Spatial and temporal distribution of cetaceans in the mid-Atlantic waters around the Azores

Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Taylor & Francis for personal use, not for redistribution. The definitive version was published in Marine Biology Research 10 (2014): 123-137, doi:10.1080/17451000.2013.793814.Cetaceans living in offshore waters are under increasing pressure from anthropogenic activities. Yet, due to the lack of survey effort, relatively little is known about the demography or ecology of these populations. Spatial and temporal distribution of cetaceans in mid-Atlantic waters were investigated using a long term dataset collected from boat surveys and land-based observations around the Azores. From 1999 to 2009, 7307 cetacean schools were sighted during 271717 km of survey effort. In 4944 h of land-based observations, 2968 cetacean groups were detected. Twenty-four species were recorded: seven baleen whales, six beaked whales, eight dolphin species, Physeter macrocephalus, Kogia breviceps and K. sima. Overall, Delphinus delphis was the most frequently sighted species but its encounter rate decreased in June- November, coinciding with presence of Stenella frontalis in the region. Tursiops truncatus, P. macrocephalus and Grampus griseus were frequently encountered yearround, whereas large baleen whales showed a distinct peak in encounter rates in March-May. Mesoplodonts were fairly common and appear to be present throughout the year. These findings fill-in a significant gap in the knowledge of cetaceans occurring in a poorly studied region of the North Atlantic, providing much needed data to inform management initiatives.This work was supported by FEDER funds, through the Competitiveness Factors Operational Programme – COMPETE, by national funds, through FCT – Foundation for Science and Technology, under projects CETAMARH (POCTI/BSE/38991/01) and TRACE (PTDC/MAR/74071/2006), and by regional funds, through DRCT/SRCTE, under project MAPCET (M2.1.2/F/012/2011). We thank the Azorean Regional Government for funding POPA, the Shipowners Proprietors and the Association of the Tuna Canning Industries for their support to the programme. MAS was supported by an FCT postdoctoral grant (SFRH/BPD/29841/2006), and IC and RP were supported by doctoral grants SFRH/BD/41192/2007 and SFRH/BD/32520/2006. IMAR-DOP/UAç is the R&D Unit #531 and part of the Associated Laboratory #9 (ISR) funded through the pluri-annual and programmatic funding schemes of FCT-MCTES and DRCTAzores

Mer receptor tyrosine kinase mediates both tethering and phagocytosis of apoptotic cells

Billions of inflammatory leukocytes die and are phagocytically cleared each day. This regular renewal facilitates the normal termination of inflammatory responses, suppressing pro-inflammatory mediators and inducing their anti-inflammatory counterparts. Here we investigate the role of the receptor tyrosine kinase (RTK) Mer and its ligands Protein S and Gas6 in the initial recognition and capture of apoptotic cells (ACs) by macrophages. We demonstrate extremely rapid binding kinetics of both ligands to phosphatidylserine (PtdSer)-displaying ACs, and show that ACs can be co-opsonized with multiple PtdSer opsonins. We further show that macrophage phagocytosis of ACs opsonized with Mer ligands can occur independently of a requirement for αV integrins. Finally, we demonstrate a novel role for Mer in the tethering of ACs to the macrophage surface, and show that Mer-mediated tethering and subsequent AC engulfment can be distinguished by their requirement for Mer kinase activity. Our results identify Mer as a receptor uniquely capable of both tethering ACs to the macrophage surface and driving their subsequent internalization

Why do dolphins form mixed-species associations in the Azores ?

Mixed-species associations are temporary associations between individuals of different species that are often observed in birds, primates and cetaceans. They have been interpreted as a strategy to reduce predation risk, enhance foraging success and/or provide a social advantage. In the archipelago of the Azores, four species of dolphins are commonly involved in mixed-species associations: the common dolphin, Delphinus delphis, the bottlenose dolphin, Tursiops truncatus, the striped dolphin, Stenella coeruleoalba, and the spotted dolphin, Stenella frontalis. In order to understand the reasons why dolphins associate, we analysed field data collected since 1999 by research scientists and trained observers placed onboard fishing vessels. In total, 113 mixed-species groups were observed out of 5720 sightings. The temporal distribution, habitat (water depth, distance to the coast), behaviour (i.e. feeding, travelling, socializing), size and composition of mixed-species groups were compared with those of single-species groups. Results did not support the predation avoidance hypothesis and gave little support to the social advantage hypothesis. The foraging advantage hypothesis was the most convincing. However, the benefits of mixed-species associations appeared to depend on the species. Associations were likely to be opportunistic in the larger bottlenose dolphin, while there seemed to be some evolutionary constraints favouring associations in the rarer striped dolphin. Comparison with previous studies suggests that the formation of mixed-species groups depends on several environmental factors, and therefore may constitute an adaptive response

Contamination status by persistent organic pollutants of the Atlantic spotted dolphin (Stenella frontalis) at the metapopulation level

