Plastic Pollution in our local fish- UR Allie

Introduction

More than eight million tons of plastic are abandoned in our oceans every year and unfortunately marine life is subjected to the impacts. Plastic pollution confuses marine animals and ultimately poisons the natural environment. Naturally curious animals like fish tend to nibble on plastic and often get tangled up in the pollution. This may result in severe mutations and deathly harm to many species. Plastic is a man made material unable to naturally decompose in the environment or digest as part of the normal diet. Internal plastic accumulation is proven to lead to blockages that shut down the digestive tract and cause death. Plastic has a decay rate of about 400 years and each year we produce more and more of it. Studies held by a team of scientists from the University of Georgia, California, Santa Barbara and Sea Education Association conduct the first ever global analysis and current statistic on plastic (Geyer et al. 2017). These researchers have discovered About half of the total amount of plastics manufactured from 1950 to 2015, have been produced in the last 13 years alone. This implies the pace of plastic production is only speeding up, even though most products are only used once before disposal. The researchers also discovered that by 2015, people had produced 8.3 billion metric tons of plastics, 6.3 billion tons of which had already become waste. Within the total waste, a mere 9 percent was recycled, 12 percent was incinerated and 79 percent resides in landfills or the natural environment- such as the ocean.

What is known

•Waterways are polluted with harmful toxic non-biodegradable material and disrupts natural habitats. (Stifferlin, 2015)

•Plastic ingestion can cause internal damages such as ulcerations and partial blockages of digestive tract resulting in starvation and death. (Macklin, 2018)

•Ingestion is noticed in both predatory fish and filter-feeders. Predatory fish can mistake plastic for food while filter-feeders sometimes ingest them unintentionally while feeding. (Blastic, 2016)

What is unknown

•Local studies of the microplastic ingestion by fish

•Studies on physical damage and excretion processes in the gastrointestinal tract of fish

•Clear differences in the amount of plastics ingested between pelagic and benthic fish

•A relationship between fish feeding habits/ diet and liability to consume plastics

Dissecting Whiting and extracting stomach

Searching for microplastics

Scientific Question

Are local fish ingesting plastic? 

Materials 

Microscope used for fish dissection

•Fish ID guide

•Measuring tape

•Camera

•Dissecting kit

•Petri dish

•Dissecting microscope

•HCl solution and pipette

•Hot plate

Methods

•Dead fish were collected from numerous location sites in Daytona Beach, FL. Each fish was measured for fork length and identified by species with the use of a fish ID guide.

•The fishes’ remains were preserved and transported to the laboratory for further examination.

•In the lab, a knife was used to cut horizontally along the abdomen of the fishes’ belly. A general fish anatomy diagram was used to remove the stomach and digestive tract.

•Utensils from the dissection kit were used to cut and dissect the contents to complete a visual survey. If microplastic fibers were discovered, they were removed, rinsed with distilled water and placed in a petri dish to be inspected under the microscope.

•Found substances were then tested by pouring HCl dilute on top of substance. This test determines if substance is composed of CaCO₃ shell material or white/ opaque plastic. If the dilute bubbles/ reacts to the substance then it can be identified as shell material.

•The substance was also tested for plastic material by applying heat to a metal and touching the hot end to the fiber. If the material shrivels up and melts, determine this to be a plastic.

General fish anatomy

Results

            After collecting, preserving and individually dissecting each fish under a microscope, one microplastic fiber (<1 cm) was found out of 11 locally caught fish. The species examined include 3 Mullet, 1 Catfish, 4 Bluefish, 1 Atlantic Croaker, 1 Whiting and 1 Pompano. This one microplastic fiber found was located in the digestive tract of a 44 cm Bluefish. This finding was tested and confirmed by the HCl dilute and heat reaction tests.

Microplastic fiber (<1 cm) found in 44 cm Bluefish

Bluefish dissected

Pompano stomach

Whiting ready for dissection

Pompano Stomach
dissected

44 cm Bluefish

The stomach of Bluefish

Discussions & Conclusions

After harvesting and dissecting 6 species of fish, it’s determined that microplastic fibers are being consumed by local fish. 

Errors

•Results could be affected by not rinsing possible plastic with distilled water before completing the HCl dilution test substance for CaCO₃ shell material or plastic. This could interfere with the determining substance composition.

•Acquiring information from remains of the fish guts is very difficult. The visibility when inspecting the guts for microplastics is low because the remains are covered in blood, bodily fluids and liquids.

Suggestions for Future Research

•A chemical analysis of fish guts may reveal more data. By extensively studying the fish guts by involving a chemical analysis of the composition, this method could exhibit more sensitivity to the presence of plastics. 

Bibliography 

University of Georgia . “More than 8.3 Billion Tons of Plastics Made: Most Has Now Been Discarded.” ScienceDaily, ScienceDaily, 19 July 2017, www.sciencedaily.com/releases/2017/07/170719140939.htm.

European Union. “Plastic Ingestion by Fish.” Blastic, 2017, www.blastic.eu/knowledge-bank/impacts/plastic-ingestion/fish/.

Sifferlin, Alexandra. “Here's How Much Plastic Ends Up In the World's Oceans.” Time, Time, 12 Feb. 2015, time.com/3707112/plastic-in-the-ocean/.

Macklin, Malorie. “Is It Really Worth the Convenience? 6 Ways Plastic Is Harming Animals, the Planet and Us.” One Green Planet, 23 Nov. 2017, www.onegreenplanet.org/environment/how-plastic-is-harming-animals-the-planet-and-us/.