Citizens as researchers are in demand in Oldenburg's marine sciences, determining water colours via smartphone, among other things. Marine physicist Oliver Zielinski talks about the turbid coastal sea, research methods that have been tried and tested for over 100 years - and a vision for the future of citizen science.
QUESTION: Mr Zielinski, have you ever been active as a citizen scientist yourself?
ZIELINSKI: I used to walk through the Bornhorst meadows as a teenager and had an eye for the landscape and nature - but I didn't systematically observe birds, for example, or report my observations to someone who collated them into a bigger picture. Perhaps there were no easy ways to communicate - and certainly no smartphones.
QUESTION: You are now investigating the presumably decreasing availability of light in coastal waters in the Coastal Ocean Darkening research project. What role do observations by citizens play in this?
ZIELINSKI: We need many observations in many places, and it is ideal if citizens participate. It's about the coastal sea, which has become cloudy over the past 100 years - for example due to nutrient inputs and increasing fishing that scours the seabed. These things happen on a long-term scale and in many places: If you want to have a lot of measurements, it's hardly feasible as a scientist. Citizens, on the other hand, are out and about in the most amazing and remote places and can provide very good observations for research. Citizens also have a very keen eye and provide re-registering students about things that we might not even have noticed. They are able to improve our methods or describe influences that we may not have recognised.
QUESTION: Can you give us an example? To what extent does contact with citizens provide new ideas?
ZIELINSKI: The EyeOnWater app alone, which we developed for colour measurement via smartphone, received a lot of input from citizens. Whether it's the ease of use, even one-handed, the use from a sea kayak or the readability in sunlight. We receive such re-registering students from citizens.
QUESTION: And how many have already become active in the current project?
ZIELINSKI: We have recorded around 10,000 new observations worldwide so far. We have re-registering students from Australia, South and North America, and of course a lot from Europe. Not everyone registers as a user on our platform, but there are probably several hundred users.
QUESTION: So people who want to join in just need a smartphone and the EyeOnWater app?
ZIELINSKI: Exactly, you can download it for free from the major platforms. That's all you need. The simplest form of observation is the colour of the water surface. To do this, I go to a location that has open water, for example on a jetty, the edge of a harbour or from a boat. There I can determine the colour of the water by taking a photo with the app. The depth of visibility at the location in question is also interesting. This can be determined by lowering a white disc and seeing how long it is still visible - a method that goes back to the Italian physicist Angelo Secchi and is over 150 years old. I can enter this kind of information via the app, but it's not absolutely necessary.
QUESTION: And how does colour determination via the app work?
ZIELINSKI: It is based on a historical colour method that is a good 120 years old: 21 colours from indigo blue to green and yellow to Coca-Cola brown cover the waters from clear oceans to bog water. We have converted this colour scale into a computer scale, that's the whole secret. This allows us to relate today's data to historical measurements. To capture the water colour correctly, the app itself offers a little guide: it's best to stand with the sun behind you and hold the smartphone as steeply as possible to capture the water and not the reflection of the sky. I can then select the right colour for the photo from the colour scale - manually. It works like the classic method from 1895, only with a smartphone. A computer algorithm then runs in the background, which also calculates the colour.
QUESTION: So you don't have to rely on people's error-free colour perception.
ZIELINSKI: No. But sometimes it is the case that you can reproduce it better from an impression. People have an enormous ability to judge that. I also use the app when I'm travelling, for example recently on an expedition to Greenland - so far there have only been observations from 1928 and the early 1950s, nothing more. We can use a historical data set with 300,000 observations worldwide, in which certain areas have already been analysed very closely, such as Russian and Japanese waters. And in terms of light penetration depth and water clarity, we can access a historical data set with as many as 600,000 measurements. We are using both of these for the project and want to relate the colour and transparency of the water to each other. Researchers have already looked at the depth of visibility according to Secchi and seen that it gets darker in the water - but no one has yet linked this to the colour information.
