Historical strandings and sightings (1989–2016) of Tursiops truncatus at 25oS in the south-western Atlantic Ocean (Paraná, Brazil) were assessed to (1) investigate temporal fluctuations; and (2) quantify biological, ecological and health parameters of regional populations. In total, 57 T. truncatus carcasses in mostly advanced stages of decomposition (~80% of all specimens) were recorded. Standardized temporal strandings (per observational effort) varied considerably and with no clear annual relationship beyond a peak in 2007, but there were consistently more strandings in winter/spring (74%) than summer/autumn (26%). While there was uncertainty over age estimation (i.e. not available for the population), individuals classified as juveniles/subadults were more frequent (80%) than calves (14%) and adults (6%). Of 28 carcasses assessed, 27 showed a positive linear relationship between TL and condyle-basal length, while one specimen had a clear southern skull morphotype. Suggestive lesions of Crassicauda sp. were recorded in 77% of assessed skulls and four types of tooth pathologies were observed. Nine individuals were more closely investigated for gross and histopathological alterations and had clear evidence of fishery interactions and various health issues associated with disease and oedema accompanied by alveolar fibrosis. While the regional frequency of T. truncatus strandings was lower than other more vulnerable cetaceans, the absolute numbers (e.g. 15 individuals in 2016) and some uncertainty concerning regional taxonomy are noteworthy, and justify ongoing spatio-temporal monitoring. Further, given the evidence of disease in some specimens, future work should not only encompass rigorous taxonomic assessments, but also health to comprehensively evaluate regional stocks. Small cetacean species are sentinels and their condition could inform ongoing environmental assessments.

Stable oxygen isotope values of inoceramid marine bivalve shells recovered from Bentiaba, Angola, are utilised as a proxy for paleotemperatures during the Late Cretaceous development of the African margin of the South Atlantic Ocean. The δ18O values derived from inoceramids show a long-term increase from –3.2‰ in the Late Turonian to values between –0.8 and –1.8‰ in the Late Campanian. Assuming a constant oceanic δ18O value, an ∼2‰ increase may reflect cooling of the shallow marine environment at Bentiaba by approximately 10°. Bentiaba values are offset by about +1‰ from published records for bathyal Inoceramus at Walvis Ridge. This offset in δ18O values suggests a temperature difference of ∼5° between coastal and deeper water offshore Angola. Cooler temperatures implied by the δ18O curve at Bentiaba coincide with the stratigraphic distribution of diverse marine amniotes, including mosasaurs, at Bentiaba.

The Risso's dolphins, Grampus griseus, are widely distributed, moderately large delphinids, inhabiting deep waters of the continental slope and outer shelf through the tropics and temperate regions. Until recently, their occurrence in the Western South Atlantic (WSA) ocean was poorly documented. This paper reports the first stranding record in the state of Paraíba (6°57′45″S 34°51′28″W), on the north-eastern coast of Brazil. Information on measurements, cause of death and the mapping of 46 records of G. griseus are provided. The data summarized in this report suggests that the distribution of G. griseus is continuous in the WSA, but with a higher frequency in colder waters further south. The available information for the WSA showed that negative interactions between Risso's dolphins and fisheries are more frequent in Brazil and need further investigation for conservation purposes.

Studies of the feeding habits of sea turtles are important in identifying their feeding grounds and preferred prey, thus helping with management decisions regarding habitat protection. The present study describes, for the first time, the feeding habits of the sea turtles Caretta caretta and Lepidochelys olivacea in Rio de Janeiro State, south-eastern Brazil (22°06′S–22°55′S). The stomach contents of five C. caretta and five L. olivacea recovered between 2009 and 2010 were analysed to identify the prey species. A common feeding pattern was noted for both species, with bottom-dwelling prey (fish, crustaceans, molluscs and echinoderms), common in shallow environments, constituting the main food items. All fish and brachyuran crustacean species identified in the stomach contents were by-catch in small-scale shrimp fisheries that operate along the study area. The coastal waters of Rio de Janeiro State represent a new feeding ground for L. olivacea, expanding its preferential habitat during the non-reproductive period. The results provide strong evidence for the likelihood that sea turtles are interacting with fisheries due to an overlapping between feeding and fishery grounds. An evaluation of carcasses washed up on beaches is needed for a better understanding of the effects on the population dynamics of sea turtles.

