Fish kill lessons and data needs: a spatiotemporal analysis of citizen fish kill reports in coastal SW Florida

ABSTRACT: Fish kill events threaten aquatic life, local economies, and human health worldwide. However, due to their unpredictable and often short-lived nature, information about fish kill spatiotemporal trends, as well as the species composition and abundance of carcasses, remains limited. In coastal SW Florida, fish kill events are frequent, but much of what we know is based on citizen reports to the Florida Fish Kill Hotline and fisher experiences. This study aimed to identify spatiotemporal patterns of fish kill events in coastal SW Florida from 2010 to 2022 by analyzing open access Florida Fish Kill Hotline reports, red tide-related manatee mortality cases, and environmental monitoring data. Additionally, fish categories identified in Fish Kill Hotline reports were compared to carcass enumeration surveys conducted by the authors during a fish kill event in Tampa Bay, Florida, in July 2021. The results of the 2010-2022 dataset analysis indicate that Fish Kill Hotline reports were useful in identifying the location and duration of fish kills. The number of reports has also increased over the past 12 yr, particularly during the warmer summer months. However, Fish Kill Hotline reports were spatially biased and did not provide carcass enumeration results. Additionally, Fish Kill Hotline reports mainly included recreational fish groups, whereas enumeration surveys indicated the abundance of pinfish Lagodon rhomboides and demersal fish. These findings highlight the need for resources that enable citizens to accurately identify and enumerate carcasses accurately.