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- First direct evidence of adult European eels migrating to their breeding place in the Sargasso SeaPublication . Wright, Rosalind M.; Piper, Adam T.; Aarestrup, Kim; Azevedo, José M. N.; Cowan, George; Don, Andy; Gollock, Matthew; Rodriguez Ramallo, Sara; Velterop, Randolph; Walker, Alan; Westerberg, Håkan; Righton, DavidThe European eel (Anguilla anguilla) is critically endangered (according to the most recent IUCN assessment) and has suffered a 95% decline in recruitment since the 1980s, attributed in part to factors occurring during the marine phases of its life-cycle. As an adult, the European eel undertakes the longest spawning migration of all anguillid eels, a distance of 5000 to 10,000 km across the Atlantic Ocean to the Sargasso Sea. However, despite the passage of almost 100 years since Johannes Schmidt proposed the Sargasso Sea as the breeding place of European eels on the basis of larval surveys, no eggs or spawning adults have ever been sampled there to confirm this. Fundamental questions therefore remain about the oceanic migration of adult eels, including navigation mechanisms, the routes taken, timings of arrival, swimming speed and spawning locations. We attached satellite tags to 26 eels from rivers in the Azores archipelago and tracked them for periods between 40 and 366 days at speeds between 3 and 12 km day−1, and provide the first direct evidence of adult European eels reaching their presumed breeding place in the Sargasso Sea.
- Trophic position of dolphins tracks recent changes in the pelagic ecosystem of the Macaronesian region (NE Atlantic)Publication . Bode, Antonio; Saavedra, Camilo; Álvarez-González, Miguel; Arregui, Marina; Arbelo, Manuel; Fernández, Antonio; Freitas, Luís; Silva, Mónica A.; Prieto, Rui; Azevedo, José M. N.; Giménez, Joan; Pierce, Graham J.; Santos, M. BegoñaDolphins play a key role in marine food webs as predators of mid-trophic-level consumers. Because of their mobility and relatively long life span, they can be used as indicators of large-scale changes in the ecosystem. In this study, we calculated the trophic position (TP) of 5 dolphin species from the Canary, Madeira and Azores Islands using bulk and compound-specific stable isotope ratios from muscle tissue to assess trophic adaptations to recent changes in the availability of feeding resources. Dolphin TP values were then compared with those of 7 other species of cetaceans from this region. Analysis of stable nitrogen isotopes in amino acids of the common dolphin indicated non-significant effects of changes in the basal resources of the food web and thus supported the use of bulk samples for TP estimations. Dolphins occupied an intermediate TP (mean: 3.91 to 4.20) between fin (3.25) and sperm whales (4.95). Species-specific TP were equivalent among islands. However, TP increased for the common dolphin and decreased for the bottlenose dolphin (the latter also becoming more oceanic) between 2000 and 2018 in the Canary Islands. These results suggest different impacts of recent changes in the oceanography and in the pelagic food web of the Macaronesian region on the trophic ecology of dolphin species.
- Updated checklist of Azores Chondrichthyes (Vertebrata: Gnathostomata)Publication . Barcelos, Luis M. D.; Azevedo, José M. N.; Barreiros, João P.Chondrichthyes are commonly known as cartilaginous fishes and includes chimeras, sharks and rays. They can be found from the cold deep-sea to subtropical and tropical waters (Greemberg 2009). Sharks and rays have a great recreational and ecological interest (Vieira et al. 2020); however, many species worldwide are declining due to global overfishing (Worm et al. 2013). The total estimation for risk extinction, according to the IUCN Red List criteria, indicates that a quarter of all shark and ray species are threatened (Dulvy et al. 2014). The first comprehensive chondrichthyan checklist for Azores was published over 20 years ago by Santos et al. (1997). After that, some updates were made, most of them integrated in marine fish or biodiversity lists (e.g. Porteiro et al. 2010). In the meantime, new publications have emerged regarding new records (e.g. Catarino et al. 2020) or with new information on species already recorded for Azores (e.g. Das and Afonso 2017, Barcelos et al. 2018). The present work gives taxonomic updates and information regarding the conservation status (IUCN) for all chondrichthyan species from the Azores' EEZ. This is the first complete and updated list of chondrichthyans that can be found in the GBIF online platform (Barcelos et al. 2020).
