Banca de QUALIFICAÇÃO: CLAUDIO NONA MORADO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : CLAUDIO NONA MORADO
DATE: 06/06/2025
TIME: 09:00
LOCAL: on-line
TITLE:

ETHNO-KNOWLEDGE OF ARTISANAL FISHERS FROM THE COAST OF RIO DE JANEIRO STATE ON ANTHROPOGENIC INFLUENCES ON THE ICHTHYOFAUNA AND THE BIOECOLOGY OF TWO MAIN TARGET SPECIES

KEY WORDS:

Anthropogenic actions; Bays; Bioecology; Ethno-knowledge; Ichthyofauna; Trophic level; Artisanal Fishers

PAGES: 65
BIG AREA: Ciências Biológicas
AREA: Zoologia
SUBÁREA: Zoologia Aplicada
SUMMARY:

The Local Ecological Knowledge (LEK) of Artisanal Fishers is essential for understanding changes in coastal environments, contributing to biodiversity conservation, sustainable fisheries management, and the reduction of socio-environmental problems. This knowledge was used to assess temporal changes in fish abundance, main anthropogenic actions related to these changes, temporal averages of trophic levels by testing the “fishing down marine food web” hypothesis, and also the bioecology of two main target species, Mugil liza Valenciennes, 1836 and Micropogonias furnieri (Desmarest, 1823), in the three bays of the state of Rio de Janeiro (Sepetiba Bay, Ilha Grande Bay, and Guanabara Bay). Semi-structured interviews were conducted with 267 respondents in 59 traditional communities along these three bays. The “snowball” technique was used for conducting the  interviews, where each interviewee recommended another artisanal fisher deemed knowledgeable to answer the questionnaire. The IRAMUTEQ software was used for data processing and analysis, facilitating the contextualization of individual responses at a collective level. The temporal average of the trophic level was obtained by comparing the mean trophic level of the most commonly caught species today with that of the most
commonly caught species in past decades. In Chapter 1, we investigated the LEK of 40 artisanal fishers from two communities in Sepetiba Bay regarding the diversity and temporal abundance of fish. They indicated that the most commonly caught species today are: M. furnieri (67.5% of respondents); M. liza (60%); Mugil curema
Valenciennes, 1836 (27.5%); Aspistor luniscutis (Valenciennes, 1840) (25%); Isopisthus parvipinnis (Cuvier, 1830) (22.5%); Centropomus undecimalis (Bloch, 1792) (17.5%); Oligoplites saliens (Bloch, 1793) (17.5%). The species that experienced the greatest reduction in abundance over the decades were: Scomberomorus brasiliensis Collette, Russo & Zavala-Camin, 1978 (50.25%); I. parvipinnis (48.5%); Pomatomus saltatrix
(Linnaeus, 1766) (48.5%); Mycteroperca acutirostris (Valenciennes, 1828) (29.5%); Sardinella brasiliensis (Steindachner, 1879) (24.25%); Caranx hippos (Linnaeus, 1766) (24.25%); Pogonias cromis (Linnaeus, 1766) (23.25%); O. saliens (21.5%). Higher fish abundance and diversity were associated with warmer waters and prevailing north winds. The main anthropogenic causes of decreased fish abundance and richness, identified by 80% of fishers, were large industrial facilities and resulting pollution (50%), industrial bottom-trawl fishing (27.5%), and lighting from cargo ships and other anchored vessels (10%). In Chapter 2, the LEK of 198 artisanal fishers from Sepetiba and Ilha Grande Bays was used to evaluate temporal changes in fish abundance and average trophic levels as possible effects of anthropogenic actions, testing the "fishing down marine food web" hypothesis. The most commonly caught species today are: M. furnieri (61.5%); M. liza (29%); C. undecimalis (20%). The species with the greatest reductions in abundance were: S. brasiliensis (17%); P. saltatrix (15%); Scomberomorus cavalla (Cuvier, 1829) (13%). The main anthropogenic actions likely responsible for these declines were: operation of industrial sardine fishing vessels and shrimp trawlers (36%); industrial pollution (16%); and large-scale industrial developments (10%). The average trophic level of the most caught species by artisanal fisheries has declined over the decades, showing changes in the food web’s trophic structure and supporting the “fishing down marine food web” hypothesis. In Chapter 3, the LEK of 69 artisanal fishers from Guanabara Bay was used to assess temporal changes in fish abundance and average trophic levels, pointing to anthropogenic actions and testing the "fishing down marine food web" hypothesis. The most commonly caught species today are: M. furnieri (67%); M. liza (49%). The species with the greatest reductions in abundance were: P. saltatrix (19%); Epinephelus itajara (Lichtenstein, 1822) (16%). The main anthropogenic actions likely responsible for these reductions are: pollution (39%); industrial fishing (22%); industrial shrimp trawling (15%); and the 2000 oil spill (7.5%). Unfortunately, much of this occurs intentionally, as a consequence of public authorities’ complicity with capitalist logic, which prioritizes more profitable economic activities at the expense of the socio-environmental health of the bay—something these authorities should be protecting. The average trophic level of species most caught by artisanal fishers has decreased over the decades, indicating changes in the food web’s trophic structure and supporting the “fishing down marine food web” hypothesis. In Chapter 4, the LEK of 40 artisanal (Caiçara) fishers from Sepetiba Bay was used to investigate biological and ecological aspects of M. furnieri. This included migration patterns, reproduction, feeding habits, and interactions such as parasitism. The fishers’ information matched academic literature on several aspects of the species’ biology and ecology. Additionally, they provided new pattern descriptions that contributed to a deeper understanding of the species’ natural history. These included observations of reproduction occurring almost year-round, the influence of east and north winds on the species’ entry into the bay, interactions with sea catfish (Ariidae), and noteworthy records of Cymothoidae isopods as important parasites of M. furnieri. In Chapter 5, the LEK of 198 artisanal Caiçara and Quilombola fishers from Sepetiba and Ilha Grande Bays was analyzed regarding aspects of the bioecology and abundance of M. liza. Most respondents reported that the species reproduces in winter, confirming information from the literature. However, many artisanal fishers from both bays also mentioned M. liza reproducing in summer in Sepetiba Bay, suggesting the possible existence of a resident metapopulation in this bay or a seasonal migration of M. liza populations from Cabo Frio to the bay in summer. Regarding health status, respondents reported that M. liza may be becoming hosts to Cymothoidae parasites in both bays. A decrease in M. liza abundance was also observed in both bays, mainly associated with increased industrial pollution from large developments and growing fishing pressure on the species by industrial fisheries in southern Brazil, which is, in part, related to a new commercial export market for M. liza roe. The LEK of artisanal fishers provided valuable information on current fish diversity and abundance; the decline of ichthyofauna due to anthropogenic actions; temporal changes in marine trophic structure; and the bioecology of two species important to artisanal fishing. This confirms the importance of cultural diversity for biodiversity conservation, ecosystem health, mitigation of socio-environmental issues, and reduction of conflicts.

COMMITTEE MEMBERS:
Externo à Instituição - José da Silva Mourão - UEPB
Externo à Instituição - NATALIA HANAZAKI - UFSC
Interno - 387200 - FRANCISCO GERSON ARAUJO