Guide for detecting and monitoring introduced marine species

Until the middle of the Twentieth century, the main concern of ecologists was to understand and explain the natural world, ignoring anthropogenic habitats, ecosystems and influences. Human interference was seen as noise that would only confound the main goal. But, around 40 years ago, ecologists began to examine urban ecosystems, fragmented and degraded landscapes, polluted regions and the global effects of human activities began to dominate the discussion. Subsequently, introduced species (species that have been intentionally or accidentally introduced in a region by anthropogenic vectors) began to be perceived as one of the major human impacts on ecosystems. At the same time, commerce became globalized during these last 50 years and transportation of species escalated at even greater rates (Carlton & Geller 1993). Now, introduced species are generally understood as one of the most prejudicial aspects of global change (Vitousek et al., 1996; Bright, 1999; Occhipinti-Ambrogi & Savini, 2003) and that introduced species should be considered as biological pollution (Elliott, 2003; Olenin et al., 2011).