Environmental and anthropogenic factors structuring waterbird habitats of tropical coastal lagoons: Implications for management. (June 2015)

• Record Type: Journal Article
• Authors: Tavares, Davi Castro; Guadagnin, Demétrio Luis; de Moura, Jailson Fulgencio; Siciliano, Salvatore; Merico, Agostino
• Is Part Of: Biological conservation. Volume 186(2015)
• Page Start: 12
• Page End: 21
• Publication Date: 2015-06
• Subjects: Aquatic birds -- Conservation -- Generalized Linear Mixed Models -- Human-induced changes -- Management -- Tropical biology -- Water depth -- Waterfowl -- Wetlands; Conservation of natural resources -- Periodicals; Nature conservation -- Periodicals; Ecology -- Periodicals; Environment -- Periodicals; Environmental Pollution -- Periodicals; Electronic journals; 333.9516
• DOI: 10.1016/j.biocon.2015.02.027
• Languages: English
• ISSNs: 0006-3207

Abstract

Graphical abstract: Highlights: Waterbird abundance of tropical coastal lagoons is used as metric for habitat use. Lagoon's depth is the most important factor affecting habitat use. Also anthropogenic factors affect habitat use of most guilds. Lagoon size and water pH play a minor role with respect to all other variables. Management practices should focus primarily on water depth and land use. Abstract: Tropical coastal lagoons are among the most threatened ecosystems on Earth due to multiple factors. The loss and degradation of coastal lagoons can adversely affect waterbirds, which depend crucially on wetland habitats. This study investigates the effects of a number of environmental variables on waterbird habitat use. Specifically, we assessed the abundances of six waterbird guilds in relation to hydrochemical, structural, and anthropogenic factors in 351 survey blocks of 22 tropical coastal lagoons of southeastern Brazil. Patterns of habitat use were analyzed using generalized mixed models. We found that water depth was the most important variable influencing the waterbird assemblage. Increasing water depth reduced the abundance of small and large wading birds, dabbling ducks, and diving birds. Extreme values of salinity negatively affected diving birds and large wading birds. Vegetation height influenced shorebirds negatively, while it influenced vegetation gleaners positively. Anthropogenic factors played an important role in structuring the habitat of small wading birds, dabbling ducks, diving birds and fishing birds. Our study indicates that the various guilds showed specific responses to different habitat variables. We conclude that the maintenance of water depths in the range of 0–20 cm, the preservation of a mosaic of vegetation heights, and the reduction of livestock grazing pressure are among the most important aspects for supporting high avian abundance and biodiversity in tropical coastal lagoons. Management strategies should therefore address a specific number of structural and hydrochemical attributes of coastal lagoons and should carefully consider the effects of land use practices.