Preventing Pelican Injuries From Angler Gear
Beachgoers in North and South America may observe Brown Pelicans, large and elegant birds who catch fishes in their extended beaks and store them in their throat pouches. A common problem Brown Pelicans face is entanglement in fishing gear like fishing lines, especially near crowded piers. Injury and death from these accidents are common and may harm their population.
There are many suggested causes of pelican entanglement, such as the time of day, season, the number of anglers near a fishing pier, and the food scraps they leave behind. However, it is not well understood which factors cause the most harm.
Researchers observed Brown Pelicans over the course of one year at four public fishing piers (the Gulf, Bay, North Skyway, and South Skyway piers) in the Tampa Bay region of Florida. Every other week between 2019-2020, the researchers counted free and entangled pelicans through binoculars and recorded conditions that might be related to entanglement. Specifically, they looked at the pier itself, pier closures due to COVID-19, the time of day, the season, the number of fishers, and the number of Brown Pelicans present at each location. They also noted incidents that typically draw seabirds to a given location (e.g., discarding dead fishes into the water).
Over the course of the study, 3,766 Brown Pelicans were observed over 144 observations. 254 of the birds (7%) were entangled or had signs of injury from entanglement, and 17 were dead. The researchers and volunteers captured entangled birds when possible to rehabilitate them. 6,054 anglers were counted across all four piers, and they did not appear to throw fileted carcasses, bait, or dead fishes into the water very often.
Only the pier, the time of day, and COVID-19 closures were strongly related to pelican entanglement. There were more entanglements in the morning and mid-day when pelicans were most often diving for fishes and when the piers were open to anglers. The South Skyway and Gulf piers also had more entanglements than the Bay and North Skyway piers, although the difference could not be explained by any of the other measured factors.
The researchers were curious about why there was a difference in entanglement rates at the Gulf and South Skyway piers and observed that perches close to the piers might be the culprit. Pelicans were seen perching on rocks and bridges within 10 meters of the South Skyway and Gulf piers. Similar perches were farther away from the North Skyway pier and Bay pier. It was also noted that, during the COVID-19 pier closures, entanglements decreased even though boat fishing became popular. This suggests that Brown Pelicans may become entangled based on their tendency to fly underneath elevated pier structures, running into transparent fishing lines hanging down from the pier.
Thanks to the research, managers at the Gulf Pier prohibited fishing next to the exposed rocks where pelicans often perch, which decreased the number of pelicans hurt due to entanglement. More research into the causes of pelican entanglement and efforts to remove perches or prevent fishing near perches could save even more pelicans’ lives. Advocates can help by calling upon their local governments to ban pier fishing and deter seabirds from perching near piers. Furthermore, they can educate community members about what to do if they encounter an entangled bird.