NETLAKE Citizen Science

Thank you for taking an interest in using the NETLAKE protocols to assess the water quality of your local lake!

All protocols can be downloaded as .pdf files. In general, every time you apply any of these protocols, please write down:

• Date and time of measurement
• Google maps location (GPS)
• Are conditions clear, cloudy, rain lightly or heavily?
• How much of the sky is covered with clouds? (%)
• Is it windy enough to make waves? (This has an impact on the Secchi reading and makes it harder to determine colour).

We strongly recommend that you attach a note to everything you leave behind in your lake: "Please do not touch, research in progress”. Remember that iButtons and tea bags will remain in the lakes for 3 months, and that the weather can influence your notes and labelling!

Below, you'll find short descriptions that explain why a particular method is being used: 

1. iButton

DOWNLOAD PROTOCOL Water temperature fluctuates throughout the year following local air temperature and determines many processes in the lake. For instance, it affects the rate of photosynthesis and the amount of oxygen dissolved in the water. Both are vital characteristics for life in water.

2. Tea Bag Index (TBI) 

NOTE: the Lipton tea bags have changed! you can only use the old tea bags provided last year

DOWNLOAD PROTOCOL  / APPENDIX A / APPENDIX B The Tea bag index (TBI) has been developed by scientists from Utrecht University to understand the global carbon cycling (see scientific background). The TBI was originally created to determine the decomposition process on land. Together with TBI developer Joost Keuskamp, we have developed a TBI for lakes!

Can drinking tea help us understand climate change?

Yes. Teabags can provide vital information on the global carbon cycle. And using this method consumers worldwide can improve climate modelling without much effort or instrumentation. Multinational tea distributors communicate with consumers at a scale not attainable by scientists. That is why we want tea consumers to become our researchers and take part in one of the largest crowdsourcing efforts to date. We developed a simple and cheap method to measure decay rates by making use of tea consumers. The method consists of burying tea bags with green tea and rooibos, and does not require a large effort or complicated instruments. This method was developed and tested by a team of researchers from the University of Utrecht, The Netherlands Institute of Ecology and the University of Iceland.

The scientific value of this new method has already been acknowledged, and experiments are currently running in countries all over the world. The idea is to use this new method to collect data on decay rates from all over the world to feed databases in the global soil map, and consequently improve global climate models.

• Video: https://www.facebook.com/enda.fields/videos/10204991963433605/

• Where to buy tea bags (via decolab): http://www.decolab.org/tbi/protocol.html

• The Tea Bag Index (TBI): http://www.decolab.org/

3. Secchi

DOWNLOAD PROTOCOL Water transparency, or clarity, is one of the first things to notice while visiting a water body. High clarity encourages swimmers and divers and can, but does not have to, indicate a healthy fresh water ecosystem.

The more particles are present in the water, such as algae or sediment, the lower water transparency will be.

Measuring water transparency has been done since the start of water research. In 1865, Angelo Secchi came up with a way to measure this consistently by using a Secchi disk.

Various designs are used nowadays, ranging from a white disk (mostly used in marine) to a disk with black and white patterning (mostly used in fresh water).

The latter will be used in this NETLAKE protocol.

• Video: https://www.facebook.com/laura.seelen/videos/g.519728288152200/10207419766510600/?type=2

4. Water colour

DOWNLOAD PROTOCOL / PROTOCOL FOR MANUAL TESTING Water colour is one of the oldest physical characteristics measured in water. Water colour is determined and affected by three different factors in lakes.

• Firstly, phytoplankton: algae contain chlorophyll which mostly give the water a green coloration.
• Secondly, particles (other than algae) such as fine sediment. These generally give a cloudy effect the color of which is dependent on the origin of the material (brownish or reddish).
• Thirdly, dissolved colored matter such as organic compounds: these humic acids originate from terrestrial and aquatic plants and give the water a yellow to brownish coloration.

Different combinations of these three factors will give distinctly different water colours. The most used method to determine water colour is by comparing it to a standardized colour scale, the Forel-Ule scale. This colour scale has been used since the 1890s in conjunction with the Secchi disk.

5. Reed width

DOWNLOAD PROTOCOL The width of the leaf of macrophytes as common reed is related to the nutrient status of the lake; a wider leaf indicates a higher concentration of nutrients in the lake.

Leaf width, thus nutrient concentrations, Secchi depth and water colour, are the three measures needed to be able to classify our lakes according to their trophic state.

6. Microplastics (only 2016!)

DOWNLOAD PROTOCOL Global plastic consumption is increasing rapidly resulting directly in a growing accumulation of end-of-life plastics. Improperly discarded plastic ends up in both terrestrial and aquatic ecosystems and, due to its longevity, is becoming an emerging environmental problem.

Plastic sources are not only discarded bottles on lake shores but can also originate from agriculture (plastic wrappings) or fishing activities (broken lines etc.).

Microplastics are plastic pieces smaller than 5 mm which originate mostly from cosmetic sources or synthetic clothing. Think about peelings and toothpastes that use plastic beads to remove skin cells and stains, or washing fleece clothing of which small fleece particles are washed away with the draining water.

These microplastics are currently hardly removed in wastewater treatment plants, and EU legislation is aiming to improve this. As an example: 15,6 kg/day of microplastic input is estimated to end up in the Rhine for the Netherlands alone.

• Microplastics in freshwater ecosystems: what we know and what we need to know: http://enveurope.springeropen.com/articles/10.1186/s12302-014-0012-7
• Using your plastic sampler: https://www.facebook.com/enda.fields/videos/10204991795989419/
• http://www.ilvo.vlaanderen.be/Portals/74/Documents/2Seas_Annuel_event_2013.pdf

7/8. Sedimentation NEW

Sediment accumulates at the bottom of a lake over time.  This sediment can be several meters deep.  The material that sediments to the bottom includes sand, silt and clay brought in by any inflowing rivers, and dead organic matter from the lake water column, from for example, algal blooms and the dead bodies of zooplankton, fish and indeed any creatures that feed in the lake.  As it contains organic matter, this sediment will contain a large percentage of carbon.  Some of this carbon may quickly be released as methane or carbon dioxide as bacteria break down the organic material near the surface sediments.  However, the accumulated buried sediment represents a store of carbon that may never be released.   Lakes have different rates of sedimentation, and knowing these can be used to estimate the carbon stored in the lake beds. 

The aim of this project is to use citizens to gather information on sedimentation rates in lakes across Europe suing simple sediment traps and simple follow-up analysis of the material collected in those traps.  The sediment will be collected over a minimum of six months.  The traps can be emptied each month, or after six months.  The experiment can then be continued to collect sediment over one year, or indeed more than one year.  The material collected is dried (at 40oC) and weighed to give an estimate of sediment per square meter of lake per year.