Table 3-4. — Relative abundance indices (see Fager and McCowan 1963) for zooplankton from plankton stations, Ocean 250 spill. 



Species 



Mean 

 Rank' 



Domi- 

 nance' 



Range' 



Median' 



Mean' 



Disper- 

 sion' 



SD 



Fre- 

 quency' 



% occur- 

 rence' 



Bongo 0.333 mm zooplankton, 20 March 1978 (RV Strider Cruise 78-01) 



Oikopleura sp. 



26.00 



2/4 



26,501-61,331 



42,937 43,426.8 



v. ,419.301 



16,696.39 



4/4 



100.0 



Balanus sp. nauplii 



24.00 



0/4 



1,892-12,746 



5,80. 



i 6,562.3 



3,148.500 



4,545.46 



4/4 



100.0 



Pseudocalanus minutus adult 



23.38 



0/4 



2,524-11,863 



5,016 6,105.0 



3,044.235 



4,311.04 



4/4 



100.0 



Pseudocalanus minutus copepodite 



21.00 



0/4 



442-12,998 



2,997 4,858.5 



6,360.352 



5,558.94 



4/4 



100.0 



Gastropod eggs 



20.88 



0/4 



1,892- 



4,795 



2,71. 



1 3,028.5 



633.433 



1,385.05 



4/4 



100.0 



Sagitta sp. 



20.50 



0/4 



1,262- 



4,038 



2,902 2,776.3 



657.720 



1,351.29 



4/4 



100.0 



Tortanus discaudatus copepodite 



20.25 



0/4 



505- 



4,543 



2,55! 



2,539.5 



1,290.035 



1,809.98 



4/4 



100.0 



Torianus discaudatus adult 



20.13 



0/4 



442- 



3,912 



2,93: 



2,555.3 



903.989 



1,519.84 



4/4 



100.0 



Acartia sp. adults 



18.00 



0/4 



441- 



4,398 



1,262 1,840.8 



1,712.073 



1,775.25 



4/4 



100.0 



Polychaete larvae 



17.75 



0/4 



505- 



2,145 



1,262 1,293.5 



642.924 



911.93 



4/4 



100.0 



Invertebrate eggs 



17.38 



0/4 



505- 



1,893 



85 



1,025.3 



368.573 



614.72 



4/4 



100.0 



Oithona sp. 



16.50 



0/4 



126- 



4,291 



1,29: 



1,751.0 



1,810.931 



1,780.71 



4/4 



100.0 



Temora longicomis adult 



13.38 



0/4 



63- 



884 



409 441.5 



271.028 



345.92 



4/4 



100.0 



Centropages hamatus adult 



12.25 



0/4 



252- 



378 



28. 



1 299.3 



12.158 



60.32 



4/4 



100.0 



Acartia sp. copepodite 



10.63 



0/4 



310- 



379 



379 267.0 



122.629 



180.95 



3/4 



75.0 



Medusae 



10.13 



0/4 



252- 



379 



252 220.8 



114.348 



158.88 



3/4 



75.0 



Pteropoda 



9.38 



0/4 



126- 



883 



252 315.3 



488.013 



392.23 



3/4 



75.0 



Centropages hamatus copepodite 



6.63 



0/4 



63- 



252 





' 78.8 



180.600 



119.26 



2/4 



50.0 



Eurytemora herdmani adult 



5.75 



0/4 



252- 



252 





' 63.0 



252.000 



126.00 



1/4 



25.0 



Temora longicomis copepodite 



5.75 



0/4 



252- 



252 





' 63.0 



252.000 



126.00 



1/4 



25.0 



Cladocera 



5.50 



0/4 



126- 



126 





• 31.5 



126.000 



63.00 



1/4 



25.0 



Copepod nauplii 



5.50 



0/4 



126- 



126 





' 31.5 



126.000 



63.00 



1/4 



25.0 



Bivalve larvae 



5.13 



0/4 



126- 



126 





' 31.5 



126.000 



63.00 



1/4 



25.0 



Eurytemora herdmani copepodite 



5.13 



0/4 



126- 



126 





' 31.5 



126.000 



63.00 



1/4 



25.0 



Harpacticus sp. 



5.13 



0/4 



126- 



126 





31.5 



126.000 



63.00 



1/4 



25.0 



Siphonophora 



5.00 



0/4 



63- 



63 





' 15.8 



63.000 



31.50 



1/4 



25.0 



Bongo 0.505 mm zooplankton, 20 March 1978 (RV Strider cruise 78-01) 



Oikopleura sp. 



Sagitta sp. 



Tortanus discaudatus adult 



Balanus sp. nauplii 



Tortanus discaudatus copepodite 



Polychaete larvae 



Pseudocalanus minutus adult 



Centropages hamatus adult 



Temora longicomis adult 



Gastropod eggs 



Medusae 



Harpacticus sp. 



