How Recreational Fishing Videos are Aiding Management Efforts

By Nina Colagiovanni, SRC intern

As technology advances in today’s world, scientists are becoming more aware of the benefits of data gathered from platforms like YouTube. Research conducted by Sbragaglia et al. collected YouTube videos relating to recreational fishing of four species of grouper: dusky (Epinephelus marginatus), white (Epinephelus aeneus), goldblotch (Epinephelus costae) and dogtooth (Epinephelus caninus). Recreational fishing refers to any fishing activity that is not done for commercial purposes (Giovos et al., 2018).

Figure 1:  mA Fishing Rod and Reel Set Up [Wynand van Poortvliet via Unsplash]

This research was carried out in Italy between the years of 2011 and 2017 in order to understand the ecological patterns of groupers in the Mediterranean Sea and to demonstrate how data can aid in conservation science (Sbragaglia et al., 2020). Data was obtained from anglers and spearfishers who had uploaded videos of their catches publicly. 

Prior research examined recreational fishing videos of common dentex (Dentex dentex) which is an important species in the Mediterranean, and it was found that there was greater support as well as a greater mass of fish caught in angling videos versus spearfishing videos (Sbragaglia et al., 2019). 

This research focused on groupers which are currently listed under the International Union for Conservation of Nature (IUCN) Red List. Their hypothesis included that larger target species will search for protection from fishers in deeper waters, known as the “depth refuge” hypothesis (Sbragaglia et al., 2020). Additionally, they wanted to examine whether there was a northward expansion in the white grouper.

Figure 2: Number of Annual Videos Related to Recreational Fishing of Groupers [Sbragaglia et al. 2020]

A total of 2097 videos were identified over the years, with 1714 (82%) relating to spearfishing and 383 (18%) relating to angling (Sbragaglia et al., 2020). The videos were reported in regard to fishing method, which marked angling with red triangles and spearfishing with blue circles, as shown in Figure 2 (Sbragaglia et al., 2020). It can be seen that the trends differed depending on the species. For instance, the dusky, white and goldblotch groupers had more videos relating to spearfishing, while the dogtooth did not. This is due to the fact that dogtooth groupers inhabit deeper water where it is more difficult to spearfish.

In comparison to the common dentex, spearfishing videos were more representative in grouper species. This could infer that more spearfishing videos are being uploaded to YouTube or that spearfishing is a more popular method for grouper catches.

Figure 3: A Dusky Grouper [Pascal van de Vendel via Unsplash]

Overall, their results found that body mass and depth in angling videos were greater than in spearfishing videos for both the dusky and white groupers, and that there was a northward expansion of the white grouper (Sbragaglia et al., 2020). This supported their initial hypothesis, indicating that there were shifts in grouper distribution.

This research not only provides insights into the ecological patterns of groupers, but also displays how digital data gathered from platforms like YouTube can be utilized for research purposes and can contribute to management of marine species like the grouper or the common dentex in the future. 


Works cited

Giovos, I., Keramidas, I., Antoniou, C., Deidun, A., Font, T., Kleitou, P., . . . Moutopoulos, D. (2018, June 28). Identifying recreational fisheries in the Mediterranean Sea through social media. Retrieved March 10, 2021, from

Sbragaglia, V., Correia, R., Coco, S., & Arlinghaus, R. (2019, June 14). Data mining on YouTube reveals fisher Group-specific Harvesting patterns and social engagement in recreational anglers and spearfishers. Retrieved March 10, 2021, from

Sbragaglia, V., Coco, S., Correia, R., Coll, M., & Arlinghaus, R. (2020, October 04). Analyzing publicly available videos about recreational fishing reveals Key ecological and social insights: A case study ABOUT groupers in the Mediterranean Sea. Retrieved March 10, 2021, from