The role of biota in snowmelt on glaciers in Alaska

While climate change is often in international news, it's easy to forget that most research is done at the local level.

One of the researchers analyzing this localized impact is Gerard Ganey. Ganey has been studying the environment since his time as an undergraduate at the University of Vermont. He brought that interest and passion for environmental studies to the Last Frontier when he started his graduate degree at Alaska Pacific University.

Ganey's latest research connects two (at first) seemingly disparate things in the natural world: algae and snowmelt. His project was concerned with how red algae effect snowmelt, the surface runoff produced from melting snow.

Red snow algae is a type of green algae. What sets is apart from most kinds of algae is that it thrives in freezing water. It is found in high-altitude areas and coastal polar regions. It appears red due to a chemical compound know as astaxanthin, a pigment.

According to Ganey, the current scientific literature states that the algae's color acts as a protectant. In order to study the algae, he conducted an experiment. “We ran an experiment where we fertilized snow to increase algae populations and used bleach to decrease populations,” Ganey said. “We found fertilized plots – which contained more algae – melted more than others.”

Ganey conducted his fieldwork in the Harding Icefield. It was the chance to do research in an extreme location – a “spectacular and logistically challenging place to do research” – that first drew him to studying red snow algae. One of the most important things he took away from his research was the existence of a relationship between biomass and snowmelt.

“[My research] is important because glaciers and snowfields worldwide are melting,” he said. The melt is contributing to a global sea level rise and an increased loss of freshwater resources. What sets his research apart is that the impact of algae on snow is not considered in most melt models.

“A really key moment for me during this research was witnessing the vast extent of snowmelt on the Harding Icefield,” Ganey said. Through observations in the field and LandSat imagery Ganey says the equilibrium line altitude has moved a long distance up the Harding Icefield in recent years. “The amount of exposed ice was impressive,” he said, “and maybe somewhat alarming.”

Life in frigid environments on Earth is one of the best models of astrobiology for other worlds like Europa, Jupiter’s moon, where NASA announced that water vapor plumes had been detected with the Hubble Space Telescope (Spencer, 2014). On Earth, four kingdoms of life have been identified as cryophilic (Napolitano and Shain, 2004) most visible of which is red snow algae (Chlorophyta). The study of red snow algae is thus relevant to the fields of extremophile biota. In addition, red snow algae have been identified to play a role in carbon cycling, (Takeuchi et al. 2006), ice melt (Kohshima et al. 1993) astrobiology (Hodson et al. 2008). Most previous research on glaciers has been physical and earth science. This proposed project focuses on the role of Chlamydomonas nivalis, the most common red snow algae (Remias et al. 2005). Chlamydomonas algae are found on snowfields worldwide (Hoham and Duval, 2001). These widely distributed protists, along with other impurities of local and allochthonous origin have been shown to increase absorbance of electromagnetic radiation (EMR) and so reduce albedo (Thomas and Duval 1995; Painter et al. 2001;Takeuchi et al. 2013). As algae reduce albedo, they likely increase snowmelt. It is well known that impurities in snow increase snowmelt (Conway et al. 1996, Hock et al. 2005). However, three features of red snow algae make them qualitatively different than other impurities: (1) as living organisms they resurface and reproduce even after being buried by new snow, (2) they prefer wet snow, (3) their red color reflects visible EMR that is preferentially absorbed by snow crystals (Warren and Brandt, 2008). This project is an application of STEM through manipulative experiments and data analysis and will further understanding of reduction and fluctuations of the glacial cryosphere and ice-dwelling biotic communities. Besides focusing on the ecology of organisms pertinent to astrobiology and NASA’s Exobiology and Evolutionary Biology (Exo/Evo) Program, the project includes remote sensing and its application to the effects of climate change.