Examinando por Autor "Pingo, S."

Mostrando 1 - 3 de 3
  • Miniatura
    ÍtemAcceso Abierto
    Feeding ecology of the green turtle Chelonia mydas in northern Peru
    (Escuela de Ciencias del Mar, 2017) Jiménez, A.; Pingo, S.; Alfaro-Shigueto, J.; Mangel, J.C.; Hooker, Y.
    Diet and food preferences of the green turtle Chelonia mydas were analyzed based on digestive tract contents of dead specimens caught incidentally by an artisanal gillnet fishery in Sechura Bay, northern Peru. We examined 27 digestive tracts and identified 35 prey items. The sampled turtles were all juveniles (CCL = 53.7 ± 1.2 cm, range 40.5-67.0 cm). The prey items were grouped into six categories: algae, cnidarians, mollusks, arthropods, chordates and garbage/anthropogenic debris. The items with the highest Frequency of Occurrence values (% FO) were: Caulerpa filiformis (77.8%), Loligo gahi (eggs) (51.9%) and Rhodymenia corallina (44.4%). By weight (% W), the most important items, were L. gahi (eggs) (33.3%), Stomolophus sp. (7.3%) and Aphos porosus (6.5%). According to the Preponderance Index (%IP), the preponderant item was L. gahi (eggs) with 6.1% and 61.2% during winter-spring and summer-autumn, respectively. According to the Resultant Weight index (Rw) of wet items, the most important items were: C. filiformis (13.1%), L. gahi (eggs) (10.5%), R. corallina (7.4%), plastic (7.5%), Gigartina chamissoi (5.1%). Garbage/anthropogenic debris was common in the digestive tracts analyzed. Plastic items had a frequency of occurrence of 44.4%. A greater diversity of food items was observed during summer and autumn. This study shows that juvenile C. mydas forage on a variety of resources. We recommend that conservation plans, land use planning and future management plans in the Sechura Bay include green turtles as a sentinel species for monitoring biodiversity of marine resources and the degree of pollution in the Bay. © 2017, Escuela de Ciencias del Mar. All rights reserved.
  • Miniatura
    ÍtemAcceso Abierto
    Incidental capture of sea turtles in the artisanal gillnet fishery in Sechura Bay, northern Peru
    (Escuela de Ciencias del Mar, 2017) Pingo, S.; Jiménez, A.; Alfaro-Shigueto, J.; Mangel, J.C.
    Gillnets are recognized globally as one of the fishing gears with the highest levels of bycatch and mortality of sea turtles. Through onboard observer monitoring from July 2013 to June 2014 we assessed the bycatch of sea turtles by an artisanal gillnet fishery operating from Sechura Bay, Peru. One hundred and four sea turtles were incidentally caught in 53 observed fishing sets. The observed species composition of bycatch was green turtle Chelonia mydas (n = 100), hawksbill Eretmochelys imbricata (n = 3) and olive ridley Lepidochelys olivacea (n = 1). Bycatch occurred in 62.3% of monitored sets, with an average of 1.96 turtles caught per set. For all sea turtles combined, 28.8% of individuals were dead and 71.2% were alive at the time of retrieval. The majority of individuals caught were classified as juveniles and sub-adults, with an average carapace length (CCL) of 57.3 ± 0.9 cm for green turtles and 40.2 ± 2.4 cm for hawksbills. The mean annual catch per unit effort (CPUE) of sea turtles was 1.11 ± 0.31 turtles km-1 12 h-1), but varied by seasons. These results suggest that Sechura Bay is an important developmental habitat for juvenile and sub-adult green turtles and hawksbill turtles, but one subject to intense fishing interaction pressure. The development of monitoring programs, local awareness-raising activities, and enhanced management and protection of this critical foraging area and developmental habitat is recommended. © 2017, Escuela de Ciencias del Mar. All rights reserved.
  • Miniatura
    ÍtemAcceso Abierto
    Reducing green turtle bycatch in small-scale fisheries using illuminated gillnets: the cost of saving a sea turtle
    (Inter-Research, 2016) Ortiz, N.; Mangel, J.C.; Wang, J.; Alfaro-Shigueto, J.; Pingo, S.; Jimenez, A.; Suarez, T.; Swimmer, Y.; Carvalho, F.; Godley, B.J.
    Gillnet fisheries exist throughout the oceans and have been implicated in high by-catch rates of sea turtles. In this study, we examined the effectiveness of illuminating nets with light-emitting diodes (LEDs) placed on floatlines in order to reduce sea turtle bycatch in a smallscale bottom-set gillnet fishery. In Sechura Bay, northern Peru, 114 pairs of control and illuminated nets were deployed. The predicted mean catch per unit effort (CPUE) of target species, standardized for environmental variables using generalized additive model (GAM) analysis, was similar for both control and illuminated nets. In contrast, the predicted mean CPUE of green turtles Chelonia mydas was reduced by 63.9% in illuminated nets. A total of 125 green turtles were caught in control nets, while 62 were caught in illuminated nets. This statistically significant re duction (GAM analysis, p < 0.05) in sea turtle bycatch suggests that net illumination could be an effective conservation tool. Challenges to implementing the use of LEDs include equipment costs, increased net handling times, and limited awareness among fishermen regarding the effectiveness of this technology. Cost estimates for preventing a single sea turtle catch are as low as 34 USD, while the costs to outfit the entire gillnet fishery in Sechura Bay can be as low as 9200 USD. Understanding these cost challenges emphasizes the need for institutional support from national ministries, inter-national non-governmental organizations and the broader fisheries industry to make possible widespread implementation of net illumination as a sea turtle bycatch reduction strategy. © The authors 2016.