21 research outputs found

    Habitat use and abundance of goliath grouper Epinephelus itajara in Brazil: a participative survey

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    Developing survey strategies for threatened species is often limited by access to sufficient individuals to acquire information needed to design appropriate conservation measures. The goliath grouper (Epinephelus itajara) is a large reef fish, globally classified as critically endangered. In Brazil, fishing has been prohibited since 2002. Herein we investigated habitat use and abundance of E. itajara in Brazil drawn from a participative survey, which engaged volunteer divers in data-collection. A total of 188 reports were recorded between 2005 to 2011 throughout 13 Brazilian states. Our results revealed that habitat type influenced the relationship between total length and depth of occurrence of E. itajara. We observed a significant difference between habitats, artificial presented a nonlinear and natural an asymptotic relationship. This study underscores the importance of developing conservation measures addressing specific habitats and locations to enhance population recovery. Artificial structures (shipwrecks and manmade reefs) are critical habitats that must be considered as highly sensitive areas to E. itajara strategic conservation policies. We suggest the creation and implementation of marine protected areas, as key strategies for E. itajara conservation, especially for artificial habitats and aggregation sites124803810O desenvolvimento de estratégias de pesquisa para espécies ameaçadas é frequentemente limitado pelo acesso a indivíduos suficientes para adquirir informações necessárias para elaborar medidas de conservação adequadas. Dentre essas espécies, o mero (Epinephelus itajara) é um peixe recifal de grande tamanho, classificado globalmente como criticamente ameaçado. No Brasil, a pesca é proibida desde 2002. Investigou-se o uso de hábitat e abundância de E. itajara no Brasil através de uma pesquisa participativa, que engajou mergulhadores voluntários na coleta dos dados. Um total de 188 relatos foram registrados entre 2005 a 2011 em 13 estados brasileiros. Os resultados revelaram que o tipo de hábitat influenciou a relação entre o comprimento total e profundidade de ocorrência de E. itajara. Observou-se uma diferença significativa entre hábitats: hábitat artificial apresentou uma relação não linear e hábitat natural uma relação assintótica. Este estudo ressalta a importância do desenvolvimento de medidas de conservação abordando hábitats e locais específicos visando a recuperação populacional. Estruturas artificiais (naufrágios e recifes feitos pelo homem) são hábitats críticos que devem ser considerados como áreas relevantes para as estratégias políticas conservação de E. itajara. Sugere-se a criação e implementação de áreas marinhas protegidas como uma estratégia fundamental para a conservação de E. itajara, especialmente em hábitats artificiais e locais de agregaçãosem informaçã

    A global review of marine recreational spearfishing

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    24 pages, 5 figures, 2 tables, supplementary information https://doi.org/10.1007/s11160-023-09790-7.-- Data availability: The full list of papers used for the systematic review is available as a supplementary tableRecreational spearfishing is a fishing method that occurs globally, yet receives considerably less attention in the scientific literature relative to other recreational fishing methods, such as angling. Lack of scientific information on spearfishing may negatively affect the development and management of marine recreational fisheries. We conducted a systematic review of 102 peer-reviewed papers published between 1967 and 2022 pertaining to marine recreational spearfishing. Based on this literature review, we provide an overview of key insights across social, economic, and ecological dimensions of marine recreational spearfishing. While spearfishers represent less than 5% of marine recreational fishers, the participants are younger and may differ from recreational anglers in their motivations, with suggestions of increased well-being generated from a close connection with the sea during underwater fishing. Recreational spearfishers mostly target species of moderate to high levels of vulnerability that are mid to high trophic level carnivores. Though spearfishers can deliberately target larger individuals of exploited populations, this is not a generalizable pattern. Despite a growing body of research on the ecological impacts of marine recreational spearfishing, there is limited knowledge of these effects and their mechanisms across biological levels of organization (e.g., individual, population, community and ecosystem) compared with those of other fishing methods. Recreational spearfishers can contribute to advances in marine ecological knowledge, and inclusive participatory management could represent a key step towards transformative sustainable development of marine recreational spearfishing. Throughout the review, we identify gaps in the research and areas where future research is needed to better inform the socio-economic importance, ecosystem impacts and future management of marine recreational spearfishingVS was supported by a “Juan de la Cierva Incorporación” (IJC2018-035389-I), and he is now supported by a “Ramón y Cajal” research fellowships (RYC2021-033065-I) granted by the Spanish Ministry of Science and Innovation. SV and PP are supported by the Xunta de Galicia (RECREGES I and II projects under Grants ED481B2014/034-0 and ED481B2018/017), Grupo de Referencia Competitiva GI-2060 AEMI, under Grant ED431C2019/11), and Fundación Biodiversidad, Ministerio para la Transición Ecológica y el Reto Demográfico, Gobierno de España (SICORE and GT PMR projects). VJG received a postdoctoral grant (#2017/22273-0) from São Paulo Research Foundation (FAPESP). MR would like to acknowledge Portuguese national funds from FCT—Foundation for Science and Technology through projects UIDB/04326/2020, UIDP/04326/2020 and LA/P/0101/2020. MR would also like to acknowledge FCT funding through a postdoctoral grant (SFRH/BPD/116307/2016). JACCN thanks to Meros do Brasil Project sponsored by Petrobras. FJH is supported by a Sȇr Cymru European Regional Development Fund Fellowship (80761-SU-135). RA was supported by the German Federal Ministry of Education and Research (Grants 01LC1826E and 033W046A). ML is supported by the Agencia Nacional de Investigación e Innovación (ANII, POS_EXT_2020_1_165362). This work acknowledges the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S). [...] Open Access funding provided thanks to the CRUE-CSIC agreement with Springer NaturePeer reviewe

