The economic value of research in managing invasive hydrilla in Florida public lakes

Abstract Weber MA, Wainger LA, Harms NE, Nesslage GM. 2020. The economic value of research in managing invasive hydrilla in Florida public lakes. Lake Reserv Manage. XX:XX–XX. Decisions on how to allocate research funds can be informed by evaluating the benefits of research, yet past spending is rarely analyzed to gain insights for effective research allocation. We used a case study to evaluate whether research into nonnative invasive plants improved management of herbicide-resistant hydrilla (Hydrilla verticillata) in the Kissimmee Chain of Lakes (KCOL), Florida, USA. We applied a retrospective benefit–cost analysis to quantify the net economic benefits of invasive control informed by government-supported research, relative to a scenario without research funding. Using conservative assumptions, we estimated net benefits of 11 yr of research (1999–2009) and 5 yr of improved hydrilla management as $19.5 million (2017 dollars) with a benefit–cost ratio of 3.8, including avoided ecosystem service losses to angler and nonangler lake users. These benefits were about 2.2 times the annual value of recreational fishing in the KCOL. Sensitivity analysis indicated that positive net benefits were generally robust to uncertainty regarding the hydrilla intrinsic growth rate and treatment costs in the absence of research-informed protocols. We have likely underestimated research benefits because we lumped costs from multiple programs and did not measure benefits accruing to nonusers of lakes. To enable future retrospective economic analyses, we suggest some improvements in record keeping. Our findings of positive net benefits of research may be representative of cases where relatively modest research investment in invasive species control is likely to protect widely appreciated ecosystem services.