Coelho J.P.,CIIMAR – Interdisciplinary Center of Marine and Environmental |
Coelho J.P.,University of Aveiro |
Monteiro R.J.R.,CIIMAR – Interdisciplinary Center of Marine and Environmental |
Monteiro R.J.R.,University of Aveiro |
And 10 more authors.
Marine Pollution Bulletin | Year: 2016
This work evaluates the mercury (Hg) contamination status (sediments and biota) of the Bijagós archipelago, off the coast of Guinea-Bissau. Sediments exhibited very low concentrations (< 1–12 ng g−1), pointing to negligible sources of anthropogenic Hg in the region. Nevertheless, Hg is well correlated to the fine fraction, aluminium, and loss on ignition, indicating the effect of grain size and organic matter content on the presence of Hg in sediments. Mercury in the bivalves Tagelus adansoni and Senilia senilis did not vary considerably among sites, ranging within narrow intervals (0.09–0.12 and 0.12–0.14 μg g−1 (dry weight), respectively). Divergent substrate preferences/feeding tactics may justify slight differences between species. The value 11 ng g−1 is proposed as the sediment background concentration for this West-African coastal region, and concentrations within the interval 8–10 ng g−1 (wet weight) may be considered as reference range for S. senilis and T. adansoni in future monitoring studies. © 2016 Elsevier Ltd
Luis A.R.,nstituto Universitario |
Luis A.R.,Projecto Delfimcentro Portugues Of Estudo Dos Mamiferos Marinhos |
Couchinho M.N.,nstituto Universitario |
Couchinho M.N.,Projecto Delfimcentro Portugues Of Estudo Dos Mamiferos Marinhos |
And 2 more authors.
Acta Ethologica | Year: 2015
Whistles are key elements in the acoustic repertoire of bottlenose dolphins. In this species, the frequency contours of whistles are used as individual signatures. Assessing the long-lasting stability of such stereotyped signals, and the abundant production of non-stereotyped whistles in the wild, is relevant to a more complete understanding of their biological function. Additionally, studying the effects of group size and activity patterns on whistle emission rate may provide insights into the use of these calls. In this study, we document the decades-long occurrence of whistles with stereotyped frequency contours in a population of wild bottlenose dolphins, resident in the region of the Sado estuary, Portugal. Confirmed stereotypy throughout more than 20 years, and positive identification using the signature identification (SIGID) criteria, suggests that the identified stereotyped whistles are in fact signature whistles. The potential roles of non-stereotyped whistles, which represent 68 % of all whistles recorded, are still unclear and should be further investigated. Emission rates were significantly higher during food-related events. Finally, our data show a comparatively high overall whistle production for this population, and no positive correlation between group size and emission rates, suggesting social or environmental restriction mechanisms in vocal production. © 2015 Springer-Verlag Berlin Heidelberg and ISPA
Teles M.C.,nstituto Universitario |
Teles M.C.,Instituto Gulbenkian Of Ciencia |
Almeida O.,nstituto Universitario |
Almeida O.,Instituto Gulbenkian Of Ciencia |
And 4 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2015
According to the social decision-making (SDM) network hypothesis, SDM is encoded in a network of forebrain and midbrain structures in a distributed and dynamic fashion, such that the expression of a given social behaviour is better reflected by the overall profile of activation across the different loci rather than by the activity of a single node. This proposal has the implicit assumption that SDM relies on integration across brain regions, rather than on regional specialization. Here we tested the occurrence of functional localization and of functional connectivity in the SDM network. For this purpose we used zebrafish to map different social behaviour states into patterns of neuronal activity, as indicated by the expression of the immediate early genes c-fos and egr-1, across the SDM network. The results did not support functional localization, as some loci had similar patterns of activity associated with different social behaviour states, and showed socially driven changes in functional connectivity. Thus, this study provides functional support to the SDM network hypothesis and suggests that the neural context in which a given node of the network is operating (i.e. the state of its interconnected areas) is central to its functional relevance. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
Neto M.P.,ZoomarinePortugal |
Silveira M.,ZoomarinePortugal |
dos Santos M.E.,nstituto Universitario
Zoo Biology | Year: 2016
Enrichment programs may contribute to the quality of life and stress reduction in bottlenose dolphins (Tursiops truncatus) kept in zoos and aquaria. The results of these programs are generally positive in terms of welfare, but the magnitude of their effects may vary greatly between individuals of the same species, especially when the enrichment plans are based on the introduction of manipulative objects. Some animals will interact spontaneously with novel objects, even without food rewards and in the absence of the trainers, while others show no interest or even aversion toward the objects. To determine if formal training can improve these conditions, we measured the effects of an operant conditioning program in the manipulation of objects by dolphins that initially avoided them. This program took place between April and October 2013 at Zoomarine Portugal. Subjects were two female and two male bottlenose dolphins (adults with ages from 17 to 35 years) that after a preliminary analysis showed avoidance or low interest in the manipulation of various toys. The level of interaction with introduced enrichment objects was observed before and after formal training to explore the toys (sixteen 20-min observation sessions per animal “before” and “after training”). In all subjects, an index of interest in object manipulation, in the absence of trainers, increased significantly after the application of the training techniques. The results show that an initial reinforcement program focused on the manipulation of toys may overcome resistance, improving the effects of environmental enrichment plans, and it is a potentially useful strategy to increase the welfare of some captive animals. Zoo Biol. 35:210–215, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.