    Integrated ecosystem assessment around islands of the tropical South Mid-Atlantic Ridge

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    The South Mid Atlantic Ridge comprises three main oceanic islands in the equatorial and tropical portions of the Atlantic Ocean. These islands are isolated from each other and equidistant from both the continental margins of South America and Africa, sharing common patterns but with different types of human use and pressures. Moreover, the areas beyond national jurisdiction between those islands are visited and exploited by distant fishing fleets and include large areas of shipping activity for commodities. Here, a pioneering integrated ecosystem assessment (IEA) process is constructed for the region among Saint Peter and Saint Paul’s Archipelago (Brazil), Saint Helena Island and Ascension Island (UK overseas territories). For that, we used a qualitative assessment of risks arising from anthropogenic activities, representing a novel contribution to the field. The Options for Delivering Ecosystem-Based Marine Management (ODEMM) approach was applied to trace sector–pressure–component pathways. A ‘linkage framework’ was outlined including pressures affecting each ecosystem component, and supported a process of knowledge attributions that scored the impact risks. All results were validated with regional stakeholders through workshops, including local and international management bodies, non-governmental organizations (NGOs) and scientists. The approach focused on a significant area among encompassing the open ocean, shallow and deep-sea biomes, analyzing the main sectors and pressures affecting the ecological components. Our results identified 14 sectors and 16 key pressures associated with 23 ecosystem components, totaling 780 impact chains. Fishing, shipping, wastewater, and tourism/recreation appeared as the top impacting sectors. Fishing and shipping were the most connected with ecosystem components links. Litter, species extraction, contaminants, and bycatch were the pressures that had the highest risk of impact values. Lastly, demersal and pelagic fish and pelagic and demersal elasmobranchs were the groups with the highest risk related to overall impacts, which were supported by local and regional evidence from long term monitoring programs and local studies. Our study demonstrated that these seemingly pristine islands and oceanic waters are already experiencing human impacts that should be addressed by local both conservation measures and international agreements. We also highlight the pressures that should be prioritized for better monitoring and policy, as well as those linkage components that have been less investigated

    Fishers' ecological knowledge of smalleye hammerhead, Sphyrna tudes , in a tropical estuary

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    ABSTRACT Coastal hammerheads have suffered from overexploitation and environmental degradation. We interviewed 79 artisanal fishers to verify fishery aspects, temporal changes in catches and biological aspects of the smalleye hammerhead, Sphyrna tudes , in a marine protected area on Abrolhos Bank, Brazil. Data were compared between three generations of fishers: young, middle-aged and old. Fishers' age varied between 17 and 88 years. We verified significant reductions in the weight of individuals caught by younger fishers. The main types of fishing gear used to catch S. tudes were gill nets and longlines. Overfishing through gill nets and trawl fisheries were mentioned as the cause of S. tudes population collapse in the region. The shark's diet as reported by fishers consisted of fish, crab and shrimp; austral summer was the reproductive season. A strong similarity was verified between fishers' knowledge and biological data. We suggest as plausible strategies to conserve the local population of S. tudes the reduction of net fisheries impact through zoning and establishment of no take areas. These steps can help to initiate the recovery of this depleted species

