Interacting climate change effects on mussels (Mytilus edulis and M. galloprovincialis) and oysters (Crassostrea gigas and Ostrea edulis): experiments for bivalve individual growth models

• Published in: Aquatic Living Resources
• Main Authors: Kamermans, Pauline, Saurel, Camille
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: Chlorophyll; Climate change; Crassostrea gigas; Growth; Mytilus edulis; Mytilus galloprovinciallis; Ostrea edulis; Oxygen; Temperature
• Online Access: https://research.wur.nl/en/publications/interacting-climate-change-effects-on-mussels-mytilus-edulis-and-; https://doi.org/10.1051/alr/2022001

The physiological response of two species of mussels (Mytilus edulis and M. galloprovincialis) and two species of oysters (Crassostrea gigas and Ostrea edulis) to temperature, oxygen levels and food concentration, factors likely to vary as a result of climate change, was determined experimentally. Bivalves of similar size from different origins were exposed to six temperatures (3, 8, 15, 20, 25 and 30 °C) at two food regimes (2 and 10 μg Chl a L−1) for 6 weeks. In a parallel running experiment M. edulis from the same batches were exposed to three different temperatures (15, 20 and 25 °C) and three different oxygen levels (30, 50 and 100%) at two food regimes (2 and >8 μg Chl a L−1) for 3–4 weeks. Survival during the experiment ranged from 93% to 100% except for the mussels exposed to 30 °C which showed 100% mortality after three to 32 days. Higher food conditions showed higher optimal temperatures for growth of mussels and oysters. In addition, at the high food treatment, reduced O2 saturation resulted in lower growth of mussels. At the low food treatment there were no differences in growth among the different O2 levels at the same temperature. At high food concentration treatment, M. edulis growth was higher with low temperature and high oxygen level. Condition index was higher at higher food concentrations and decreased with increasing temperature. In addition, condition was lower at low oxygen saturation. Lower clearance rates were observed at high food concentrations. At 100% saturation of oxygen, mussel clearance rate increased with temperature at High food regime, but not at Low food regime. Mussel clearance rates were significantly reduced with low oxygen concentrations together with high temperature. Oxygen consumption significantly increased with temperature. Oxygen saturation was the main factor affecting mussel clearance rate. High temperature and low oxygen concentration combined significantly reduced clearance rate and increased oxygen consumption. These response curves can be used to improve ...