Dive 11: An Egg-cellent Find
This round purple object is in fact an octopod egg. It was seen while exploring at a depth of ~2,215 meters near Howland Island. Video courtesy of the NOAA Office of Ocean Exploration and Research, Discovering the Deep: Exploring Remote Pacific MPAs. Download (mp4, 18.1 MB)
For this dive, we picked up where we left the seafloor on Dive 09 and transited along a ridge from 2,227 to 2,084 meters depth. Initially, the seafloor was a sedimented plateau surrounded by exposed, high profile rock features. Along the ridge, there was a sedimented slope with a perimeter of rocky ledges, interspersed by rock boulders. Toward the end of the dive, the substrate was composed of continuous hard-rock pavement with high profile, exposed rocky substrate. The dive began at the base of the ridge, on a plateau with several large coral colonies. A small sample of an unknown chrysogorgid octocoral with a width of 1.5 meters was collected. Additional corals encountered along the ridge included other octocorals, seapens, black corals, and whips and an unknown internodal branching bamboo. This dive had typical coral and sponge associates, including crinoids, brittle stars, ctenophores, shrimp, unknown worms, and aplacophorans. One new "associate" observed was a cirrate octopod egg case attached to a paragorgid octocoral. The case was cracked open, revealing the chorion, which may expand as the octopus embryo develops. Other empty brown cases were noted on Dive 09 at a similar depth, attached to a colonial hydroid. Other invertebrates observed, either attached to the rocks or on the sediment surface, included sea cucumbers, sea stars (a possible new species was collected), solitary hydroid, sponges, a hermit crab with a zooanthid house, shrimp with stilt-like legs, xenophyophores, stalked crinoids, an asteroschema on the rock surface without a host (unusual), sea urchins, a gastropod, and a sea spider. Along the ridge, there were at least three fish species, including halosaurs and cusk eels. The ship will be returning to Baker Island tomorrow to continue characterizing the diversity and distribution of organisms within the Pacific Remote Islands Marine National Monument.