Team:Austin UTexas/Human Practices
Human Practices
Follow along on our Human Practices journey!
Background Research
The majority of our work in Integrated Human Practices focuses on tiny pieces of plastic called nurdles. The term “nurdles” officially refers to any microplastic that is less than 5 millimeters in diameter. Due to their incredibly small size, nurdles are difficult to pick up by hand and can be ingested by marine animals. Additionally, they are easily spilled during the transportation process and can pass through most methods of filtering. Nurdles are often made from polyethylene and polypropylene, which sink in water. While plastics are revered for their durability, this becomes an issue when plastics spill in the ocean since they can take hundreds or even thousands of years to break down. The extremely slow rate of degradation allows for a rapid accumulation of plastic nurdles within a few decades. It is estimated that as many as 53 billion plastic pellets are spilled into the ocean each year, and at the current rate of plastic emissions in the ocean, there will be 2.28 million tons of microplastics in the surface oceans by the year 2050. However, if the rate of microplastic emissions continues to grow as it has in the past, there will be 2.65 million tons of microplastics in the surface oceans by 2050. Current technologies for picking up nurdles are limited. Because of their small size, nurdles most either be picked up by hand or require big machines that destroy the environment as they filter for nurdles. Furthermore, none of the existing strategies aim to remove nurdles from water bodies. As far as we know no groundbreaking methods for cleaning up nurdles in water have been invented yet, but this will likely change in the near future.
Another focus of our research is oil spills, which are actually becoming far less common in recent decades. For example, the average number of spills per year totaled at 78.8 in the 1970s, in comparison to 6.3 in the 2010s. Similarly, the average quantity of oil spilled yearly has been decreasing ever since 1977 in which it peaked at over 600,000 tons. Since we are focused on oil spills that occur at sea, we will be addressing current protocols for alleviating the environmental impact of oil spills. The current standard response to an oil spill at sea is using chemicals to break the oil into smaller droplets, as well as trapping the spill with floating barriers called booms. Another method is using boats equipped with skimmers that remove thin layers of oil from the ocean surface. In situ burning is also used, where freshly spilled oil is set on fire. Unfortunately, there are a few issues with these methods. While in situ burning might remove the oil from the ocean’s surface, it creates large black plumes of smoke that pollute the air. Additionally, booms are helpful in reducing the spread of the oil spill, but do nothing to remove the oil from the water. Our hope is that by using engineered E.coli to produce plastic digesting enzymes and surfactants, we can provide a more effective solution to plastic and oil spill pollution.
Nurdle Patrol
On June 3rd, UTexas-Austin met over Zoom with Jace Tunnell, director of the estuarine institute in Aransas, Texas and founder of the citizen-scientist organization Nurdle Patrol to get a picture of how plastic pollution starts, how it affects the environment, and how federal and state agencies respond to plastic spills. He explained that, since the problem’s emergence in the 1950’s, the annual amount of nurdle pollution has grown every year, one of the consequences being significant disruptions in marine ecosystems. Fish, birds, and turtles may mistake the nurdles for prey and consume them, causing a myriad of health effects. Furthermore, nurdles may absorb harmful chemicals that worsen their effects. Despite the clear disruption that this kind of pollution causes however, the EPA does not consider plastic resin pellets to be hazardous material, which means that spills are usually left for coastal Americans to clean up themselves. Tunnell also brought up that, though PET nurdles are a significant portion of all produced nurdles, 90% of nurdles collected on beaches consist of either PE and PP; PET nurdles tend to be extremely difficult for citizen scientists to clean up because, in contrast to PE and PP, PET sinks.
