Developing twenty-first century skills: insights from an intensive interdisciplinary workshop Mosaic of Life

The Baltic Sea, one of the world’s largest semi-enclosed seas, which, with its very low salinity and quasi-isolation from the big oceans cannot decide whether it is a sea or a large lake. This geologically-unique environment supports an even more surprising and delicate marine ecosystem, where a complex community of fishes, marine mammals and important microscopic organisms creates a magical mosaic of life. Humans have enjoyed the abundance of life in the Baltic Sea for thousands of years, and major Scandinavian and Baltic cities have oriented themselves towards this geo-ecosystem in order to develop and seek ecological, economical and cultural inspiration and wealth. The ‘Mosaic of Life’ workshop aimed at going beyond the obvious in examining the meaning of the Baltic Sea by gathering together a selection of young, creative minds from different backgrounds ranging from the arts and economics to geology and life sciences. This intensive workshop was designed as a unique training opportunity to develop essential twenty-first century skills – to introduce and develop creative, critical and interdisciplinary thinking and collaborative teamwork, as well as to foster a visual and scientific literacy, using project-based learning and hands-on activities. Our final goal has been to be inspired by the resulting connections, differences and unifying concepts, creating innovative, interdisciplinary projects which would look further than the sea – further than the eye can see and further into the future

Spatial and temporal variation in the predicted dispersal of marine larvae around coastal Aotearoa New Zealand

IntroductionPatterns of larval dispersal in the marine environment have many implications for population dynamics, biodiversity, fisheries, ecosystem function, and the effectiveness of marine protected areas. There is tremendous variation in factors that influence the direction and success of marine larval dispersal, making accurate prediction exceedingly difficult. The key physical factor is the pattern of water movement, while two key biological factors are the amount of time larvae spend drifting in the ocean (pelagic larval duration - PLD) and the time of the year at which adult populations release larvae. Here, we assess the role of these factors in the variation of predicted larval dispersal and settlement patterns from 15 locations around Aotearoa New Zealand.MethodsThe Moana Project Backbone circulation model paired with OpenDrift was used to simulate Lagrangian larval dispersal in the ocean with basic vertical control across four differing PLD groups (7, 14, 30, and 70 days) for each of twelve months. ResultsConsiderable variation was observed in the pattern of particle dispersal for each major variable: release location, PLD group, and the month of release. As expected, dispersal distances increased with PLD length, but the size of this effect differed across both release location and month. Increased and directional particle dispersal matched some expectations from well-known currents, but surprisingly high self-recruitment levels were recorded in some locations.DiscussionThese predictions of larval dispersal provide, for the first time, an empirical overview of coastal larval dispersal around Aoteaora New Zealand’s main islands and highlight potential locations of “barriers” to dispersal. This dataset should prove valuable in helping predict larval connectivity across a broad range of species in this environment for diverse purposes

Mesoscale eddies influence the movements of mature female white sharks in the Gulf Stream and Sargasso Sea

© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 8 (2018): 7363, doi:10.1038/s41598-018-25565-8.Satellite-tracking of mature white sharks (Carcharodon carcharias) has revealed open-ocean movements spanning months and covering tens of thousands of kilometers. But how are the energetic demands of these active apex predators met as they leave coastal areas with relatively high prey abundance to swim across the open ocean through waters often characterized as biological deserts? Here we investigate mesoscale oceanographic variability encountered by two white sharks as they moved through the Gulf Stream region and Sargasso Sea in the North Atlantic Ocean. In the vicinity of the Gulf Stream, the two mature female white sharks exhibited extensive use of the interiors of clockwise-rotating anticyclonic eddies, characterized by positive (warm) temperature anomalies. One tagged white shark was also equipped with an archival tag that indicated this individual made frequent dives to nearly 1,000 m in anticyclones, where it was presumably foraging on mesopelagic prey. We propose that warm temperature anomalies in anticyclones make prey more accessible and energetically profitable to adult white sharks in the Gulf Stream region by reducing the physiological costs of thermoregulation in cold water. The results presented here provide valuable new insight into open ocean habitat use by mature, female white sharks that may be applicable to other large pelagic predators.This work was supported by the WHOI Ocean Life Institute and awards from NASA and NSF

