Ricardo S. Santos

Seamounts: Ecology, Fisheries & Conservation

1 Seamount characteristics. Paul Wessel. 2 How many seamounts are there and where are they located?. Adrian Kitchingman, Sherman Lai, Telmo Morato and Daniel Pauly. 3 A history of seamount research. Paul E. Brewin, Karen I. Stocks and Gui Menezes. 4 Physical processes and seamount productivity. Martin White, Igor Bashmachnikov, Javier Aristegui and Ana Martins. 5 Seamount plankton dynamics. Amatzia Genin and John F. Dower. 6 Midwater fish assemblages and seamounts. Filipe M. Porteiro and Tracey Sutton. 7 Seamount benthos. Sarah Samadi, Thomas Schlacher and Bertrand Richer de Forges. 8 Corals on seamounts. Alex D. Rogers, A. Baco, H. Griffiths, T. Hart and Jason M. Hall-Spencer. 9 Seamount fishes: ecology and life histories. Telmo Morato and Malcolm R. Clark. 10 Fish visitors to seamounts. Section A: Tunas and billfish at seamounts. Kim N. Holland and R. Dean Grubbs. Section B: Aggregations of large pelagic sharks above seamounts. Feodor Litvinov. 11 Seamounts and cephalopods. Malcolm Clarke. 12 Air-breathing visitors to seamounts. Section A: Marine mammals. Kristin Kaschner. Section B: Sea turtles. Marco A. Santos, Alan B. Bolten, Helen R. Martins, Brian Riewald and Karen A. Bjorndal. Section C: Importance of seamounts to seabirds. David R. Thompson. 13 Biogeography and biodiversity of seamounts. Karen I. Stocks and Paul J.B. Hart. 14 Raiding the larder: a quantitative evaluation framework and trophic signature for seamount food webs. Tony J. Pitcher and Cathy Bulman. 15 Modelling seamount ecosystems and their fisheries. Beth Fulton, Telmo Morato and Tony J. Pitcher. 16 Small-scale fishing on seamounts. Helder Marques da Silva and Mario Rui Pinho. 17 Large-scale distant-water trawl fisheries on seamounts. Malcolm R. Clark, Vladimir I. Vinnichenko, John D.M. Gordon, Georgy Z. Beck-Bulat, Nikolai N. Kukharev and Alexander F. Kakora. 18 Catches from world seamount fisheries. Reg Watson, Adrian Kitchingman and William Cheung. 19 Impacts of fisheries on seamounts. Malcolm R. Clark and J. Anthony Koslow. 20 Management and conservation of seamounts. P. Keith Probert, Sabine Christiansen, Kristina M. Gjerde, Susan Gubbay and Ricardo S. Santos. 21 The depths of ignorance: an ecosystem evaluation framework for seamount ecology, fisheries and conservation. Tony J. Pitcher, Telmo Morato, Paul J.B. Hart, Malcolm R. Clark, Nigel Haggan and Ricardo S. Santos

Robotic ocean vehicles for marine science applications: the European ASIMOV project

The key objective of the ASIMOV project is the development and integration of advanced technological systems to achieve coordinated operation of an Autonomous Surface Craft (ASC) and an Autonomous Underwater Vehicle (AUV) while ensuring a fast communication link between the two vehicles. The ASC/AUV ensemble is being used to study the extent of shallow water hydrothermalism and to determine the patterns of community diversity at vents in the D. Joao de Castro (DJC) bank in the Azores.

Length–weight relationships for 21 coastal fish species of the Azores, north-eastern Atlantic

Abstract Length–weight relationships were estimated for 21 coastal fish species of the Azores, namely Abudefduf luridus, Bothus podas, Chromis limbata, Coris julis, Diplodus sargus, Echiichthys vipera, Gaidropsarus guttatus, Labrus bergylta, Mullus surmuletus, Phycis phycis, Pomatomus saltator, Sarda sarda, Scorpaena maderensis, Scorpaena notata, Seriola rivoliana, Serranus atricauda, Sparisoma cretense, Sphyraena viridensis, Synodus saurus, Thalassoma pavo and Trachinotus ovatus . Significant length–weight relationships were found for all species. Sexual dimorphism did not affect the length–weight relationships, except in the cases of S. cretense and C. julis . Length–length equations for converting size measurements (standard length (SL) and fork length (FL) to total length (TL)) are also presented for all fish species.

