“In 2022 and 2023, we saw large areas below this threshold,” he said, adding projections from the research data suggest marine oxygen levels will get significantly worse by mid-century. Preliminary data gathered during 2024 and to date in 2025 suggest that the region's deep waters continue to experience oxygen starvation. Persistent low oxygen levels along the Central Coast could also cause a shift in the distribution of fish, which, unlike slower bottom-dwelling creatures, will migrate away from hypoxic areas, he said. Data about changing oxygen levels can better help inform monitoring of fish stocks and conservation decisions, he noted. The combined effects mean there is less oxygen in deep ocean water when it returns to flow over the continental shelf along the BC coast eight to 10 years later, he said.