MixONET, a new SCOR Working Group # 165 on Mixotrophy in the Ocean Traditional and contemporary methods in Biological Oceanography assume a false plant/animal dichotomy for plankton. This dichotomy has been the bedrock of marine science, operationally separating organisms into phototrophic or phagotrophic compartments wherein about half of Earths carbon fixation and oxygen production are due to activities of microscopic marine phototrophic phytoplankton. These phytoplankton are ingested by microbial zooplankton which are then preyed upon by metazoan grazers etc. We now know that most of these protist phytoplankton can photosynthesise and ingest food while a third of the microbial zooplankton can photosynthesize through acquired phototrophy in addition to hunting prey thus contributing to both primary and secondary production. These protist plankton are now recognised as an important community of marine life the mixoplankton [1-3] (Fig.1). During the current UN Ocean Decade, marine researchers are faced with the challenge of answering how climate change will impact biology, productivity and carbon sequestration, foodwebs, and allied ecosystems services in global oceans. Mixoplankton are at the heart of all these processes, for example, dominating production in various ecosystems (e.g., temperate summers) and supporting juvenile fish growth [3]. Biogeography studies have shown the ubiquity of mixoplankton [4,5]. Wellknown phytoplankters that are actually mixoplankton include the coccolithophore Emiliania huxleyi [6]; the diverse bacterivorous phytoflagellates of the microbial carbon pump [7]; the toxinproducing dinoflagellates Alexandrium and Dinophysis whose blooms result in shellfish contamination and harvesting closures [8]. The traditional microzooplankton which are now recognised as mixoplankton include various plastidic ciliates, such as Strombidium and Mesodinium that support farmed and wild fish [9] as well as the green Noctiluca scintillans, a bloom forming dinoflagellate that harbours photosynthesizing endosymbionts. Ecosystem disruptive Fig. 1. Artistic representation of example mixoplankton species. a: Lithoptera fenestrata, b: Strombidium conicum, c: Gymnodinium catenatum, d: Karlodinium veneficum, e: Akashiwo sanguinea, f: Alexandrium sp., g: Laboea strobila, h: Prorocentrum micans, i: Mesodinium rubrum, j: Pfiesteria piscicida, k: Heterocapsa triquetra, l: Tripos furca, m: Prymnesium parvum, n: Dinophysis acuta, o: Teleaulax amphioxeia, p: Noctiluca scintillans. Organism size is to scale; scale bar: 10 μm. Image credit: Claudia Traboni (2019) MixITiN project. HARMFUL ALGAE NEWS NO. 70 / 2022 blooms of this green Noctiluca are leading to the collapse of the traditional phytoplankton-mesozooplankton link in the food-web in the Arabian Sea [10]. The base of the oceanic food-web is thus comprised of photosynthesizers that also eat and consumers that also photosynthesize, muddying the photo-autotroph/phago-heterotroph distinction that has dominated biological oceanography. This recognition where most oceanic primary producers cannot be analogized as miniature plants has led to a paradigm shift in trophic studies, and there is thus a critical need to evaluate how new sampling and monitoring methods and global plankton databases can be optimized for this new perspective. A cross-disciplinary team is required to address these needs; thus in 2021 we submitted a proposal for a working group to SCOR - MixONET. The newly funded SCOR working group # 165 Mixotrophy in the Oceans; Novel Experimental designs and Tools for a new trophic paradigm (MixONET) (January 2022 December 2024) is an international brainstorming effort involving experts with knowledge of ecophysiology and molecular biology of mixoplankton, new sampling and observation technology, biogeochemical cycling and ecosystem services (Fig.2). Our overarching aim is to update biological oceanography to quantitatively accommodate the mixoplankton paradigm, and to evaluate which emerging methods and technology will enable accurate assessment of mixoplankton abundance and activities. MixONET will thus integrate the mixoplankton paradigm with traditional and novel methods of plankton research to provide tools for predicting the response of the oceans biological communities and element cycles in the face of ongoing climate change to better understand how humanity can maintain healthy sustainable oceans. MixONET is co-chaired by Aditee Mitra (Wales, UK) and George McManus (USA); the membership (Fig.3) includes Beatriz Reguera (Spain), Helga Gomes (USA), Anukul Buranapratheprat (Thailand), Amany Ismael (Egypt), Áurea Ciotti (Brazil), Ahmed Al-Alawi (Oman), Fernando Unrein (Argentina), Hae Jin Jeong (S. Korea), KB Padmakumar (India), Koji Suzuki (Japan), Luciana Santoferrara (USA), Maite 17 Harmful Algae News An IOC Newsletter on Toxic Algae and Algal Blooms No. 70 - July 2022 https://hab.ioc-unesco.org/ Mar Menor lagoon: an iconic case of ecosystem collapse Content Featured articles Mar Menor lagoon: an iconic case of ecosystem collapse, Juan M Ruiz, Jaime BernardeauEsteller, M Dolo nodosa present in Mar Menor at least in the last decades. Caulerpa contains high levels of toxigenic secondary metabolites and contributes loads of labile organic matter to the sediments. Decomposition of this organic matter fuels anoxic processes and increased levels of reduced carbon, nitrogen and age basin and is a major source of European winter vegetable production. But the transferred water resources, clearly insufficient to sustain such production, had to be complemented with aquifers that had suffered previous overexploitation and became brackish. These brackish aquifers needed treating Fig. 3. Satellite image (Sentinel 2) after torrential rainfall in September 12th and 13th in the Mar Menor watershed. Tons of