The role of androgens in the trade-off between territorial and parental behavior in the Azorean rock-pool blenny, Parablennius parvicornis

Androgen hormones have been shown to facilitate competitive ability in courtship and territorial behavior, while suppressing paternal behavior. The rock-pool blenny, Parablennius parvicornis, provides an excellent model to study the proximate regulation of such a trade-off between territorial and parental behavior, because nest-holder males of this species display these behaviors simultaneously. A field study was carried out in which territorial nest holder males were either treated with long-lasting implants filled with 11-ketotestosterone (11-KT) or with control implants. Males treated with 11-KT showed a higher frequency of aggressive behavior, were more responsive to aggressive challenges, and were more persistent in aggressive behavior than control males. In addition, territories were larger in males treated with 11-KT than in controls. We found evidence for incompatibility between defense of a large territory and high levels of parental behavior. However, contrary to expectation, 11-KT did not suppress parental behavior. We suggest that trade-offs between territorial and parental behavior may not be regulated by androgen hormones but may result from a time constraint in the individuals activity budget.

Non-indigenous marine species of the Azores

Marine benthic species introduced to the Azores are collated from scientific publications, internal reports and own data. Twelve algae and 21 invertebrates are classified as non-indigenous species, 18 as cryptogenic. Two species of algae and two ascidians are regarded as particularly invasive along the shores of this oceanic archipelago.

High gene flow in oceanic bottlenose dolphins ( Tursiops truncatus ) of the North Atlantic

Despite the openness of the oceanic environment, limited dispersal and tight social structure often induce genetic structuring in marine organisms, even in large animals such as cetaceans. In the bottlenose dolphin, mitochondrial and nuclear DNA analyses have revealed the existence of genetic differentiation between pelagic (or offshore) and coastal (or nearshore) ecotypes in the western North Atlantic, as well as between coastal populations. Because previous studies concentrated on continental margins, we analysed the population structure of bottlenose dolphins in two of the most isolated archipelagos of the North Atlantic: the Azores and Madeira. We analysed 112 samples collected on live animals in the two archipelagos, and nine samples collected on stranded animals in Madeira and mainland Portugal. Genetic analyses consisted in molecular sexing, sequencing of part of the mitochondrial hyper-variable region, and screening of ten microsatellite loci. We predicted that: (1) there is at least one pelagic and one or more coastal populations in each archipelago; (2) populations are differentiated between and possibly within archipelagos. Contrary to these predictions, results indicated a lack of population structure in the study area. In addition, comparison with published sequences revealed that the samples from the Azores and Madeira were not significantly differentiated from samples of the pelagic population of the western North Atlantic. Thus, bottlenose dolphins occurring in the pelagic waters of the North Atlantic belong to a large oceanic population, which should be regarded as a single conservation unit. Unlike what is known for coastal populations, oceanic bottlenose dolphins are able to maintain high levels of gene flow.

North Atlantic blue and fin whales suspend their spring migration to forage in middle latitudes: building up energy reserves for the journey?

