Stream-water chemistry

Stream-water sampling team at Starrigavan Creek

Stream-water sampling team at Starrigavan Creek

Sitka High students collecting a water sample

Sitka High students collecting a water sample

SALMoN participates in the Global Rivers Observatory (GRO). GRO documents river water chemistry around the world in order to understand long-term ecological changes to freshwater ecosystems. Our local streams, Indian River and Starrigavan Creek, will be studied alongside the world’s greatest rivers, including the Amazon, Yangtze, Lena, Yukon, and others.

In October 2012, Dr. Bernhard Peucker-Ehrenbrink was the Scientist in Residence at the Sitka Sound Science Center. Dr. Puecker-Ehrenbrink is a Senior Scientist at the Woods Hole Oceanographic Institute and one of the founders of GRO. During his stay in Sitka, he trained local volunteers and students in water sampling protocols. SALMON collects water samples from each stream at least once per month.

In the lab, GRO will analyze each sample for nutrient concentrations, dissolved organic carbon, major cations (Ca, Mg, Na, K) and anions (sulfate, chloride, bromide, fluoride), some trace elements (Mn, Fe, Co, As, Rb, Sr, Mo, Ba, U), and the the isotope ratio of strontium.

gro_Sampling_web_iconClick here to download the GRO water sampling protocol.

You can also view the below video



Additional links and information:

Article in Canadian Geographic:

Article on DOC in rivers:

Basically, DOC, if labile, is an energy source for microbial decomposition and hence the bottom of the food web.

Article of strontium ratios:

Basically, the 87Sr/86Sr can tell a lot about parent material (ie. bedrock) and how it has eroded

Article on hydrogen and oxygen isotope ratios:

Basically, from these ratios you can tell the source of the water (along with many other things)