Small phytoplankton dominate western North Atlantic biomass

The North Atlantic phytoplankton spring bloom is the pinnacle in an annual cycle that is driven by physical, chemical, and biological seasonality. Despite its important contributions to the global carbon cycle, transitions in plankton community composition between the winter and spring have been scarcely examined in the North Atlantic. Phytoplankton composition in early winter was compared with latitudinal transects that captured the subsequent spring bloom climax. Amplicon sequence variants (ASVs), imaging flow cytometry, and flow-cytometry provided a synoptic view of phytoplankton diversity. Phytoplankton communities were not uniform across the sites studied, but rather mapped with apparent fidelity onto subpolar- and subtropical-influenced water masses of the North Atlantic. At most stations, cells < 20-µm diameter were the main contributors to phytoplankton biomass. Winter phytoplankton communities were dominated by cyanobacteria and pico-phytoeukaryotes. These transitioned to more diverse and dynamic spring communities in which pico- and nano-phytoeukaryotes, including many prasinophyte algae, dominated. Diatoms, which are often assumed to be the dominant phytoplankton in blooms, were contributors but not the major component of biomass. We show that diverse, small phytoplankton taxa are unexpectedly common in the western North Atlantic and that regional influences play a large role in modulating community transitions during the seasonal progression of blooms

Developing twenty-first century skills: insights from an intensive interdisciplinary workshop Mosaic of Life

Tamara Milosevic, PhD, is a curriculum designer on the bachelor’s programme ‘Frontiers in Life Science’ at Paris Descartes University, France. In parallel with her postdoctoral research on learning through research methods in higher education, she is teaching several intensive, project-based courses at the undergraduate level. She finished her master’s studies in biology at Zagreb University in 2006 and completed her PhD in interdisciplinary life sciences at Paris Descartes University in 2011. She has since then been actively involved in innovative science education and teaching transversal skills. She is focused on designing courses aimed at developing critical thinking, creativity, interdisciplinary connections and project-based learning. She has international experience in managing projects and groups and organizing events and activities of different profiles (clubs, associations, workshops, symposia, international projects, administrative/research/teaching coordination teams). Alice Della Penna, M.S., is a PhD student in Marine Science between LOCEAN (Paris, France) and University of Tasmania (Hobart, Australia) through the interdisciplinary life sciences Frontieres du Vivant programme. Besides her research interests in marine biology and oceanography, she is interested in science communication through science interactive exhibits and workshops in schools and interdisciplinarity.The Baltic Sea, one of the world’s largest semi-enclosed seas, which, with its very low salinity and quasi-isolation from the big oceans cannot decide whether it is a sea or a large lake. This geologically-unique environment supports an even more surprising and delicate marine ecosystem, where a complex community of fishes, marine mammals and important microscopic organisms creates a magical mosaic of life. Humans have enjoyed the abundance of life in the Baltic Sea for thousands of years, and major Scandinavian and Baltic cities have oriented themselves towards this geo-ecosystem in order to develop and seek ecological, economical and cultural inspiration and wealth. The ‘Mosaic of Life’ workshop aimed at going beyond the obvious in examining the meaning of the Baltic Sea by gathering together a selection of young, creative minds from different backgrounds ranging from the arts and economics to geology and life sciences. This intensive workshop was designed as a unique training opportunity to develop essential twenty-first century skills – to introduce and develop creative, critical and interdisciplinary thinking and collaborative teamwork, as well as to foster a visual and scientific literacy, using project-based learning and hands-on activities. Our final goal has been to be inspired by the resulting connections, differences and unifying concepts, creating innovative, interdisciplinary projects which would look further than the sea – further than the eye can see and further into the future

Mesoscale Eddies Structure Mesopelagic Communities

Mesoscale eddies play a key role in structuring open ocean ecosystems, affecting the entire trophic web from primary producers to large pelagic predators including sharks and elephant seals. Recent advances in the tracking of pelagic predators have revealed that these animals forage in the mesopelagic and the depth and duration of their foraging dives are affected by the presence of eddies. The ways in which eddies impact the distribution of mesopelagic micronekton, however, remain largely unknown. During a multi-seasonal experiment we used a shipboard scientific echosounder transmitting at 38 kHz to observe the distribution of acoustic backscattering in the energetic mesoscale eddy field of the northwestern Atlantic. Observations were collected at 24 stations with 6 located in anticyclonic and 7 in cyclonic eddies. The sampled anticyclonic eddies are characterized by intense acoustic backscattering in the mesopelagic and changes in the intensity of acoustic backscattering layers match gradients of surface properties. Furthermore, mesopelagic daytime backscattering is positively correlated with sea level anomaly. These results suggest that anticyclonic eddies in the northwestern Atlantic impact the distribution of mesopelagic micronekton and may have the potential to locally enhance or structure spatially mesopelagic communities

Overview of (Sub)mesoscale Ocean Dynamics for the NAAMES Field Program

WOS:000476485000001International audienc

Determining the influence of mesoscale eddies on near-surface currents and phytoplankton populations in the mixed layer

