Changes in angler demography and angling patterns during the Covid-19 lockdown in spring 2020 measured through a citizen science platform.

From 11 March to end of May 2020 a lockdown was imposed in Denmark due to the Covid-19 outbreak. Concurrently a 20% increase in sales of mandatory national angling licenses was reported in Denmark, suggesting an increase in angling participation. Here, we use data collected from a citizen science platform for recreational anglers to a) explore whether the increase in participation affected multiple characteristics of the anglers that registered to the citizen science platform in spring 2020, and b) explore changes in angling effort and catch patterns during the lockdown as reported to the platform. The results indicate that the platform was able to detect changes in the characteristics of the participants in the Danish recreational angling during the Covid-19 lockdown, i.e. participants were younger, more likely to live in urban areas, less experienced, stated angling as a less important hobby, and less likely to be from outside of Denmark. The spring 2020 participants did not conduct more fishing trips compared to previous years, but their effort patterns differed. The effort patterns revealed a shift in fishing activity from weekend to weekday and, during the day, a shift in fishing activity from midday to early evening. These changes most likely reflect the extraordinary conditions that most Danes experienced during the lockdown. We found relatively lower catch rates and a trend towards retaining more fish, among the participants that registered in spring 2020. The results are discussed in relation to biological implications and lessons learned about data collection from citizen science platforms.