1998 Year of the Ocean Perspectives on Marine Environmental Quality 



such as sandmining, drilling, and shell fishing can physically disrupt benthic habitats and 

 resuspend toxic chemicals and sediments in the water column. 



The introduction of non-indigenous species often results in unexpected ecological, 

 economic, and social impacts to the coastal and marine environment. Predation and competition 

 by non-indigenous species has resulted in the eradication of some native populations and the 

 drastic reduction of others, thereby altering local food webs. This process is often compounded 

 by the exploitation of commercial fish. Overpopulation of some non-indigenous species has 

 resulted in the degradation and loss of wetland vegetation and other submerged aquatic 

 vegetation as a result of overgrazing (e.g., nutria). Additional impacts of non-indigenous species 

 can include (U.S. EPA, 1997): 



• the introduction of pathogens to coastal waters 



• alteration of water tables 



• modification of nutrient cycles or soil fertility 



• increased erosion 



• interference with navigation 



• a reduction in sport and commercial fishing yields 



• negative impacts on recreational boating and beach use 



Overfishing can portend the beginning of an ecologically unsustainable trend. Practices 

 such as "Growth overfishing"", cyanide, or dynamite fishing'* involve the taking of all marine 

 species without concern for size or species. The result is that noncommercial species are killed 

 during the harvesting process of desirable species, or that species are harvested before they reach 

 maturity and can reproduce. This removal of multiple species can alter the ecosystem. 



Climate Change'^ 



Throughout time, climate change has affected coastal and marine environments and will 

 continue to do so in the future. However, human activities and alterations to the environment 

 have rendered coastal resources more vulnerable to the effects of climate change. Such effects 

 include accelerated sea-level rise, increased siltation, altered rainfall patterns, and changes in 

 storm frequency and intensity. Over the past 100 years, the relative sea level has risen by 1 to 2.5 

 mm/yr. Climate change and a rise in sea level or changes in storms patterns could result in 

 increased erosion of shores, changes in coastal and marine habitats, increased coastal flooding, 

 changes in salinity of estuaries and freshwater aquifers, altered tidal ranges in rivers and bays, 

 changes in sediment and nutrient transport, and changes in the pattern of chemical and 

 microbiological contamination of coastal areas. Projections based on long-range climate models 



'7 Growth overfishing refers to harvesting that results in a reduction in the average size of tlsh or shellfish landed, and often 



involves taking fish prior to their reaching sufficient size for reproduction. 



'8 In some regions of the world, cyanide and dynamite are used in the harvesting offish. This method kills not only the target 



species but all marine life in the area. 



'9 For more information on oceans and climate change issues such as relative sea-level change, tectonic subsidence, sediment 



budgets and longshore currents, see the Climate and Weather Year of the Ocean Discussion Paper. 



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