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The southwestern Atlantic Ocean is an important foraging ground throughout the year for several albatross and petrel species. Longline fishing fleets in the region currently pose the main threat for this group of seabirds at sea, and conservation measures are urgently required. We present information on bycatch rates of seabirds in the Brazilian domestic pelagic longline fishery from 2001 to 2007, and review bycatch rates reported for the demersal and pelagic longline fisheries in the southwestern Atlantic Ocean. Overall seabird capture rate for the Brazilian pelagic longline fleet during 63 cruises (656 sets and 788 446 hooks) was 0.229 birds per 1000 hooks, varying from 0 to 0.542 according to season. Capture rates were higher between June and November (cold season) and affected mainly the black-browed albatross Thalassarche melanophris (55% of birds captured), the white-chinned petrel Procellaria aequinoctialis, the spectacled petrel Procellaria conspicillata and the Atlantic yellow-nosed albatross Thalassarche chlororhynchos. Capture rates previously reported in the SW Atlantic varied from 0 to 5.03 birds per 1000 hooks, with those reports based on logbooks or fishermen interviews tending to underestimate capture rates, whereas those based on small numbers of hooks or short time periods tend to greatly overestimate rates in both pelagic and demersal longline fisheries. Previous studies have played an important role in delimiting the seabird bycatch problem, forming a baseline for mitigation actions and serving as a guide for improvements in data collection. However, data collected by onboard seabird-dedicated observers are more reliable, provide a greater range of information relating to bycatch, and form a baseline for more robust analysis and addressing further questions. The current study highlights the stochastic nature of seabird fatalities in longline fisheries and the need for extensive sampling to obtain realistic estimates of capture rates covering different years, seasons, vessels, and the range of fishing gear and practices.

ABSTRACT. Revision and updating of the list of birds of Rio Grande do Sul, Brazil. The list of birds of the state of Rio Grande do Sul (281,749 sq. km), southern Brazil, is revised and updated. Species were included in the list according to two main criteria: (i) occurrence in the state documented with tangible evidence -study skin or complete specimen, photograph, video or vocal recording -published in the literature or available for independent verification in scientific collections or archives of public access, or (ii) at least one state record supported by non-material evidence allowing an unequivocal diagnosis of the taxon, such as a circumstantiated report, published or provided to the authors, containing a detailed description of or reference to the diagnostic features observed. Species mentioned for the state that do not conform to these criteria were not included in the main list and were regarded as probable or hypothetical, according to the evidence available and the distributional coherence of the existing records. The final list comprises 661 species, of which 649 are documented by physical evidence. Another 10 and 16 species are listed as probable and hypothetical, respectively. Compared with the previous list, 44 species were added and seven were excluded or substituted, resulting in a net increase of 37 species. Fregetta grallaria (Vieillot, 1818), Polytmus guainumbi (Pallas, 1764), Nonnula rubecula (Spix, 1824), Stymphalornis acutirostris Bornschein, Reinert & Teixeira, 1995, Fluvicola albiventer (Spix, 1825, and Xenopsaris albinucha (Burmeister, 1869) are mentioned for the state for the first time. The number of species added since the last review corresponds to an average increase of slightly more than four species per year. By examining the recent additions in retrospect, it is clear that the number of bird species known to occur in Rio Grande do Sul should continue to grow at a similar rate over the next decade or so. In view of this, some guidelines for improving future revisions of the state checklist are proposed. In order to better understand new occurrences of birds over time, the use of adequate criteria to distinguish range extensions from range expansions, and instances of vagrancy from pseudo-vagrancy, is recommended.KEYWORDS. Avifauna, distribution records, new occurrences, documentation, collections. RESUMO.Neste artigo, a lista das aves do estado do Rio Grande do Sul (281.749 km 2 ) é revisada e atualizada. A inclusão de espécies na lista seguiu dois critérios principais: (i) ocorrência no estado documentada por evidência tangível -pele ou espécime completo, foto, vídeo ou gravação de áudio -publicada na literatura ou disponível para verificação independente em coleções ou arquivos científicos de acesso público, ou (ii) pelo menos um registro no estado acompanhado de evidência não-material que permita a identificação segura do táxon, tal como um relato circunstanciado, publicado ou fornecido aos autores, contendo descrição detalhada ou referência às características diagnósticas ...

ABSTRACT1. Incidental catches by the pelagic longline fishery is a major global threat for loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) sea turtles.2. The reduction of incidental capture and post-release mortality of sea turtles in the Brazilian pelagic longline fishery, operating in the south-western Atlantic Ocean, was investigated by comparing the performance of 18/0 circle hooks with 9/0 J-type (control) hooks. Hook selectivity experiments were performed between 2004 and 2008, in a total of 26 trips, 229 sets and 145 828 hooks. The experimental design included alternating control and experimental hooks along sections of the mainline.3. An overall decrease in capture rates for loggerhead turtles of 55% and for leatherbacks of 65% were observed when using circle hooks. In addition, deep-hooking in loggerheads decreased significantly from 25% using J-hooks to 5.8% with circle hooks, potentially increasing post-release survival.4. Circle hooks increased catch rates of most of the main target species, including tunas (bigeye Thunnus obesus and albacore T. alalunga), and sharks (blue Prionace glauca and requiem sharks of the genus Carcharinus), with no difference in the capture rates of yellowfin tuna (T. albacares), shortfin mako shark (Isurus oxyrinchus), hammerhead sharks (Sphyrna lewini and S. zygaena), and dolphinfish or mahi mahi (Coryphaena hippurus). On the other hand, a significant decrease in the capture rate of swordfish (Xiphias gladius) was detected when using circle hooks.5. Overall, results support the effectiveness of using circle hooks for the conservation of loggerhead and leatherback sea turtles, with positive effects on capture of most target species of the south-western Atlantic longline fishery.

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The identification of geographic areas where the densities of animals are highest across their annual cycles is a crucial step in conservation planning. In marine environments, however, it can be particularly difficult to map the distribution of species, and the methods used are usually biased towards adults, neglecting the distribution of other life‐history stages even though they can represent a substantial proportion of the total population. Here we develop a methodological framework for estimating population‐level density distributions of seabirds, integrating tracking data across the main life‐history stages (adult breeders and non‐breeders, juveniles and immatures). We incorporate demographic information (adult and juvenile/immature survival, breeding frequency and success, age at first breeding) and phenological data (average timing of breeding and migration) to weight distribution maps according to the proportion of the population represented by each life‐history stage. We demonstrate the utility of this framework by applying it to 22 species of albatrosses and petrels that are of conservation concern due to interactions with fisheries. Because juveniles, immatures and non‐breeding adults account for 47%–81% of all individuals of the populations analysed, ignoring the distributions of birds in these stages leads to biased estimates of overlap with threats, and may misdirect management and conservation efforts. Population‐level distribution maps using only adult distributions underestimated exposure to longline fishing effort by 18%–42%, compared with overlap scores based on data from all life‐history stages. Synthesis and applications. Our framework synthesizes and improves on previous approaches to estimate seabird densities at sea, is applicable for data‐poor situations, and provides a standard and repeatable method that can be easily updated as new tracking and demographic data become available. We provide scripts in the R language and a Shiny app to facilitate future applications of our approach. We recommend that where sufficient tracking data are available, this framework be used to assess overlap of seabirds with at‐sea threats such as overharvesting, fisheries bycatch, shipping, offshore industry and pollutants. Based on such an analysis, conservation interventions could be directed towards areas where they have the greatest impact on populations.

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