Microplastic Survey of the Soko Islands, Hong Kong

Microplastics - Broken down fragments of our plastic addiction. Photo: Colin Sim
OceansAsia are currently conducting research into the microplastics found on the Soko Islands in Hong Kong. This small group of islands located on the western edge of Hong Kong at the mouth of the Pearl River Delta is as far away from downtown Hong Kong as you can get. The isolation of these islands make it a perfect candidate for our research as the beaches have generations of marine debris build up that is rarely cleaned up. Our research beach has a east facing beach that carries much of the debris from along the south coast of Hong Kong as well as debris from the Pearl River. The make up of the debris shows a variety of fishing gear, household trash as well as some more bizarre findings.
Whilst we are focusing on microplastics we are also documenting the monthly shift in the debris as well as the composition. Using drones to map out the beach and near shore debris we hope to be able to produce a comprehensive report at the end of our survey period.
One of our two sample sites covering a 50cm x 50cm area.
A broad range of marine debris all mixed up with a bed of microplastics. Photo: Colin Sim
The next wave of marine debris arriving on every wave. Photo: Colin Sim
Utilizing drone technology to map the beaches for later analysis. Photo: Colin Sim

After the samples are collected they are laid out to dry ready for sorting. Before doing anything the samples are photographed for records. The larger pieces are removed and kept to one side. The next step is to begin sorting the organics and polystyrene beads from the smaller plastic fragments and nurdles (pre-production plastic pellets). At this point we are only photographing the polystyrene and organics. This way we can tell approximately what percentage of the total these make up. The small plastic fragments and nurdles are then seperated and counted. The results of these will be published in a report in the near future.

Extracting nurdles and then micro fragments from a sample
A sample laid out to dry before analysing

One of the most concerning issues with micro-plastics is that they are being found inside seabirds and fish, fish that are destined for human consumption. Nurdles or pre-production plastic pellets are the raw component of all plastic items. They are transported in large sacks and spillage is rife during both transportation and inside the factories. Factory floors are often washed down and the nurdles end up washing down the drains and into rivers leading to the sea. Nurdles are found on almost every beach worldwide.

Micro-plastics often have rough, coarse surfaces that attract pollutants and toxins like a sponge. Marine life that mistakenly eat these micro-plastics are often found either dead or malnourished as the plastics accumulate in the animals stomach, taking up essential space needed for food to energy transfer. Once in the stomach of an animal, the toxins then transfer to the flesh. This is where the concern lies with humans that consume seafood, eating flesh that has been marinated in toxins.

Several of the many nurdles from a sample under a microscope. The coarse surface of the raw plastic pellets act as a sponge for toxins.