Welker Seamount peaks around 700m depth in the Northeast Pacific. Pillow lava is pictured here at 2700m depth, indicating an eruption on the seamount flank. The base is ~3500m. Gorgonians have settled nearby. Unidentified hexactinellid sponges with crabs and anemones are part of the habitat. This one below is relatively large. The lasers are set 10cm apart. This is one of many similar microhabitats at this depth range on the Northeast Pacific seamounts. Every sponge is an island.
These image are from Alvin Dive 4033 on the NOAA Gulf of Alaska 2004 Expedition, courtesy of NOAA’s Office of Ocean Exploration, Woods Hole Oceanographic Institution, the Alvin Group, and the Gulf of Alaska Seamount Expedition Science Party.