Matching Fishers’ Knowledge and Landing Data to Overcome Data Missing in Small-Scale Fisheries

RESEARCH ARTICLE Matching Fishers’ Knowledge and Landing Data to Overcome Data Missing in SmallScale Fisheries Ludmila de Melo Alves Damasio1*, Priscila F. M. Lopes2,3, Rafael D. Guariento4, Adriana R. Carvalho2 1 Graduation Program in Development and Environment at Federal University of Rio Grande do Norte/ UFRN, Natal, RN, Brazil, 2 Department of Ecology at Federal University of Rio Grande do Norte/UFRN, Natal, RN, Brazil, 3 Fisheries and Food Institute, Santos, SP, Brazil, 4 Center of Biological and Health Sciences University of Mato Grosso do Sul/UFMS, Campo Grande, MS, Brazil * Abstract OPEN ACCESS Background Citation: Damasio LdMA, Lopes PFM, Guariento RD, Carvalho AR (2015) Matching Fishers’ Knowledge and Landing Data to Overcome Data Missing in Small-Scale Fisheries. PLoS ONE 10(7): e0133122. doi:10.1371/journal.pone.0133122 In small-scale fishery, information provided by fishers has been useful to complement current and past lack of knowledge on species and environment. Editor: Konstantinos I Stergiou, Aristotle University of Thessaloniki, GREECE Through interviews, 82 fishers from the largest fishing communities on the north and south borders of a Brazilian northeastern coastal state provided estimates of the catch per unit effort (CPUE) and rank of species abundance of their main target fishes for three time points: current year (2013 at the time of the research), 10, and 20 years past. This information was contrasted to other available data sources: scientific sampling of fish landing (2013), governmental statistics (2003), and information provided by expert fishers (1993), respectively. Received: March 5, 2015 Accepted: June 24, 2015 Published: July 15, 2015 Copyright: © 2015 Damasio et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper. Funding: LMAD received a masters' grant from Coordination for the Improvement of Higher Education Personnel (CAPES) (http://www.capes. gov.br/). PFML received a research grant from Rio Grande do Norte Research Foundation, through the First Research Program Call (http://www.fapern.rn. gov.br/). Competing Interests: The authors have declared that no competing interests exist. Methodology Principal Findings Fishers were more accurate when reporting information about their maximum CPUE for 2013, but except for three species, which they estimated accurately, fishers overestimated their mean CPUE per species. Fishers were also accurate at establishing ranks of abundance of their main target species for all periods. Fishers' beliefs that fish abundance has not changed over the last 10 years (2003–2013) were corroborated by governmental and scientific landing data. Conclusions The comparison between official and formal landing records and fishers' perceptions revealed that fishers are accurate when reporting maximum CPUE, but not when reporting mean CPUE. Moreover, fishers are less precise the less common a species is in their PLOS ONE | DOI:10.1371/journal.pone.0133122 July 15, 2015 1 / 13 Comparing Official Landing Data to Fishers' Information catches, suggesting that they could provide better information for management purposes on their current target species. Introduction Small-scale fisheries (SSFs) provide food security, welfare, and livelihood sustenance for many coastal communities in the poorest countries in the world [1]. Despite and also due to their relevance, fishing resources have been intensively exploited, causing large effects on marine ecosystems worldwide [2]. Marine and continental fisheries (including aquaculture) are estimated to have produced 154 million tons of fish worldwide in 2011 [3]. About 55 million direct jobs are generated by these activities, of which up to 90% are occupied by small-scale fishers who end up supplying half of the world's fish [4]. Brazil produced 1.4 million tons of fish in 2011, including aquaculture, marine, and continental fishing. Following the world trend, small-scale fishers catch 45% of the continental and marine fish in Brazil. Most of these fisheries are located at the northeastern coast, which alone provides 32% of the Brazilian production. The Brazilian small-scale fishing sector employs 957,000 people, showing its social and economic relevance [5]. Nevertheless, the Brazilian SSFs are highly overlooked, which also seems to be a tendency worldwide for SSFs [6] [7]. The lack of public policies for the sector results in unreported and unregulated activity around the world, for which there are barely any financial resources, staff, logistics, or skills in management agencies to collect fishery data [8]. What is known usually comes from a few independent, usually short-term, and research-based endeavors [9]. In the absence of reliable information, we can only obtain a partial picture of what is happening to fish stocks and what could be the best management actions to avoid resource and subsequent societal collapse, as the SSFs are mostly concentrated in the poorest segments of societies [10]. Therefore, in the absence of data, researchers have increasingly used information provided by fishers [11] [12] to fulfill both long- and short-term data gaps [13] [14] [15] [16] [17]. However, although fishers' knowledge can provide detailed information and helpful material to management, especially when there is no other data available [18], it is often difficult to contrast such information with official data. Such comparisons could identify if all or parts of the information provided by fishers were comparable to what would be obtained through formal methods. Fishers hold facts and memories that may not be registered elsewhere [13]; therefore, an understanding of the accuracy of this information could define what can and cannot be applied to management in the absence of better data or as a complement to it. Further, this understanding could avoid costly data sampling procedures [19] and could complement information over temporal scales [20] [21]. Here, we contrasted two formal datasets (governmental and scientific) with data provided by fishers to assess the agreement between the different sources. Specifically, we tested if fishers' perception of past and current catches per unit effort (CPUE) (mean and maximum catches) and rank of species abundance in the catches matched the formal landing data. Understanding the aspects where information agrees and disagrees could show that not all information provided by fishers is the same, which could direct future research addressing unreported but sometimes valuable past and present information to direct management. PLOS ONE | DOI:10.1371/journal.pone.0133122 July 15, 2015 2 / 13 Comparing Official Landing Data to Fishers' Information Materials and Methods Sampling s (...truncated)