Shifted baselines and the policy placebo effect in conservation S AMANTHA L OVELL,AYANA E LIZABETH J OHNSON R OBIN R AMDEEN and L OREN M C C LENACHAN Abstract Coastal ecosystems have been degraded by human whose history of degradation can be obscured by a lack of activity over centuries, with loss of memory about past states ecological data from the past (Jackson et al., ). Failure resulting in shifted baselines. More recently conservation ef- to document past change can lead to the shifting baseline forts have resulted in localized recoveries of species and eco- syndrome, in which knowledge of past ecosystem produc- systems. Given the dynamism of ecosystem degradation and tivity is lost over the course of generations (Pauly, ). recovery, understanding how communities perceive long- Shifted baselines have been documented among marine term and recent changes is important for developing and resource users; for example, in both Mexico and Brazil implementing conservation measures. We interviewed older fishers named more fish species and fishing stakeholders on three Caribbean islands and identified a sites as depleted than younger fishers (Sáenz-Arroyo shifted baseline with respect to the extent and degree of et al., ; Giglio et al., ). In Curaçao and Bonaire long-term declines in marine animal populations; stake- (Netherlands), fishers’ baselines were not shifted because holders with more experience identified more species as de- stories of plentiful past catches were passed down within pleted and key species as less abundant than those with less these communities, whereas scuba divers had unrealis- experience. Notably, the average respondent with , years tically positive perceptions of the health of the reefs and of experience listed no species as depleted despite clear evi- fish populations because they lacked this information dence of declines. We also identified a phenomenon we call (Johnson & Jackson, ). Such shifted baselines have im- the policy placebo effect, in which interviewees perceived plications for conservation, as they may lead to reduced some animal populations as recently recovering following restoration targets for exploited species (McClenachan passage of new conservation legislation but in the absence et al., , ). of evidence for actual recovery. Although shifted baselines Change in Caribbean marine ecosystems has been docu- have a negative effect on conservation as they can lower mented over century-long time scales, with historical losses recovery goals, the outcomes of a policy placebo effect of large vertebrates fundamentally altering trophic dynamics are unclear. If the public prematurely perceives recovery, (McClenachan et al., ; McClenachan & Cooper, ), motivation for continued conservation could decline. losses of herbivorous fishes such as parrotfish (Scarus spp.) Alternatively, perception of rapid success could lead com- contributing to declines in reef accretion rates (Cramer et al., munities to set more ambitious conservation goals. ), and reductions in the spatial distribution of coral reef habitats (McClenachan et al., ). In recent decades, the Keywords Historical ecology, local ecological knowledge, three-dimensional structure of Caribbean reefs has been re- marine conservation, marine protected areas, policy pla- duced (Alvarez-Filip et al., ), and hard coral cover de- cebo, recovery, shifting baselines clined on average by % between the s and early Supplementary material for this article is available at s, with shifts to non-framework building species https://doi.org/./S (Jackson et al., ). Together with ongoing overfishing, these changes have led to declines in the density of both exploited and unexploited reef fishes (Paddack et al., Introduction ). A phase shift from coral to algal dominance was triggered and maintained by a combination of a disease nformation on long-term change is important for conser- in the sea urchin Diadema antillarum in the early s, Ivation and management, particularly in coastal ecosystems, overexploitation of parrotfish and other algal grazers (Jackson et al., ), and land-based pollution (Cramer et al., , ). More recently, climate change, disease, SAMANTHA LOVELL* and LOREN McCLENACHAN (Corresponding author) Environmental Studies Program, Colby College, 5351 Mayflower Hill Drive, and invasive species have added additional stresses Waterville, Maine, USA. E-mail [email protected] (Hoegh-Guldberg et al., ;Greenetal.,;Randall AYANA ELIZABETH JOHNSON, Ocean Collective, Brooklyn, New York, USA &vanWoesik,). ROBIN RAMDEEN, Waitt Institute, Montserrat, West Indies Despite these longer-term declines in Caribbean marine *Also at: Environmental Defense Fund, Washington, DC, USA ecosystems, some recent conservation