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McClanahan TR, Azali MK, Kosgei JK. Fish catch responses to Covid-19 disease curfews dependent on compliance, fisheries management, and environmental contexts. MARINE POLICY 2022; 144:105239. [PMID: 35911785 PMCID: PMC9314266 DOI: 10.1016/j.marpol.2022.105239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 07/20/2022] [Accepted: 07/24/2022] [Indexed: 06/15/2023]
Abstract
The responses of small-scale coastal fisheries to pauses in effort and trade are an important test of natural resource management theories with implications for the many challenges of managing common-pool resources. Three Covid-19 curfews provided a natural experiment to evaluate fisheries responses adjacent a marine reserve and in a management system that restricted small-mesh drag nets. Daily catch weights in ten fish landings were compared before and after the curfew period to test the catch-only hypothesis that the curfew would reduce effort and increase catch per unit effort, per area yields, and incomes. Interviews with key informants indicated that fisheries effort and trade were disrupted but less so in the gear-restricted rural district than the more urbanized reserve landing sites. The expected increase in catches and incomes was evident in some sites adjacent the reserve but not the rural gear restricted fisheries. Differences in compliance and effort initiated by the curfew, changes in gear, and various negative environmental conditions are among the explanations for the variable catch responses. Rates of change over longer periods in CPUE were stable among marine reserve adjacent landing sites but declined faster after the curfew in the gear-restricted fisheries. Two landing sites nearest the southern end of the reserve displayed a daily 45 % increase in CPUE, 25-30 % increase in CPUA, and a 45-56 % increase in incomes. Results suggest that recovering stocks will succeed where authorities can achieve compliance, near marine reserves, and fisheries lacking additional environmental stresses.
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Affiliation(s)
- T R McClanahan
- Wildlife Conservation Society, Global Marine Programs, Bronx, NY 10460, USA
| | - M K Azali
- Wildlife Conservation Society, Kenya Marine Program, Mombasa, Kenya
| | - J K Kosgei
- Wildlife Conservation Society, Kenya Marine Program, Mombasa, Kenya
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Flower J, Estep A, James K, Ramdeen R, Runge CA, Thomas L, Lester SE. An experimental evaluation of the effect of escape gaps on the quantity, diversity, and size of fish caught in traps in Montserrat. PLoS One 2021; 16:e0261119. [PMID: 34890426 PMCID: PMC8664196 DOI: 10.1371/journal.pone.0261119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 11/24/2021] [Indexed: 11/20/2022] Open
Abstract
Coral reef fisheries are vital to the livelihoods of millions of people worldwide but are challenging to manage due to the high diversity of fish species that are harvested and the multiple types of fishing gear that are used. Fish traps are a commonly used gear in reef fisheries in the Caribbean and other regions, but they have poor selectivity and frequently capture juvenile fish, impacting the sustainability of the fishery. One option for managing trap fisheries is the addition of escape gaps, which allow small fish to escape. We compared catches of traps with and without two 2.5 cm (1 inch) escape gaps on the Caribbean island of Montserrat. No significant differences were found in the mean fish length, total fish biomass, number of fish, fish species richness, and Shannon diversity index between hauls of the two trap designs, though traps with escape gaps did catch larger proportions of wider-bodied fish and smaller proportions of narrow-bodied fish. Furthermore, traps with gaps caught a smaller proportion of small-sized fish and fewer immature fish (though differences were not statistically significant). Linear mixed effect models predict that soak time (the length of time between trap hauls) increases the mean catch length, total catch biomass and total number of species in the catch. The relatively modest evidence for the effect of the gaps on catch may be explained by the long soak times used, which could have allowed most smaller-sized fish to escape or be consumed by larger individuals before hauling in both traps with and without escape gaps. Despite the small differences detected in this study, escape gaps may still offer one of the best options for improving sustainability of catches from fish traps, but larger escape gaps should be tested with varying soak times to determine optimum escape gap size.
