FISHERY BULLETIN: VOL. 80, NO. 4 



Table 6.— Grand mean estimate of bio- 

 mass density (g DW/m 2 ) for common spe- 

 cies in the littoral zone (excluding panne) 

 over the 13-mo period (January 1978-Janu- 

 ary 1979) from the best estimate criteria. 



Species 



Xg DW/m 2 ±1 SE 



Athennops alfinis (adult) 

 A. affinis 



Fundulus parvipinnis 

 Gambusia affinis 

 Clevelandia ios 

 Anchoa compressa 

 Cymatogaster aggregata 

 Gillichthys mirabilis 

 Anchoa delicatissima 

 Mugil cephalus 

 Quielula ycauda 

 llypnus gilberti 

 Hypsopsetta guttulata 

 Engraulis mordax 

 Lepomis macrochirus 

 Lepomis cyanellus 



0.1043±0.0602 

 1.1590±0.2573 

 0.1064±0.0223 

 0.001 5±0 0028 

 0.0261 ±0.01 17 

 0.1195±0.0493 

 0.0167 ±0.0158 

 0.01 31 ±0.0035 

 0.0077+0.0053 

 0.0024+0.0018 

 0.0029±0.0025 

 0.0021 ±0.0021 

 0.0043±0.0035 

 0.0019±0.0018 

 0.0006+0.0005 

 0.0003+00001 



1.5688 g DW/m 2 



Clevelandia ios, determined by total area cover- 

 age was 0.013 g/m 2 (about 0.003 g DW/m 2 ). The 

 value based on best estimate (using square enclo- 

 sures and small seine estimates) was about 10 

 times higher at 0.03 g DW/m 2 . This large dis- 

 crepancy is due to the low efficiency of the bag 

 seine for capturing this species. Since the bag 

 seine covered the largest area of any of the sam- 

 pling gears (220 m 2 ), its addition to the density 

 determination for C. ios led to the large under- 

 estimate. The total biomass density of all species 

 by total area was 4. 13 g/m 2 (or about 1.02 g DW/ 

 m 2 ) which again was lower than the best estimate 

 grand mean density of 1.57 g DW/m 2 . 



Average standing stock for the upper bay spe- 

 cies during 1978 was 784 kg DW, based on an 

 estimate of 50 ha of habitable littoral zone in 

 upper Newport Bay. This is equivalent to 3,136 

 kg (wet weight) or 6,899 lb of fish. By the same 

 procedure, the average standing stock of A. 

 affinis was 631.6 kg DW and that of C. ios, 13.1 

 kg DW. 



The annual production of 9.35 g DW/m 2 for the 

 upper Newport Bay littoral zone in 1978 ranked 

 among the highest values recorded for studies 

 with comparable production determinations of 

 production models (Table 7). 



The Newport Bay production estimate in 1978 

 was surpassed only by the estimate for Fundulus 

 heteroclitus (Meredith and Lotrich 1979), an es- 

 tuarine species of the east coast of the United 

 States. Fundulus heteroclitus represented a very 

 efficient energy link between the marsh and the 

 littoral zone in their study. However, as Mere- 

 dith and Lotrich pointed out, the production 

 value may be an overestimation due to the under- 



estimation of the area of marsh utilized by the 

 fish. The value 4.6 g DW/m 2 obtained by Adams 

 (1976b) for fishes inhabiting east coast eelgrass 

 beds, which are acknowledged as highly produc- 

 tive areas, is half the estimate for the littoral zone 

 of upper Newport Bay. 



Short food chains have been implicated as the 

 primary reason for high production in estuarine 

 fish communities (Adams 1976b), a contention 

 which is supported by the findings of this study. 

 Young-of-the-year Atherinops affinis accounted 

 for 85% of the annual production and formed a 

 direct link through their herbivorous/detritivor- 

 ous diet to the high primary productivity of this 

 estuarine system. The remaining, numerically 

 important species of the littoral zone were low- 

 level carnivores. There is little doubt that this 

 assemblage represents an example of "food chain 

 telescoping" as described by Odum (1970). 



Even though the fish production in the littoral 

 zone of upper Newport Bay was high compared 

 with most comparable studies, the value pre- 

 sented here is undoubtedly an underestimate. 

 The largest species of the system, adult Mugil 

 cephalus, was not represented in the production 

 estimates due to inadequate sampling. Inclusion 

 of this species would have substantially increased 

 the production value. It is unlikely, however, that 

 productivity of adult M. cephalus could approach 

 that of juvenile Atherinops affinis which were 

 responsible for 85% of the annual fish produc- 

 tion. 



Influence of Abiotic Factors 



The positive correlations between tempera- 

 ture and total abundance, biomass and number 

 of species, and between salinity and total abun- 

 dance and biomass indicate the general impor- 



Table 7.— Comparison of annual fish production (P) for ma- 

 rine or estuarine studies with comparable production determi- 

 nations. Wet weights were converted by multiplying by 0.25. 

 Values are for all species except where noted. 



Estimated 

 annual P 

 Study (g DW/m 2 ) 



Locale and habitat 



Delaware salt marsh creek 

 {Fundulus heteroclitus) 

 Newport Bay littoral zone 

 Mexican coastal lagoon 

 Cuban freshwater lagoons 

 No. Carolina eelgrass beds 

 Bermuda Coral Reef 

 Texas lagoon (Laguna Madre) 

 English Channel pelagic 



and demersal fishes 

 Georges Bank commercial 

 fishes 





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