Diane Wilson
Diane Wilson is a former shrimper and famous environmentalist from Texas who is known for suing Formosa Plastics, one of the largest plastic manufacturers in our region. Diane is from the same city that Formosa Plastics is based in, Point Comfort, Texas, and was the one responsible for investigating Formosa's pollution of nurdles and plastic powder into the surrounding environment. She sued them with a 50 million dollar settlement that was put towards programs supporting pollution mitigation, habitat restoration, public education and other environmental efforts on the middle Texas Gulf Coast. One of these programs was Nurdle Patrol, who we previously spoke to. In our meeting with Diane Wilson, we discussed the plastic pollution along the Gulf Coast by polluters such as Formosa Plastics. We also learned about ongoing legislation for preventative care in order to address this issue. Importantly, Diane emphasized that while measures are being taken to prevent further plastic pollution, there is currently no solution to address the existing pollution crisis. With this in mind, Diane helped narrow our focus to plastic pellets that float in the water, as their tiny size impedes efforts for cleanup.
Nurdle collection
In an effort to get our hands directly on the problem, members of the team visited three beaches in Galveston and two wetlands at Point Comfort. At these five locations we collected nurdles to input new data into the Nurdle Patrol database. Each of these entries is called a "survey", where we stop at one area and see how many nurdles can get picked up by hand by one person in 10 minutes. After completing 10 surveys across the 5 locations, we brought the nurdles back to our lab space and sampled them for cultures to see which species would be best for our phage delivery system. We found Pseudomonas species on the nurdles in several locations, which is also a host of our phage, P1.
Clean Gulf Associates
Clean Gulf Associates, Inc. is a non-profit oil spill cooperative that provides continuous coverage, state-of-the-art equipment, and expert personnel to 85 major and small independent companies. In our meeting with James Hanzalik, the vice president, we discussed various different oil spill clean-up solutions that are currently being used around the Gulf of Mexico. We specifically learned about various of different dispersants such as Accell Clean® DWD and COREXIT ® 9500. We learned how they function, to decide how we would apply dispersant properties to our phage delivery system.
Integrated Human Practices
Learn about how our human practices helped shape and modify our project
Integrated Human Practices
Through our meeting with Jace Tunnell from Nurdle Patrol, we gained a lot of information about the impact of the nurdle pollution within the Gulf of Mexico. Specifically, Jace emphasized that the vast majority of nurdles collected were either polyethylene or polypropylene. This led us to focus specifically on polyethylene terepthalate (PET), due to the abundance of research on PETase. Importantly, we were originally focused on targeting nurdles that float. However, through our meeting with Jace Tunnell, we soon discovered that due to the density of PET, these nurdles do not float in water and would therefore largely be inaccessible to our phage system. Thus, we narrowed our focus to target nurdles on wetlands, which are also incredibly difficult to clean up. According to Jace, the current cleanup methods are dependent on power jets and nets that are invasive and detrimental to the environment. Overall, from our meeting with Jace Tunnell, we were able to close the gap between our phage system design and the actual implementation of our system in the environment by focusing on PET nurdles in wetlands.
Our meeting with Diane Wilson further confirmed our implementation plans. Diane emphasized that current efforts are largely focused on preventative measures but little is being done to target the existing plastic pollution crisis. As she explained, while larger plastic pellets could be cleaned up through volunteer efforts such as Nurdle Patrol, smaller pellets, such as nurdles, can only be cleaned up using leaf blowers and pool nets. Diane further brought another type of pollution to our attention: plastic powder. This powder was being dumped into streams and their small size completely evades clean up methods. With this information, we presented our project idea and implementation, to which she confirmed that our proposal would be an effective means to target the existing plastic pollution without relying heavily on citizenry.
After gathering all this information, our iGEM team went to the coast to experience the issue up close. After conducting five nurdle patrol surveys on the Texas coast, we saw firsthand that wetland areas were neglected, compared to cleaner coastal beaches. This substantiated our plan to target wetlands, as suggested by both Jace Tunnell and Diane Wilson. Furthermore, we preserved some samples during our nurdle collection to determine the microbial community on the plastic. The 16S DNA sequencing from our nurdle swabs revealed a wide variety of microbes growing on the nurdles. Thus, from these results, we determined that an effective phage delivery system would have a broad host range in order to maximize infection and delivery of plastic degrading genes. Therefore, we decided to use the bacteriophage P1.
By meeting with environmental experts and conducting nurdle patrol collections ourselves, we redefined our plan to focus on wetland areas using P1 to target the large microbial population with greatest access to these nurdles.