Trabajo presentado en la Ocean Sciences Meeting, celebrada en San Diego del 16 al 21 de febrero de 2020.Space-born radiometers used to estimate near-surface phytoplankton community properties measure light reflected from the ocean in the visible spectrum. The depth of penetration of electromagnetic radiation in this frequency range is a function of the opacity of the ocean's surface, ranging from a few tens of centimeters in optically-dense water to many tens of meters in clear water. The physical variability of this near-surface strata is primarily wind-driven and is nearly always entirely constrained to the so called surface mixed layer. Yet, the systematic and persistent influence of geostrophic motions, such as eddies and meanders, which dominate variability below the mixed layer, can be observed in ocean color observations, suggesting that the near-surface wind-driven “slab" is permeable, allowing fluxes of biologically relevant quantities to occur in conjunction with mesoscale modulations of the oceans interior. The interaction of the wind-driven ocean’s surface with its' geostrophically-dominated interior has been a topic of much interest in the field of physical oceanography for decades. Multiple dynamically-consistent analytical models exist that can be used to inform the interpretation of ocean color data. Here we present the investigation of how the near-surface, wind-driven “permeable slab'' interacts with the geostorophically-dominated interior ocean by analyzing a global acoustic Doppler current profiler (ADCP) database along with global eddy-resolving data assimilating models in conjunction with the trajectories and characteristics of mesoscale eddies and meanders identified in global maps of sea level anomaly. The goal of this project is to establish a mechanistic understanding of when and where mesoscale eddies modulate and effectively trap the near surface mixed layer.Peer reviewe

Autonomous profiling float observations of the high-biomass plume downstream of the Kerguelen Plateau in the Southern Ocean

International audienceNatural iron fertilisation from Southern Ocean islands results in high primary production and phytoplank-ton biomass accumulations readily visible in satellite ocean colour observations. These images reveal great spatial complexity with highly varying concentrations of chlorophyll, presumably reflecting both variations in iron supply and conditions favouring phytoplankton accumulation. To examine the second aspect, in particular the influences of variations in temperature and mixed layer depth, we deployed four autonomous profiling floats in the Antarctic Circumpo-lar Current near the Kerguelen Plateau in the Indian sector of the Southern Ocean. Each "bio-profiler" measured more than 250 profiles of temperature (T), salinity (S), dissolved oxygen, chlorophyll a (Chl a) fluorescence, and particulate backscattering (b bp) in the top 300 m of the water column, sampling up to 5 profiles per day along meandering trajecto-ries extending up to 1000 km. Comparison of surface Chl a estimates (analogous to values from satellite images) with total water column inventories revealed largely linear relationships , suggesting that these images provide credible information on total and not just surface biomass spatial distributions. However, they also showed that physical mixed layer depths are often not a reliable guide to biomass distributions. Regions of very high Chl a accumulation (1.5-10 µg L −1) were associated predominantly with a narrow T-S class of surface waters. In contrast, waters with only moderate Chl a enrichments (0.5-1.5 µg L −1) displayed no clear correlation with specific water properties, including no dependence on mixed layer depth or the intensity of stratifica-tion. Geostrophic trajectory analysis suggests that both these observations can be explained if the main determinant of biomass in a given water parcel is the time since leaving the Kerguelen Plateau. One float became trapped in a cyclonic eddy, allowing temporal evaluation of the water column in early autumn. During this period, decreasing surface Chl a inventories corresponded with decreases in oxygen inventories on sub-mixed-layer density surfaces, consistent with significant export of organic matter (∼ 35 %) and its respiration and storage as dissolved inorganic carbon in the ocean interior. These results are encouraging for the expanded use of autonomous observing platforms to study biogeochemical, carbon cycle, and ecological problems, although the complex blend of Lagrangian and Eulerian sampling achieved by the floats suggests that arrays rather than single floats will often be required, and that frequent profiling offers important benefits in terms of resolving the role of mesoscale structures on biomass accumulation

Quasi-planktonic behavior of foraging top marine predators

International audienceMonitoring marine top predators is fundamental for assessing the health and functioning of open ocean ecosystems. Although recently tracking observations have substantially increased, factors determining the horizontal exploration of the ocean by marine predators are still largely unknown, especially at the scale of behavioral switches (1–100 km, days-weeks). It is commonly assumed that the influence of water movement can be neglected for animals capable of swimming faster than the current. Here, we challenge this assumption by combining the use of biologging (GPS and accelerometry), satellite altimetry and in-situ oceanographic data (ADCP and drifting buoys) to investigate the effect of the mesoscale ocean dynamics on a marine predator, the southern elephant seal. A Lagrangian approach reveals that trajectories of elephant seals are characterized by quasi-planktonic bouts where the animals are horizontally drifting. These bouts correspond to periods of increased foraging effort, indicating that in the quasi-planktonic conditions energy is allocated to diving and chasing, rather than in horizontal search of favourable grounds. These results suggest that mesoscale features like eddies and fronts may act as a focal points for trophic interactions not only by bottom-up modulation of nutrient injection, but also by directly entraining horizontal displacements of the upper trophic levels