Predicting Invasion Success: Freshwater Fishes in California as a Model

Abstract

Articles Streams, lakes, and estuaries are among the most highly invaded ecosystems in the world; in many of them, alien organisms are now a significant part of the biota (Cohen 2002). The best-documented invaders in these systems are fishes. Because many fish species are widely introduced, there is concern among scientists and managers over the homogenization of freshwater fish faunas worldwide (McKinney and Lockwood 1999, Rahel 2002. Invasions by alien species also have high ecological and economic costs. Efforts to prevent the spread of unwanted fish and other organisms, however, are still small compared with the size of the problem (Meyerson and Reaser 2003), in part because policymakers and the public often fail to appreciate the seriousness of the invasions. Many harmful alien fishes, for example, are also favorite food and game fishes. Thus, to make predictions useful for the management and control of alien species, scientists need to understand the nature of invaders, the invasion process, and the impact of invasions, and to communicate that knowledge effectively.Because "any species can invade and any environment can be invaded" (Moyle and Light 1996), a search for generalities that would be useful for predicting the success of potential invaders may be futile. Kolar and Lodge (2001) argue, however, that quantitative approaches (including meta-analysis of diverse sources of information) can produce useful predictions. In particular, they argue for the need to analyze data on failed invasions. We think there is also a need to focus analyses at regional scales, because studies at continental or global scales tend to yield results with limited predictive ability (Gido and Brown 1999, Lockwood 1999, Ruesink 2005. In this article we address these issues of approach and scale in relation to fish invasions by synthesizing recent studies in California, mainly our own. We focus on these studies because the scope and completeness of our data sets make our studies widely applicable. After introducing California as a laboratory for the study of fish invasions, we focus on the potential for predicting success and impacts of freshwater fish invasions based on (a) symbiotic characteristics (the relationship of the fish to humans), (b) biological characteristics of the invaders, (c) characteristics of the invasion site, and (d) the invasion process. We then briefly address the question, Do alien fishes alter the ecosystems they invade? Peter B. Moyle (e-mail: pbmoyle@ucdavis.edu

Tradeoffs among Ecosystem Services Associated with Global Tilapia Introductions

“…The United States exists at the very edge of the environmental tolerances of tilapia (Zambrano et al, 2006) and winter die-offs occur even in southern states (Germany and Noble, 1977). Meanwhile Sri Lanka is environmentally well suited for tilapia but there are few if any native freshwater fish species (De Silva, 1989) to resist or be affected by introductions (Moyle and Marchetti, 2006). Thus the ecological effects and resulting tradeoffs reported in the United States and Sri Lankan habitats may not be comparable to other regions or countries, despite the fact that these countries are the largest contributors to tilapia ecology publications.…”

Diet shift of Red Belly Pacu Piaractus brachypomus (Cuvier, 1818) (Characiformes: Serrasalmidae), a Neotropical fish, in the Sepik-Ramu River Basin, Papua New Guinea

“…A plastic diet, large body size and longevity (up to 70 cm SL and 28 years; Loubens & Panfili, 2001), and the capacity to achieve large local abundances and wide distributions, are characteristics that, according to invasive species theory (Ruesink et al, 1995;Moyle & Marchetti, 2006), may have contributed to successful establishment of P. brachypomus in the lower Sepik. One remarkable aspect of this establishment is that despite the complex long-distance migratory reproductive behavior of the species in its natural distribution (Barthem & Goulding 2007), P. brachypomus are successfully reproducing in this system.…”

A successful case of biological invasion: the fish Cichla piquiti, an Amazonian species introduced into the Pantanal, Brazil

“…According to Moyle and Marchetti (2006) a set of characteristics of fishes belonging to the genus Cichla, such as a history of success of invasion in several environments (Zaret,1974;Shafland, 1995;1999a;1999b;Latini and Petrere-Jr, 2004), parental care, medium to long life span, moderate size and being piscivorous, can explain the success of invasion of the fishes belonging to this genus as is occurring in the Pantanal.…”

“…Several aspects enable cichlids to be successful in the exploration and use of lentic environments, such as their fins and associated musculature ideally suited for accurate and fine controlled movements, including the ability to fan water, which makes them capable to rear young in oxygen-depleted lakes by providing a steady flow of water over the developing eggs, and the well-developed oral incubation of young or nesting, providing protection against predation in this critical phase of development. According to Moyle and Marchetti (2006), there are a number of characteristics, both of the invader and of the place to be invaded, that increases the probability of an invader being successful, such as if it has a history of successful establishment outside its native range, if it has characteristics likely to promote success at multiple stages of the invasion process, introduction into a habitat that more or less matches its native habitats, comparatively high fish species richness and if it is introduced repeatedly with propagule sizes exceeding 100 individuals.…”