Citizen Science Project:

Mapping the Tasmanian discharge of alkalinity into the ocean

We need River (mouth) water samples from all over Tasmania.

Please help us getting them!

Motivation (short story):

We want to know how much alkalinity leaks out of Tasmania into the oceans.

Why? Because alkalinity influences how much CO2 can be stored in seawater.

Motivation (long story):

"Alkalinity" is a chemical unit that largely determines how much CO2 can be absorbed in water. Generally, more alkalinity means more CO2 absorption potential.

     Alkalinity is generated during the slow dissolution of certain rock minerals in water (i.e. chemical rock weathering). This happens a lot on land when rainwater washes over rocks and slowly dissolves them over thousands of years. The alkalinity generated that way then enters the ocean mostly via rivers.

      It has been suggested to accelerate chemical weathering (and thus alkalinity production) to absorb additional CO2 from the atmosphere and to counteract climate change (see here). This could be achieved by grinding rock to powder and distributing it all over warm and wet land surfaces, for example in Tasmania.

  Such operations would presumably increase the Tasmanian alkalinity discharge. However, the problem is we currently do not know how much alkalinity is already leaching out of Tasmania naturally.

    Thus, we want to determine this "natural value" in order to have a baseline before future applications of "Ocean Alkalinity Enhancement" may be rolled out.  

Where to sample?

Near the mouth of rivers but above the zone influenced by tides. Rivers to larger creeks should be sampled. I cover the Hobart area (Derwent, Huon) largely myself so samples from the south, west, north and north-east are more valuable. Especially if you go into remote and hard to access regions!

How to sample?

We fill ~60 mL of river water into a small beaker. The volume should be filtered (with materials I will provide). The exact procedure how to take alkalinity samples can be found below.

Alkalinity sampling procedure
How to sample Alkalinity.pdf
Adobe Acrobat Document 62.5 KB

Interested to join the effort? If so, please contact me at


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Comments: 1
  • #1

    Peter Edington (Thursday, 18 February 2021 02:47)

    Hi Lennart,

    I am leading an expedition by sailing vessel round Cape Horn and on to South Georgia and then Arctic Norway. We are interested in gathering data on Ocean Degradation caused by human activity and by Climate Change. The expedition offers an opportunity for a researcher to spend between 4 and 6 weeks on board in these high latitude oceans to conduct experiments or collect data.

    There are 3 sponsored places in all: 5 weeks from NZ to Ushuaia, 6 weeks from Ushuaia to South Georgia and Brazil, 4 weeks from Dublin to Hammerfest.

    Each place is being offered as a scholarship for a researcher with an experiment or data-gathering project that could be conducted on board a 60 foot yacht travelling at about 100-150 miles per day.

    I would appreciate hearing your thoughts or suggestions on who among your associates might be interested in joining us on board.

    Of course we understand that work commitments may mean senior staff cannot jon us, in which case have they a project we could undertake for them?

    Kind regards,

    Peter Edington, currently in Sydney on +61 405 430525
    Challenge Leader, Ends of the Earth Climate Challenge
    RYA Yachtmaster Ocean Instructor
    MCA Master of Yachts