The Invasive Species Challenge in Estuarine and Coastal Environments: Marrying Management and Science

Abstract

Despite the widely acknowledged threat posed by invasive species in coastal estuaries, there are substantial gaps at the intersection of science and policy that are impeding invasive species management. In the face of pressing management needs in coastal and estuarine environments, we advocate that introduced species should receive the kind of management effort dedicated, for example, to reducing pollution. We support our argument with some examples of economic costs of estuarine and coastal introduced species and a summary of recent evidence for the ecological costs. We highlight some of the issues that either thwart or facilitate the successful marriage between science and management of introduced species, including the regulatory framework for management. We use the available information on coastal eradication programs, including case histories of the programs for Caulerpa taxifolia and Spartina alterniflora (and hybrids) in the western USA, to indicate the feasibility of managing introduced species and to help point out how management and science can improve the outcome. We close with a research agenda that focuses primarily on science that will really assist with invasive species management and reflects our own experience and the opinions of managers directly involved with this issue.

Nonnative macrobenthos in the Wadden Sea ecosystem

“…Without such a decision, environmental management would embark on an endless chain of manipulating species compositions and species interactions, which would be in conflict with the aim to let natural processes proceed as far as possible in this protected nature area. On the other hand, mitigating the ongoing flood of alien invasions by controlling the vectors and attempting eradications before a firm establishment has occurred (Williams and Grosholz, 2008) should deserve priority in the nature management of the Wadden Sea and beyond.…”

“…Global trade by shipping is accelerating the rate of introduction of nonnative species in marine communities of European coasts (Leppäkoski et al, 2002;Steftaris et al, 2005), and is in particular transforming estuarine ecosystems (Campbell et al, 2007;Carlton, 1989;Ruiz et al, 1997;Williams and Grosholz, 2008;Wolff, 1999). It is widely assumed that invasions by alien species are a leading cause of recent species extinctions which is mainly concluded from studies on oceanic islands and freshwater lakes (Fritts and Rodda, 1998;Gurevitch and Padilla, 2004;Lockwood, 2004).…”

Valuing the benefits of improved marine environmental quality under multiple stressors

“…Only a small percentage of the introduced non-indigenous species in the Baltic Sea have had negative impacts determined so far (HELCOM, 2010). However, non-indigenous species may potentially cause severe and often irreversible changes ecosystems that might bring economic loss and human health risks (Lovell et al, 2006;Williams and Grosholz, 2008).…”

Modeling invasion risk for coastal marine species utilizing environmental and transport vector data

“…Research and management efforts have targeted species when they are exported, in transit, entering a new environment, after introduction, and once established. In many cases, it is difficult to eradicate a species once established, though there are examples of successful efforts (e.g., see Williams & Grosholz, 2008), and prevention and early detection can be the most viable management strategies (Lovell & Drake, 2009).…”

“…Given the complexity of the invasion process, any foresight into where a species will likely invade can be used for more judicious and targeted management (Leung et al, 2004). For species that arrive in a new location, early detection can increase the likelihood for successful eradication prior to establishment and spread, reducing the costs associated with invasive species (Williams & Grosholz, 2008).…”