In productivity estimates, it is assumed that the intertidal seaweed biomass 

 is turned over once a year. Rough approximations of seaweed productivity are 

 commonly made by assuming one biomass turnover per year (Luning 1968). One 

 cycle of intertidal seaweed carbon per year therefore yields a productivity of 

 823 g C/m^ /yr . MacFarlane (1952) and Westlake (1963) reported a similar 

 productivity of 640 to 840 g C/m^/year in rockweed populations in Nova Scotia. 



An examination of wetlands identified by the NWI shows that the area of dense 

 intertidal macroalgal colonization may be approximated by summing marine and 

 estuarine intertidal rocky shore areas. The assumption is made that this area 

 is equivalent to that designated as suitable substrata [composed of stones 

 greater than 2.5 inches (6.4 cm) in diameter ] that would support dense 

 populations of intertidal fucoid seaweeds. Data from 99 randomly selected 

 sampling sites in Lincoln County indicate the rocky shore habitats identified 

 by the NV/1 included reflective areas above the seaweed zone as part of 

 intertidal areas. To correct for this situation, the estimated area of 

 seaweed habitat was estimated to be 56% of the identified rocky shore habitat 

 (Topinka, unpublished ) . Based upon adjusted NWI habitat data and the above 

 productivity data, intertidal seaweed productivity values were calculated 

 (table 5-4). Intertidal seaweed contributes about 40% of total estuarine 

 primary production, and dominates estuarine primary production in regions 3, 

 4, and 5. 



Table 5-4. Estimate of Net Annual Primary Production (kgC/y X 10 ) by 



Region and Percentage Contribution to the Total Productivity 

 of Producers Found in the Estuarine System.^ 



Reg ion 



6 All regions 



Intertidal seaweed 

 % 



5.2 

 32 



2.1 

 8 



45 



18,6 11.3 

 53 51 



12.5 

 41 



58.4 

 39 



Estuarine emergent marsh 4.4 10.0 2.2 1.9 4.4 5.4 28.3 



% 27 37 12 6 20 17 19 



Estuarine phytoplankton 6.7 15.0 8.2 14.4 6.5 12.8 63.6 



% 41 55 43 41 29 42 42 



Total production 

 % 



16.3 27.1 19.1 34.9 22.2 30.7 150.3 

 100 100 100 100 100 100 100 



^Topinka, unpublished , 



5-74 



