A Best Practices Case Study for Scientific Collaboration between Researchers and Managers.

Effective engagement among scientists, government agency staff, and policymakers is necessary for solving fisheries challenges, but remains challenging for a variety of reasons. We present seven practices learned from a collaborative project focused on invasive species in the Great Lakes region (USA-CAN). These practices were based on a researcher-manager model composed of a research team, a management advisory board, and a bridging organization. We suggest this type of system functions well when (1) the management advisory board is provided compelling rationale for engagement; (2) the process uses key individuals as communicators; (3) the research team thoughtfully selects organizations and individuals involved; (4) the funding entity provides logistical support and allows for (5) a flexible structure that prioritizes management needs; (6) a bridging organization sustains communication between in-person meetings; and (7) the project team determines and enacts a project endpoint. We predict these approaches apply equally effectively to other challenges at the research-management-policy interface, including reductions of water pollution, transitions to renewable energy, increasing food security, and addressing climate change.

Use of structured expert judgment to forecast invasions by bighead and silver carp in Lake Erie.

Identifying which nonindigenous species will become invasive and forecasting the damage they will cause is difficult and presents a significant problem for natural resource management. Often, the data or resources necessary for ecological risk assessment are incomplete or absent, leaving environmental decision makers ill equipped to effectively manage valuable natural resources. Structured expert judgment (SEJ) is a mathematical and performance-based method of eliciting, weighting, and aggregating expert judgments. In contrast to other methods of eliciting and aggregating expert judgments (where, for example, equal weights may be assigned to experts), SEJ weights each expert on the basis of his or her statistical accuracy and informativeness through performance measurement on a set of calibration variables. We used SEJ to forecast impacts of nonindigenous Asian carp (Hypophthalmichthys spp.) in Lake Erie, where it is believed not to be established. Experts quantified Asian carp biomass, production, and consumption and their impact on 4 fish species if Asian carp were to become established. According to experts, in Lake Erie Asian carp have the potential to achieve biomass levels that are similar to the sum of biomasses for several fishes that are harvested commercially or recreationally. However, the impact of Asian carp on the biomass of these fishes was estimated by experts to be small, relative to long term average biomasses, with little uncertainty. Impacts of Asian carp in tributaries and on recreational activities, water quality, or other species were not addressed. SEJ can be used to quantify key uncertainties of invasion biology and also provide a decision-support tool when the necessary information for natural resource management and policy is not available.

Out-of-sample validation for structured expert judgment of Asian carp establishment in Lake Erie.

Structured expert judgment (SEJ) is used to quantify the uncertainty of nonindigenous fish (bighead carp [Hypophthalmichthys nobilis] and silver carp [H. molitrix]) establishment in Lake Erie. The classical model for structured expert judgment model is applied. Forming a weighted combination (called a decision maker) of experts' distributions, with weights derived from performance on a set of calibration variables from the experts' field, exhibits greater statistical accuracy and greater informativeness than simple averaging with equal weights. New methods of cross validation are applied and suggest that performance characteristics relative to equal weighting could be predicted with a small number (1-2) of calibration variables. The performance-based decision maker is somewhat degraded on out-of-sample prediction, but remained superior to the equal weight decision maker in terms of statistical accuracy and informativeness.

Using structured expert judgment to assess invasive species prevention: Asian carp and the Mississippi-Great Lakes hydrologic connection.

Recently, authors have theorized that invasive species prevention is more cost-effective than control in protecting ecosystem services. However, quantification of the effectiveness of prevention is rare because experiments at field scales are expensive or infeasible. We therefore used structured expert judgment to quantify the efficacy of 17 proposed strategies to prevent Asian carp invasion of the Laurentian Great Lakes via the hydrologic connection between the Mississippi and Great Lakes watersheds. Performance-weighted expert estimates indicated that hydrologic separation would prevent 99% (95,100; median, 5th and 95th percentiles) of Asian carp access, while electric and acoustic-bubble-strobe barriers would prevent 92% (85,95) and 92% (75,95), respectively. For all other strategies, estimated effectiveness was lower, with greater uncertainty. When potential invasions by other taxa are considered, the effectiveness of hydrologic separation increases relative to strategies that are effective primarily for fishes. These results could help guide invasive species management in many waterways globally.

Limitations of gravity models in predicting the spread of Eurasian watermilfoil.

The effects of non-native invasive species are costly and environmentally damaging, and resources to slow their spread and reduce their effects are scarce. Models that accurately predict where new invasions will occur could guide the efficient allocation of resources to slow colonization. We assessed the accuracy of a model that predicts the probability of colonization of lakes in Wisconsin by Eurasian watermilfoil (Myriophyllum spicatum). We based this predictive model on 9 years (1990-1999) of sequence data of milfoil colonization of lakes larger than 25 ha (n =1803). We used milfoil colonization sequence data from 2000 to 2006 to test whether the model accurately predicted the number of lakes that actually were colonized from among the 200 lakes identified as being most likely to be colonized. We found that a lake's predicted probability of colonization was not correlated with whether a lake actually was colonized. Given the low predictability of colonization of specific lakes, we compared the efficacy of preventing milfoil from leaving occupied sites, which does not require predicting colonization probability, with protecting vacant sites from being colonized, which does require predicting colonization probability. Preventing organisms from leaving colonized sites reduced the likelihood of spread more than protecting vacant sites. Although we focused on the spread of a single species in a particular region, our results show the shortcomings of gravity models in predicting the spread of numerous non-native species to a variety of locations via a wide range of vectors.