1998 Year of the Ocean Perspectives on Marine Environmental Quality 



• increased coastal flooding 



• changed sediment and nutrient transport patterns 



• changed patterns of chemical and microbiological contamination in coastal areas 



Secondary impacts from climate change that may occur include inundation of waste disposal 

 sites and landfills from storm surges which result in the reintroduction of toxic materials and 

 increased siltation into the marine environment. Areas in the U.S. Gulf Coast are experiencing a 

 relative sea level rise of 10 mm/year. In Oahu, Hawaii, one quarter of the beaches have been lost 

 or significantly degraded over the past 50 years due a multiple of marine environmental 

 pressures, but heightened storm surges could greatly increase this rate. 



Adverse Biological Effects''' 



The over-exploitation of living resources, the physical destruction of habitats, pollution, 

 changes in climate, and the introduction of non-indigenous species, all combine to threaten the 

 biodiversity, integrity, and productivity of marine and coastal ecosystems. Over-exploitation of 

 species reduces their ability to maintain population levels.'^ Overfishing can create an imbalance 

 in ecosystems by depleting food resources for predators while allowing populations on which 

 depleted species would have otherwise fed to grow. This can be the beginning of an ecologically 

 unsustainable trend. 



The introduction of exotic or non-indigenous species into an area, whether intentionally 

 or accidentally, often results in unexpected ecological, economic, and social impacts to the 

 marine and estuarine environment. These occurrences often pose threats to local species that are 

 relied upon for food, medicine, recreation, and raw materials (Norse, 1993). Through predation 

 and competition, introduced species have contributed to the eradication of some native 

 populations and drastically reduced others, fundamentally altering food webs. In San Francisco 

 Bay, California, Amur River clams have become so abundant that they can filter a significant 

 volume of the Bay in less than a day, removing the bacteria, phytoplankton, and zooplankton that 

 are necessary to support the local food web. Zebra mussels are responsible for millions of dollars 

 in water supply maintenance costs in the Great Lakes. In the Delaware Estuary, Haplosporidium 

 nelsoni, a parasitic protozoan, has caused catastrophic die-offs of American Oyster. It is thought 

 that this organism was transferred from Asia or the U.S. West Coast via ballast water (Ford, 

 1996). The Asian clam, Corbicula fluminea, dominates the bivalve community in the area 

 between Trenton, New Jersey and the Chesapeake and Delaware Canal. In some areas, this exotic 

 clam makes up 94 percent of the total benthic invertebrate biomass (Maiden, 1993). 



26 For more information, see the Year of the Ocean Living Resources Discussion Paper. 



27 For example, total finfish landings have declined from 2.9 million pounds in 1980 to less than 340,000 pounds in 1989, 

 mainly as a result of "growth overfishing", a reduction in the size offish caught and stock depletion. Of the species found in the 

 Indian River Lagoon basin in Florida, 75 are listed as rare, threatened, endangered, or species of special concern by state or 

 federal agencies. In Corpus Christi, Texas, the numbers of shrimp landed in the bay fishery have increased more than 300 

 percent since 1972. In 1996, 1,871 bay shrimp boat license holders plus 1,806 bait shrimp license holders trawled in these bays 

 harvesting an already depleted stock, 



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