The need to balance energy reserves during migration is a critical factor for most long-distance migrants and an important determinant of migratory strategies in birds, insects and land mammals. Large baleen whales migrate annually between foraging and breeding sites, crossing vast ocean areas where food is seldom abundant. How whales respond to the demands and constraints of such long migrations remains unknown. We applied a behaviour discriminating hierarchical state-space model to the satellite tracking data of 12 fin whales and 3 blue whales tagged off the Azores, to investigate their movements, behaviour (transiting and area-restricted search, ARS) and daily activity cycles during the spring migration. Fin and blue whales remained at middle latitudes for prolonged periods, spending most of their time there in ARS behaviour. While near the Azores, fin whale ARS behaviour occurred within a restricted area, with a high degree of overlap among whales. There were noticeable behavioural differences along the migratory pathway of fin whales tracked to higher latitudes: ARS occurred only in the Azores and north of 56°N, whereas in between these areas whales travelled at higher overall speeds while maintaining a nearly direct trajectory. This suggests fin whales may alternate periods of active migration with periods of extended use of specific habitats along the migratory route. ARS behaviour in blue whales occurred over a much wider area as whales slowly progressed northwards. The tracks of these whales terminated still at middle latitudes, before any behavioural switch was detected. Fin whales exhibited behavioural-specific diel rhythms in swimming speed but these varied significantly between geographic areas, possibly due to differences in the day-night cycle across areas. Finally, we show a link between fin whales seen in the Azores and those summering in eastern Greenland-western Iceland along a migratory corridor located in central Atlantic waters.

Context-Aware Emotion-Based Model for Group Decision Making

This context-aware emotion-based model can help design intelligent agents for group decision making processes. Experiments show that agents with emotional awareness reach agreement more quickly than those without it.

Extreme diving behaviour in devil rays links surface waters and the deep ocean

Ecological connections between surface waters and the deep ocean remain poorly studied despite the high biomass of fishes and squids residing at depths beyond the euphotic zone. These animals likely support pelagic food webs containing a suite of predators that include commercially important fishes and marine mammals. Here we deploy pop-up satellite archival transmitting tags on 15 Chilean devil rays (Mobula tarapacana) in the central North Atlantic Ocean, which provide movement patterns of individuals for up to 9 months. Devil rays were considered surface dwellers but our data reveal individuals descending at speeds up to 6.0 m s−1 to depths of almost 2,000 m and water temperatures <4 °C. The shape of the dive profiles suggests that the rays are foraging at these depths in deep scattering layers. Our results provide evidence of an important link between predators in the surface ocean and forage species occupying pelagic habitats below the euphotic zone in ocean ecosystems.

Enrichment in trace metals (Al, Mn, Co, Cu, Mo, Cd, Fe, Zn, Pb and Hg) of macro-invertebrate habitats at hydrothermal vents along the Mid Atlantic Ridge

The present study describes several features of the aquatic environment with the emphasis on the total vs. filter-passing fraction (FP) of heavy metals in microhabitats of two typical deep-sea vent organisms: the filter-feeder, symbiont-bearing Bathymodiolus and the grazer shrimps Rimicaris/Mirocaris from the Mid-Atlantic Ridge (MAR). The concentration of 10 trace elements: Al, Mn, Co, Cu, Mo, Cd, Fe, Zn, Pb and Hg was explored highlighting common and distinctive features among the five hydrothermal vent sites of the MAR: Menez Gwen, Lucky Strike, Rainbow, Saldanha, and Menez Hom that are all geo-chemically different when looking at the undiluted hydrothermal fluid composition. The drop off in the percentage of FP from total metal concentration in mussel and/or shrimp inhabited water samples (in mussel beds at Rainbow, for instance, FP fraction of Fe was below 23%, Zn 24 %, Al 65%, Cu 70%, and Mn 89%) as compared to non-inhabited areas (where 94% of the Fe, 90% of the Zn, 100% of the other metals was in the FP fraction) may indicate an influence of vent organisms on their habitat’s chemistry, which in turn may determine adaptational strategies to elevated levels of toxic heavy metals. Predominance of particulate fraction over the soluble metals, jointly with the morphological structure and elemental composition of typical particles in these vent habitats suggest a more limited metal bioavailability to vent organisms as previously thought. In addition, it is evoked that vent invertebrates may have developed highly efficient metal-handling strategies targeting particulate phase of various metals present in the mixing zones that enables their survival under these extreme conditions.