debor042

by Luca Marazzi* Last week about 800 ecologists from 72 countries, including myself, attended and presented their research at the 10 th INTECOL Wetlands conference in the beautiful city of Changshu (2 hrs west of Shanghai). Before this event that takes place every four years (in 2012 we were in Orlando for INTECOL 9 ), I was honored to give a long seminar on my work on the algal communities of the Okavango Delta and Everglades at the Nanjing Institute of Geography and Limnology (NIGLAS) of the Chinese Academy of Sciences. I was invited to do that by my friend Xuhui Dong (we studied together for our PhD at the UCL Environmental Change Research Center in the UK). Xuhui and his colleagues recently conducted a paleolimnology study of several floodplain lakes along the mighty Yangtze River (Dong et al., 2016), where they found large numbers of Aulacoseira granulata [ (Ehrenberg) Simonsen 1979] , which is therefore our September diatom (a belated post). ...

by Luca Marazzi* Many algae are able to form blooms, sometimes releasing dangerous toxins for aquatic organisms and people. Cyanobacteria are most infamous for producing blooms such as those ongoing in Florida's coastal waters , but other algae, including diatoms, can create such vast colonies too. The large ( 100,001-1,000,000 µm 3 ) asymmetrical biraphid Didymosphenia geminata , or colloquially ‘didymo’ is one of them; it attaches to stones in rivers by stalks (made of mucopolysaccharides, long chains of sugar molecules)   that can be 1 m long! Didymo is invasive in Argentina, Chile, and New Zealand, where this video was released in 2008 to inform the fishing community that they should clean and dry all their gear to avoid spreading this species to other water bodies. Fig. 1.   (top)  Didymosphenia geminata ( scalebar = 10 µm ; p hoto by Mart Schmidt ); (bottom)   n umerous cells and mucilage stalks from South Boulder Creek (November 2011) - c redit/source: ...

  The Peril of Peat: Sea Level Rise in South Florida: Part 1 Post by: Ben Wilson      Ben Wilson having some fun in the mud I love mud. Seems like I have for a long time now. It’s squishy and smelly, and once you get a little bit on you, you might as well go all out. I’m lucky in that the two most recent places I’ve lived, coastal Alabama and now in Miami, have had ample areas for me to get my mud fix. However, over the past century those areas have been dramatically decreasing, and given current and future climate change, they may disappear at an even greater rate. Over the next two blog posts, I will tell you how human development has altered water flow in the past, further exacerbating the problem of today: sea level rise. In order to save the mud, we must first look at what caused this problem in the first place. Drain, baby, Drain Whole books have been written on why and how the Everglades have been modified and managed, but I will just hit the highli...

by Luca Marazzi* Nitzschia amphibia belongs to the nitzschioid group : its v alves are symmetrical to both apical and transapical axes, and taper to bluntly rounded apices ; the raphe is well developed near the valve margin, and enclosed within a canal 1 . The original description was made by Albert Grunow in 1852, when the US President was Millard Fillmore, the  last one not to be affiliated with either the Democratic   or   Republican party . This is how ‘old’ are some of the species names of algae and other organisms that persist to this day, while new species are continuously described at an increasing rate. Grunow was one of the eight most ‘profilic’ algal taxonomists who described more than 1,000 species during their career, the others being Kützing, Gottfried, Hustedt, Agardh, Harvey, who worked in the 1800s, and Lange-Bertalot (the only one still alive and active ) and Skvortsov in the 1900s 2 . Fig. 1.   a)  Nitzschia amphibia  in valve view and ...

by Luca Marazzi* This month’s diatom comes from quite far, some 5,000 miles or 8,100 km North-East of Florida: Northern Italy. Its name is Eunotia cisalpina (on this side of the  Alps , the  south ern   side) , and it was described a few years ago 1 by Marco Cantonati, the Science Museum of Trento ’s (MUSE) Head Limnologist and Phycologist whom I am visiting this week. We are at the foot of the famous and wonderful Dolomites mountains , one of over 50 UNESCO World Heritage sites in Italy, comprising some of the highest limestone walls in the world. North-west from here, small mountain lakes, springs, and mire pools dot the landscape of the Adamello and Cevedale mountain ranges; their waters have lower mineral content than the calcareous Dolomites due to the prevalence of siliceous rocks, such as granites. These oligotrophic, acidic, low conductivity habitats are perfect for E. cisalpina (and for E. fallacoides and E. insubrica , other new taxa to science described in ...