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IMBeR Newsletter
Your news from the Integrated Marine Biosphere Research International Project Office
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Building Successful International Summer Schools to Enhance the Capacity of Marine Early Career Researchers | |
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Author: Christopher Cvitanovic, Jessica Blythe, Ingrid van Putten, Lisa Maddison, Laurent Bopp, Stephanie Brodie, Elizabeth A. Fulton, Priscila F. M. Lopes, Gretta Pecl, Jerneja Penca & U. Rashid Sumaila
Journal: Ocean and Society
The development of informal science learning programs is a key strategy for supplementing traditional training for early career researchers (ECR). Within the marine sector, there has been a proliferation of international summer schools (a form of informal science learning program) to support ECRs to develop the networks, skills, and attributes needed to tackle ocean sustainability challenges and support the attainment of the Sustainable Development Goals (e.g., collaboration across disciplines, policy engagement, etc.). Yet, there exists very little evidence on the impact generated by such informal science learning programs or the design strategies that can confer their success. This commentary seeks to address this knowledge gap by considering the successful biennial Climate and Ecosystems (ClimEco) marine summer school series that has run since 2008. Specifically, we draw on the perspectives of lecturers and organisers, in combination with a survey of ClimEco participants (n = 38 ECRs) to understand the drivers and motivations of ECRs to attend summer schools, the types of outcomes and impacts that summer schools can have for marine ECRs, and the key factors that led to the successful attainment of these impacts, outcomes, and benefits. In doing so, we develop guidance that would enable global summer school convenors to effectively support the next generation of marine researchers to advance ocean sustainability.
Click to read the full paper
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Fig.1: Motivations of participants for attending ClimEco summer schools.
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This month’s Editor Picks bring forward eight studies offering insights on marine ecosystem dynamics, climate-driven transformations, and strategies for sustainable management. Research on Antarctic and Arctic giant viruses, based on metagenome-assembled genomes, identifies unique cold-adapted traits in virus populations potentially affected by climate warming. In the Baltic Sea, simulations of nutrient load reduction show that efforts have mitigated eutrophication severity but emphasize the importance of sustained nutrient management. Long-term data from the Sargasso Sea demonstrates subsurface phytoplankton biomass increases in response to warming, underscoring the need for comprehensive monitoring beyond satellite observations. Whale shark tracking data predict distribution shifts that may increase co-occurrence with shipping routes under high-emission scenarios. In the Barents Sea, trials with artificial lighting reveal that haddock, saithe, and redfish respond differently to red and white light, information valuable for selective fishing design, while cod show no response. A global synthesis on deep-pelagic fish biodiversity introduces the concept of 'diel-modulated realized niche' for better modeling of ecological diversity in pelagic fishes. A new method using isotopes and hydrodynamic models maps sardine migration, accurately depicting seasonal fish movement patterns. Arctic fish population modeling among Atlantic cod, capelin, and polar cod indicates that sea ice loss may favor capelin, potentially altering food web dynamics.
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Adaptation strategies of giant viruses to
low-temperature marine ecosystems
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Authors: Marianne Buscaglia, José Luis Iriarte, Frederik Schulz, Beatriz Díez
Journal: The ISME Journal
Microbes in marine ecosystems have evolved their gene content to thrive successfully in the cold. Although this process has been reasonably well studied in bacteria and selected eukaryotes, less is known about the impact of cold environments on the genomes of viruses that infect eukaryotes. Here, we analyzed cold adaptations in giant viruses (Nucleocytoviricota and Mirusviricota) from austral marine environments and compared them with their Arctic and temperate counterparts. We recovered giant virus metagenome-assembled genomes (98 Nucleocytoviricota and 12 Mirusviricota MAGs) from 61 newly sequenced metagenomes and metaviromes from sub-Antarctic Patagonian fjords and Antarctic seawater samples. When analyzing our data set alongside Antarctic and Arctic giant viruses MAGs already deposited in the Global Ocean Eukaryotic Viral database, we found that Antarctic and Arctic giant viruses predominantly inhabit sub-10°C environments, featuring a high proportion of unique phylotypes in each ecosystem. In contrast, giant viruses in Patagonian fjords were subject to broader temperature ranges and showed a lower degree of endemicity. However, despite differences in their distribution, giant viruses inhabiting low-temperature marine ecosystems evolved genomic cold-adaptation strategies that led to changes in genetic functions and amino acid frequencies that ultimately affect both gene content and protein structure. Such changes seem to be absent in their mesophilic counterparts. The uniqueness of these cold-adapted marine giant viruses may now be threatened by climate change, leading to a potential reduction in their biodiversity.
