Species Distribution Models of Freshwater Stream Fishes in Maryland and Their Implications for Management

Abstract

Species distribution models (SDMs) are often used in conservation planning, but their utility can be improved by assessing the relationships between environmental and species response variables. We constructed SDMs for 30 stream fishes of Maryland, USA, using watershed attributes as environmental variables and presence/absence as species responses. SDMs showed substantial agreement between observed and predicted values for 17 species. Most important variables were natural attributes (e.g., ecoregion, watershed area, latitude/ longitude); land cover (e.g., %impervious, %row crop) was important for three species. Focused analyses on four representative species (central stoneroller, creek chub, largemouth bass, and white sucker) showed the probability of presence of each species increased non-linearly with watershed area. For these species, SDMs built to predict absent, low, and high densities were similar to presence/absence predictions but provided probable locations of high densities (e.g., probability of high-density creek chub decreased rapidly with watershed area). We applied SDMs to predict suitability of watersheds within the study area for each species. Maps of suitability and the environmental and species response relationships can help develop better management plans.

Natural abiotic factors more than anthropogenic perturbation shape the invasion of Eastern Mosquitofish (Gambusia holbrooki)

“…Mosquitofish have been generally neglected in similar models, except by Lauzeral et al (2011) who noted some climate niche shifts. Our SDM is one of the first in which anthropogenic landscape features were considered for a freshwater species (see also Markovic et al 2012, Liang et al 2013, Maloney et al 2013. We hope to improve our understanding of factors mediating mosquitofish invasion and to identify areas where mosquitofish may already be present or is likely to invade.…”

Large scale patterns in the diversity of lake fish assemblages in China and the effect of environmental factors

“…Indeed, the PDM modifies the hydrological conditions of lakes directly, such as water content, water depth and transparency, and nutrients (Wetzel 2001), which in turn affect fish lives and distributions (Brazner & Beals 1997;Petry et al 2003;Teixeira-de Mello et al 2009;Kang et al 2013). Indeed, besides these factors, there are still many others that could affect and hinder fish distribution and biodiversity, such as land-cover, geographical variables, topological variables, biological invasion, artificial impacts and even net primary production (Park et al 2006;Buisson et al 2008;Gevrey et al 2009;Maloney et al 2013;Kang et al 2013). Thus, in future studies, more impact factors should be considered comprehensively.…”

“…Growing evidence has shown that fish assemblages and diversity are influenced by a wide range of environmental factors, such as climatic variables, surface area, landcover, geographical variables, topological variables, biological invasion, anthropogenic activities and even net primary production (Park et al 2006;Buisson et al 2008;He et al 2011;Maloney et al 2013;Kang et al 2013). These factors may affect fish assemblages and diversity by directly altering, for instance, the light intensity, organic matter, nutrient or sediment load of fish habitats, and indirectly by interacting with other anthropogenic activities such as climate change, species invasion and dam construction (Sutherland et al 2002;Strayer et al 2003).…”

“…Therefore, quantifying and understanding how fish assemblages and decomposed diversity respond to environments in catchments are important for fish resources management, conservation and the restoration of aquatic ecosystems, and has thus become global research hotspot in ecology, biogeography, evolution and conservation sciences all over the world (Park et al 2006;Sharma et al 2007;Buisson et al 2008;He et al 2011;Maloney et al 2013). However, compared with other aquatic ecosystems, lakes still remain poorly studied despite the fact that they are among the most important aquatic ecosystems on earth and can be ideal fields for studying fish distribution and assemblage since they are natural bio-geographical islands (but see Zhao et al 2006;Brucet et al 2013).…”

Predicting fish species richness and assemblages with climatic, geographic and morphometric factors: A broad-scale study in Chinese lakes

“…However, we have to acknowledge that it is only a showcase limited by the data available nowadays, which predict fish patterns with climatic (temperature and precipitation), geographic (altitude) and morphometric (lake area) factors in a broad scale. A number of other factors have been identified as potentially affecting fish distribution and diversity, such as land-cover, geographic variables, topological variables, biological invasion, artificial impacts and net primary production (Park et al, 2006;Buisson et al, 2008a,b;Gevery et al, 2009;Maloney et al, 2013;Kang et al, 2013). Further research therefore requires the inclusion of such factors in order to obtain more powerful explanations.…”