The effects of persistent pesticides used in the past on forests and farms 

 are still present in Maine. Although only traces or undetectable amounts of 

 these chemicals are now found in natural waters, chemicals applied from 1954 

 to 1967 still are concentrated in the food chain. A major example is the 

 harmful amounts of organochlorine chemicals still being found in bald eagles 

 and in their eggs. Reproduction of bald eagles has been limited seriously by 

 persistent pesticides (DDT and its degradation products) that are no longer in 

 use. The effects of pesticides on bald eagles are discussed in chapter 

 16, "Terrestrial Birds." 



Most of today's pesticides are short-lived compared to chlorinated 

 hydrocarbons (i.e., DDT) but they are still extremely toxic. The potential 

 for damage to wildlife exists largely at the time of application. 



Habitat Modification 



Land-clearing modifies habitats to a greater degree than any other human 

 activity. Most of the land currently in agriculture has been farmed for many 

 years. The oldest farm sites were developed primarily in upland areas, where 

 the forests were cleared first. Abandoned agricultural land in Maine reverts 

 to oldfields and eventually to forest. However, suburban expansion has taken 

 over agricultural land in many of the more populated areas of the coastal zone 

 (regions 1 to 5) . 



MINERAL EXTRACTION 



The materials currently being extracted from coastal Maine are sand and 

 gravel, peat (regions 5 and 6), limestone (region 3), and granite (region 6; 

 see atlas map 3). Abandoned copper mines in the Blue Hill area (region 4) and 

 granite quarries along the coast (primarily regions 4 and 5) continue to 

 influence the local environment. Potential exists for future mining in 

 coastal Maine. Nickel may be mined and the extraction of sand, gravel, and 

 peat may be expanded in Knox County (region 4). Environmental impacts 

 associated with mining include the generation of waste materials (air and 

 water pollution) and the alteration of habitats. 



Sand and gravel are extracted primarily from eskers (long sand or gravel 

 ridges deposited in the bed of subglacial streams), which are especially 

 numerous and well developed in Maine in comparison to other parts of the 

 United States. Eskers are unique features of high scientific interest. They 

 are valuable to geologists in interpreting glacial events. No estimates are 

 available of the total length of eskers in the coastal zone. However, there 

 are 1420 miles (2272 km) of eskers in Maine as a whole or about 0.8 cu mi 

 (3.3km3) in volume (Borns 1979). A relatively large number of Maine eskers 

 have been totally or partially removed for construction purposes and the rate 

 of removal has greatly increased in the last 15 years (Borns 1979). For 

 example, about 45% of the 37 miles (60 km) of eskers in the area encompassed 

 by the Bangor 15-minute quadrangle map has been extracted since 1955. These 

 trends are as high or higher in the Portland and Augusta areas (Borns 1979). 

 Commercial exploitation of eskers is the greatest threat to their continued 

 existence. The Maine State Planning Office is currently evaluating eskers of 

 high scientific and educational value for designation as critical areas (Borns 

 1979). 



3-13 



10-80 