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|  | Fig. 2: Temperature- and geography-driven distribution of giant viruses from cold marine environments. Distribution of Nucleocytoviricota or Mirusviricota MAGs from the Arctic (GOEV database), Antarctic (this study + GOEV database), and Patagonian fjords (this study). The X-axis corresponds to metagenomes, and the Y-axis corresponds to GVMAGs. The MAG source indicates where the GVMAG was obtained (Antarctic, Arctic, or Patagonian marine samples), whereas the metagenome source indicates where the metagenome was obtained (Antarctic, Arctic, Patagonian, or temperate marine samples). All GVMAGs were obtained either from the pico-size fraction (0.2–3 μm) or, when generated from co-assemblies, had a metagenomic signal of more than 70% in the pico-size-like fraction (0.2–5 μm) (summarized in Fig. S2) [9]. To analyze giant virus distribution, read mapping was conducted using pico-size metagenomes from this study and public databases, covering a temperature range of −1.4°C to 30°C. A GVMAG was considered present in a sample if it had an average read depth of 2X along at least 70% of the MAG length; otherwise, it was treated as absent. |  | |
Fig. 4: Upper panel: Conceptual illustration of the steps and time-lags related to eutrophication control in the Baltic Sea exemplified with time-series of P variables: total P inputs peaked in the 1980s (a), but the pool of P in water and surface sediments continued to accumulate until the 2000s (b), and eutrophication symptoms like surface total P concentrations in the Baltic Proper peaked in the last decade (c). Note that y-axes do not start at 0. Lower panel: Examples of the development of nutrient loads to coastal systems over time from different continents. Loads are shown 5-yr average input of N (d) and P (e) divided by catchment area. The map insert shows the location of the three systems: loads to the Gulf of Mexico from the Mississippi river and it tributary the Atchafalaya (Turner and Rabalais 1991; Lee 2023), to the Baltic Sea from all major rivers in the catchment (Gustafsson et al. 2012, this study) and to the East China Sea from the Changjiang (Yangtze) river (Wu et al. 2023). Note that Changjiang loads only include inorganic nutrients (DIN and DIP), while for the other systems, total N and P loads are given. See accompanying dataset (Gustafsson and Ehrnsten 2024) for details on the data. | |
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Climate-driven global redistribution of
an ocean giant predicts increased threat from shipping
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Authors: Freya C. Womersley, Lara L. Sousa, Nicolas E. Humphries, Kátya Abrantes, Gonzalo Araujo, Steffen S. Bach, Adam Barnett, Michael L. Berumen, Sandra Bessudo Lion, Camrin D. Braun, Elizabeth Clingham, Jesse E. M. Cochran, Rafael de la Parra, Stella Diamant, Alistair D. M. Dove, Carlos M. Duarte, Christine L. Dudgeon, Mark V. Erdmann, Eduardo Espinoza, Luciana C. Ferreira, Richard Fitzpatrick, Jaime González Cano, Jonathan R. Green, Hector M. Guzman, Royale Hardenstine, Abdi Hasan, Fábio H. V. Hazin, Alex R. Hearn, Robert E. Hueter, Mohammed Y. Jaidah, Jessica Labaja, Felipe Ladino, Bruno C. L. Macena, Mark G. Meekan, John J. Morris Jr., Bradley M. Norman, Cesar R. Peñaherrera-Palma, Simon J. Pierce, Lina Maria Quintero, Dení Ramírez-Macías, Samantha D. Reynolds, David P. Robinson, Christoph A. Rohner, David R. L. Rowat, Ana M. M. Sequeira, Marcus Sheaves, Mahmood S. Shivji, Abraham B. Sianipar, Gregory B. Skomal, German Soler, Ismail Syakurachman, Simon R. Thorrold, Michele Thums, John P. Tyminski, D. Harry Webb, Bradley M. Wetherbee, Nuno Queiroz & David W. Sims
Journal: Nature Climate Change
Climate change is shifting animal distributions. However, the extent to which future global habitats of threatened marine megafauna will overlap existing human threats remains unresolved. Here we use global climate models and habitat suitability estimated from long-term satellite-tracking data of the world’s largest fish, the whale shark, to show that redistributions of present-day habitats are projected to increase the species’ co-occurrence with global shipping. Our model projects core habitat area losses of >50% within some national waters by 2100, with geographic shifts of over 1,000 km (∼12 km yr−1). Greater habitat suitability is predicted in current range-edge areas, increasing the co-occurrence of sharks with large ships. This future increase was ∼15,000 times greater under high emissions compared with a sustainable development scenario. Results demonstrate that climate-induced global species redistributions that increase exposure to direct sources of mortality are possible, emphasizing the need for quantitative climate-threat predictions in conservation assessments of endangered marine megafauna.
