Proposed bycatch-reduction modifications of shrimp fyke nets used in South American lagoons

Abstract

Domingos M.M., Dantas D.V. 2019. Proposed bycatch-reduction modifications of shrimp fyke nets used in South American lagoons. Acta Ichthyol. Piscat. 49 (1): 1-7.Background. Shrimp fisheries using fyke nets have been associated with a massive acquisition of teleost fishes as bycatch, potentially resulting in the decimation of their stocks. Based on this assumption, the presently reported study intended to test an alternative modification of a commonly used fyke net, in order to minimize the impact of its low selectivity. Materials and methods. To evaluate the alternative design proposed in this work, a total of 44 sampling efforts, including 22 with a control gear (CG) and 22 with a modified gear (MG), were conducted at a subtropical coastal lagoon system located in southern Brazil. In all trials, the fyke nets were installed at the fishing area approximately at 18:00 h and removed approximately at 06:00 h. The duration of each trial was nearly 12 h, which was similar to the catching time preferred by local fishermen. Results. Bycatch (BC) was preponderant in both modalities but the results showed that MG presented a reduction by 66 percentage points in BC catches, being more selective than CG. Additionally, the non-parametric test showed no significant differences of shrimp catches between the fishing gears used (MG and CG). So, the tested bycatch reduction devices (BRD) reduced the bony fishes acquisition preserving the volume of the target catch. Conclusion. The vertical opening reduction due the adoption of guiding panel + fan upper panel contributed to bycatch reduction, being a consistent BRD to reduce the potential impacts of this fishing gear over the bony fishes stocks.

Ictiofauna acompanhante associada a pesca do camarão-da-amazônia Macrobrachium amazonicum (Heller, 1862) (Decapoda, Palaeomonidae): subsídios para gestão ambiental e ordenamento da pesca

“…Também não foi constatado diferença significativa (p>0,05) em relação aos números de exemplares (CPUE/N/h), com os maiores valores médios constatados em junho (20,75±3,01) e outubro (17,58±2,78) (Figura 3B). A biomassa de camarões-da-amazônia capturada em Santarém foi consideravelmente superior à ictiofauna acompanhante, diferentemente de outros tipos de pescaria de camarões, como aquelas praticadas com redes de arrastos, onde o volume da fauna acompanhante é extremamente superior (mais de 87%), com elevados valores de descartes que podem atingir grandes proporções quando se determina a razão entre a biomassa da espécie alvo e a ictiofauna (peixes) capturada (Lima e Montagner 2014;Vieira et al 2017;Pinheiro e Martins 2018;Farias et al 2019). Nesse caso, a alta captura de fauna acompanhante reflete em baixa produtividade de camarões quando utilizado redes de arrastos, principalmente quando se comparada as armadilhas semifixas.…”

Artificial attractors in small scale fisheries gillnets on Araguaia river, Brazil

“…Several artificial light intensities and wavelength emitted can impact the bony fish species behavior (Marchesan, 2014). In this sense, artificial lights are one of the most prominent AA adopted by fishermen around the world (Hazin et al, 2005;Nguyen & Winger, 2019;Farias et al, 2019), with highlighted to chemical sticks (lightsticks), that optimizes the fishing effort increasing the selectivity in commercial and sportfishing (Nguyen & Winger, 2019).…”

“…Research, Society andDevelopment, v. 9, n. 8, e913986364, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i8.6364 According to Nguyen & Winger (2019), AA are devices allocated in fishing gears to increase the catches of some target species. LED lights in shrimp nets and lightsticks in longlines are AA examples adopted by coastal and oceanic fisheries (Nguyen & Winger, 2019;Farias et al, 2019). In the other hand, AA can increase the fishing selectivity, ensuring bycatch reduction (Virgili et al, 2018).…”

Risk tolerance and control perception in a game-theoretic bioeconomic model for small-scale fisheries

“…This passive fishing apparatus has two sleeves, a conic tunnel, and a bagger, and attracts fish using a lighted sign. Using a unique LED lamp, six fyke nets can be combined in a circular layout (electronic supplementary material, S4), trapping shrimp from all directions [39]. This fishery, and particularly this resource, is very important for the surrounding communities, both economically and culturally [38].…”