terrigenous sediments, carbon, nitrogen and phosphorous are dragged by water runoff from agricultural lands into the Mar Menor lagoon (downloaded from https://www. copernicus provided by President and Staff of the harbours Club Nautico Lo Pagán, Club Náutico La Puntica and Centro de Actividades Náuticas (San Pedro del Pinatar, Murcia, Spain). References 1. Ruiz JM et al 2020. Informe de asesoramiento técnico del IEO, 165pp 2. Belando MB et al 2019. Front. Mar. Sci. Conf The Mar Menor Oyster Initiative, a strategy to prevent algal blooms in a eutrophic lagoon in Spain Fig. 1. Map of study in Mar Menor, Murcia, SE Spain Marine ecosystems are exposed to a wide range of pressures including water quality degradation, habitat decline, overfishing and climate change, in flats, located in the south basin of the lagoon. The rationale of this project is to involve all interested stakeholders for successful large-scale restoration programs, which need public and political support, research, and outreach actions [13]. Acknowledgements Project RemediOS is developed with Multi-specific Harmful Algal Bloom in a Chilean Fjord: A dangerous phytoplankton cocktail Fig. 1. Maps of study area showing: left, NW Patagonian fjords; right, Quitralco Fjord Harmful Algal Blooms (HABs) in Southern Chile (Patagonian fjords) have followed the global trend of increasing reports an Fig. 3. Vertical distribution of A) temperature (blue line), salinity (red line) and chlorophyll a (green line); B) Pseudo-nitzschia spp; C) A. catenella; D) D. acuminata; E) P. reticulatum at a sampling station close to the head of Quitralco Fjord on February 22, 2022 reticulatum (18.3 x 103 cells Red Tide Adaptation and Response Network (REARMAR): bridging local, scientific and policy knowledge for smallscale benthic fisheries in the northern Chilean Patagonia Fig. 1. Expansion of Alexandrium catenella-related PSP outbreaks recorded in the last four decades in Chilean Patagonia. Dashed line l l fishermen leaders and fishery and health authorities were considered inappropriate. Several coordination problems arose when an authorized 6,000 loco landing could not be placed on the market because results of laboratory tests detecting toxins slightly above the regulatory limit (80 ug STX eq An unprecedented harmful algae bloom in the beaches of Rio, Brazil Fig. 1. Images acquired by Sentinel-3s Ocean and Land Colour Instrument OLCI, on A) November 16th, 2021; B) December 5th, 2021. The dark water patch indicates the algal bloom. Source: Priscila Kienteca Lange, UFRJ An extensive and Tetraselmis). We speculate that these calm inlets could have possibly been the source of the massive offshore bloom, but further image and data analysis needs to be conducted. The coast of Rio de Janeiro state is subject to coastal upwelling of the South Atlantic Central Water (SACW water mass) at A High Biomass Bloom of a dinoflagellate (Scrippsiella sp.) in a tropical estuary in northern Bahia State, Northeast Brazil A bloom of Scrippsiella sp. was observed in the Rio Real estuary of Northeast Brazil (Figure 1A; 11o 18 28 S; 37o 16 45 W). According to the KöppenGeiger climate classification [ Limnoraphis robusta bloom in Hanabanilla reservoir, central-southern Cuba Fig. 1. Map showing the areas where the Limnoraphis robusta bloom occurred in Hanabanilla reservoir. Harmful cyanobacterial blooms in freshwater ecosystems can form major water discolorations, threaten ecosystem functioning from Hanabanilla was mainly in early vegetative stage. In contrast, some morphological characters which are indicators of later growth stage such as red-brownish trichomes and hormogonia were present in high abundance in a previous L. robusta bloom from Hanabanilla reservoir [5]. L. robusta occurred MixONET, a new SCOR Working Group # 165 on Mixotrophy in the Ocean Traditional and contemporary methods in Biological Oceanography assume a false plant/animal dichotomy for plankton. This dichotomy has been the bedrock of marine science, operationally separating organisms into phototrophic or phagot Maldonado (Canada), Mengmeng Tong (China), Michaela Larsson (Australia), Patricio Diaz (Chile), Robinson Mugo (Kenya), Tina Šilović (France). The first meeting of the working group was held in silico (February 2022) with the second hybrid meeting scheduled to be held in Baiona (Galicia, Spain) in Ju GlobalHAB/EuroMarine Workshop on Modelling and Prediction of Harmful Algal Blooms The typical harmful algal bloom is a regional- or local-scale phenomenon, a perfect storm of environmental conditions, ocean transport and mixing patterns, and microbial ecology. Because of this complexity, prediction Meeting of the GlobalHAB Scientific Steering Committee, Glasgow, Scotland, May 2022 On May 14th -15th, 2022, the Scientific Steering Committee (SSC) of the IOCSCOR programme, GlobalHAB, celebrated its first hybrid meeting in Glasgow, UK, following virtual meetings throughout the Covid19 pandemic. Th The international community is invited to participate in the GlobalHAB programme, through seeking endorsement of relevant research, monitoring, and modelling activities GlobalHAB APPLICATION FORM FOR ENDORSEMENT OF ACTIVITIES AND PROJECTS To be completed in English and emailed to the Chair of the G Is the activity part of, coordinated with, or af4iliated with, other international/regional programs? Yes: ___ No. ____ If yes, give program title: 8. FUNDING Has funding been obtained? Yes: No: (Prospective) source(s): 9. CONTRIBUTION TO UN DECADE OF OCEAN SCIENCE FOR SUSTAINABLE DEVELOPMENT 203 Microbial life cycles Microbial life cycles in a changing ocean in a changing ocean Contributions that address the following topics are welcome: Contributions that address the following topics are welcome: Diversity of microbial life cycles in different habitats and environments Diversity of micr