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Affiliation(s)
- Jason Flower
- Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA, United States of America
- Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, CA, United States of America
- Environmental Market Solutions Lab, University of California, Santa Barbara, Santa Barbara, CA, United States of America
- * E-mail:
| | - Andy Estep
- Waitt Institute, La Jolla, CA, United States of America
| | - Keinan James
- Youth Apprenticeship Program, Ministry of Education, Youth Affairs & Sports, Brades, Montserrat
| | - Robin Ramdeen
- Waitt Institute, La Jolla, CA, United States of America
| | - Claire A. Runge
- School of Earth and Environmental Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Lennon Thomas
- Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA, United States of America
- Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, CA, United States of America
- Environmental Market Solutions Lab, University of California, Santa Barbara, Santa Barbara, CA, United States of America
| | - Sarah E. Lester
- Department of Geography, Florida State University, Tallahassee, FL, United States of America
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Mbaru EK, Hicks CC, Gurney GG, Cinner JE. Evaluating outcomes of conservation with multidimensional indicators of well-being. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2021; 35:1417-1425. [PMID: 33938596 DOI: 10.1111/cobi.13743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 01/11/2021] [Accepted: 01/16/2021] [Indexed: 06/12/2023]
Abstract
Many conservation interventions are hypothesized to be beneficial for both the environment and people's well-being, but this has rarely been tested rigorously. We examined the effects of adoption or nonadoption of a conservation intervention on 3 dimensions of people's well-being (material, relational, and subjective) over time. We focused on a fisheries bycatch management initiative intended to reduce environmental externalities associated with resource extraction. We collected panel data from fishers (n = 250) in villages with (adopters and nonadopters) and without (control) the conservation intervention 3 times over 2 years. We found no evidence that adoption reduced any of the 3 dimensions of well-being in the local populations affected by the intervention. There were modest improvements in material (t = -1.58) and subjective livelihood well-being (p = 0.04) for adopters relative to nonadopters over time. The variations in well-being experiences (in terms of magnitude of change) among adopters, nonadopters, and controls across the different domains over time affirmed the dynamic and social nature of well-being.
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Affiliation(s)
- Emmanuel K Mbaru
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
- Kenya Marine and Fisheries Research Institute (KMFRI), Mombasa, Kenya
| | | | - Georgina G Gurney
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
| | - Joshua E Cinner
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
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Mbaru EK, Graham NAJ, McClanahan TR, Cinner JE. Functional traits illuminate the selective impacts of different fishing gears on coral reefs. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13547] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Emmanuel K. Mbaru
- ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Qld Australia
- Kenya Marine and Fisheries Research Institute (KMFRI) Mombasa Kenya
| | | | | | - Joshua E. Cinner
- ARC Centre of Excellence for Coral Reef Studies James Cook University Townsville Qld Australia
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McClanahan TR, Kosgei JK. Outcomes of gear and closure subsidies in artisanal coral reef fisheries. CONSERVATION SCIENCE AND PRACTICE 2019. [DOI: 10.1111/csp2.114] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
| | - Jesse K. Kosgei
- Wildlife Conservation Society, Coral Reef Conservation Project Mombasa Kenya
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Social-ecological alignment and ecological conditions in coral reefs. Nat Commun 2019; 10:2039. [PMID: 31053708 PMCID: PMC6499785 DOI: 10.1038/s41467-019-09994-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 04/12/2019] [Indexed: 12/03/2022] Open
Abstract
Complex social-ecological interactions underpin many environmental problems. To help capture this complexity, we advance an interdisciplinary network modeling framework to identify important relationships between people and nature that can influence environmental conditions. Drawing on comprehensive social and ecological data from five coral reef fishing communities in Kenya; including interviews with 648 fishers, underwater visual census data of reef ecosystem condition, and time-series landings data; we show that positive ecological conditions are associated with ‘social-ecological network closure’ – i.e., fully linked and thus closed network structures between social actors and ecological resources. Our results suggest that when fishers facing common dilemmas form cooperative communication ties with direct resource competitors, they may achieve positive gains in reef fish biomass and functional richness. Our work provides key empirical insight to a growing body of research on social-ecological alignment, and helps to advance an integrative framework that can be applied empirically in different social-ecological contexts. The relationships between people can have important consequences for the systems they depend on. Here the authors show that when coral reef fishers face commons dilemmas, the formation of cooperative communication with competitors can lead to positive gains in reef fish biomass and functional richness.
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