Craig, N. I. National Oceanic and Atmospheric Administration, NANCY.CRAIG@NOAA.GOV
, . I. ,
DO SUBSURFACE DETRITIVORES REALLY EXIST?
Deposit feeders are thought to rely on a very poor food source consisting of mineral grains and refractory organic matter. The problem of being a deposit feeder worsens as feeding depth increases since diagenetic theory predicts the average quality and quantity of organic matter decreases exponentially with depth in sediment. Nevertheless, large subsurface deposit feeders are common in near shore and shelf benthic communities.
The solution to the mystery of how large subsurface deposit feeders subsist on reworked organic detritus, may in fact be that they do not. The ability of some subsurface deposit feeders to successfully exploit their environment may depend on their ability to modify that environment, thereby altering the flow and availability of energy and reactive organic matter in the system.
The maldanid polychaete Clymenella torquata provides one clear example. Population level bioengineering of sediment structure by C. torquata, coupled with physical and biological irrigation, created a large-scale biogeochemical hot spot conducive to the capture, production and turnover of reactive organic matter in an intertidal sandflat. C. torquata essentially constructed and maintained a municipal structure for mutual population benefit to solve the problem of being a deep head down deposit feeder. The question then becomes: Are there any real subsurface deposit feeders?
Day: Thursday, Feb. 4
Location: Sweeney Center