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Published 12.11.2019 - Updated 12.11.2019

The smallest phytoplankton may be bigger than we first thought

The ability of flow cytometry to sort hundreds of thousands of phytoplankton cells in minutes has been used in marine science for over 30 years. However, the differentiation of these cells into different types and then further into size distributions and optical properties still requires the manual interpretation of skilled analysts.

We have developed and implemented an automated scheme on the large Atlantic Meridional Transect flow cytometric database consisting of around 104 samples and 109 cells. This unique, well-calibrated dataset covers 100° of latitude between the UK and the Falklands, and has multiple samples between the surface and 200m. The results clearly show that Prochlorococcus, which are very small marine cyanobacteria, are consistently larger (>0.65 µm) than previously thought and have a distinctive double peak (0.75 µm and 1.75 µm) in their size distribution, which varies strongly with depth. This is coupled with changes in their optical properties: a term we have coined as “opto-types”. Synechococcus by contrast are strongly monodispersed and are typically 1.5 µm in diameter.

This work has uncovered new information regarding the size distribution of the smallest phytoplankton and has implications for how energy is transferred between different biological organisms.

Tim Smyth, Glen Tarran and Shubha Sathyendranath from the Plymouth Marine Laboratory, UK

https://doi.org/10.1364/AO.58.008802

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Published 18.10.2019 - Updated 18.10.2019

Congratulations from IMBeR to Jess Melbourne-Thomas!

Jess Melbourne-Thomas was recently named as the Australian of the Year by her home state of Tasmania.

Jess is an ecosystem modeller and much of her research focused on how underwater ecosystems respond to climate change and other human impacts. In her current position at CSIRO, she is working on bridging the science-policy-society divide, and how best to communicate and engage regarding change and management for marine social-ecological systems.

Jess´s passion for the ocean and her desire to help women in science led her to co-found the Homeward Bound project, that took 78 female scientists to Antarctica in 2016. She also co-founded the Women in Polar Science network, which has well over 4000 members worldwide.

IMBeR has been very lucky to have Jess involved in its Integrated Climate and Ecosystem Dynamics in the Southern Ocean (ICED) regional programme in various capacities.

Amazing work! Well done, Jess. This is a very well-deserved accolade!

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Published 03.10.2019 - Updated 03.10.2019

IPCC Special Report on the Ocean and Cryosphere in a Changing Climate

The Intergovernmental Panel on Climate Change (IPCC) has just published its Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC; published 25 Sept 2019). The SROCC further illustrates the urgent need to address climate change by reducing greenhouse gas emissions, protecting and restoring ecosystems, and carefully managing the use of natural resources, concluding that “choices made now are critical for the future of our ocean and cryosphere” and also for people.

Several of the SROCC authors have been heavily engaged in IMBeR –

Javier Arístegui 1,4, Jean-Pierre Gattuso 1,3, Niki Gruber 1,3, Nianzhi Jiao 4, Lisa Levin 3, Jess Melbourne-Thomas 2,4, Geir Ottersen5 and Carol Turley 1,3 (in alphabetical order)

have served or are currently serving as –

1IMBeR SSC members, 2 IMBeR Regional Programme SSC members or leaders of Regional Programme task teams, 3IMBeR Working Group SSC members,  4conveners of workshops at an IMBeR IMBIZO, 5 leader of an IMBeR-endorsed project 

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Published 02.09.2019 - Updated 02.09.2019

Perceptions of system-identity and regime shift for marine ecosystems

Management of marine ecosystems often seeks to maintain systems in stable states that are close to their historical pristine state, or a state where pressures and resource extraction does not degrade the system beyond a point of no return. When regime shifts occur these can therefore considered to be failures in management. Regime shifts should be recognisable as the system departs from the status quo or away from a desirable state and transgresses over some definitive reference points. However, Ingrid van Putten* and colleagues from CSIRO (Commonwealth Scientific and Industrial Research Organisation) and the University of Tasmania found that there is limited consensus among marine scientists as to what actually constitutes a regime shift. Thus, the authors identified a fundamental ambiguity in a key concept for ecosystem based management.

See full paper:

Ingrid van Putten*, Fabio Boschetti, Scott Ling, and Shane A. Richards (2019) Perceptions of system-identity and regime shift for marine ecosystems. ICES Journal of Marine Science, fsz058 

The idea for this research was first conceptualized at the marine regime shift workshop at the fourth IMBeR IMBIZO meeting: Marine and human systems: Addressing multiple scales and multiple stressors, hosted by the Istituto Nazionale di Oceanografia and Geofisica Sperimentale in Trieste, Italy, October 2015. 

*Ingrid van Putten is Chair of the IMBeR Human Dimensions Working Group.

