Davies,
Sarah, Ali Griffiths, and T. E. Reimchen. 2007. Pacific Hagfish (Eptatretus stoutii),
Spotted Ratfish (Hydrolagus colliei) and scavenger activity near tethered carrion
in subtidal benthic communities.
Abstract: The influence of pelagic
carrion food falls on marine benthic scavenging communities was investigated at
two depths (10 m, 50 m) in Barkley Sound, west Vancouver
Island, British Columbia from
12 May to 4 June, 2003. A
remotely operated vehicle (ROV) equipped with video cameras was used to monitor
anchored carrion (15 kg pig leg) during daylight and darkness. The videos were
subsequently analyzed for species diversity, abundance and the intensity of
scavenging. At 10 m, Redrock Crab (Cancer productus) and Kelp Greenling (Hexagrammos
decagrammus) dominated, while at 50 m, Spot
Shrimp (Pandalus platyceros),
Spotted Ratfish (Hydrolagus colliei) and Pacific Hagfish (Eptatretus
stoutii) were the dominant species, most of which
were nocturnal. Hagfish were the major consumers of the carrion and after 23
days, no soft tissues remained at 50 m while 40% remained at 10 m. Within 24
hours of the carrion deployment, two of eleven ratfish succumbed probably due
to the direct clogging effects of hagfish mucus on the respiratory apparatus of
the ratfish. These field observations are consistent with laboratory results
suggesting high efficacy of hagfish mucus in competitive interactions.
Keywords: marine scavengers,
carrion, remotely operated vehicle (ROV), nutrient cycling, Eptatretus
stoutii, Hydrolagus colliei, Pandalus platyceros, Cancer productus,
Hexagrammos decagrammus