iQQTV

Thermal Stress and Early Life Stage Performance in Emerging Aquaculture Species of the Arabian Gulf

Aquaculture in the Arabian Gulf is expanding to meet regional food security targets, but the Gulf is the warmest sea in the world. Summer surface temperatures regularly exceed 35 °C and salinity sits well above the ocean average. Hatchery methods used across the region were developed in the Mediterranean, where seabream are reared 8 to 15 °C cooler. Embryos and larvae are the stages least able to tolerate that difference, and losses at this point remain a major constraint on production.

Temperature governs how fast an embryo develops, whether it hatches, how efficiently it uses its yolk, and whether it forms normally. Alongside this, hatcheries routinely disinfect eggs to reduce microbial load and prevent disease. Both practices are well established on their own, but their combined effect has limited research available. Disinfectant efficacy and toxicity are both known to shift with temperature, which means a dose that is standard in a Mediterranean hatchery may not be safe in a Gulf one.

This project addresses that gap: Fertilised eggs of Gilthead Seabream (Sparus aurata), Sobaity Seabream (Sparidentex hasta) and Orange-Spotted Grouper (Epinephelus coioides) will be reared under a factorial design crossing three temperatures, representing present and near-future Gulf conditions, with standard and alternative egg disinfection treatments plus untreated controls.

Embryonic development will be tracked using light microscopy and image morphometrics, measuring egg diameter, yolk absorption, hatching time and deformity incidence. Larval performance will be assessed through behavioural assays covering swimming activity, feeding response and phototaxis, alongside growth and survival. Water quality and microbial load will be monitored throughout to separate treatment effects from background variation.

The aim is to identify the temperature and disinfection combinations that support healthy development, and the thresholds beyond which performance declines. The outputs are intended to be directly usable by commercial hatcheries and conservation breeding programmes in the region, and to contribute to a wider understanding of how warm-water fish respond to combined thermal and husbandry stress.

Supervisors: 

Dr Helena Reinardy, iQQTV (primary supervisor)

Dr Mairie Cowan, iQQTV 

Dr Silvana Birchenough, College of Marine Science and Aquatic Biology and Sharjah Marine Science Research Centre, University of Khorfakkan, UAE

Start date:

01 October 2026