 

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Published 27.08.2019 - Updated 27.08.2019

Drivers of abundance and biomass of Brazilian parrotfishes

The long Brazilian coast encompasses most of the reef environments of the southwestern Atlantic, and are characterized by unique reef formations and high rates of endemism. Parrotfishes (Labridae: Scarinae) are among the most ubiquitous and dominant reef fish worldwide, and in Brazil, 60% of the group are comprised of six endemic species. It is known that parrotfishes can affect the physical structure and composition of benthic communities through grazing and bioerosion. Despite their ecological importance, parrotfishes have been intensively targeted in many regions of the world. In Brazil, four of the endemic species are now threatened to some degree due to overfishing, including the largest, Scarus trispinosus, which can reach a length of 90 cm. Signs of depletion of these species strengthen our need to inform conservation and management through a better understanding of their patterns of abundance, biomass, habitat preferences, and assemblage structure across different reef types. We assessed abundance and size class distributions of six parrotfishes in northeastern Brazil and identified habitat preferences based on reef attributes. Species’ distributions were variable and related to their respective feeding modes and reef types. Such heterogeneity in habitat use suggests functional complementarity rather than functional redundancy among Brazilian parrotfish assemblages. Outer-shelf reefs sustained larger individuals for most of the species, whereas inner-shelf reefs supported higher abundances of small individuals. Despite being nurseries or developing areas, shallow inshore reefs sustain intense artisanal fishing activities targeting parrotfishes. The ongoing fishing pressure in nursery habitats may be causing significant declines in adult numbers in deeper outer-shelf reefs that are yet to be quantified. Such information may have important implications for management and conservation in the face of increasing fishing pressure. Conservation of Brazilian endemic parrotfishes requires protection of reefs with diverse attributes in order to conserve functional diversity.

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Published 22.08.2019 - Updated 22.08.2019

Call for Abstracts - IMBeR endorsed Forum “Experiencing China – Dialogue on the Maritime Silk Road”

The “Experiencing China” series, initiated by the China Scholarship Council (CSC, www.csc.edu.cn), is designed to give its scholarship students the opportunity to explore academic and industrial possibilities, and give insight into the Chinese culture. As a part of the 2019 “Experiencing China” activities, a Doctoral Forum entitled “Dialogue on the Maritime Silk Road” will be hosted by East China Normal University (ECNU, www.ecnu.edu.cn) in Shanghai, China from 10-13 October 2019.

The Forum will cover “Culture and Civilization”, “Estuaries and Coast” and “Economics and Trade” and will consist of three concurrent but interacting sessions. The sessions are: 1) The Maritime Silk Road and cultural exchange across regions, 2) Estuarine and coastal science and technology and sustainable ecosystems, and 3) Building a world of common prosperity through win-win cooperation. The Forum will include keynote lectures, presentations and discussions, as well as a workshop on career planning and a field trip to the Yangshan Deep Water Port or China Maritime Museum. After the Forum, students will be invited to submit a short paper for a special issue of the Journal of East China Normal University (Natural Sciences).

Deadline for applications is 10 September 2019

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Published 05.08.2019 - Updated 05.08.2019

Kuroshio Current: Physical, Biogeochemical, and Ecosystem Dynamics - New book of findings by the IMBeR endorsed project – SKED

The North Pacific western boundary Kuroshio current, transports large amounts of heat, chemicals, and organisms, but is known to be nutrient-poor. Despite the low-nutrient concentration of Kuroshio water, the Kuroshio is an important spawning and nursery ground for various fish species, and a productive fishing ground. To understand the mechanisms of how this high fisheries productivity results from the oligotrophic conditions, i.e., the Kuroshio Paradox, and to determine how to use the ecosystem services sustainably, the Study of Kuroshio Ecosystem Dynamics for Sustainable Fisheries (SKED) started in October 2011. This ten-year project was funded by the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT). This recently published book is based largely on the results from the SKED project. Physical, chemical, and biological aspects of the Kuroshio are described and compared to those of the Gulf Stream, the western boundary current of the North Atlantic Ocean, to understand the similarity and differences between them.

 

Volume highlights include:

  • New insights into the role of the Kuroshio as a nutrient stream
  • The first interdisciplinary examination of the Kuroshio Paradox
  • Reflections on the influence of the Kuroshio on Japanese culture
  • Research results on both the lower and higher trophic levels in the Kuroshio ecosystem
  • Comparisons of nutrient dynamics in the Kuroshio and Gulf Stream
  • Predictions of ecosystem responses to future climate variability

 

Kuroshio Current: Physical, Biogeochemical, and Ecosystem Dynamics, Geophysical Monograph 243, First Edition.
Edited by Takeyoshi Nagai, Hiroaki Saito, Koji Suzuki, and Motomitsu Takahashi.
©2019 American Geophysical Union. Published 2019 by John Wiley & Sons, Inc.

Preview the book that is available in print from Wiley.com or Amazon.com

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