#phytoplankton — Public Fediverse posts

NOT so harmless...

Excerpt: "Introducing #KareniaMikimotoi

"The species responsible for recent events in #SouthAustralia beaches, #KMikimotoi, causes harmful #algal blooms in #Asia, #Europe, #SouthAfrica and #SouthAmerica, as well as #Australia and #NewZealand. These blooms all caused fish deaths, and some also caused #breathing difficulties among local #beachgoers.

"The most drastic of these K. mikimotoi blooms have occurred in China over the past two decades. In 2012, more than 300 square kilometres of abalone farms were affected, causing about A$525 million in lost production.

Explaining the toxic effects

"Microalgae can damage the gills of fish and shellfish, preventing them from breathing. This is the main cause of death. But some studies have also found damage to the gastrointestinal tracts and livers of fish.

"Tests using fish gill cells clearly show the dramatic toxic effect of K. mikimotoi. When the fish gill cells were exposed to intact K. mikimotoi cells, after 3.5 hours more than 80% of the fish cells had died.

"Fortunately, the toxin does not persist in the environment after the K. mikimotoi cells are dead. So once the bloom is over, the marine environment can recover relatively quickly.

"Its toxicity is partly due to the algae’s production of 'reactive oxygen species', reactive forms of oxygen molecules which can cause the deaths of cells in high doses. K. mikimotoi cells may also produce lipid (fat) molecules that cause some toxic effects.

"Finally, a very dense bloom of microalgae can sometimes reduce the amount of dissolved oxygen in the water column, which means there is less oxygen for other marine life.

"The human health effects are not very well known but probably relate to the reactive oxygen species being an irritant.

"K. mikimitoi cells can also produce 'mucilage', a type of thick, gluey substance made of complex sugars, which can accumulate #bacteria inside it. This can cause 'sea foam', which was evident on beaches last week.

"A question for many people is whether increasing water temperatures make blooms of K. mikimotoi more likely.

"Another concern is whether nutrient runoff from farms, cities and #aquaculture could cause more harmful algal blooms.

"Unfortunately, for Australia at least, the answer to these questions is we don’t know yet. While we know some harmful algal blooms do increase when nutrient runoff is higher, others actually prefer fewer nutrients or colder temperatures.

"We do know warmer water species seem to be moving further south along the Australian coastline, changing #phytoplankton species abundance and distribution.

"While some microalgal blooms can cause bioluminescence that is beautiful to watch, others such as K. mikimotoi can cause skin and respiratory irritations.

If you notice discoloured water, fish deaths or excessive sea foam along the coast or in an estuary, avoid fishing or swimming in the area and notify local primary industry or environmental authorities in your state."

https://theconversation.com/mystery-solved-our-tests-reveal-the-tiny-algae-killing-fish-and-harming-surfers-on-sa-beaches-252810

#OceanHealth #Beaches Algae #SeaFoam #HABs #HarmfulAlgaeBlooms #KareniaMikimotoi #WarmingOceans #Radioactivity #NutrientRunoff #OceansAreLife #ROS #SkinIrritations #RespiratoryIrration #ReactiveOxygenSpecies #DeadZones

Tracking #algae species #interactions to help predict harmful algae #blooms

#Pseudo-nitzschia #HAB #phytoplankton #aquaculture #competition

https://phys.org/news/2025-02-tracking-algae-species-interactions-blooms.html

A New Interactive [Mapping] Research Tool For The Antarctic Sea-Ice Zone [Nilas]
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https://phys.org/news/2023-02-interactive-tool-antarctic-sea-ice-zone.html <-- shared article
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https://nilas.org/#1/-90/0 <-- NILAS software
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“The Southern Ocean Mapping Platform - Nilas is a mapping tool (beta) which displays multiple layers of physical and biogeochemical variables. The data displayed are primarily derived from remotely sense products and updated as source data becomes available. The Australian Antarctic Division developed this tool to cover the Antarctic sea-ice zone and to support their research and operational activities…"
#GIS #spatial #mapping #Nilas #marine #data #research #planning #science #Antarctic #seaice #geospatial #ice #climatechange #water #hydrology #hydrospatial #SouthernOceanMappingPlatform #mapportal #opendata #SouthernOcean #spatiotemporal #historicdata #climateresearch #climate #chlorophyll #phytoplankton #seasurfacetemperature #Antarctica #ecosystem #spatialanalysis #remotesensing #satellite #instrumentation