Predicting Cetacean Distributions in the Eastern North Atlantic to Support Marine Management

Acknowledgments We thank all the volunteers for their contribution and dedication during the monitoring campaigns. This manscript is a product of the work of every observer who participated in the CETUS Project. We are extremely grateful to TRANSINSULAR, the cargo ship company that provided all the logistic support, and to the ships’ crews for their hospitality. We also thank Vasilis Valavanis for his valuable advice about the use of oceanographic variables.Peer reviewedPublisher PD

Trophic ecology of common bottlenose dolphins in a pelagic insular environment inferred by stable isotopes

The common bottlenose dolphin (Tursiops truncatus) is a top marine predator widely dispersed in coastal and pelagic habitats and with a generalist feeding behavior. Yet, information on the trophic ecology of animals inhabiting pelagic environments is still scarce. Using carbon (& delta;C-13: C-13/C-12) and nitrogen (& delta;N-15: N-15/N-14) stable isotope ratios, we identified and quantified the main groups of prey assimilated by bottlenose dolphins inhabiting an oceanic habitat (Madeira Island, East Atlantic). Bottlenose dolphins assimilated pelagic, schooling fish (such as blue jack mackerel, Trachurus picturatus) and mesopelagic and demersal squids, which reinforces the pelagic dietary composition of insular/oceanic dolphins. Also, intra-seasonal differences were found in their stable isotope ratios, which suggest intraspecific variability in the feeding behavior among individuals living in the same area. Sex was not the main factor contributing to these differences, suggesting the lack of trophic niche segregation between adult males and females in this offshore environment. Nonetheless, further studies including different life stages and information on the ecophysiological requirements are necessary to disclose the factors responsible for the observed variability. This study showed that insular dolphins fed primarily on economically important pelagic prey, highlighting the need of developing management strategies that integrate conservation in fisheries plans.NORTE01-0145-FEDER-000031; M1420-01-0145-FEDER-000001-OOM; LA/P/0069/2020; M1420-09-5369-FSE-000002info:eu-repo/semantics/publishedVersio

Opportunistic data: use it or lose it?

34th European Cetacean Society Conference, O Grove, 16-20 April 2023Data collection is a challenge, especially when dealing with highly mobile species, as is the case of cetaceans, and surveying dynamic open ocean areas, which comes with several logistic constrains. Therefore, it is of extreme relevance to be able to use all available data to study the distribution and habitat of cetacean. The CETUS Project is a cetacean monitoring programme that uses platforms of opportunity to survey long line-transect routes in the eastern North Atlantic. The CETUS dataset contains data on cetacean occurrence collected both during dedicated monitoring effort and opportunistically (with interrupted monitoring effort). Here, we aim to compare opportunistic and dedicated data for the assessment of cetacean diversity, distribution and habitat. Due to the large amount of data collected over an 11-year period (2012-2022), we were able to compile sufficient opportunistic records to characterize the cetacean community in the area, but only for the most frequently sighted species. For frequent, easily detected and identified species (e.g., common dolphin, Delphinus delphis), the results for spatial distribution patterns and habitat range are similar when using dedicated and opportunistic data. On the other hand, for species that are less frequent, elusive and difficult to identify (e.g., Cuvier´s beaked whale, Ziphius cavirostris), there were important differences. For some of these species, there were several regions where the only available data on occurrence were collected opportunistically, and inclusion of such data would thus increase assessed distribution and habitat range. The results obtained evidence that there is high value of opportunistically collected data, and the rarer the species, the more relevant such data is. Ultimately, if possible, opportunistic occurrence data should be used in the analytical process and not lostN

Environmental DNA as a cetacean monitoring tool in the Northern Coast of Continental Portugal

