Salinity and temperature affect sperm motility, ATP content, fertilization success, embryonic development, and mitochondrial function in mussels Mytilus edulis from the Baltic and North Seas

This dataset provides experimental results from a study investigating the impacts of climate-driven temperature and salinity changes on the reproductive capacity of blue mussels (Mytilus edulis) in the Baltic Sea and North Sea.

In this study, we have measured and calculated sperm motility, ATP content, fertilization success, and embryonic developmental stage distribution of mussels from the Baltic and North Seas. Temperature (5°C, 10°C, 15°C, 20°C, 25°C)and salinity (5, 9, 13, 17, 21 for BS mussels and 9, 17, 21, 30, 35 for NS mussels) exposures were carried out in separate experimental runs.

Notably, sperm mitochondrial function assays were conducted only on the Baltic Sea mussels under the combined temperature (15°C, 20°C, 25°C) and osmolarity (630, 510, 390, 270, 150 mOsm) conditions. Sperm mitochondrial respiration and ROS production at oxidative phosphorylation (OXPHOS) and LEAK status were measured. The respiratory control ratio (RCR) and fractional electron leak (FEL) were calculated based on the measured traits.

These data support mechanistic insights into how climate-induced environmental variability may impair mussel reproduction, with implications for population resilience modeling in marginal seas. Researchers can reuse this dataset to validate ecophysiological models or compare adaptive thresholds across marine bivalve species.