Ingested micro plastics have been shown to effect the way other contaminants are sorbed by fish. To test this idea this study used four groups of zebra fish with different feeding protocols. Group A was a control, Group B had feed supplemented by micro plastics, Group C had feed supplemented with micro plastics with a mix of PCBS, BFRs, PFCs and methyl-mercury, Group D had feed supplemented with the contaminants only. This study was conducted for three weeks. After completion, the fish are dissected, and the liver, intestines, brain and muscular tissue were examined.
The results of the study were interesting. Group B which was the feeding group with microplastics didn't show a significant amount of change in gene expression. Group D (which was the feeding group that had food supplemented with chemical contaminants) showed a significant amount of difference in gene expression. The fish that were in Group C (which was the group with plastic and contaminants) showed the highest amount of difference in gene expression. These genes are known as biomarkers and there changes can be troublesome. This data can be observed in Figure 2.
FIGURE 2. Differential gene expression of three genes in fish livers.
The most prominent effects of the treatments were detected in the livers at the microscopic and molecular levels. The results of the study show that while micro plastics are harmful, they are even more harmful in the presence of contaminants. The micro plastics were found to have a magnifying effect on the harmfulness of the contaminants
Citation: Rainieri, S., Conlledo, N., Barranco, A., Larsen, B. K.,
& Granby, K. (2018). Combined effects of microplastics and chemical
contaminants on the organ toxicity of zebrafish (Danio rerio). Environmental
Research, 162135-143. doi:10.1016/j.envres.2017.12.019
Microplastics in marine environments are very concerning. An article in the National Geographic pointed out the issue with microplastics really started to be acknowledged due to the little plastic beads used in face wash, toothpaste, and other household items, all which were getting washed down the drain. It is predicted that these plastic beads could accumulate to 93-236 thousand tons. It was also found that oysters that have consumed microplastic beads eat more algae as well and absorb it more easily. This is turn causes their ability to reproduce to be halved. This could effect the overall oyster population and change food web dynamics. These studies just demonstrate how harmful these microplastics could be for marine organisms and ecosystems.
ReplyDeleteMicroplastics are a prominent health concern in marine environments. The fact that the research found the largest amount of effects in the liver is concerning because the liver is utilized to break down toxins in the body. The review linked below states that an estimated 10% of plastics produced ends up in the ocean. Since microplastics are so small they are bioavailable to a wide range of organisms. The review linked below discussed a study that hypothesized that plankton will mistake small bits of white plastic for food. Check out Table 1 in this review to see more information on organisms that have been shown to ingest microplastics. There are still unresolved questions as to the effects of microplastics to marine organisms and more studies will need to be done to solve them.
ReplyDeletehttps://www.sciencedirect.com/science/article/pii/S0025326X11005133
Microplastics have recently become a concern in Lake Erie. These are found to disrupt aquatic food web systems. Lake Erie is the worst lake in the Great Lakes with the level of microplastics found. Microplastics can be ingested by a variety of aquatic organisms such as copepods, fish, and mussels. The main concern with microplastics is that they will impair organisms' ability to feed. This is just something to bring this home.
ReplyDeleteOverall, the topic of microplastics makes me think twice on littering, especially by a marine environment. I was raised to not litter, but never really understood the real harm of littering. However, in lecture we have learned that as we travel up the food web, energy from primary consumers will eventually be transformed into our own bodies. To piggy back off of Daniel's point, if the liver does not break down harmful toxin's within, per say, a fish's body, then these toxins could be passed up the food web to consumers. Ultimately, we (humans) are the end consumer. Therefore, it is important that what we are eating does not contain toxins, even if it is jut a little bit.
ReplyDelete