Biology Professors Explore Effects of Pollution, Climate Change on Local Environment

Nikolas Stasulli, Ph.D., is concerned about the impact of pollution – specifically plastics – on the environment. His current research is exploring the impact that microplastics – small plastic pieces less than five millimeters long that can be harmful to the ocean and aquatic life – are having on fish in the lower Quinnipiac River and in New Haven Harbor.

Dr. Stasulli acknowledges that plastics have had a positive impact on the world, but he is concerned about the harm they are inflicting on wildlife, particularly because they are not easily broken down. He is also interested in the impact of bacteria on the environment since they impact such critical processes as oxygen production and the bioremediation of pollution.

Funded by a $19,000 grant from the Quinnipiac River Fund, Dr. Stasulli’s current research brings together both of these interests. With a focus on characterizing the gut microbiomes of estuarine fish, Dr. Stasulli is working with fellow University of New Haven biology and environmental science professor Chris Conroy, Ph.D., to explore the effects of microplastics on the gut and overall health of fish.

“We were both really excited when we heard we had received the grant funding,” said Dr. Stasulli, coordinator of the University’s biology and genetics & biotechnology programs. “This project interests me because we get to link the problematic part of plastics to the fundamental nature of bacteria. Ideally, we can even go a step further and try to cultivate bacteria from these fish that may be able to degrade the plastics they encountered while they were helping the fish digest.”

‘We are hoping to get a better insight into the effects that microplastics can have’

Drs. Stasulli and Conroy are assessing the relationships between environmental conditions, the prevalence of microplastics, and the animals’ diet. Dr. Conroy has previously conducted research with Jean-Paul Simjouw, Ph.D., a biology and environmental science lecturer at the University, that identified the types of microplastics found in fish in the Quinnipiac River. The current project will further explore how ingesting microplastics affects the health of fish by determining how microplastics influence their gut microbiota.

From May through October, the researchers are collecting fish – specifically, mummichogs, a small killifish – at sites along the Quinnipiac River to assess how the fish and their microbiomes change throughout the season. They are collecting fecal samples from the fish and performing genomic sequencing to identify the species of bacteria found in the fish. They hope to correlate changes in the fish to the microplastics the fish have ingested.

“Gut microbiomes play a really important role in animal health,” Dr. Stasulli explained. “Without gut bacteria, animals can’t get enough nutrients out of food to survive. We are hoping to get a better insight into the effects that microplastics can have on animal gut health and how that can affect overall health of the animal.

“Microplastics could affect both the types of microbes and amount of nutrients that are available in the gut,” he continued. “Getting a sense of these detrimental influences will, hopefully, help influence the regulation of microplastics and the efforts that are put into removing them from the environment.”

‘It is imperative that we understand how to keep our sources of freshwater as healthy as possible’

The grant enables Drs. Stasulli and Conroy to have two students help with the research over the summer, as well as during the upcoming academic year. The project is one of two being conducted by University faculty that has received a grant from the Quinnipiac River Fund.

The other, led by R. Christopher O’Brien, Ph.D., will explore the effects of seasonal water temperature variations on crayfish behavior. He is examining whether crayfish behavior could affect the health of the Quinnipiac River.

Dr. O’Brien and his fellow researchers are recording the activities of wildlife and attracting crayfish by using a baited underwater camera system. Meanwhile, they are keeping crayfish they caught in the Quinnipiac River in a laboratory, creating artificial environments for the animals that mimic the river.

Researchers are testing the effects of water temperature changes – changes that could, say, resemble summer heat waves or winter cold snaps – on the crayfish, observing their levels of aggression, lethargy, and appetite. They will record their behavior, collecting images from the video to analyze behavioral changes.

“As climate change becomes more and more real and its effects are more fully realized, it is imperative that we understand how to keep our sources of freshwater as healthy as possible,” said Dr. O’Brien. “So, we must first determine if crayfish are affected by changes in temperature, then their productivity as omnivores and keystone species could be tested later.”

‘It is imperative that we understand how to keep our sources of freshwater as healthy as possible’

Building off the Quinnipiac River Fund-supported research he conducted last summer, Dr. O’Brien’s work also enables students to gain hands-on experience. He hopes their work will lead to further research and interest in the local habitat.

“I want to further inform the public and local communities along the Quinnipiac River how important these crayfish are and how they can help sustain the health of the river as we continue to combat climate change,” he said. “Furthermore, I aim to conduct a project and create a dataset that can be used in later research projects, to continuously build upon our Quinnipiac River knowledge base.”