Acartia sp. adult 



Invertebrate eggs 



Crangon septemspinosus larvae 



Gammarus sp. 



Balanus sp. cypris larvae 



Unidentified polychaete 



Oithona sp. 



Crab zoea 



Eurytemora herdmani adult 



Pteropoda 



Tomoplerus sp. 



Crab megalops 



Siphonophora 



Cumacea 



Copepod nauplii 



Centropages hamatus copepodite 



Centropages typicus adult 



Cladocera 



Temora longicomis copepodite 



Bivalve larvae 



Neomysis americana 



Pseudodiaptomous coronatus 



33.89 



3/9 



32.22 



0/9 



31.78 



0/9 



30.17 



0/9 



29.06 



0/9 



28.78 



0/9 



27.39 



0/9 



25.44 



0/9 



24.39 



0/9 



21.50 



0/9 



21.17 



0/9 



20.94 



0/9 



20.89 



0/9 



19.11 



0/9 



18.78 



0/9 



16.72 



0/9 



14.95 



0/9 



13.78 



0/9 



12.44 



0/9 



11.50 



0/9 



10.83 



0/9 



10.72 



0/9 



10.72 



0/9 



10.33 



0/9 



10.06 



0/9 



9.89 



0/9 



9.83 



0/9 



9.72 



0/9 



9.72 



0/9 



9.72 



0/9 



9.72 



0/9 



9.61 



0/9 



9.61 



0/9 



9.61 



0/9 



327-25,176 

 60- 2,902 

 51- 1,451 



118- 



54- 



15- 



13- 



14- 



4- 



5- 



12- 



3- 



3- 



20- 



4- 



16- 



8- 



4- 



8- 



3- 



8- 



1- 



1- 



63- 



39- 



16- 



31- 



946 

 678 

 568 

 599 



122 



174 

 1,293 



189 

 43 

 63 



134 

 31 



221 

 71 

 31 

 31 

 16 



8- 8 

 8- 8 



4- 4 



3,013 



6,730.4 



11,495.074 



8.795.85 



986 



1,266.3 



803.357 



1,008.62 



835 



794.2 



187.835 



386.24 



272 



402.6 



184.049 



272.19 



213 



325.9 



142.052 



215.16 



229 



253.1 



203.612 



227.02 



189 



190.1 



185.885 



187.99 



62 



61.3 



21.461 



36.28 



55 



57.3 



44.080 



50.27 



160 



256.0 



798.081 



452.01 



63 



58.2 



62.454 



60.30 



16 



19.1 



9.922 



13.77 



31 



26.9 



15.261 



20.26 



63 



45.1 



49.780 



47.39 



8 



12.7 



9.928 



11.21 



39 



40.2 



124.445 



70.75 



27 



14.9 



39.013 



24.10 



19 



8.2 



21.186 



13.20 



8 



5.2 



20.191 



10.27 





2.1 



13.316 



5.30 





1.8 



7.000 



3.53 





0.6 



3.200 



1.33 





1.0 



7.000 



2.65 





7.0 



63.000 



21.00 





4.3 



39.000 



13.00 





1.8 



16.000 



5.33 





3.4 



31.000 



10.33 





0.1 



1.000 



0.33 





0.1 



1.000 



0.33 





0.1 



1.000 



0.33 





0.1 



1.000 



0.33 





0.9 



8.000 



2.67 





0.9 



8.000 



2.67 





0.4 



4.000 



1.33 



9/9 

 9/9 

 9/9 

 9/9 

 9/9 

 9/9 

 9/9 

 9/9 

 9/9 

 6/9 

 7/9 

 9/9 

 8/9 

 6/9 

 8/9 

 5/9 

 4/9 

 4/9 

 3/9 

 2/9 

 2/9 

 2/9 

 2/9 

 1/9 

 1/9 

 1/9 

 1/9 

 1/9 

 1/9 

 1/9 

 1/9 

 1/9 

 1/9 

 1/9 



100.0 

 100.0 

 100.0 

 100.0 

 100.0 

 100.0 

 100.0 

 100.0 

 100.0 

 66.7 

 77.8 

 100.0 

 88.9 

 66.7 

 88.9 

 55.6 

 44.4 

 44.4 

 33.3 

 22.2 

 22.2 

 22.2 

 22.2 



'Mean rank: Species were ranked within each sample on the basis of numbers of individuals and ranks for each species were averaged over the samples. 



'Dominance: The number of samples in which the species made up 50% or more of the individuals. 



'Range: Smallest and largest nonzero values. 



'Median: Value for which there are an equal number of nonzero values above and below; • no median calculated because there were <3 values. 



22 



