Research by the CLIOTOP Marine Predator Isotopes Task Team was recently published in Global Change Biology. The study compiled more than 5000 stable isotope values from 2000 to 2015 of three tuna species sampled globally. Their analyses, unprecedented in scope and spatial range, found a decline in tuna δ13C values of up to 2.5‰ which was up to five-fold larger than expected from the Suess effect alone, i.e. fossil fuel-derived and isotopically-light carbon incorporated into marine food webs. The team used time-series analysis and Bayesian modelling to relate the observed temporal trend to various processes known to influence ocean carbon cycling in the global oceans. The study concluded that tuna isotope signatures are not only indicating changes in fossil-fuel derived carbon emissions but also a substantial shift in phytoplankton communities (from a likely dominance of larger diatoms to smaller coccolithophorids, flagellates or cyanobacteria).

More than 90% of the heat associated with global warming, and more than 30% of the fossil-fuel carbon emissions have been absorbed by the oceans. While such processes are predicted to impact marine biota through changes in ocean stratification and ocean acidification, current estimates of trends are based on localized ocean time series or satellite observations with significant uncertainties.

The findings from this CLIOTOP study could have broad ramifications for marine food webs. Such shifts in phytoplankton could decrease the availability of energy and some essential macro and micro nutrients to fish and human consumers. The study represents a heretofore unrecognized application of stable isotope analyses to reveal decadal changes in the ocean carbon cycle. Such empirical data will be invaluable in calibrating and validating global earth system models used by the IPCC to project the effects of climate change on oceanic productivity.

The 2019 “global carbon budget” was published on 4 December. It provides an assessment of anthropogenic CO_² emissions and their distribution in the atmosphere, ocean, and land. This is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. It shows that emissions are still increasing, but have slowed due to the global decrease in coal burning. Continued and increased global action is needed to reverse the trends.

Global carbon budget 2019 by Pierre Friedlingstein et al. is licensed under CC BY 4.0

IMBeR´s ESSAS Regional Programme will hold its 2020 Annual Science Meeting at Hokkaido University in Sapporo, Japan from 1–3 June 2020

ESSAS´s goal is to compare, quantify and predict the impact of climate variability on the productivity and sustainability of Subarctic and Arctic marine ecosystems. The theme of the 2020 meeting is Linking past and present marine ecosystems to inform future fisheries and aquaculture. This builds on a Belmont Forum-funded project that examined the resilience and adaptive capacity of Arctic and Subarctic marine systems, and aims to gain greater understanding of the mechanisms by which climate change will affect aquaculture and capture fisheries, how these changes will affect resource-dependent communities, and how management can foster resilience in these systems.

Registration and abstract submission are now open. We invite you to submit abstracts that address these themes to help inform our understanding of future changes affecting fisheries and aquaculture in high-latitude marine ecosystems. We welcome contributions from different marine science fields, including paleoecology, contemporary ecology and the social sciences. In an effort to reduce our carbon footprint, presentations can be delivered via a video conference system if you cannot atttend the meeting.

If you would like to join the optional excursion to the UPOPOY National Ainu Museum and Park on 5 June, please sign up for it when you register.

Deadline for abstract submission: 31 January, 2020

Deadline for online registration: 30 April 2020

Registration fee: Students: 2,500 JPY, Others: 5,000 JPY

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

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!

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