MUSSEL SYSTEM 



(METHANE BASED) 



SESSILE MF.fiAEALNA 



MOBILE MF.fiAfAl 'ISA. 



SEDIMENTARY SOURCE OF METHANE ( ■ 37 6 TO ■ 53 9 ) 

 AND OTHER HYDROCARBONS ( - Z7.0 ) 



HJBE WORM SYSTEM 



(SULFTDE/METHANE BASED ■•) 



SESSILE MEGAF AUNA 



GORGON1ANS 17.5 



ACESTA IM 



ACESTA COMMENSAL JO.) 

 POLYCHAETE 



MOBILE MEGAFAUNA 

 CA7_AnSHE»I II! 



EPIZQAN SUSPENSION 

 FEEDERS 

 BARNACLES - 27 2 



TUBEWORMS 

 ( 18.0 TO 60.0 ) 



CLAM SYSTEM 

 (SULFIDE BASED) 



SESSILE ME-WM^A 



PREDATORS 



NEOOASTROPOD 

 (- IS.0TO. 33 0) 



MOBILE MEGAFAUNA 



EPIZOAN BROWSER 

 NONE OBVIOUS 



THE TUBEWORM SYSTEM IS DIFFICULT TO SAMPLE DUE TO AWKWARD 

 SIZE AND SHAPE. ASSOCIATED FAUNA NOT WELL SAMPLED COINCI ■ 

 DENTAL TO WORM COLLECTION (WILL BEIMPROVED) 



CLAMS 



( -31 0TO-3J0 ) 



INTERNAL COMMENSALS 



NONE REPORTED SO FAR 



~~7 7 7 7 7 7 7 7 7 



STRUCTURE DEAD SHELLS DOMINATE LIVE MATERIAL 



SEDIMENTARY SOURCE OF HYDROGEN SULFIDE 



FUTURE WORK WILL INCLUDE BETTER SAMPLING 



Figure 4. Initial isotopic measurements on the 1987 Johnson Sea 

 Link cruise samples showing relationships between system 

 components. Values represent carbon isotope values in per 

 mil (o/oo) relative to the PDB standard. 



125 