QUESTION: So you are also looking into the past.
ZIELINSKI: Exactly, once we look back a century - these two data sources are just great for that. And for the look into the present, we are integrating citizen science, among other things, in order to obtain current data, but also other modern methods such as satellite observation. So far, all measurements in this field have ended in the year 2000, so it will be interesting to see whether the coastal waters have continued to darken recently or whether the trend has perhaps been halted.
QUESTION: How long will your project run for?
ZIELINSKI: It will run for a total of four years, one of which is over. We were able to pick up where we left off with a three-year EU project. In the project called Citclops, we developed the app, among other things. It's good that we were able to get started straight away, because citizen science naturally takes time.
QUESTION: What does the dialogue between science and citizens ideally look like?
ZIELINSKI: There are different levels. The simplest form is crowdsourcing, where citizens are involved in data collection but not in critically scrutinising the methods. The next level also involves citizens in the further development of the methodology or the interpretation of the data. Not everyone may have the desire or expertise to do this, but there are citizens who are so committed and enjoy it that they can also be involved at this higher level. We did this, for example, by involving a sea kayaking club and a "Junior Ranger" group active in the Wadden Sea National Park. Such groups with a connection to the topic can provide a lot of great feedback that goes beyond pure measurement. You could go one step further and involve citizens in the scientific concept and the development of the research questions. However, we have not pursued this approach.
QUESTION: Would this possibly weaken scientific standards? In other words, is this still science - or is the focus of such projects then on exchange?
ZIELINSKI: Involving citizens is not primarily about communication; that is a side effect. Of course, we want to involve citizens, inform them and sensitise them to our research. But citizen science definitely goes one step further - towards involving people with their ideas and their creative potential. Of course, we researchers have to let go a little of the idea of being the master of the situation and having to define everything precisely. But this risk is rewarded. Collaborating with people who are involved with the topic - in our case water - in their leisure or professional lives is particularly rewarding. For the standard tourist who contributes a few photos of the North Sea island, the idea of communication is certainly stronger. But citizen science clearly has the approach of recognising citizens and not just "using" them.
QUESTION: When you say that you have to abandon the idea of being the master of the situation as a scientist, you are nevertheless looking at the scientific quality. Is data quality something you have to keep a close eye on?
ZIELINSKI: Indeed. Of course, I always know best what I have measured myself. When others take measurements, I have to take a close look. The spread of the measurements, perhaps also the error bars, is greater - but the number of measurements is also many times greater. And in statistics, errors can also be minimised by the number of measurements. I just have to think about what I want: one high-quality measurement by a trained scientist in one place at one time - or a thousand measurements by motivated citizens in a thousand places at different times?
QUESTION: As a member of the European Marine Board, you worked on a strategy paper and drafted a vision for citizen science in marine research. What does it look like?
ZIELINSKI: The vision is that citizen science is accepted as a valuable element in marine research. For this to be possible, the framework conditions must be right: Scientists should make their methods and tools available so that not every citizen science project has to develop them from scratch. We need better data management and more observations, including in the open sea. On the other hand, we need to avoid over-commitment, i.e. to sensitise people to the fact that citizen science is not a free pass for entering nature conservation areas. And we need to work more closely with the social sciences: How do I reach citizens, how do I give them feedback, how do I involve them?
QUESTION: You are currently the director of the ICBM. Do you see this as a major focus in the near future?
ZIELINSKI: In my opinion, it is also an important issue for the ICBM, and we currently have several projects that contain citizen science elements: for example, the macroplastics project, which uses wood drifters and thus reaches a large number of people along the coast. This shows us that this is an important path that we will continue to follow - but I believe that this is not just a path for the ICBM, but at university level. That's why I also suggested that we join forces with interested parties from all disciplines. That way, biologists, social scientists, computer scientists, everyone working on this could have a good exchange.
Interview: Deike Stolz