Sea Whip Habitat for Rockfish

5 June 2007  Pribilof Canyon

"Sea Whips" are a member of the Pennatulacean corals.  At over 2 meters high, Halipteris willemoesei is the tallest coral recorded in Pribilof Canyon. We will refer to three sources of data on its distribution and ecology:  a trawl-ROV study by Brodeur (2001), the NOAA Groundfish Observer online database, and the Greenpeace Bering Sea Canyons Submarine Expedition (2007). 

In the Brodeur (2001) study, the author reports observing dense aggregations of  Pacific Ocean Perch (Sebastes alutus) (>30 fish per minute) occupying "forests" of Halipteris willemoesii colonies. Colonies were evenly spaced about 2 m apart. This study contrasted these findings with areas in which no sea whips were found ... Pacific Ocean Perch were also absent.

NOAA_seawhip

The NOAA Groundfish Observer database invertebrate bycatch maps (right)show that seawhip bycatch in the pelagic trawl fishery occurred in the head of the canyon as well as on the shallower shelf just above the canyon in 2006. 

Sea Whips & POP

Submarine pilots also observed dense aggregations of Halipterus willemoesii in upper Pribilof Canyon during dives in 2007 (left). Like Brodeur, many observations of these sea whips revealed a close association with Pacific Ocean Perch, especially when whip density was higher. 

We are looking forward to seeing whether the sonar backscatter data can detect seawhips on the flat, sedimentary seafloor terrain they occupy.