MALONE: RELATIVE IMPORTANCE OK NANNOPLANKTON AND NETPLANKTON 



ductivity and chlorophyll concentrations off- it was located near the boundary between the 

 shore, however, exceeded 1.0 mgC m^^ hr"' and Davidson and California Currents which is 

 0.10 mgChl-a m-^ only once. The highest levels marked by a surface divergence and associated 

 of productivity and chlorophyll were found at upwelling. In this connection, it is also note- 

 inshore station 63 and were equivalent to the worthy that nannoplankton productivity and 

 maximum values observed at CalCOFI 3 during chlorophyll levels were about twice those ob- 

 the two most intense upwelling pulses. served previously for transitional and offshore 



This inshore-offshore decrease in surface pro- regions, 



ductivity and chlorophyll was not observed over Phji;oplankton assimilation ratios were simi- 



the first 225 km of the November transect when lar to those observed at CalCOFI 3, most values 



subsidence rather than upwelling characterized. falling between 5 and 10. Excluding inshore 



the coastal hydrographic regime. Productivity stations, the mean assimilation ratio was 7.7 ± 



and chlorophyll concentrations were relatively 1.1, which is not significantly different from the 



constant out to station 12 (Figure 10) and cor- mean observed at CalCOFI 3. Nannoplankton 



responded with the minimum values observed ratios averaged 8.3 ± 1.2 v.'hich is twice the ob- 



at CalCOFI 3 during the Oceanic Period. served mean netplankton ratio of 4.1 ± 0.8. 



Both nannoplankton and netplankton produc- Both means are equivalent to those observed at 



tivity and chlorophyll decreased markedly be- CalCOFI 3. 

 tween inshore and offshore stations along the 



July-August transects (Figure 10). Nanno- VERTICAL DISTRIBUTION OF PIGMENTS 

 plankton values fell by as much as an order of 



magnitude from above 4.0 mgC m-^ hr-> and Inshore-offshore variations in the chlorophyll- 



0.60 mgChl-a m-^ to less than 1.2 and 0.18, re- ^ content of the water column (0 to 200 m) dur- 



spectively. The netplankton, however, exhibited i„or the July-August transects were similar in 



the greatest decline. Netplankton productivity trend but less in amplitude than that observed 



decreased by 2 to 3 orders of magnitude from ^t the surface. Inshore, chlorophyll varied from 



1..5 to 51.3 mgC m-3 hr"' to offshore levels of 27.32 to 217.68 mg m-^ compared with the 

 0.01 to 0.26. Similarly, netplankton chlorophyll 

 values were 0.12 to 10.14 mg m~' inshore and 



0.002 to 0.052 offshore. This decline in the net- ^ , ., , 



,,, J. .. ,,. iii iii Table 4. — Netplankton-nannoplankton ratios in the Cal- 



plankton fraction relative to the nannoplankton :f^^„:^ r„rv»„t c„o+  ^ *• ■! Vdd 



' ,. rr \ ^ A\ iiornia Current system: primary productivity (PP =: 



is reflected m the net/nanno ratios (lable 4). ^igC m-3 hr-'), chlorophyll-a m-^ and chlorophyll-a 



Inshore productivity ratios ranged from 0.23 to m-2. 



4.95, while offshore ratios varied from 0.02 to ^;^„ i ^ \ —, 1 ~, 



0.36. Chlorophyll ratios followed the same pat- 03 023 ^ ^-j^ 



tern but tended to be higher. os 0.30 o.48 0.36 



The pattern observed in November was quite 24 02 05 oh 



different. Levels of netplankton productivity ~ ~ ^3 o.n 0.22 006 



and chlorophyll were low along the entire tran- "^i '^^ --^ 



sect and were within the range commonly found ss 0.09 0.19 0.I6 



offshore and during oceanic phases inshore (Fig- 33 g,, °27 H^ 



ure 10). Nannoplankton productivity declined ^ ■^9"] 73"; -g- 



slightly from an inshore maximum of 3.20 to <>^ 0.03 o.is 0.33 



an offshore minimum of 1.21. Variations in sur- 34 03^ °'32 g^^ 



face chlorophyll were similar except the maxi- 83 00"^ ^^ ~^ 



mum of 0.40 was observed at station 5 which is 03 0.07 017 T12 



150 km from shore. Station 5 is particularly in- 11 002 010 is 



teresting because netplankton productivity and 12 o!o3 1^ 0I0 



chlorophyll also exhibited small peaks here, and °3 om oj7 16 



811 



