Navegando por Assunto "Atlantic Ocean"

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Artigo
Green turtle (Chelonia mydas) nesting on Atol das Rocas, north-eastern Brazil, 1990–2008
(2012-04-25) Bellini, C.; Santos, A.J.B; Grossman, A.; Barata, P.C.R.; Marcovaldi, M.A.
In this paper, information is presented on green turtle (Chelonia mydas) nesting on Atol das Rocas (Rocas Atoll), north eastern Brazil. The temporal distribution of nesting events per season, annual number of nests, carapace length of nesting females, clutch size, hatching success, incubation period, internesting interval, clutch frequency, observed reproductive life span, and remigration period are reported. The study period included the nesting seasons from 1990 to 2008, but no regular beach monitoring was carried out in 1998 and 1999. Two sorts of methods were applied to the estimation of the annual number of nests in some seasons. Taking into account the estimated annual numbers of nests, the mean annual number of nests in the study period, excluding 1998–1999, was 335 (standard deviation ¼ 139, range ¼ 136–563, N ¼ 17). An analysis of the available data indicates that the average nesting levels at the beginning of the study period (the first five seasons) and at its end (the last five seasons) were roughly the same. The mean curved carapace length of the nesting turtles decreased significantly during the study period, from 115.9 cm in 1990–1992 to 112.9 cm in 2006 –2008. Atol das Rocas was established as a federal biological reserve in 1979, but regular sea turtle conservation activities actually started there in 1990. Since that year, the killing of nesting turtles has ceased, nesting activity by the turtles can proceed in an undisturbed fashion, and their clutches can incubate in a protected environment.
Artigo
Green Turtle Nesting on Trindade Island: Trend, Abundance and Biometrics
(ENDANGERED SPECIES RESEARCH, 2011-08-31) ALMEIDA, A. P.; MOREIRA, L. M. P.; BRUNO, S. C.; THOMÉ, J .C. A.; MARTINS, A. S.; BOLTEN, A. B.; BJORDAL, K. A.
ABSTRACT: Green turtles Chelonia mydas nesting at Trindade Island, 1140 km off the coast of Brazil, were monitored discontinuously from 1982/83 to 2008/09. For 7 years during this period, the majority of nesting was monitored, and the number of nests deposited on Trindade varied from 1333 to 5261. Based on these nest counts, Trindade is among the most important known Atlantic nesting sites for green turtles. The population remained stable between 1991 and 2008. Data on female body size, clutch size, internesting intervals, remigration intervals, and hatching success are also presented.
Artigo
Green Turtle Nesting on Trindade Island: Trend, Abundance and Biometrics
(2011) Almeida, Antonio de Padua; Moreira, Luciana M. P.; Bruno, Soraya Christina; Thomé, João Carlos A.; Martins, Agnaldo S.; Bolten, Alan B.; Bjorndal, Karen A.
Green turtles Chelonia mydas nesting at Trindade Island, 1140 km off the coast of Brazil, were monitored discontinuously from 1982/83 to 2008/09. For 7 years during this period, the majority of nesting was monitored, and the number of nests deposited on Trindade varied from 1333 to 5261. Based on these nest counts, Trindade is among the most important known Atlantic nesting sites for green turtles. The population remained stable between 1991 and 2008. Data on female body size, clutch size, internesting intervals, remigration intervals, and hatching success are also presented.
Artigo
Intentional killing and extensive aggressive handling of albatrosses and petrels at sea in the southwestern Atlantic Ocean
(Biological Conservation, 2020) Dimas, Gianuca; Bugoni, Leandro; Jiménez, Sebastián; Daudt, Nicholas W.; Miller, Philip; Canani, Gabriel; Silva-Costa, Augusto; Faria, Fernando A.; Bastida, Julian; Pon, Juan Pablo Seco; Yates, Oli; Serafini, Patrícia P.; Bond, Alexander L.
Large Procellariiformes (albatrosses and petrels) constitute a highly threatened group of birds, for which bycatch in fisheries is the most prevalent threat. At-sea intentional killing and post-capture, handling-related injuries, remain poorly understood menaces. Here, we report fishermen off southern Brazil trying to reduce bait depredation in pole-and-line and handlining fisheries by hitting birds with a metal piece attached to a pole-and-line on four occasions. Fishermen also mutilated or killed birds caught alive on the lines (aggressive handling). In addition, we present a compilation of records of Procellariiformes with bill mutilations across the southwest Atlantic Ocean. Related to the intentional killing events, 16 birds of four species (two globally threatened) were recorded dead (n = 13) or injured (n = 3) with head trauma, broken limbs, wounds or bill mutilation. Observations spanning 1999–2019 across the waters of Brazil, Uruguay and Argentina totalize 46 Procellariiformes of eight species (four globally threatened) recorded with bill mutilations (29 alive and 17 dead). Mutilations were likely caused by aggressive handling of birds caught alive, potentially in Brazilian hook-and-line fisheries or in demersal and pelagic longline fisheries across the southwest Atlantic. Observations of deliberate killing from multiple vessels and the recurrent records of mutilated birds suggest those practices represent pervasive but largely undocumented threats to seabirds and could complicate the detection of fishery-related population effects. Coordinated actions by international bodies and national authorities are urgently needed to address this threat, including increasing at-sea observation, enforcement actions and campaigns targeting better handling practices among fishermen.
Artigo
Satellite-tracked movements of female Dermochelys coriacea from southeastern Brazil
(2011-10-21) ALMEIDA, A. P.; ECKERT, S. A.; BRUNO, S. C.; SCALFONI, J. T.; Giffoni, B.; LÓPEZ-MENDILAHARSU, M.; THOMÉ, J. C. A.
Four female leatherback sea turtles Dermochelys coriacea were satellite tracked from the southeastern coast of Brazil (3 from nesting beaches in the state of Espírito Santo, and 1 recovered from a driftnet off the coast of the state of São Paulo), representing the first study of movements of leatherbacks nesting on Brazilian grounds. The results suggest that during the internesting period, leatherbacks may disperse up to 160 km from the nesting beach using an area of 4400 km2. Tracking also revealed shared feeding areas in southern South America, comprising Brazilian, Uruguayan, and Argentinean waters, and highlighted important interactions with fish eries along nesting, migratory, and feeding habitats. The presence in migratory/foraging areas of turtles from at least 2 different nesting populations from both sides of the South Atlantic Ocean supports the concept that management efforts for this species must incorporate a broad regional perspective.
Artigo
Satellite-tracked Movements of Female Dermochelys coriacea From Southeastern Brazil
(Endangered Species Research, 2011-10-21) ALMEIDA, A. P; ECKERT, S. A; BRUNO, S. C; SCALFONI, J. T; Giffoni, B; LÓPEZ-MENDILAHARSU, M.; THOMÉ, J. C. A
Four female leatherback sea turtles Dermochelys coriacea were satellite tracked from the southeastern coast of Brazil (3 from nesting beaches in the state of Espírito Santo, and 1 recovered from a driftnet off the coast of the state of São Paulo), representing the first study of movements of leatherbacks nesting on Brazilian grounds. The results suggest that during the internesting period, leatherbacks may disperse up to 160 km from the nesting beach using an area of 4400 km2 . Tracking also revealed shared feeding areas in southern South America, comprising Brazilian, Uruguayan, and Argentinean waters, and highlighted important interactions with fish eries along nesting, migratory, and feeding habitats. The presence in migratory/foraging areas of turtles from at least 2 different nesting populations from both sides of the South Atlantic Ocean supports the concept that management efforts for this species must incorporate a broad regional perspective.