Factors Influencing Tropical Island Freshwater Fishes: Species, Status, and Management Implications in Puerto Rico

Abstract

Anthropogenic effects including river regulation, watershed development, contamination, and fish introductions have substantially affected the majority of freshwater habitats in Europe and North America. This pattern of resource development and degradation is widespread in the tropics, and often little is known about the resources before they are lost. This article describes the freshwater resources of Puerto Rico and identifies factors that threaten conservation of native fishes. The fishes found in freshwater habitats of Puerto Rico represent a moderately diverse assemblage composed of 14 orders, 29 families, and 82 species. There are fewer than 10 species of native peripherally‐freshwater fish that require a link to marine systems. Introductions of nonindigenous species have greatly expanded fish diversity in freshwater systems, and native estuarine and marine species (18 families) also commonly enter lowland rivers and brackish lagoons. Environmental alterations, including land use and development, stream channelization, pollution, and the impoundment of rivers, combined with nonnative species introductions threaten the health and sustainability of aquatic resources in Puerto Rico. Six principal areas for attention that are important influences on the current and future status of the freshwater fish resources of Puerto Rico are identified and discussed.

Fish assemblage structure in urban streams of Puerto Rico: the importance of reach- and catchment-scale abiotic factors

“…For example, predatory species of fish influence the migratory behavior and longitudinal distribution of freshwater shrimps (Hein et al, 2011). Several of these fishes are also important for subsistence fisheries, have potential as sport fishes and/or are culturally significant on the island (Neal et al, 2009). …”

Life-history characteristics of eleotrid fishes of the western hemisphere, and perils of life in a vanishing environment

“…Information from collections of Ruple (1984), Rakocinski et al (1996), Peterson et al (2000), and Hernández et al (2003) along the Gulf coast of USA is strongly suggestive of an amphidromous life cycle for D. maculatus. The species was also considered to be amphidromous on Puerto Rico (Neal et al 2009). Hubbs et al (1991) called the species estuarine in Texas waters; Darnell (1962) had suggested that D. maculatus breeds primarily in brackish-water lagoons and estuaries.…”

“…The species was suggested to be amphidromous on Puerto Rico (where it was identified as E. pisonis) (Neal et al 2009). That conclusion was also reached here, assuming that postlarvae of both E. amblyopsis and E. perniger were represented in the ''tismiche'' at Tortuguero, and that the Eleotris species present in the ''goby-fry'' of Dominica, is E. perniger.…”

Movement of Bigmouth Sleeper, Gobiomorus dormitor, in the Río Cañas, Puerto Rico, revealed by radio telemetry, and a discussion of the species’ amphidromous characterization

“…They are euryhaline and inhabit coastal lagoons and freshwater rivers (Gilmore 1992, Hernández-Saavedra et al 2004). In Puerto Rico, Bigmouth Sleeper is the only native riverine fish species that grows well in artificial impoundments (Neal et al 2009). The Puerto Rico Department of Natural and Environmental Resources (DNER) expressed interest in using Bigmouth Sleeper as a native alternative to the current introduced reservoir sport fish assemblage.…”