pathway, where it is augmented by inputs from benthic and planktonic 

 primary producers. This conclusion is consistent with the results 

 of Teal (1962), Odum and Heald (1975), and similar studies of 

 estuarine food chains. 



VI. CONCLUSIONS 



The structure and trophic relations of fish and invertebrate 

 communities were studied in several marsh and estuarine habitats of 

 Siletz and Netarts bays, Oregon. These marshes do not appear to 

 directly play a dominant role in aquatic food chains of these 

 estuaries. Fish diversity was low in marsh habitats (tidal creek, 

 pan, slough, and submerged level marsh) , although juvenile chum 

 salmon, staghorn sculpin, and threespine stickleback were occasionally 

 abundant. In other Pacific Northwest marshes, several freshwater 

 species plus additional species of juvenile Pacific salmon occur. 

 Fish in the Oregon marshes consumed minor amounts of terrestrial 

 foods in comparison to aquatic foods. Only juvenile chum salmon 

 feeding over submerged level marshes consumed substantial amounts 

 of terrestrial insects and spiders. In general, these marshes 

 apparently do not form a nursery area for a high diversity of marine 

 species as occurs in Atlantic coast marshes. The paucity of marine 

 species may relate to low salinity or to a lack of extensive marsh 

 aquatic habitats. 



Detritivores dominated the food chains in most of the Oregon 

 marsh habitats, although herbivores were dominant in the upper 

 vegetation of high marshes. This overall emphasis of detritus- 

 based food chains coincides with conclusions based on studies of 

 Atlantic coast marshes. The study of Oregon marshes indicates that 

 many invertebrate taxa are common to both Atlantic and Pacific coast 

 marshes, and that there is a tendency among the marshes for similar 

 taxa to be numerically dominant. However, enough differences exist 

 in invertebrate and especially fish communities to suggest that 

 assessments of the trophic value of western marshes should be based 

 on direct study of these marshes rather than on inferences made 

 from marshes located elsewhere. 



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