Report of Injuries in Batoids Caught in Small-Scale Fisheries: Implications for Management Plans

Abstract

Despite of the ecological importance of several batoids caught as bycatch, little attention is given to the individual resilience in risk assessments. The report of physical condition is imperative for a realistic understanding of the impacts caused by fishing, as a way to reduce the negative consequences of bycatch and improvement of management protocols. In this context, the present study provides an analysis of injuries observed in nine species of batoids caught by small scale fisheries by adopting a non-lethal approach. Levels of injury were determined according to severity and the relation between fishing time and injury/mortality was assessed. Results showed that injury levels and release condition were strongly influenced by fishing effort and time until release, with fishing effort lower than 110 min related with minor injuries, lower capture mortality rates (10.6%) and better release conditions. Since the frequency of batoids in small scale fisheries as accompanying fauna is high, the cooperation between researchers, fishermen and authorities is essential to reduce the negative consequences of bycatch. Based in the data presented here, we recommend that management plans establish fishing effort times and immediate release in areas of ecological importance for endangered species, thus helping to promote batoids conservation.

Capture‐induced vulnerability in male Shortnose guitarfish during their reproductive period

“…Fishing injuries are often neglected and little is known about their influence on mortality. Rodrigues et al (2019) characterized external injuries in nine batoid species, associating their occurrence and severity with fishing effort and apparatus employed. The injuries observed herein in Shortnose guitarfish individuals ranged from mild (bruises) to severe (flaring, intestinal eversion, gallbladder rupture and tail fracture).…”

Atlantoraja castelnaui: Pollom, R., Barreto, R., Charvet, P., Chiaramonte, G.E., Cuevas, J.M., Faria, V., Herman, K., Motta, F., Paesch, L. & Rincon, G.

“…Artisanal fisheries there are also intense, and 58% of stocks targeted by artisanal fishers were over-exploited by 2010 and half of those had collapsed (Vasconcellos et al 2011). In São Paulo state alone, there are over 300 small-scale trawl vessels (Rodrigues et al 2019). In Uruguay, the industrial trawl fleet was developed in the late 1970s, and many stocks were over-exploited by the 1990s (Defeo et al 2011, Lorenzo et al 2015.…”

Pesca de emalhe e conservação de recursos pesqueiros: um estudo de caso no litoral sul do Brasil

“…Afinal, o poder seletivo das malhas não exime as redes de impactarem o meio, principalmente por dois motivos (The Gear Technology Subcommittee, 1994): primeiro, por atingirem fauna sem interesse pesqueiro e/ ou animais carismáticos, como elasmobrânquios, tartarugas, aves e mamíferos; e, segundo, pelas grandes dimensões e o longo tempo de exposição, frequentemente sofrendo extravio, com risco de pesca-fantasma. Ambos os impactos aplicam-se ao litoral sul do Brasil (Pupo et al, 2006, Chaves & Robert, 2009, Cardoso et al, 2011, Rodrigues et al, 2019. Visto que na região os recursos-alvo também ocorrem como bycatch, Chaves & Silva (2019) was studied during 2014 and 2015.…”