary during its life history. These results introduce what should be a productive line of research desperately needed to better understand the migrations of these unique and imperilled fishes.