The earliest known eukaryotes, the ancestors of all complex life on Earth, lived in oxygenated, shallow marine environments nearly 1.7 billion years ago, according to a new study led by researchers at McGill University and the University of California, Santa Barbara. The findings cast doubt on the long-held belief that early complex life emerged in oxygen-poor environments or floated freely in the open ocean.

A new study of the blue button (Porpita porpita), a small and elusive sea creature which lives on the surface of the ocean, has found that it may live for several years adrift at sea, much longer than previously estimated. Researchers from the University of Tokyo’s Misaki Marine Biological Station also found that the float which keeps the animal adrift expands by growing new rings from its outermost layer. Blue buttons are notoriously difficult to keep alive in captivity, so this is a step closer towards eventually understanding their full life cycle.

In the latest in a series of studies showing how lab-raised fish differ from those raised in more natural environments, researchers found that medaka maintained in more natural settings ovulated earlier than those in the laboratory. These findings highlight the challenges of inferring natural behavior from that observed in the laboratory.

In a new study published in China Welding, researchers have optimized pulse frequency in local dry underwater laser welding (LDU-LW) of Q355B steel. The optimized pulsed laser process significantly improves weld formation, mechanical properties and corrosion resistance, offering a reliable solution for underwater repair and manufacturing of marine engineering structures.

A new, consolidated checklist of diatoms—a major group of photosynthetic microalgae—has been compiled for the Salish Sea, northeast Pacific, by a team of Canadian scientists. Integrating historical records with new reports, this first comprehensive baseline establishes a foundation for assessing diatom diversity in the region. As primary producers at the base of marine food webs, diatoms are key indicators of environmental change, providing critical insight into the health and resilience of the Salish Sea bioregion. The checklist is now published in the open-access Biodiversity Data Journal.