Climate change impact: Implications of shortening winters and rising sea water temperatures on captive marine fish brood stock management in Abu Al Abyad Island fish hatchery, Abu Dhabi, United Arab Emirates

Rapidly warming oceans temperatures and the occurrence of marine heatwaves are increasing at unprecedented rates and is further expected to increase the vulnerability of the already extreme marine environment of the relatively shallow Arabian Gulf to climate change impacts. The region's marine ecosystems are under ever-increasing pressures due to activities associated with the rapid urban development, making the Arabian Gulf one of the highest anthropogenically impacted regions in the world. Winters have shortened and temperatures have risen significantly over the last 24 years. In the channel waters of Abu Al Abyad Island, part of the southern Arabian Gulf, the average low winter sea surface temperature (SST) in January/February of 16.71 ± 0.9°C recorded during the years 2001-2004 increased to18.28 ± 0.7°C (an increase of 1.57°C) during the same period in 2020-2024. Similarly, the average high summer (July/August) SST of 34.75+0.4°C recorded in the years 2001-2004 increased to 36.04±0.7°C (an increase of 1.3°C) during the same period in 2020-2024. At the Aquaculture and Marine Studies Center (AMSC), Abu Al Abyad Island, Abu Dhabi, spawning data for Goldlined seabream (Rhabdosargus sarba), Silver black porgy (Sparidentex hasta) and White-spotted rabbitfish (Siganus canaliculatus), recorded during these years, showed a significant declining trend (P<0.05) in the duration of the spawning window relative to the optimal thermal regime for spawning of each species. Adoption of advanced technologies like climate controlled Recirculatory Aquaculture Systems (RAS) and selective breeding is recommended for the brood stock managers, to counter the negative effects of climate change.