Collaboration has become a common alternative to traditional top-down approaches to environmental management and conservation. One critique of collaborative processes is that science is not sufficiently linked to conservation actions. To better understand how science is used in collaborative decisions, we asked how the use of science is affected by the structure of collaborative processes, paying specific attention to the role of explanatory variables such as stakeholder engagement, how information is gathered, and how decisions are made. Case survey methods (a form of systematic review) were used to analyze 30 case studies of collaborative management of marine, estuarine, and coastal systems across the United States. We found that increased stakeholder participation (i.e., two-way flow of information between parties), face-to-face communication among stakeholders, increased contribution of information from academic stakeholders, careful consideration and selection of participants (e.g., stakeholder analysis), participants' ability to influence decisions, and structured methods of collecting and aggregating information were all positively associated with the use of science in collaborative processes. These findings suggest ways to improve the structure of collaborative processes to enhance the use of science for environmental management and conservation.
Non-native species have the potential to cause ecological and economic harm to coastal and estuarine ecosystems. Understanding which habitat types are most vulnerable to biological invasions, where invasions originate, and the vectors by which they arrive can help direct limited resources to prevent or mitigate ecological and socio-economic harm. Information about the occurrence of non-native species can help guide interventions at all stages of invasion, from first introduction, to naturalization and invasion. However, monitoring at relevant scales requires considerable investment of time, resources, and taxonomic expertise. Environmental DNA (eDNA) metabarcoding methods sample coastal ecosystems at broad spatial and temporal scales to augment established monitoring methods. We use COI mtDNA eDNA sampling to survey a diverse assemblage of species across distinct habitats in the Salish Sea in Washington State, USA, and classify each as non-native, native, or indeterminate in origin. The non-native species detected include both well-documented invaders and species not previously reported within the Salish Sea. We find a non-native assemblage dominated by shellfish and algae with native ranges in the temperate western Pacific, and find more-retentive estuarine habitats to be invaded at far higher levels than better-flushed rocky shores. Furthermore, we find an increase in invasion level with higher water temperatures in spring and summer across habitat types. This analysis contributes to a growing understanding of the biotic and abiotic factors that influence invasion level, and underscores the utility of eDNA surveys to monitor biological invasions and to better understand the factors that drive these invasions.