Effects of River Impoundment on Ecosystem Services of Large Tropical Rivers: Embodied Energy and Market Value of Artisanal Fisheries

Abstract

Applying the ecosystem services concept to conservation initiatives or in managing ecosystem services requires understanding how environmental impacts affect the ecology of key species or functional groups providing the services. We examined effects of river impoundments, one of the leading threats to freshwater biodiversity, on an important ecosystem service provided by large tropical rivers (i.e., artisanal fisheries). The societal and economic importance of this ecosystem service in developing countries may provide leverage to advance conservation agendas where future impoundments are being considered. We assessed impoundment effects on the energetic costs of fisheries production (embodied energy) and commercial market value of the artisanal fishery of the Paraná River, Brazil, before and after formation of Itaipu Reservoir. High-value migratory species that dominated the fishery before the impoundment was built constituted a minor component of the contemporary fishery that is based heavily on reservoir-adapted introduced species. Cascading effects of river impoundment resulted in a mismatch between embodied energy and market value: energetic costs of fisheries production increased, whereas market value decreased. This was partially attributable to changes in species functional composition but also strongly linked to species identities that affected market value as a result of consumer preferences even when species were functionally similar. Similar trends are expected in other large tropical rivers following impoundment. In addition to identifying consequences of a common anthropogenic impact on an important ecosystem service, our assessment provides insight into the sustainability of fisheries production in tropical rivers and priorities for regional biodiversity conservation.

Aquatic food webs in mangrove and seagrass habitats of Centla Wetland, a Biosphere Reserve in Southeastern Mexico

“…Small differences in trophic position can therefore have important natural resource management and conservation implications, such as for fisheries sustainability (e.g. Hoeinghaus et al, 2009).…”

Influence of limnological zones on the spatial distribution of fish assemblages in three Brazilian reservoirs

“…The dominance of non-native species in the new environment is another concern (Hoeinghaus et al, 2009) because reservoirs often shift from native-dominated stream fishes to non-native invasive-dominated fish assemblages (Clavero and Hermoso, 2010). This occurs because of intentional and accidental introductions of non-natives to support fisheries and to help control pest organisms, plus the greater environmental tolerances to anthropogenic disturbance of the introduced species (Moyle and Light, 1996;Hughes et al, 2005;Terra et al, 2010).…”

“…Thus, loss of connectivity is another relevant issue related to river damming, and it is associated with degraded fish assemblage condition (Musil et al, 2012). Dams disrupt migration routes (Hoeinghaus et al, 2009) that are particularly important for fish species with long-distance migrations that depend on long river reaches for reproduction and growth. Many native species are not tolerant enough to become competitive in the new environment because lotic species are replaced by lentic species (Irz et al, 2002;Hughes et al, 2005;Sanches et al, 2016).…”

Integração entre curvas de permanência de quantidade e qualidade da água como uma ferramenta para a gestão eficiente dos recursos hídricos

“…O equilíbrio entre os usos da água e a capacidade suporte dos ecossistemas, aliado à garantia dos serviços ambientais (e.g. amortecimento de cheias e autodepuração), são fatores necessários para assegurar a preservação da biodiversidade, a manutenção dos processos ecológicos e a perenidade de rios, aquíferos, lagos e reservatórios (HOEINGHAUS et al, 2009;ARTHINGTON et al, 2010).…”