- Updated checklist of Azores Actinopterygii (Gnathostomata: Osteichthyes)Publication . Barcelos, Luis M. D.; Azevedo, José M. N.; Barreiros, João P.BACKGROUND Since the first published comprehensive checklist of Azorean fishes - covering the whole Exclusive Economic Zone (EEZ) region - several new records have been published and an updated checklist published in 2010. This new dataset covers all confirmed species of actinopterygians for the Azorean EEZ. NEW INFORMATION In this update, we made corrections to the previous checklists, updated the taxonomy according to the most recent bibliography and added two new species to the Azorean Actinopterygii checklist.
- Marine algal flora of Santa Maria Island, AzoresPublication . Neto, Ana I.; Parente, Manuela I.; Cacabelos, Eva; Costa, Ana C.; Botelho, Andrea Z.; Ballesteros, Enric; Monteiro, Sandra; Resendes, Roberto; Afonso, Pedro; Prestes, Afonso L.; Patarra, Rita F.; Álvaro, Nuno V.; Milla-Figueras, David; Neto, Raul M. A.; Azevedo, José M. N.; Moreu, IgnacioBACKGROUND: The algal flora of the Island of Santa Maria (eastern group of the Azores archipelago) has attracted interest of researchers on past occasions (Drouët 1866, Agardh 1870, Trelease 1897, Schmidt 1931, Ardré et al. 1974, Fralick and Hehre 1990, Neto et al. 1991, Morton and Britton 2000, Amen et al. 2005, Wallenstein and Neto 2006, Tittley et al. 2009, Wallenstein et al. 2009a, Wallenstein et al. 2010, Botelho et al. 2010, Torres et al. 2010, León-Cisneros et al. 2011, Martins et al. 2014, Micael et al. 2014, Rebelo et al. 2014, Ávila et al. 2015, Ávila et al. 2016, Machín-Sánchez et al. 2016, Uchman et al. 2016, Johnson et al. 2017, Parente et al. 2018). Nevertheless, the Island macroalgal flora is not well-known as published information reflects limited collections obtained in short-term visits by scientists. To overcome this, a thorough investigation, encompassing collections and presence data recording, was undertaken at both the littoral and sublittoral levels down to a depth of approximately 40 m, covering an area of approximately 64 km2. The resultant taxonomic records are listed in the present paper which also provides information on species ecology and occurrence around the Island, improving, thereby, the knowledge of the Azorean macroalgal flora at both local and regional scales. NEW INFORMATION: A total of 2329 specimens (including some taxa identified only to genus level) belonging to 261 taxa of macroalgae are registered, comprising 152 Rhodophyta, 43 Chlorophyta and 66 Ochrophyta (Phaeophyceae). Of these, 174 were identified to species level (102 Rhodophyta, 29 Chlorophyta and 43 Ochrophyta), encompassing 52 new records for the Island (30 Rhodophyta, 9 Chlorophyta and 13 Ochrophyta), 2 Macaronesian endemics (Laurencia viridis Gil-Rodríguez & Haroun; and Millerella tinerfensis (Seoane-Camba) S.M.Boo & J.M.Rico), 10 introduced (the Rhodophyta Acrothamnion preissii (Sonder) E.M.Wollaston, Antithamnion hubbsii E.Y.Dawson, Asparagopsis armata Harvey, Bonnemaisonia hamifera Hariot, Melanothamnus harveyi (Bailey) Díaz-Tapia & Maggs, Scinaia acuta M.J.Wynne and Symphyocladia marchantioides (Harvey) Falkenberg; the Chlorophyta Codium fragile subsp. fragile (Suringar) Hariot; and the Ochrophyta Hydroclathrus tilesii (Endlicher) Santiañez & M.J.Wynne, and Papenfussiella kuromo (Yendo) Inagaki) and 18 species of uncertain status (11 Rhodophyta, 3 Chlorophyta and 4 Ochrophyta).
