Course Blog

Bio-Monitor and Microplastics


Micro-plastics are small plastic pieces less than five millimetres long which can be harmful to our ocean and aquatic life. Micro-plastics come from a variety of sources, including from larger plastic debris that degrades into smaller and smaller pieces. In addition, microbeads, a type of microplastic, are very tiny pieces of manufactured polyethene plastic that are added as exfoliants to health and beauty products, such as some cleansers and toothpaste. These tiny particles easily pass through water filtration systems and end up in the ocean and Great Lakes, posing a potential threat to aquatic life.

Related Work

Other research focused more on the following Pollution source; H: harbours, IND: industries (i.e. lead/zinc ore deposit, chlor-alkali plants, Zn factory, shrimp farm, land-based fish farms, soda ash industry), UA: urban areas, IDW: industrial and domestic wastewaters, WD: wastewater discharge-sewage outlet/outfall, MA: mining activity, WTP: wastewater treatment plants, VHA: volcanic and hydrothermal activity, LDNI: land-derived nutrient inputs, RDP: river discharge points. (García-Seoane et al., 2018)

Or instead, other methods used to assess microplastics are net sampling, bulk sampling with subsequent filtration screening Continuous Plankton Recorder (CPR) samples, using directly in situ filtrations, direct fractionated pressure filtering of large (>1 m3) volumes of water through a filter cascade (developed by -4H-JENA engineering GmbH). (Löder & Gerdts, 2015)


The inspiration for project

1.We need to locate the microplastics because they are quite minute and particles making them extremely easy to be accidentally ingested.

2.The previous method of detecting the microplastics like Gastrointestinal Tract of Fishes was tedious and it can not be used in daily life. Based on that we want to try some useful method to use the aquatic plant to make it become a monitor called “bio-monitor”. Therefore, bio-monitors used are originally part of the sea, we are not adding foreign things and thus keeping the balance of sea habitats. For our project, we are interested in macroalgae, kelp, and seagrass.

3.Moreover, we want to acquire the status of the microplastics in different kinds of the environment to analyze the changes of microplastics.

Design and Application

Firstly, we would like to use the seaweed to make it become a monitor to detect the microplastics. We design an “island” for the detecting. Here is the paper prototype for our idea.

Paper Prototype

Then, we use 3D modelling to build our first prototype. There has a cover for the prototype, it likely to protect the seaweed to not be eaten. And the material of this model is quite similar to coral because it would not produce the pollution for the water. To notify the number of microplastics accumulated, biomonitors will be stained beforehand possibly with Nile Red stain. A possible drawback of this staining approach is the possibility that false positives might be introduced because of staining biological organisms such as marine algae (Maes et al., 2017). Moreover, there is another way to detect it is to implant some sort of sensor.


The next step is to that get the status of information. We considered that it’s quite a long processing to detect the changes of microplastics so that it can be recorded manually.

Future Development

There are two directions for our project. One is that making some changes to the monitor that can be afforded in different kinds of water like the river, lake even the whole water system. Another is that to make it usable in the home so that most people could recognize the importance of microplastics.


Löder, M. G., & Gerdts, G. (2015). Methodology used for the detection and identification of microplastics—A critical appraisal. In Marine anthropogenic litter (pp. 201-227). Springer, Cham.

García-Seoane, R., Fernández, J. A., Villares, R., & Aboal, J. R. (2018). Use of macroalgae to biomonitor pollutants in coastal waters: Optimization of the methodology. Ecological Indicators84, 710-726.

Gutow, L., Eckerlebe, A., Giménez, L., & Saborowski, R. (2015). Experimental evaluation of seaweeds as a vector for microplastics into marine food webs. Environmental science & technology50(2), 915-923.

Maes, T., Jessop, R., Wellner, N., Haupt, K., & Mayes, A. G. (2017). A rapid-screening approach to detect and quantify microplastics based on fluorescent tagging with Nile Red. Scientific Reports7, 44501.