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|  | Fig. 5: Future redistributions in the context of global shipping. a, Projected change in habitat suitability from baseline (absolute, 2005–2019) for 14 LMEs defined as medium importance, in which the result from a Kruskal–Wallis rank-sum test is shown at top left (χ² = 32.00, P = 5.93 × 10−6). Circles denote individual LME values, the thick line denotes the median and boxes bound the interquartile range (25th to 75th percentile), with whiskers extending to the maximum and minimum values. Upper and lower boundaries of violin plots extend to the maximum and minimum values, respectively, and width represents the density of observations. b, Global distribution of areas of high (yellow) and low (purple) shipping traffic density defined as the total count of vessels from a 2019 monthly average. c–e, These areas are shown in close-up in c–e, respectively. c–e, Areas of high (yellow) and low (purple) shipping traffic density from a 2019 monthly average (left) and areas of habitat suitability gain (red) and loss (blue) predicted from GAMs (right) shown in the national waters in the United States of America, marine region identification (ID), US part of the north Pacific Ocean (c); Sierra Leone, marine region ID, Sierra Leonian part of the north Atlantic Ocean (d); Japan, marine region ID, Japanese part of the eastern China Sea (e). |  | |
Simple visualization of fish migration history based on
high-resolution otolith δ18O profiles and hydrodynamic models
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Authors: Tatsuya Sakamoto
Journal: Limnology and Oceanography Letters
Oxygen-stable isotope (δ18O) in otoliths has been useful to infer marine fish migrations. However, because otolith δ18O is affected by two parameters, temperature and δ18O of ambient water, its interpretation becomes challenging when neither of them is constant. Here, I describe a simple method using hydrodynamic models to visualize potential migration histories from high-resolution otolith δ18O chronologies. By predicting the distribution of potential otolith δ18O, that is, otolith δ18O isoscape from modeled temperature and salinity distributions and comparing these with observed values, possible fish locations can be inferred. The demonstration of sardine juveniles in the western North Pacific region reproduced their seasonal northward migrations accurately. The predicted locations were consistent with the results of sampling surveys of eggs and juveniles and correctly approached the point where fish were caught. The methodological recommendations and the successful demonstration in this study may help in planning future sclerochronology research using carbonate δ18O values.
Click to read the full paper
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Fig. 6: Schematic of the method using a data assimilation model to estimate fish migration history from otolith δ18O value. | |
Deep-pelagic fishes are anything but similar: A global synthesis | |
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Authors: Leandro Nolé Eduardo, Michael Maia Mincarone, Tracey Sutton, Arnaud Bertrand
Journal: Ecology Letters
Deep-pelagic fishes are among the most abundant vertebrates on Earth. They play a critical role in sequestering carbon, providing prey for harvestable fishing stocks and linking oceanic layers and trophic levels. However, knowledge of these fishes is scarce and fragmented, hampering the ability of both the scientific community and stakeholders to address them effectively. While modelling approaches incorporating these organisms have advanced, they often oversimplify their functional and ecological diversity, potentially leading to misconceptions. To address these gaps, this synthesis examines the biodiversity and ecology of global deep-pelagic fishes. We review pelagic ecosystem classifications and propose a new semantic framework for deep-pelagic fishes. We evaluate different sampling methods, detailing their strengths, limitations and complementarities. We provide an assessment of the world's deep-pelagic fishes comprising 1554 species, highlighting major groups and discussing regional variability. By describing their morphological, behavioural and ecological diversity, we show that these organisms are far from homogeneous. Building on this, we call for a more realistic approach to the ecology of deep-pelagic fishes transitioning between very different ecological niches during diel vertical migrations. To facilitate this, we introduce the concept of 'diel-modulated realised niche' and propose a conceptual model synthesising the multiple drivers responsible for such transitions.