efforts have been suc- Received August . Revision requested October . cessful, and localized recoveries of marine species and eco- Accepted January . systems are occurring. Although Caribbean green turtle Oryx, Page 1 of 9 © 2018 Fauna & Flora International doi:10.1017/S0030605318000169 Downloaded from https://www.cambridge.org/core. CBB Consortium, on 15 Jul 2019 at 14:31:51, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605318000169 2 S. Lovell et al. Chelonia mydas populations are estimated to be , %of they had personally observed. During interviews on their historical abundance (McClenachan et al., ), ef- Montserrat we asked about abundance before and after fective local conservation has resulted in local population re- the eruption of the Soufriére Hills volcano ()because covery (Hays, ; Troëng & Rankin, ). Parrotfish the eruption and resulting ash caused large-scale damage recovery has been documented after a ban on fish traps to the marine environment surrounding the island. We (O’Farrell et al., ), giving hope for broader ecosystem re- also asked interviewees to identify additional species covery, as these grazing fish facilitate coral growth (Cramer whose abundance they perceived to be increasing or de- et al., ). In marine reserves where parrotfish and other creasing over these same time scales. Responses were re- herbivores are protected, coral recovered from bleaching sig- corded on a categorical scale, with absence equivalent to nificantly faster compared to coral in unprotected areas and superabundant equivalent to . We then compared the (Mumby & Harborne, ). Diadema urchins have also re- mean perceived abundance ranking for each taxon over covered locally, facilitating coral recruitment and in- time and among islands. To confirm trends derived from creased abundance of juvenile coral on Caribbean reefs ranked abundances we also asked interviewees if they had (Edmunds & Carpenter, ; Carpenter & Edmunds, ). perceived a change in abundance over time in these key Although both long-term declines and recent recoveries taxa. Finally, we asked interviewees about any additional in the Caribbean have been documented, the ways in which changes they had observed in these taxa (e.g. geographical resource users view these changes have not been well stud- range or body size), and causes of any perceived changes. ied. Here, we use local ecological knowledge to understand To evaluate evidence for shifted baselines, we compared how residents on the Caribbean islands of Montserrat, both the perceived extent and degree of depletion of marine Antigua and Barbuda perceive the timing and extent of taxa to interviewees’ years of experience fishing or diving. long-term and recent changes in a suite of marine taxa, Extent of depletion was measured as the number of species and the causes of these changes. Our results illuminate per- perceived as declining; degree of depletion was measured as ceptions about ecosystem change and the implications of the perceived current abundance of the five species most com- those perceptions on development and implementation of monly cited as declining. For any species determined to be in- conservation measures. creasing, we identified conservation policies that would have affected the populations of these species, comparing the timing Methods of implementation of these policies to the generation time of each species, to determine if protection had been in place long We conducted in-person interviews with fishers and divers enough for a change to have resulted. To put these changes on the islands of Montserrat, Antigua and Barbuda in January into an ecological and historical context we also compared . Interviewees were identified and introductions facili- interviewee perceptions of change to all available ecological tated by the Waitt Institute’s Blue Halo Initiative (Waitt, and historical information on changes in those taxa. ), and by approaching fishers as they returned from fishing and/or were selling their catches. After each inter- Results view we asked the interviewee if he or she knew of any other fishers or divers we should speak with, a technique We conducted a total of interviews: on Montserrat, known as snowball sampling. This approach was intended on Barbuda and five on Antigua (Supplementary Table ). to target knowledgeable community members, to assess The mean age of interviewees was years (range –), the perception of those most likely to be aware of changes. and the mean experience fishing or diving was years We identified marine animal taxa of historical, cultural (range –). We grouped interviewees into three age or economic importance to the islands. Four were individual categories: # years ( interviewees), – years ( inter-