- Marine algal flora of Formigas Islets, AzoresPublication . Neto, Ana I.; Prestes, Afonso L.; Azevedo, José M. N.; Resendes, Roberto; Álvaro, Nuno V.; Neto, Raul M. A.; Moreu, IgnacioBACKGROUND: The oldest reference to marine life in Formigas Islets (oriental group of the Azores archipelago) goes back to the 16th century. Nevertheless, their macroalgal flora is poorly known, the published information mainly resulting from occasional collections of sporadic visitors. To overcome this and contribute to the knowledge of Azorean macroalgal flora at both local and regional scales, a thorough investigation was conducted in 1990 and 1991 under two expeditions promoted by the Marine Biology Research Group of the Department of Biology, University of the Azores. Collections and presence data recordings were undertaken at the littoral and sublittoral levels down to approximately 40 m, in an area of approximately 0.04 km2. This paper lists the taxonomic records and provides information regarding each species’ ecology and occurrence on the Islets’ littoral. NEW INFORMATION: A total of 320 specimens are registered (including taxa identified only at generic level) belonging to 90 taxa of macroalgae, from which 70 were diagnosed at species level. The confirmed species comprise 39 Rhodophyta, 12 Chlorophyta and 19 Ochrophyta (Phaeophyceae), distributed in 22 orders (13 Rhodophyta, 3 Chlorophyta and 6 Ochrophyta) and 37 families (24 Rhodophyta, 6 Chlorophyta and 7 Ochrophyta). Sixty-one species represent new records for the Islets, from which Botryocladia macaronesica Afonso-Carrillo, Sobrino, Tittley & Neto and Laurencia viridis Gil-Rodriguez & Haroun are Macaronesian endemisms. Most species are native to the Azores, but six have an uncertain origin and four are introduced (the Rhodophyta Asparagopsis armata Harvey; Laurencia dendroidea J.Agardh; Neoizziella divaricata (C.K.Tseng) S.-M.Lin, S.-Y.Yang & Huisman and the Ochrophyta Hydroclathrus tilesii (Endlicher) Santiañez & M.J.Wynne).
- Dolphin whistle repertoires around São Miguel (Azores) : Are you common or spotted?Publication . Gannier, Alexandre; Fuchs, Sandra; Gannier, Adrien; Fernandez, Marc; Azevedo, José M. N.Short-beaked common dolphins (Delphinus delphis) and Atlantic spotted dolphins (Stenella frontalis) are both common in the Azores archipelago during summer. Because both species are sympatric, at least in part of their range, they may use acoustic features to recognize conspecifics and maintain school cohesion throughout their different activities. Delphinid whistles were recorded with a 96-kHz sampling rate using towed hydrophone system during surveys held in summer of 2013 and 2014 around São Miguel Island (Azores, Portugal). A total of 256 whistles attributed to either short-beaked common dolphin (n = 133) or Atlantic spotted dolphin (n = 123) were selected and processed with a contour extraction software. Elementary statistical analysis showed that duration, frequency and slope variables were significantly different for both species, although in most cases their range overlapped. We performed a discriminant analysis to test species classification: the dataset was randomly split into one calibration subset (186 whistles) and one validation subset (70 whistles). The discriminant analysis retained four variables (global slope, duration, minimal and final frequencies) as useful for classification. The discriminant function resulted in correct classification rates of 78.5% (calibration subset) and 81.4% (validation subset). Common dolphin whistles were better classified than Atlantic spotted dolphin whistles (83.4% and 74.8%) respectively. This study shows that reliable species identification can be achieved for common and spotted dolphins using their whistle repertoire characteristics.
- Marine algal flora of Flores and Corvo Islands, AzoresPublication . Neto, Ana I.; Parente, Manuela I.; Tittley, Ian; Fletcher, Robert L.; Farnham, William F.; Costa, Ana C.; Botelho, Andrea Z.; Monteiro, Sandra; Resendes, Roberto; Afonso, Pedro; Prestes, Afonso L.; Álvaro, Nuno V.; Milla-Figueras, David; Neto, Raul M. A.; Azevedo, José M. N.; Moreu, IgnacioBACKGROUND The algal flora of the western group of the Azores archipelago (Islands of Flores and Corvo) has attracted the interest of many researchers on numerous past occasions (such as Drouet 1866, Trelease 1897, Gain 1914, Schmidt 1929, Schmidt 1931, Azevedo et al. 1990, Fralick and Hehre 1990, Neto and Azevedo 1990, Neto and Baldwin 1990, Neto 1996, Neto 1997, Neto 1999, Tittley and Neto 1996, Tittley and Neto 2000, Tittley and Neto 2005, Tittley and Neto 2006, Azevedo 1998, Azevedo 1999, Tittley et al. 1998, Dionísio et al. 2008, Neto et al. 2008). Despite this interest, the macroalgal flora of the Islands cannot be described as well-known with the published information reflecting limited collections preformed in short-term visits by scientists. To overcome this, a thorough investigation, encompassing collections and