Female angel sharks (Squatina squatina) are skipping their traditional breeding grounds as sea temperatures continue to rise — a climate-induced shift that could threaten the survival of this Critically Endangered species, according to a groundbreaking new study published in Global Change Biology.
🔥 Ocean Heatwaves Are Altering Shark Mating Behavior
Marine researchers from Lancaster University and the Angel Shark Project: Canary Islands have found that prolonged ocean warming around the Canary Islands is severely disrupting the reproductive patterns of female angel sharks. Using acoustic tracking over five years (2018–2023), they monitored the movements of more than 100 angel sharks and linked them to changing environmental conditions.
In 2022, sea surface temperatures in the region soared past 23.8°C, with temperatures above 22.5°C lasting nearly three times longer than in previous years. These record-high temperatures persisted throughout the mating season, which typically begins in late autumn.
🧬 Key Finding: Female angel sharks were largely absent from the La Graciosa Marine Reserve—Spain’s largest protected marine area—during peak mating months, while males returned as usual, hoping to find mates.
⚠️ Female Sharks Avoid Mating Grounds to Stay Cool
The study reveals that female angel sharks are more sensitive to temperature increases, likely due to their higher energetic demands related to reproduction. Unlike their male counterparts, they prioritize staying within a comfortable thermal range rather than risking physiological stress from warmer waters.
Dr. David Jacoby, a zoology lecturer at Lancaster University and the study’s lead investigator, explains:
“These extreme marine heatwaves are like underwater wildfires. While males still pursue mating despite high temperatures, females are avoiding breeding sites, which creates a major disconnect in reproductive timing.”
🌍 Canary Islands: A Crucial Habitat at Risk
The Canary Islands represent the southernmost limit of the angel shark’s natural range and are considered one of the last strongholds for the species. Adult and juvenile sharks are commonly seen, and the species plays a vital role in supporting the local diving economy and maintaining ecological balance in the marine food web.
However, with climate change driving ocean warming, this refuge may become uninhabitable for female sharks.
Dr. Lucy Mead, co-author from the Zoological Society of London and Lancaster University, warned:
“Angel sharks are ectothermic, meaning their body temperature is directly influenced by ocean temperature. Females seem more affected, which could reduce future breeding success if temperatures keep rising.”
📈 Five-Year Data Shows Alarming Trends
The long-term monitoring study observed:
- A steady increase in sea surface temperatures each year
- A rise in the number of days above 22.5°C from 30 days in 2019 to 85 days in 2022
- An extended hot season with high temperatures lingering into late November, overlapping with the entire mating window
This data confirms that 22.5°C may be a thermal threshold for female angel sharks, beyond which they avoid critical mating areas altogether.
🐟 Conservation Urgency in a Warming World
According to Eva Meyers from the Leibniz Institute and co-lead of the Angel Shark Project:
“These findings are a wake-up call. Climate extremes are already altering the behavior of endangered marine species. We need long-term monitoring and conservation strategies to protect these vital ecosystems.”
Dr. David Jiménez Alvarado from the EcoAQUA Institute adds:
“Changes in ocean temperature and chemistry are shifting predator behavior and habitat use. Since apex predators like angel sharks are crucial for ecological balance, understanding these impacts is essential for sustainable marine management.”
📢 Final Thoughts: Why It Matters
This study not only provides critical insight into the sex-specific impacts of ocean warming on angel sharks, but also raises broader concerns about climate resilience in marine predators. With rising global temperatures, the future of endangered ocean species depends on our ability to act now.
Protecting critical habitats like the Canary Islands must become a cornerstone of marine biodiversity strategies to prevent further population collapse of species like the angel shark.
🔗 Source:
Study Title: Rapid ocean warming drives sexually divergent habitat use in a threatened predatory marine ectotherm
Published In: Global Change Biology (2025)
DOI: 10.1111/gcb.70331