Chapter 7 

 The Lacustrine 

 System 



Authors: Ronald Davis, Meryl Freeman, Stewart Fefef 



This chapter describes the freshwater bodies (lacustrine system) of the Maine 

 coast, including natural lakes, natural lakes with water control structures, 

 deep ponds, abandoned quarries that have become flooded, flooded gravel pits, 

 reservoirs, and impounded streams and rivers. Data are not available for all 

 the lacustrine water bodies. The lacustrine system of the coastal zone of 

 Maine comprises slightly less than 3% of the zone's total land and freshwater 

 area . 



Natural lakes that are larger than 10 acres (4 ha) are, according to Maine 

 law, owned by the public. However, the adjacent lands often are owned 

 privately and public access is highly limited. Most of the lakes are used for 

 recreation, water supplies, and/or scenic backgrounds for residential (mostly 

 seasonal cottages) developments. 



Lacustrine systems are bodies of fresh water that have depths >7 feet (>2 m) 

 at low water (bodies of water having depths <2 m are classified as 

 palustrine). Where data on depth are not available lacustrine systems include 

 those freshwater bodies that are larger than 20 acres (8 ha) , are not 

 contained within a channel, and are without persistent vegetation. The 

 lacustrine system has been classified hierarchically, based upon depth and 

 bottom characteristics (figure 7-1). The limnetic subsystem is the deep-water 

 part of the lake (>2 m in depth) , while the littoral subsystem is the shallow 

 section of the lacustrine system. Each subsystem has component classes. It 

 should be noted that lacustrine systems are often bordered by palustrine 

 systems (defined by the presence of persistent emergent plants, e.g., Scirpus 

 spp . ) , but they are classified separately by the National Wetlands Inventory 

 (NWI). Specific locations of lacustrine systems are included in atlas map 1. 



The definitions of the terms lacustrine, littoral, and limnetic, used by the 

 National Wetlands Inventory, differ from those used by many limnologists . 

 Those definitions conform to the system of Cowardin and coworkers (1979) which 

 provides the framework for chapters on wetland and aquatic systems. This 

 framework is described in chapter 1. Common names of species are used except 



7-1 



10-80 