presence data recording, has been undertaken for both the littoral and sublittoral regions, down to a depth of approximately 40 m, covering a relatively large area on both Islands (approximately 143 km² for Flores and 17 km² for Corvo). This paper lists the resultant taxonomic records and provides information on species ecology and occurrence around both these Islands, thereby improving the knowledge of the Azorean macroalgal flora at both local and regional scales. NEW INFORMATION For the Island of Flores, a total of 1687 specimens (including some taxa identified only to genus level) belonging to 196 taxa of macroalgae are registered, comprising 120 Rhodophyta, 35 Chlorophyta and 41 Ochrophyta (Phaeophyceae). Of these taxa, 128 were identified to species level (80 Rhodophyta, 22 Chlorophyta and 26 Ochrophyta), encompassing 37 new records for the Island (20 Rhodophyta, 6 Chlorophyta and 11 Ochrophyta); two Macaronesian endemics (Laurencia viridis Gil-Rodríguez & Haroun and Millerella tinerfensis (Seoane-Camba) S.M.Boo & J.M.Rico); six introduced (the Rhodophyta Asparagopsis armata Harvey, Neoizziella divaricata (C.K.Tseng) S.-M.Lin, S.-Y.Yang & Huisman and Symphyocladia marchantioides (Harvey) Falkenberg; the Chlorophyta Codium fragile subsp. fragile (Suringar) Hariot; and the Ochrophyta Hydroclathrus tilesii (Endlicher) Santiañez & M.J.Wynne and Papenfussiella kuromo (Yendo) Inagaki); and 14 species of uncertain status (10 Rhodophyta, two Chlorophyta and two Ochrophyta). For the Island of Corvo, a total of 390 specimens distributed in 56 taxa of macroalgae are registered, comprising 30 Rhodophyta, nine Chlorophyta and 17 Ochrophyta (Phaeophyceae). Whilst a number of taxa were identified only to the genus level, 43 were identified to species level (22 Rhodophyta, eight Chlorophyta and 13 Ochrophyta), comprising 22 new records for the Island (nine Rhodophyta, four Chlorophyta and nine Ochrophyta), two introduced species (the Rhodophyta Asparagopsis armata and the Chlorophyta Codium fragile subsp. fragile and seven species of uncertain status (five Rhodophyta and two Ochrophyta).
- Life goes on : Oblada melanura (Linnaeus, 1758) (Perciformes, Sparidae), the saddled seabream, expands its distribution range westwards to the AzoresPublication . Azevedo, José M. N.; Neto, Raul M. A.A group of 10 individuals of the saddled seabream, Oblada melanura (Linnaeus, 1758), was photographed at Lajes do Pico Bay, on Pico Island, Azores. This finding represents a significant westward expansion of the known range of this species and may be linked to global warming. A call is therefore made for a monitoring program of the coastal fish fauna of the Azores which would improve the understanding of the effects of climate change and other anthropogenic stressors on marine communities.
- A novel expert-driven methodology to develop thermal response curves and project habitat thermal suitability for cetaceans under a changing climatePublication . Sousa, Andreia G.; Fernandez, Marc; Alves, Filipe M. A.; Arranz, Patricia; Dinis, Ana; González García, Laura; Morales, Misael; Lettrich, Matthew D.; Coelho, R. Encarnação; Costa, Hugo; Lourenço, T. Capela; Azevedo, José M. N.; Santos, Catarina FrazãoOver the last decades, global warming has contributed to changes in marine species composition, abundance and distribution, in response to changes in oceanographic conditions such as temperature, acidification, and deoxygenation. Experimentally derived thermal limits, which are known to be related to observed latitudinal ranges, have been used to assess variations in species distribution patterns. However, such experiments cannot be undertaken on free-swimming large marine predators with wide-range distribution, like cetaceans. An alternative approach is to elicit expert's knowledge to derive species' thermal suitability and assess their thermal responses, something that has never been tested in these taxa. We developed and applied a methodology based on expert-derived thermal suitability curves and projected future responses for several species under different climate scenarios. We tested this approach with ten cetacean species currently present in the biogeographic area of Macaronesia (North Atlantic) under Representative Concentration Pathways 2.6, 4.5 and 8.5, until 2050. Overall, increases in annual thermal suitability were found for Balaenoptera edeni, Globicephala macrorhynchus, Mesoplodon densirostris, Physeter macrocephalus, Stenella frontalis, Tursiops truncatus and Ziphius cavirostris. Conversely, our results indicated a decline in thermal suitability for B. physalus, Delphinus delphis, and Grampus griseus. Our study reveals potential responses in cetaceans' thermal suitability, and potentially in other highly mobile and large predators, and it tests this method's applicability, which is a novel application for this purpose and group of species. It aims to be a cost-efficient tool to support conservation managers and practitioners.