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3 Posts tagged with the cyanobacteria tag
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Dr Kanako Ishikawa from Lake Biwa Environmental Research Institute, Otsu, Japan, visited Dr Anne D Jungblut (NHM Life Sciences Department) in April 2012 as part of a project supported by a Daiwa Foundation Small Grant that aims to establish a Lake Biwa periphyton species list and carry out public engagement events on biodiversity, management and conservation of Lake Biwa, Japan.

 

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Proliferation of macrophytes and periphyton in Lake Biwa

 

Lake Biwa is the largest lake in Japan and one of the twenty oldest lakes in the world. It has many endemic species, and supplies 14 million people with drinking water including the megalopolises Osaka, Kyoto and Kobe Cities. It is a breeding ground for freshwater fish and supports commercial fishing.

 

Microalgae such as cyanobacteria and green algae growing on leaves and stems of submerged water plants (macrophytes) or rock surface are defined as periphyton. These microalgae are not only an important food source for fish and other animals, but can also become nuisance for fishing equipment, water supply system and leisure activities.

 

Periphyton.jpgPeriphyton collected from Lake Biwa

 

In recent years macrophytes have become highly abundant in Lake Biwa and as a consequence periphyton growth has dramatically increased. However, little is still known about the species diversity of Lake Biwa periphyton, in particular the presence of non-native and potentially harmful species. During the visit, Kanako Ishikawa and Anne Jungblut carried out DNA-based analyses on periphyton samples collected from Lake Biwa using culture-independent methods.

 

Lab.jpgKanaka Ishikawa and Anne Jungblut preparing DNA samples for PCR

 

Anne Jungblut will visit the research laboratory of Dr. Kanako Ishikawa (Lake Biwa Environmental Research Institute) and Dr Taisuke Ohtsuka (Lake Biwa Museum) in Shiga prefecture, Japan, in July.

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Anne Jungblut, a botany research scientist at the NHM, has been awarded the US Antarctica Service Medal. The medal was established by US Congress in 1960 to honour service personnel and civilians who contribute to US Antarctic expeditions.

 

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Anne has been taking part in Antarctic expeditions since 2005 with the New Zealand and US Antarctic Program, and has represented The Natural History Museum on these expeditions since 2009.  Her blog gives details of expeditions to look  at cyanobacteria in Antarctica, which form thick mats in meltwater pools.  We are always intrigued by the sampling equipment that appears in some of the photographs!

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Dr Anne Jungblut works in the Antarctic on cyanobacteria - a summary of her recent work is taken from the Botany annual report

 

The Antarctic is characterized by extreme cold and aquatic ecosystems that are dominated by microbes. Cyanobacteria can be found in polar lakes, ponds and streams, and often dominate total ecosystem biomass and productivity by forming benthic mats and films. These organisms are highly tolerant of the harsh polar conditions and overcome nutrient limitation by recycling and scavenging inorganic and organic nutrients.

 

In the ice-covered lakes of the Dry Valleys of Antarctica, cyanobacteria-dominated microbial mats form pinnacle structures that are potential analogues to microbialites found in fossil records. However, despite the importance of cyanobacteria to Antarctic ecosystems, ecology and geo-biology, their diversity, community structure and ecology have been little studied.

 

Two field events took place during the austral summer 2010-2011. The first project aims to evaluate the diversity of Antarctic cyanobacteria along spatial and temporal scales. During the field trip to Antarctica in collaboration with Dr Ian Hawes, Dr Jenny Webster-Brown and Hannah Christenson, University of Canterbury, Christchurch, New Zealand), collection sites were targeted on Ross Island and McMurdo Ice Shelf that were visited by the British National Antarctic Expedition (Discovery Expedition 1901–04), the British Antarctic Expedition (Terra Nova Expedition 1910-13) led by R.F. Scott and the British Antarctic Expedition (Nimrod Expedition 1907-09) led by E. H. Shackleton in order to test how present-day diversity compares with cyanobacterial mat specimens from 100 years ago. The fieldwork was supported by Antarctica, New Zealand and the project “Antarctic Aquatic Inland Ecosystems: Icebased ecosystems” (Project Leader: Dr Ian Hawes).

 

The second project is in collaboration with Dr Dale Anderson (Principal Investigator, SETI Institute, CA, USA), Dr Dawn Sumner and Tyler Mackey (US Davis, CA, USA) and Dr Ian Hawes (University of Canterbury, Christchurch, New Zealand). The objective is to gain a better understanding of pinnacle formations in cyanobacteria-dominated microbial mats in the perennial ice-covered Lakes Joyce, Vanda and Hoare in the Antarctic Dry
Valley, which will help to interpret ancient microbialite morphology in fossil records. A field event was carried out as part of the US Antarctic Program and supported by research grant from NASA. As part of the fieldwork in the Dry Valleys, pinnacle morphologies were characterized, photosynthesis capabilities examined and cyanobacterial diversity assessed by way of microscopic analysis. Ongoing research in the NHM Botany Department will determine community structure of cyanobacteria within microbialite structures to evaluate the role of cyanobacteria in the formation of microbialite structures, and to study the phylogenetics of cyanobacteria from these unique Antarctic cryo-ecosystems.

 

Anne wrote a blog on her experiences in the Antarctic - a day-by-day account from the early part of 2011.