The Atlantic spotted dolphin (Stenella frontalis) is an endemic species of the tropical-temperate Atlantic Ocean with widespread distribution. Although this species has been the subject of a large number of studies throughout its range, it remains in the "data deficient" category of the International Union for Conservation of Nature (IUCN). Chemical pollution by persistent organic pollutants (POPs) has been listed as one of the major threats to this species, however, there is no information on a wide scale. Thus, the aim of the present study was to investigate the contamination status of spotted dolphins on the metapopulation level as well as determine spatial and temporal variations in POP concentrations and bioaccumulation. A total of 115 blubber samples collected from a large part of the Atlantic basin were analysed for PCBs, DDTs, PBDEs, chlordanes, HCB and mirex. Although PCBs and DDTs were the predominant compounds in all areas, inter-location differences in POP concentrations were observed. Dolphins found at Sao Paulo, southeastern coast of Brazil, had the highest PCB concentrations (median: 10.5 mu g/g lw) and Canary Islands dolphins had the highest DDT concentrations (median: 5.13 mu g/g lw). Differences in PCB patterns among locations were also observed. Dolphins from the Azores and Sao Paulo demonstrated a similar pattern, with relatively highly contributions of tetra- (6.8 and 5.2%, respectively) and penta-CBs (25.6 and 23.8%, respectively) and lower contributions of hepta-CBs (20.8 and 23.5%, respectively) in comparison to other areas. Moreover, the sex of the animals and the year in which sampling or capture occurred exerted an important influence on the majority of the POPs analysed. Comparisons with toxicity thresholds available in the literature reveal that the Sao Paulo and Canary Island dolphins are the most vulnerable populations and should be considered in future conservation and management programs for the Atlantic spotted dolphin

Population structure of the Atlantic spotted dolphin (Stenella frontalis) inferred through ecological markers

Population structure studies play an increasingly integral role in conservation and management of marine mammal species. Genetic markers are commonly used; however, ecological markers (i.e. chemical compounds) are a fairly recent and useful tool to investigate ecological management units. The objective of this study is to investigate the population structure of the Atlantic spotted dolphin (Stenella frontalis) within its distribution in the Atlantic Ocean using data from stable isotopes of delta C-13 and delta N-15 and persistent organic pollutants as ecological markers. Based on previous studies that addressed distribution, morphometric analyses and molecular and ecological markers, we hypothesize that there are several ecological management units within the Atlantic Ocean. Our results confirmed population differentiation previously detected using genetic markers. Additionally, dolphins from the south-eastern coast of Brazil do not show complete ecological segregation from the Caribbean ones, while molecular analyses suggested genetic differentiation between the two regions. In the light of these results, we propose that at least two ecological management units should be considered, east and west of the Atlantic Ocean; however, the presence of one or two management units along the Atlantic coast of Central and South America needs further investigation

Cytokine pattern in very early rheumatoid arthritis favours B-cell activation and survival

© The Author 2010. Published by Oxford University Press on behalf of the British Society for Rheumatology.Objectives. B cells play an important role in the perpetuation of RA, particularly as autoantibody-producing cells. The ICs that further develop deposit in the joints and aggravate the inflammatory process. However, B-cell contribution in the very early stage of the disease remains unknown. The main goal of this work was to determine the concentration of cytokines potentially relevant for B-cell activation in serum from very early polyarthritis patients, with <6 weeks of disease duration, who latter on evolved into very early RA (VERA). Methods. A proliferation-inducing ligand (APRIL), B-cell activating factor (BAFF) and IL-21 levels were measured by ELISA in the serum of VERA, other very early arthritis (VEA), established RA patients and controls. SF samples of established RA were also analysed. Results. VERA patients have higher levels of APRIL and BAFF as compared with VEA, established RA and controls. Furthermore, APRIL and BAFF levels are also significantly elevated in RA-SF when compared with serum. Conclusions. The increased levels of APRIL and BAFF in VERA patients suggests that B-cell activation and the development of autoreactive B-cell responses might be crucial in early phases of RA. Therefore, APRIL and BAFF could be promising targets for therapy in the early phase of RA.Sociedade Portuguesa de Reumatologia/Schering-Plough 2005. R.A.M. and R.C. were funded by Fundação para a Ciência e a Tecnologia (FCT) SFRH/BD/30247/2006 and SFRH/BD/40513/2007, respectively. M.M.S.-C. was funded by Marie Curie Intra-European Fellowship PERG-2008-239422 and an EULAR Young Investigator Award

Transboundary water interaction II:the influence of 'soft' power

This paper seeks to broaden the analysis of transboundary water interaction, by examining and interpreting the influence of 'soft' power therein. The 'soft' power of persuasion is understood to be exercised through discursive and to a lesser extent ideational means, and is interpreted in terms of compliance related to distributive (conflictual) or integrative (consensual) ends (after Scott (1994)). The focus is on inter-state water conflicts in hegemonic political contexts, where, it is found, the 'first among equals' has a greater ability to exploit 'soft' power and to determine the outcome. 'Soft' power is also seen to influence the choices states make or avoid in their transboundary water interaction, which explains in part how treaties intending to manage conflict may in fact delay or perpetuate it. For example, 'soft' power can be used by the basin hegemon to frame inequitable forms of cooperation in a cooperative light, such that unfair and ultimately unsustainable transboundary arrangements are replicated by the international donor community. Non-hegemonic riparian states also employ their capacity of 'soft' power, though may find themselves with little choice other than to comply with the arrangement established by the basin hegemon. The findings stress the importance of analysts questioning claims of interaction promoted as 'cooperative', and of examining the 'soft' power plays that underlie all transboundary water arrangements. Exemplification is provided through transboundary river basins and aquifers around the globe