34th European Cetacean Society Conference, O Grove, 16-20 April 2023In recent decades, environmental DNA (eDNA) has emerged as a utopian monitoring tool in the marine conservation landscape, for its potential to collect data on presence and abundance of biological communities with insufficient knowledge and/or difficult access. In the ATLANTIDA Project, this tool is being optimized with the ultimate goal of detecting and identifying cetacean species on the northern coast of continental Portugal without relying on visual monitoring. To this end, a molecular biology-based methodology is being developed and tested in positive control samples, consisting of a mixture of DNA extracted directly from muscle tissue or gums of cetaceans with eDNA samples collected in ATLANTIDA dedicated at-sea surveys. Firstly, in silico analysis using metagenomic data was performed to assess the pair of primers directed to mitochondrial DNA presenting the highest variability and, consequently, a higher probability of distinction among the target species. For that purpose, different sets of primers previously described in the bibliography were analysed and unique single nucleotide polymorphisms between the species of interest were counted. After the selection of the most suitable primer set, several optimization tests have been conducted, through conventional PCR, in order to identify the most efficient DNA amplification protocol for the gene of interest. From these tests, we were able to identify the ideal annealing temperature, the best TAQ polymerase enzyme, and the detection of cetacean DNA up to very low concentrations (~5ng/μL) was achieved, with salt water not inhibiting the reaction. In environmental samples, we were still not able to detect cetacean DNA, probably because of its concentration below our detection limit in the samples tested. In conclusion, although the effectiveness of resorting to eDNA for cetacean monitoring programs remains unclear, these results represent a step forward towards that goalN

Blow microbiota of free-ranging short-finned pilot whales: comparison of two 16S rRNA primers for studies of blow prokaryotic communities

34th European Cetacean Society Conference, O Grove, 16-20 April 2023Respiratory disease is one of the main causes of death in cetaceans. Characterizing the microbial communities harbored in the exhaled breath condensate (EBC), or blow, has been proposed as a suitable methodology to assess cetacean health. However, still few studies in the literature focus on the respiratory microbiota of free-ranging animals. In the present study the short-finned pilot whales (Globicephala macrorhynchus) were used as a model species to: 1) develop a sampling/analysis protocol for the characterization of the microbial diversity in the EBC of free-ranging cetaceans; 2) perform a comprehensive comparison of two 16S rRNA gene primers set (regarding amplification and taxa coverage) able to describe the microbial communities of their respiratory tracts; 3) highlight possible potential pathogens in the animal‟s airway microbiota. For this purpose, a total of 12 pilot whale EBC samples were collected during at-sea campaigns in Madeiran waters, in the autumn 2018. Environmental DNA was extracted from the samples and then sequenced using the Illumina MiSeq platform to amplify V3-V4 and V4-V5 hypervariable regions of the 16S rRNA gene. DADA2 bioinformatic pipeline was used to process sequences and analyze the diversity and taxonomic profiles of blow prokaryotic communities. Results showed that, independently of the primer set used, all the sampled animals share Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria phyla in their blow composition. The V4-V5 dataset showed higher microbial richness (rare biosphere and potentially pathogenic taxa), whereas V3-V4 captured more diversity. This research contributes to bringing new knowledge on the characterization of the respiratory-associated microbial communities, towards a non-invasive tool for monitoring the physiological state of the airways in cetaceans. However, the methodology still requires research effort and development / optimization of techniques to further advance the implementation of such monitoring toolN

Mamíferos Marinhos

UID/HIS/04666/2019publishersversionpublishe

The rulers were also children

Yo le diría a alguien que aspire a ser presidente de Colombia que no se le olvide que alguna vez fue niño, que alguna vez fue adolescente y que también será adulto mayor. Que se ponga en los zapatos de todos.I would tell someone who aspires to be president of Colombia that he or she must not forget that once he was a child, that once he was a teenager and that he will also be an older adult. A president must have the ablity to wear everyone's shoes

Five-year spatial and temporal distribution of cetaceans in the Macaronesian waters - Analyzing habitat preferences in the area

31st Conference of the Eropean Cetacean Society, Conservation in the light of marine spatial use, Middelfart, Denmark, 1st to 3rd May 2017In the Eastern Atlantic Ocean, Macaronesia constitutes habitat for many resident and migratory cetaceans, providing a wide range of habitat characteristics due to its many topographic features (seamounts, canyons, abyssal plains), oceanographic dynamics (Portuguese and African coastal upwellings, influence of several oceanic currents) and oceanic archipelagos (Azores, Madeira, Canaries and Cape Verde).N