LEARNING ABOUT EUTROPHICATION: WHAT ARE STUDENTS THINKING?

 Eutrophication is an important socio-scientific issue, and an example of a complex phenomenon that many future biologists will encounter. Multiple university courses teach eutrophication in a variety of disciplines (e.g., biology, geology). However, students struggle with emergent phenomena, so educators are  challenged  to help students reason about the consequences of the interactions within ecosystems. This study aims to develop an open-response item (in which students use their own words to answer a question) to encourage systems thinking related to eutrophication. A lake eutrophication assessment item was given to 225 undergraduate students in four different courses (two in fisheries departments and two in general biology departments) across three universities. Student responses were coded using a systems- thinking coding scheme consisting of: 1) Phenomena, 2) Mechanisms, and 3) Components (PMC). Preliminary results (Fig 1) indicate that more fisheries than general biology students correctly stated that the phenomenon was eutrophication (20% as compared to 5%) or algal bloom (60% as compared to 25%),  and  fisheries students also include ideas related to fish kills and stratification. Mechanistic reasoning, as identified by Mechanism codes, was rare (<15%). Instead, students typically wrote that algae "sucked up all the oxygen" giving no mechanism for oxygen removal. Most students tended to reason in absolutes (e.g., all the oxygen) instead of relatively or proportionally. Additionally, most students (>75%) recognized oxygen as an important component in the system. Although the question provided context that the lake was next to a woodland, students added non-relevant components to the system (e.g., fertilizers, ocean). We found that s tudents were more  readily able  to identify  system  components, but not their interactions. Data collected this fall will be used for assessment improvement. Outcomes will reveal patterns in students' reasoning about complex systems and concepts that could be addressed to students or personnel who transfer between general biology and fisheries disciplines. Findings will inform intervention recommendations for instructors (e.g., teachers, extension educators) to improve students' systems thinking and scientific literacy.