Long-spined sea urchins
Long-spined sea urchins (National Marine Sanctuaries/CC BY 4.0)

Transglobal Spread of a Sea Urchin Parasite

The study identified the parasite that devastated 95 percent of long-spined sea urchins in affected areas in the Caribbean Sea two years ago. It burrows into the tissue of the sea urchins and triggers abnormal behaviour. The urchins droop and lose their ability to control their tube feet, which are crucial for movement. They lose their spines, then tissue necrosis sets in, leading to the death of the sea urchins.

Tones & Tonality: Contributors' Picks

Photo by Scott Bennett: Bigeye jacks, Sipadan, Malaysia—cool tones. Gear: Nikon D200 camera, Sigma 10-20mm lens at 10mm, Hugyfot housing, two Ikelite D125 strobes. Exposure: ISO 100, f/6.3, 1/80s.

We asked our contributors to share their favorite underwater photos that showcase tones and tonality, and they returned with a range of wide-angle and macro shots featuring a variety of marine life, reefs and topography.