5-20 Salinity (ppt) , flushing time (number of tides) , 



mean tidal velocity (km/hr) , and non-tidal velocity 



(km/hr) as predicted by the Ketchum estuarine flushing 



model for the Union estuary. Data are plotted from 



the head of the estuary CO km) downstream to the point 



of predicted oceanic salinity 5-34 



5-21 Salinity (ppt) , flushing time (number of tides) , 



mean tidal velocity (km/hr) , and non-tidal velocity 



(km/hr) as predicted by the Ketchum estuarine flushing 



model for the Narraguagus estuary. Data are plotted 



from the head of the estuary (0 km) downstream 



to the point of predicted oceanic salinity 5-34 



5-22 Salinity (ppt), flushing time (number of tides), 



mean tidal velocity (km/hr) , and non-tidal velocity 



(km/hr) as predicted by the Ketchum estuarine flushing 



model for the Machias estuary. Data are plotted 



from the head of the estuary (0 km) downstream 



to the point of predicted oceanic salinity 5-35 



5-23 Salinity (ppt) , flushing time (number of tides) , 



mean tidal velocity (km/hr) , and non-xidal velocity 



(km/hr) as predicted by the Ketchum estuarine flushing 



model for the Dennys estuary. Data are plotted 



from the head of the estuary (0 km) downstream 



to the point of predicted oceanic salinity 5-35 



5-24 Salinity (ppt) , flushing time (number of tides) , 



mean tidal velocity (km/hr) , and non-tidal velocity 



(km/hr) as predicted by the Ketchum estuarine flushing 



model for the St. Croix estuary. Data are 



plotted from the head of the estuary (0 km) 



downstream to the point of predicted oceanic salinity .... 5-37 



5-25 Feeding habits of estuarine fishes 5-45 



5-26 Simple representation of the energetic 



relationships between trophic levels 5-48 



5-27 Generalized food web for the estuarine 



system of coastal Maine 5-49 



5-28 A comparison of the primary productivity (tons of dry 

 weight produced per acre per year) for different types 

 of terrestrial and aquatic systems in the world. Shaded 

 bars indicate general ranges (Teal and Teal 1969) 5-50 



5-29 Simplified energy flow model for an 



estuarine system in Maine 5-51 



5-30 The relationship between depth of water and nitrate 

 concentration (a) , and the subsequent nutrient 

 character of the marine waters entering the marine 

 waters entering the Sheepscot and Kennebec 

 estuaries (b) (Garside, unpublished ) 5-55 



xiii 10-80 



