Table 1.— Total number of individuals per square meter averaged over five quarterly cruises (August 1973-September 1974). 





Depth (m) 



Sediment organic 



level 





Sediment type 







Very 

 coarse- 

 coarse 



sand 



Medium 

 sand 



Fine- 

 very 

 fine 

 sand 



Coarse- 





High 



>5% 



Medium 

 3-5% 



Low 

 <3% 



medium 



Taxonomic group 



0-24 



25-49 



silt 



Phylum Coelenterata 



470 



2.170 



1.910 



340 



390 



60 



120 



1.710 



750 



Class Anthozoa 



470 



2.170 



1.910 



340 



390 



60 



120 



1.710 



750 



Edwardsia spp. (£. elegcms and E. sipunculoides) 



10 



190 



130 



30 



40 







10 



110 



80 



Ceriantheopsis americanus 



460 



1,980 



1.780 



310 



350 



60 



no 



1.600 



670 



Phylum Phoronida 



360 



1,080 



930 



210 



300 



10 



170 



970 



290 



Plwronis archilecla 



360 



1,080 



930 



210 



300 



10 



170 



970 



290 



Phylum Mollusca 



12.390 



42,154 



44.810 



1.247 



8.487 



1.150 



2.500 



37.954 



12.940 



Class Gastropoda 



50 



60 



20 



20 



70 







30 



80 







Nassarius trivittatus 



50 



60 



20 



20 



70 







30 



80 







Class Bivalvia 



12.340 



42.094 



44.790 



1,227 



8.417 



1,150 



2,470 



37,874 



12,940 



Nucula pro.xima 



7,500 



39,840 



43.970 



620 



2,750 



560 



550 



33,600 



12,630 



Astarte casianea 



510 



110 











620 



390 



70 



160 







Arctica islandica 



10 



144 



80 



47 



27 











124 



30 



Cerastoderma pinnulaium 



30 



170 



110 



50 



40 



30 



20 



120 



30 



Pilar morrhuamts 



190 



690 



400 



110 



370 



20 



50 



640 



170 



Spisula solidissima 



630 



20 







20 



630 



10 



260 



380 







Tellina agilis 



3.450 



1,080 



220 



380 



3.930 



140 



1,490 



2.820 



80 



Ensis directus 



20 



40 



10 







50 







30 



30 







Phylum Annelida 



47.943 



65,380 



30,234 



14.237 



68.852 



21,770 



23,264 



58.292 



9.997 



Class Polychaeta 



43.782 



64,016 



30,207 



13.147 



64.444 



19.980 



20,537 



57.301 



9,980 



Order Archiannelida 





















Polygordius tricstinus 



4.161 



1 .364 



27 



1,090 



4.408 



1.790 



2,727 



991 



17 



Order Phyllodocida 





















Phyllodoce arenae 



208 



215 



31 



30 



362 



17 



101 



298 



7 



Eteone longa 



47 



194 



110 



50 



81 



50 



20 



111 



60 



Harmoihoe exlenuala 



141 



189 



61 



54 



215 



87 



101 



115 



27 



Slhenetais limicola 



372 



187 



40 



47 



472 



17 



151 



381 



10 



Glycera dibranchiata 



1.117 



1.287 



40 



187 



2.177 



147 



610 



1,647 







Goiiiadella gracilis 



1.477 



107 



17 



110 



1 .457 



600 



737 



237 



10 



Nephtys bucera 



1.017 



188 



30 



27 



1.148 



200 



507 



468 



30 



Nephtys iiicisa 



597 



1.990 



1.980 



267 



340 



130 



47 



1,700 



710 



Nephtys picta 



538 



121 







27 



632 



44 



291 



324 







Nephtys (Aglaophamus) circinata 



280 



194 







20 



454 



10 



150 



314 







Order Capiiellida 





















Capitella capiiaia 



34 



6.145 



5.028 



20 



1.131 







1.027 



5.131 



21 



Mediomastus amhiscia 



546 



7.334 



6,430 



380 



1,070 



320 



308 



2.242 



5.010 



Travisia carnca 



137 



71 











208 



24 



48 



136 







Order Spionida 





















Spiofilicomis 



349 



862 



51 



440 



720 



87 



228 



889 



7 



Prionospio steenstrupi 



1.165 



2.780 



610 



1.460 



1.875 



977 



944 



1.774 



250 



Polydora ligni 



228 



208 



81 



40 



315 



20 



161 



211 



44 



Splophanes bombyx 



9.511 



9.080 



460 



590 



17.541 



400 



3.901 



14.120 



170 



Paraonis gracilis 



54 



1.128 



1.097 



14 



71 



10 



24 



838 



310 



Aricidea catherinae 



924 



401 



47 



74 



1.204 



590 



217 



511 



7 



Order Eunieida 





















Lumbrincrules acuta 



351 



80 



10 



10 



411 



287 



107 



27 



10 



Lumbrineris fragilis 



622 



594 



67 



310 



839 



490 



278 



428 



20 



Lumbrineris tenuis 



>64 



1.537 



600 



410 



1.091 



410 



327 



1.234 



130 



Ninoe nigripes 



344 



1.484 



470 



300 



1.058 



340 



120 



1.168 



200 



Drilonereis longa 



522 



351 



130 



100 



343 



48 



107 



368 



50 



Order Magelonida 





















Magclona riojai 



238 



7 











245 



10 



88 



147 







Order Cirratulida 





















Tliaryx acutus 



19.048 



17.927 



7.880 



6.680 



22.415 



14.070 



8.381 



13.304 



1.220 



Tharyx annulosus 



748 



2.957 



1.540 



860 



1,305 



310 



247 



2.918 



230 



Caultcriclla killariensis 



297 



97 



10 



10 



374 



37 



190 



167 







Cossura longocirrata 



40 



370 



400 



10 















260 



150 



Order Terebellida 





















Ampharclc arctica 



322 



224 



67 



130 



349 



57 



107 



365 



17 



Asabcllidcs oculata 



1.712 



3.370 



1.010 



120 



3.952 



81 



801 



4.090 



110 



Order Flabelligerida 





















Phcrusa affinis 



572 



2.707 



2.310 



380 



589 



110 



211 



1.638 



1.320 



Phylum Arthropoda 



4.230 



1.340 



380 



270 



4.920 



410 



1.740 



3,120 



300 



Class Cruslaeea 



4.230 



1.340 



380 



270 



4.920 



410 



1.740 



3.120 



300 



Order Isopoda 





















Edotea triloba 



150 



240 



30 



40 



320 



10 



100 



260 



20 