Click to read the full paper
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Interaction between three key species
in the sea ice-reduced Arctic Barents Sea system
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Authors: Joël M. Durant, Nicolas Dupont, Kotaro Ono & Øystein Langangen
Journal: Proceedings of the Royal Society B
Population dynamics depend on trophic interactions that are affected by climate change. The rise in sea temperature is associated with the disappearance of sea ice in the Arctic. In the Arctic part of the Barents Sea, Atlantic cod, capelin and polar cod are three fish populations that interact and are confronted with climate-induced sea ice reductions. The first is a major predator in the system, while the last two are key species in Arctic and sub-Arctic ecosystems, respectively. There are still many unknowns regarding how predicted environmental change may influence the joint dynamics of these populations. Using time series from a 32 year long survey, we developed a state-space model that jointly modelled the dynamics of cod, capelin and polar cod. Using a hindcast scenario approach, we projected the effect of reduced sea ice on these populations. We show that the impact of sea ice reduction and concomitant sea temperature increase may lead to a decrease of polar cod abundance at the benefit of capelin but not of cod which may decrease, resulting in strong changes in the food web. Our analyses show that climate change in the Arcto-boreal system can generate different species assemblages and new trophic interactions, which is the knowledge needed for effective management measures.
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|  | Fig. 7: Approximate feeding distributions in the Barents Sea of northeast Arctic cod (grey), capelin (red) and polar cod (green). The map is redrawn from [32]. | |
Observing fish behavior in towed fishing gear -
is there an influence of artificial light?
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Authors: Jesse Brinkhof, Manu Sistiaga, Bent Herrmann, Junita D. Karlsen, Eduardo Grimaldo, Nadine Jacques & Zita Bak-Jensen
Journal: Reviews in Fish Biology and Fisheries
Fish behavior is important to consider when developing selective fishing gear. In studies designed to investigate the size selective properties of towed fishing gears such as trawls, fish behavior is mainly documented by underwater video recordings. Because fishing gear can be operated at great depths or in other low light environments, artificial light is often required for underwater recordings. However, artificial light can influence fish behavior, which casts doubt on the validity of behavioral observations obtained in the presence of artificial light. However, removing artificial light disables video recordings and the possibility to study fish behavior in relation to selectivity devices towed fishing gears in low light environments. To date, little is known about the extent to which artificial light used for video observations affects fish behavior with respect to fishing gear. Therefore, we conducted fishing trials in the Barents Sea demersal trawl fishery to assess the effect of light sources on fish behavior by using size selectivity results in towed fishing gears. We found that the behavior of cod (Gadus morhua) was unaffected by the light sources, whereas the behavior of haddock (Melanogrammus aeglefinus), saithe (Pollachius virens) and redfish (Sebastes spp.) significantly changed when red light and white light were employed. Our results also demonstrated significant differences in fish behavior between white and red light.
Click to read the full paper
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Fig. 8: Schematic overview of the assessment method used to determine if fish behavior related to size selectivity is affected by artificial light. | |
Events, Webinars and Conferences | |
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Information shared by our contacts:
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Forum on the Progress Analysis of China-Europe Ocean Science & Technology (CAS-EurASc Frontier Forum), 18-19 November 2024, Shanghai, China & online. Please stay tuned for more details!
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Information shared by our contacts:
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If you would like to put some recruitment information in the IMBeR monthly newsletter, please contact us through imber@ecnu.edu.cn. | |
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Contact us
IMBeR International Project Office
State Key Laboratory of Estuarine and Coastal Research, East China Normal University
500 Dongchuan Rd., Shanghai 200241, China
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