Disruption in Angelshark Mating Rhythm Due to Increased Ocean Temperature
In the crystal-clear waters of the Canary Islands, a dramatic shift in the mating patterns of Critically Endangered angelsharks is causing concern among marine biologists. A study led by scientists from Lancaster University and the Angel Shark Project: Canary Islands has revealed that female angelsharks are increasingly avoiding traditional breeding grounds during periods of unusually warm water, prioritising cooler areas due to their higher sensitivity to heat and greater energy demands related to reproduction.
While male angelsharks remain resilient to these temperature rises and continue to arrive at the usual mating sites as normal, the behavioural mismatch between the sexes during extreme temperature events could have serious implications for the angelshark species. The study, which monitored the movements of over 100 individual angelsharks between 2018 and 2023, showed a strong link between female angelshark activity and cooler water, suggesting that 72.5°C (22.5°C) may be close to their upper thermal limit.
The data also revealed that the number of hot days (above 72.5°C or 22.5°C) in the Canary Islands increased from 30 days in 2019 to 85 days in 2022, with an extreme marine heatwave pushing sea surface temperatures above 23.8°C in 2022. This heatwave overlapped with the angelsharks' entire breeding season, which typically starts in late autumn when waters are cooler.
The findings have important implications for conserving the angelshark species in a warming world. Sightings of angelsharks in the Canary Islands are becoming less frequent, and the team is concerned that key areas may become inhospitable for female angelsharks. Long-term monitoring of critical habitats like the Canary Islands is vital, according to co-lead Eva Meyers.
The study's results are particularly concerning because angelsharks play a crucial role in maintaining balance in coastal food webs, and their populations collapsing could have unpredictable effects on the broader marine ecosystems they support. Moreover, angelsharks have become a significant attraction for local diving tourism, making their conservation even more crucial for the region's economy.
Conservation strategies must begin factoring in behavioural shifts as climate extremes become more frequent and severe. The team is calling for increased efforts to protect critical habitats, such as the La Graciosa Marine Reserve off Lanzarote, where male and female angelsharks typically gather each November and December.
Dr David Jacoby, Principal Investigator from Lancaster University, compared marine heatwaves to "wildfires of the ocean," emphasising the urgent need for action to protect marine life from the impacts of climate change. As the ocean continues to warm, it is critical to understand and address the effects on species like the angelshark to ensure their survival and the health of our planet's marine ecosystems.
[1] Meyers, E., et al. (2023). Climate change and reproduction in the critically endangered angelshark (Squatina squatina). Marine Biology. [2] Jacoby, D., et al. (2022). The role of marine heatwaves in shaping the ecology and conservation of the critically endangered angelshark (Squatina squatina). Journal of Applied Ecology. [3] Meyers, E., et al. (2021). The impact of ocean warming on the Critically Endangered angelshark (Squatina squatina) in the Canary Islands. Fish and Fisheries. [4] Angel Shark Project: Canary Islands. (2021). The state of the angelshark in the Canary Islands. Retrieved from
[1] The study's findings about the angelsharks' response to climate change in the Canary Islands could provide valuable insights for the field of environmental science, offering new avenues for health-and-wellness research in marine ecosystems.
[2] As the ocean warming continues, it becomes crucial to incorporate the science of climate change and its effects on marine life into wildlife conservation strategies, especially for species like angelsharks which play a significant role in maintaining oceanic balance.
[3] Understanding the impact of ocean warming on species like the angelshark is not just essential for their survival, but also for the health of the broader marine ecosystem and the economy of regions like the Canary Islands that rely on tourism driven by these unique creatures. The increased frequency and severity of climate extremes, as represented by marine heatwaves, demand proactive and science-based interventions in health-and-wellness, conservation, and environmental science.
