Influence of environmental parameters on movements and habitat utilization of humpback whales (Megaptera novaeangliae) in the Madagascar breeding ground

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Royal Society Open Science 3 (2016): 160616, doi:10.1098/rsos.160616.Assessing the movement patterns and key habitat features of breeding humpback whales is a prerequisite for the conservation management of this philopatric species. To investigate the interactions between humpback whale movements and environmental conditions off Madagascar, we deployed 25 satellite tags in the northeast and southwest coast of Madagascar. For each recorded position, we collated estimates of environmental variables and computed two behavioural metrics: behavioural state of ‘transiting’ (consistent/directional) versus ‘localized’ (variable/non-directional), and active swimming speed (i.e. speed relative to the current). On coastal habitats (i.e. bathymetry < 200 m and in adjacent areas), females showed localized behaviour in deep waters (191 ± 20 m) and at large distances (14 ± 0.6 km) from shore, suggesting that their breeding habitat extends beyond the shallowest waters available close to the coastline. Males' active swimming speed decreased in shallow waters, but environmental parameters did not influence their likelihood to exhibit localized movements, which was probably dominated by social factors instead. In oceanic habitats, both males and females showed localized behaviours in shallow waters and favoured high chlorophyll-a concentrations. Active swimming speed accounts for a large proportion of observed movement speed; however, breeding humpback whales probably exploit prevailing ocean currents to maximize displacement. This study provides evidence that coastal areas, generally subject to strong human pressure, remain the core habitat of humpback whales off Madagascar. Our results expand the knowledge of humpback whale habitat use in oceanic habitat and response to variability of environmental factors such as oceanic current and chlorophyll level.Funding was provided by Total Foundation to NeuroPSI, and by individuals and foundations to the WCS Ocean Giants Program

A molecular phylogenetic appraisal of the systematics of the Aglaopheniidae (Cnidaria: Hydrozoa, Leptothecata) from the north-east Atlantic and west Mediterranean

The hydrozoan family Aglaopheniidae (Cnidaria) is widespread worldwide and contains some of the most easily recognizable hydroids because of their large colony size and characteristic microscopic structure. The systematics of the group has, however, been controversial and dedicated molecular analyses are lacking. We therefore analysed existing and new 16S rRNA sequences of Aglaopheniidae, in a total of 98 16S sequences corresponding to 25 putative species (25 nominal and three undescribed) from seven genera. The monophyly of the subfamilies Gymnangiinae and Aglaopheniinae, and tribes Aglaopheniini and Cladocarpini were not verified with 16S sequence data. The genera Gymnangium and Aglaophenia can only be considered valid if both Gymnangium gracicaule and Aglaophenia latecarinata are removed from their respective genera. The phenotypically similar Cladocarpus and Streptocaulus are probably monophyletic and clearly distinct genetically. The genus Lytocarpia may be polyphyletic. The nominal species Aglaophenia pluma, Aglaophenia tubiformis, and Aglaophenia octodonta are probably conspecific, as are also the species Aglaophenia acacia and Aglaophenia elongata. The 16S data revealed the existence of two potentially unnamed species of Aglaophenia respectively from the Azores and Madeira. The phylogeographical structure of the taxa with the greatest representation of haplotypes from the north-east Atlantic and Mediterranean, revealed the influence of Mediterranean waters in Madeira and the Azores, and gene flow between deep waters of the Mediterranean and Atlantic. The last glaciations in Europe may have caused genetic bottlenecks but also high intraspecific haplotype diversity. Finally, Macrorhynchia philippina was detected in samples from Madeira and possibly represents an invasive species. © 2012 The Linnean Society of London

The Builders of the Oceans – Part I: Coral Architecture from the Tropics to the Poles, from the Shallow to the Deep

At any scale, corals are live buildings. Their carbonate skeletons constitute three-dimensional frameworks allowing the delicate coral polyp to emerge from the sea bottom and populate vast areas of the ocean. These constructions, reminders of the structural complexity found in the forest, are found everywhere in the Earth’s oceans, from the polar regions to the tropics and from the tidal pools to the dark abyssal plains. They can be found as solitary or in modest aggregations of a few centimeters in size or gargantuan colonies of mythological proportions; when many, they can create the largest nonhuman structures built by organisms. Life and death of the coral “trees” are influenced by the mineral architecture and the presence of bioeroders. Shape and size facilitate or restrict their access to food and light and influence structural strength tested by currents and swells. The role that corals play in the oceans defies any attempt at simplification since it transcends the life span of the small polyp, geological time, and ecological space. Long after the polyps are gone, coral skeletons continue to harbor numerous organisms of disparate nature by overgrowing, drilling, and dissolving the carbonates. These chapters are a personal journey into the coral forest of the world’s oceans, with stations along singular aspects of their present and past. Our point of departure is the ecosystem engineering of the coral polyp through the construction of its skeleton, followed by selected examples of human interactions with the “stone from the sea” ( see Chapter “The Builders of the Oceans – Part II: Corals from the Past to the Present (The Stone from the Sea)