Fishers and groupers (Epinephelus marginatus and E. morio) in the coast of Brazil: integrating information for conservation

Abstract

BackgroundGroupers are a vulnerable but economically important group of fish, especially for small-scale fisheries. We investigated catches and local ecological knowledge (LEK) of diet, habitat, and past fishing experiences.MethodsLandings, prices, interviews, and restaurants demand for two species, Epinephelus marginatus (dusky grouper) and Epinephelus morio (red grouper), were registered.ResultsWe visited 74 markets and 79 sites on the coast of Brazil in 2017–2018, and we interviewed 71 fishers: Bahia (NE), Rio de Janeiro and São Paulo (SE), and Santa Catarina (S). The landings sampled of dusky grouper (2016–2017) in Rio de Janeiro were: n = 222, size 38–109 cm, weight 1–24 kg, average 3.84 kg; in São Paulo, São Sebastião were: n = 47, size 39–106 cm, weight 2–8 kg, average of 2.77 kg; and at Santos: n = 80, 26–120 cm, weight 0.36–15 kg, average 2.72 kg. Red grouper was observed in markets in the northeastern Brazil. We did not observe Epinephelus marginatus from Bahia northward; a maximum size of 200 cm was reported south of the Bahia, besides Rio de Janeiro and São Paulo coasts, 20 years ago (or longer) by 12 fishers. Local knowledge of fishers was important for grouper data of habitat and diet; the reproduction period was identified by fishers as September to March.ConclusionsGroupers can be considered as a cultural and ecological keystone species. We suggest protective measures: 1) fishing zoning, 2) islands (MPAs) with the surveillance of fishers, 3) late Spring and early Summer as key periods for management (grouper reproduction), 4) studies on grouper larvae, 5) mapping of fishing spots, 6) studies on local knowledge. Collaboration with small-scale fishers and local knowledge could contribute to low-conflict management measures. In that regard, integrative models of management from Latin America, by using local knowledge and citizen science, could produce successful grouper management for Brazilian data-poor fisheries, a contrasting reality to the Mediterranean areas. Finally, the distribution of E. marginatus in Brazil leave us with questions: a) Have dusky groupers disappeared from Bahia because of a decline in the population? b) Was it uncommon in Northeast Brazil? c) Did changes in water temperatures forced a movement southward?

Filling gaps: fishing, genetics, and conservation of groupers, especially the comb grouper (badejo) (Mycteroperca acutirostris), in SE Brazil (2013-2020)

“…We observed a total of 490 individuals, among which weights were obtained for 466 individuals and showed a total catch of 630.39 kg. Mature gonads for comb grouper, were observed in April, September and October: these spring months coincide with mature gonads being observed in dusky grouper [16,18,28] (Fig 2).…”

“…The studies that were begun by Begossi and Silvano [15] included results about the local knowledge of fishers regarding diet and habitat, fishing locations, weight and length (TL), and stomach contents, among other features (sample of 40 individuals from 2006-2007). This study was followed by that of Begossi et al [17], which included fishing locations (fishing spots), weight and length (TL), macroscopic analysis of gonads by trained fishers (800 individuals from 2013 to 2015); Begossi et al [18]: locations, weight and length (TL), macroscopic analysis of gonads by trained fishers…”

“…Copacabana Beach that was established in 1923. Fishing is conducted from small motorboats by using set gillnets, hooks and lines and by spearfishing [18,19]. Recently, spearfishing by diving has become important, especially among young fishers.…”

“…Sampling of fins for genetic analyses. A total of 96 samples were obtained along the coast of Brazil (see details in [18]) from specimens belonging to two genera (Epinephelus and For each genus, samples were demultiplexed, and the raw read sequences were filtered with the module "process_radtags" in the Stacks program (version 1.42) [23]. SNP calling retained only SNP per sequenced tag, with a minimum sequencing depth of 5X, frequency of the least common allele ≥ 0.05 and occurring in at least 90% of individuals within each species.…”

The use of fishers’ Local Ecological Knowledge to reconstruct fish behavioural traits and fishers’ perception of conservation relevance of elasmobranchs in the Mediterranean Sea

“…In the marine environment, LEK usually involves fishers and has been demonstrated to provide relevant information, mainly on species abundances and distributions and their changes over time (e.g., Azzurro et al, 2011Azzurro et al, , 2019Maynou et al, 2011;Fortibuoni et al, 2016;Bastari et al, 2017;Peñaherrera-Palma et al, 2018;Taylor et al, 2018;Colloca et al, 2020), as well as on seascape management (Berkström et al, 2019). For some species, LEK may also provide information on the habitat, diet, reproductive season and even behaviours, such as the occurrence of aggregations (Colin et al, 2003;Moreno et al, 2007;Gerhardinger et al, 2009;Begossi, 2008;Begossi et al, 2019).…”