Faunal succession on deep-sea whale falls

Craig R. Smith, Ph.D. and Amy Baco
University of Hawaii at Manoa

David Kadko and Dan Schuller
University of Miami

Wednesday, March 27, 2002
3:00 p.m.–Pacific Forum

To evaluate faunal succession and persistence times of whale-fall communities, we are conducting time-series studies of three implanted whale carcasses and radiometric dating of two natural whale skeletons harboring chemoautotrophic assemblages. Implanted carcasses (5000-35,000 kg) indicate that whale-fall communities pass through three successional stages:

1. A mobile scavenger stage, lasting ~4 months to >1.5 years, during which deep-sea necrophages (hagfish, lysianassid amphipods, macrourid fish, sleeper sharks) remove most soft tissue.
2. An enrichment opportunist stage, wherein surrounding sediments are heavily colonized by newly discovered chrysopetalid and dorvilleid polychaetes, cumaceans, and in some cases, juvenile gastropods and bivalves.
3. A sulfophilic (chemoautotrophic) stage containing >200 macrofaunal species, 10 of which also occur at hydrothermal vents and 12 at cold seeps. The sulfophilic stage includes mussels (Idas washingtonia) which appear early in the evolutionary lineage of the vent-seep subfamily Bathymodiolinae. Measurements of ²¹⁰Pb/²²⁶Ra disequilibrium suggest that the sulfophilic stage on large skeletons lasts decades.