Satellite transmitters were attached to eight adult spectacled petrels Procellaria conspicillata Gould captured during the early incubation period at their breeding grounds on Inaccessible Island, one of the Tristan da Cunha Islands in the central South Atlantic Ocean. Data on their at-sea distribution was obtained for up to six months. All birds remained within the South Atlantic from 24–44°S, with most between 25 and 40°S. Breeding birds mainly foraged in oceanic waters, but failed breeders or non-breeders concentrated their foraging activity over the Rio Grande Rise and the Walvis Ridge and along the shelf break off the east coast of South America. Little foraging occurred along the Benguela shelf break off southern Africa. Non-breeders favoured relatively warm water with low chlorophyll concentrations, reducing the risk of bycatch in fisheries. Tracked birds spent 16% of their time in areas with high levels of tuna longline fishing activity, with overlap greater for non-breeding birds (22%) than breeding birds (3%). Birds in this study foraged in shallower waters along the continental shelf edge off South America than spectacled petrels tracked in this area in winter, potentially increasing their risk of exposure to demersal longline fisheries in this area in summer.

The objective of this study was to analyse the differences in shape of the cephalothorax in four fishery stocks of sea-bob shrimp Xiphopenaeus kroyeri that are distributed on the east coast of Brazil, applying geometric morphometry as the analytical tool. Samples were collected at the fishing ports of Caravelas (17°43′S 39°15′W), Vitória (20°15′S 40°14′W), Atafona (21°35′S 41°01′W) and Farol de São Tomé (22°02′S 41°02′W), and variations in shape of the cephalothorax of the shrimps were evaluated by univariate and multivariate techniques. Analysis of variance followed by the Tukey test indicated that shrimps collected at the port of Farol de São Tomé were significantly smaller than the others, and size of individuals was inversely related to latitude. Discriminant analysis revealed the formation of two morphologically different groups between the areas of collection. Individuals collected in Caravelas, Vitória and Atafona, suffering permanent influence of freshwater discharge, associated with sandy–muddy substrate, constituted a different group compared to individuals collected in Farol de São Tomé, area without this kind of influence and with sandy substrate, where the average water temperature is lower and salinity is higher. Considering the commercial importance of the target species, the technique could be applied to its fisheries management. It allows the recognition of stocks and inference about the processes of fishing area occupation.

Records of beaked whales stranded in the Falkland Islands and at South Georgia were collated for the period 1866 to 2008. Thirty-eight records, involving at least seven species in four genera, were documented. Strap-toothed whales (Mesoplodon layardii Gray, 1865) were the most common species with 11 records, including two neonates. Andrews' beaked whales (M. bowdoini Andrews, 1908), Arnoux's beaked whales (Berardius arnuxii Duvernoy, 1851), Cuvier's beaked whales (Ziphius cavirostris Gray, 1823), Gray's beaked whale (M. grayi van Haast, 1876), Hector's beaked whales (M. hectori Gray, 1871) and southern bottlenose whales (Hyperoodon planifrons Flower, 1882) were recorded on three to five occasions. In several cases, records suggested potential temporal changes in range. For example, Arnoux's beaked whale has not been recorded in the Falkland Islands since 1965, whilst Gray's beaked whale was not recorded prior to 1981, and Andrews' beaked whale was not recorded before 1987. Although the number of records for each species is low, this could reflect changes in water temperatures and/or prey availability. Overall, this study confirms that the Falkland Islands–Tierra del Fuego region is one of the world's key areas for beaked whales.

The black-browed (Thalassarche melanophrys) and Atlantic yellow-nosed (Thalassarche chlororhynchos) albatrosses and the white-chinned petrel (Procellaria aequinoctialis) are the seabird species most frequently captured by pelagic longline fisheries in the southwest Atlantic. This study estimates this type of bycatch and describes the spatial-temporal patterns of the incidental capture of these species by the Uruguayan pelagic longline fleet, based on data collected by scientific observers on 47 fishing trips from 2004 to 2007. Three generalized linear models (GLM) models were employed to predict bycatch for each species based on the observed data. We also developed a spatio-temporal species-specific analysis. Captures were recorded in Uruguayan waters, mainly over the slope and depth waters, and in international waters adjacent to Uruguay, the north of Argentina, and the south of Brazil. The highest catch rates for black-browed albatrosses and white-chinned petrels were recorded on the Uruguayan slope from fall to spring, while the highest values for Atlantic yellow-nosed albatrosses were recorded further to the north, in the international waters off Brazil in late winter. The average estimated number of black-browed and Atlantic yellow-nosed albatrosses and white-chinned petrels caught during the study period was 1683, 257 and 239 birds, respectively. Taking into account the total effort of the fleet, these values represent an estimated catch rate of 0.276, 0.042, and 0.039 birds/1000 hooks for these species, respectively. The results of the present study suggest that the annual impact of this fishery is medium to high on the black-browed albatross, low on the Atlantic yellow-nosed albatross and low on the white-chinned petrel. However, the situation of these species in the southwest Atlantic should be viewed with considerable concern, as our understanding of the impact of the bycatch on their populations requires more research. Any effort to reduce seabird mortality in the southern hemisphere should target this geographic region.