GENERALIZED FOOD WEB FOR A MACROCYSTIS PYRIFERA FOREST 



1° Producers 

 + Import from 

 Drift and 

 Plankton 



1° Consumers 



2° Consumers 



3° Consumers 



Imported drift 

 macroalgae 

 (various) 



; export; 

 y 



Benthic algae 

 Microcystis 

 Understory 



Grazers 



Tegula 

 Nornsia 

 Urchins 

 Abalone 



Herbivorous fish 

 and crabs 



Invertebrate 

 predators 

 Pisaster 

 Sea stars 

 Crabs 

 Octopus 

 Nudibranchs 



Vertebrate predators 

 Fish 



Sharks and rays 

 Harbor seals 



Decomposers 



DOM = dissolved organic matter. 



Invertebrate detritus 

 feeders 

 Urchins 

 Abalone 

 Patiria 

 Polychaetes 

 Crustaceans 

 Brittle stars 

 Sea cucumbers 



Vertebrate predators 

 Fish 



Sheephead 



Kelp bass 



Rockfish 



Lingcod 



Garibaldi 



Surfperch 



Sharks and rays 

 Birds 

 Otters 



■ Parasites 



Al 1 above 



i> 

 Bacteria 

 Fungi 



: 



Imported and resident 

 plankton 



Phytoplankton 

 Zooplankton 

 Hysids 

 Squid 



Invertebrate filter- 

 suspension feeders 

 Bryozoans 

 Tunicates 

 Sponges 

 Anemones 

 Cora 1 s 

 Gorgonians 

 Hydroids 



Scavengers 

 Patiria 

 Crabs 

 Lobster 

 Kelettia 

 leTi 



Vertebrate predators 

 Juv. and adult 

 rockfish 

 Blacksmith 



POM = particulate organic matter. 



Scavengers 

 (as above) 



Invertebrate detritus 

 and filter-suspension 

 feeders 

 (as above) 



Figure 11. A generalized food web for a kelp forest, 

 energy flow. 



Arrows indicate the direction of 



to vascular plants, Bedford and Moore 

 (1984) point out that drift seaweeds have 

 few structural polysaccharides, lack waxy 

 coverings, and may exude fewer protective 

 chemicals, making them more directly 

 palatable to detritivores. This suggests 

 that the fate of subtidal algal drift 

 (directly to detritivores) may be 

 fundamentally different from that of 

 vascular plant detritus (through microbes 

 to detritivores). Furthermore, this 

 difference may be ultimately reflected in 

 the high abundances of fish in kelp 

 forests; many of these fish feed on small 

 crustaceans and polychaetes that are 



probably detritivores 

 4.4.2.8 and 4.5). 



(see Sections 



Our understanding of energy flow 

 through the remainder of the giant kelp 

 forest community is based largely on 

 feeding observations, with few quantita- 

 tive studies. Rosenthal et al . (1974) 

 constructed a food web from feeding 

 observations in a kelp stand near Del Mar 

 which, with additions from observations 

 made in other areas, is summarized in the 

 generalized giant kelp forest food web of 

 Figure 11. As might be expected from the 

 variety of ways energy can enter the 



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