    Marine life preferences and perceptions among recreational divers in Brazilian coral reefs

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    Understanding diver preferences and perceptions of environmental attributes can help inform dive tourism management. We interviewed 190 recreational divers and examined their preferences for marine life in the Abrolhos National Marine Park, eastern Brazil. We also assessed divers' perceptions of changes in fish abundance when they revisit the dive site. Marine life preferences changed according with the divers' experience level. Novice divers preferred encounters with megafauna, whereas experienced divers preferred to see cryptic species. Individual perceptions of decline in fish abundance were influenced by longer time interval between visits. Visitors elicited the end of fish feeding, and illegal fishing, as the main causes of decline. Strategies to limit decline in the quality of marine life attributes, such as zoning and visitation limits based on carrying capacity estimates should be also based in divers' preferences and perceptions. Therefore, understanding divers' motivations and preferences will help maximize visitors' enjoyment and guide the dive industry into a more sustainable mode in the future.9 page(s

    Recreational diver behavior and contacts with benthic organisms in the Abrolhos National Marine Park, Brazil

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    In the last two decades, coral reefs have become popular among recreational divers, especially inside marine protected areas. However, the impact caused by divers on benthic organisms may be contributing to the degradation of coral reefs. We analyzed the behavior of 142 scuba divers in the Abrolhos National Marine Park, Brazil. We tested the effect of diver profile, reef type, use of additional equipment, timing, and group size on diver behavior and their contacts with benthic organisms. Eighty-eight percent of divers contacted benthic organism at least once, with an average of eight touches and one damage per dive. No significant differences in contacts were verified among gender, group size, or experience level. Artificial reef received a higher rate of contact than pinnacle and fringe reefs. Specialist photographers and sidemount users had the highest rates, while non-users of additional equipment and mini camera users had the lowest contact rates. The majority of contacts were incidental and the highest rates occurred in the beginning of a dive. Our findings highlight the need of management actions, such as the provision of pre-dive briefing including ecological aspects of corals and beginning dives over sand bottoms or places with low coral abundance. Gathering data on diver behavior provides managers with information that can be used for tourism management.12 page(s

    Multidecadal fishers’ knowledge reveals overexploitation of sharks in southeastern Brazil

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    Abstract Assessing the impacts caused by fisheries requires long-term data series and continuous landing monitoring, which are still scarce in several low and middle-income countries. Alternative approaches, such as fishers’ local ecological knowledge (LEK) have been employed to assess the history of marine resources and overcome the challenges of missing data. We documented temporal changes over the last 60 years in small-scale fisheries in Arraial do Cabo, Brazil. Interviews with 155 fishers revealed the capture of six shark species (one genus), all under extinction risk according to the global and the national Red Lists. Among these, Carcharhinus brevipinna, Carcharhinus plumbeus, and Isurus oxyrinchus are commercially important. While LEK suggests an increase in fishing efforts, with new fishing grounds emerging after 2006, the number of individuals caught has decreased over time. Historical shark exploitation has led to substantial declines in the catches of C. plumbeus and C. brevipinna, which have rare occurrences in the region. Although landing data are critical information for building local fisheries management plans and setting conservation strategies, monitoring in the region is discontinuous and should be prioritized by public policies

    Follower fish of the goldspotted eel Myrichthys ocellatus with a review on anguilliform fish as nuclear species

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    Abstract In a nuclear-follower fish foraging association, the follower benefits from food uncovered or flushed out when the nuclear fish disturbs the bottom, while nuclear species generally do not seem to be benefiting. Among nuclear species, eels (anguilliform fish) are known to be one of the most represented groups. Here we investigated the frequency and time duration of foraging associations among the goldspotted eel Myrichthys ocellatus and reef fish in a subtropical marginal reef. In addition, we reviewed nuclear eel species and their followers described in the literature. From a total of 211 goldspotted eels observed, seven follower species were recorded in 19% of the samples. The average time of the following associations per species ranged from 40 to 190 s. Four species were reported for the first time as M. ocellatus followers (Bodianus rufus, B. pulchellus, Stephanolepis hispidus, and Serranus baldwini) and three of them have never been reported in the literature as eel followers (B. pulchellus, S. hispidus, and S. baldwini). The literature describes 13 eel species acting as nuclear for 66 fish species, represented mainly by groupers and sea basses. The size of the eel was not correlated with the size of its follower and neither with the number of described follower species. The nuclear role of eels is likely to be an important component of the trophic ecology of small and medium-sized macrocarnivore fish
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