The sources of these nutrients — 

 suburban yards, farm fields, hog lots 

 and chicken houses, industry, sewage 

 treatment plants and fossil fuel emis- 

 sions — are all part of a thriving 

 economy and the industrialized, build- 

 bigger, grow-larger society we live in. 



And if the flow of nutrients to 

 coastal water seems heavy now, it may 

 soon be gushing as North Carolina's 

 Coastal Plain continues on its course of 

 population growth, development and 

 industrialization. 



Although many people welcome 

 economic development in eastern North 

 Carolina, they must also realize its cost, 

 Paerl says. 



"We're simply making our 

 estuaries and nearshore waters too 

 productive," he says. "And much of 

 what they're producing is undesirable. 

 If you compared it to agriculture, it's 

 like growing weeds instead of soybeans 

 or corn." 



Already, the Neuse River has been 

 designated one of the nation's 20 most 

 threatened rivers by a national environ- 

 mental group, American Rivers. For 

 more than a decade, the Chowan River 

 has experienced recurring blooms of 

 blue-green algae. 



Because our estuaries "have 

 exceeded their tolerance threshold," 

 Paerl predicts: 



• Fisherman may soon be catching 

 catfish instead of flounder because of 

 changes in the food web and reduced 

 oxygen. 



• Scientists will see increasing 

 blooms of toxic dinoflagellates, blue- 

 green algae and other nuisance algae 

 that may reduce the production of fish 

 and shellfish and decrease tourism at 

 waterfront resorts and recreational 

 areas. 



• Fish kills will become more 

 prevalent as massive dying blooms of 

 phytoplankton rob coastal waters of 

 oxygen needed to sustain fish and 

 shellfish. 



And the problem isn't just North 

 Carolina's to tackle. In coastal waters 

 in other parts of the world, the nutrient 

 load is greater and the problems more 



serious. In the Baltic, North and 

 Mediterranean seas and Sea of Japan, 

 Paerl says scientists are seeing open 

 ocean blooms of algae and dinoflagel- 

 lates. 



In fact, Paerl believes that coastal 

 eutrophication may be the repository 

 for some of the missing carbon dioxide 

 that has atmospheric and global-change 

 scientists mystified worldwide. 



It seems the Earth's carbon 

 dioxide checking account doesn't 

 balance. The amount of carbon dioxide 

 in the atmosphere doesn't match what 

 is used by terrestrial plants. There's 

 some missing. 



Since phytoplankton "breathe" 

 carbon dioxide like land plants, Paerl 

 speculates that increased algal produc- 

 tion worldwide has created a growing 

 coastal "sink" for carbon dioxide, one 

 of the greenhouse gases. As the algae 

 die, they fall to the bottom, creating 

 carbon depositories in coastal sedi- 

 ments. 



These sinks may help in negating 

 the greenhouse effect, Paerl says, but 

 the cost of increased algal production 

 is too high and the effects of carbon 

 storage in coastal sediments is un- 

 known. 



So what are the solutions? 



The flow of nutrients to coastal 

 waters must be reduced, and everyone 

 from the Durham homeowner to the 

 Sampson County hog farmer to the 

 Raleigh legislator needs to think how 

 that flow can be slowed. It may require 

 tougher water quality standards; 

 controlled releases of nutrients during 

 less bloom-prone times of year; more 

 and improved holding ponds for animal 

 lots; more prudent applications of 

 fertilizer on farm fields, back yards 

 and golf courses; and cleaner fuel 

 sources for cars. 



The list is endless, but the message 

 is clear, according to Paerl and 

 Pinckney. If we don't stem the tide of 

 nutrients, the quality of coastal waters 

 will continue to degrade, and red tides 

 and algal blooms will become as much 

 a part of the coastal landscape as sea 

 oats and salt marsh grasses. □ 



Glossary of Terms 



• algae — small, floating, 

 nonwoody plants that inhabit 

 fresh and salt water. 



• algal bloom — rapid algal 

 growth that usually results in 

 a discoloration of the water. 



• chlorophyll — the photosyn- 

 thetic pigment responsible 

 for converting light energy 



to chemical energy used 

 for plant growth. 



• dinoflagellate — a 

 microscopic algae that is 

 commonly found in coastal 

 waters. 



• eutrophication — the 

 excessive addition of nutrients 

 that spurs accelerated algal 

 growth, creating more plant 

 biomass than the ecosystem is 

 capable of using. 



• nitrogen — a biologically 

 important nutrient essential to 

 plant growth, which exists in 

 solid, gaseous and liquid 

 states. Nitrogen supply 

 regulates plant growth in 

 North Carolina's estuarine 

 waters. 



• phosphorus — a mineral 

 nutrient also required for 

 growth, which exists mainly 



as phosphate, a dissolved solid. 



• photosynthesis — the 

 conversion of light energy to 

 chemical energy. Plants use 

 water, carbon dioxide and 

 sunlight to manufacture sugars 

 that are used for growth. 



• phytoplankton — micro- 

 scopic, photosynthetic plants 

 that are suspended in the 

 water column. 



• plankton — organisms, both 

 plants and animals, that are 

 suspended in the water column 

 and transported by tides and 

 currents. 



• pigments — large, colored 

 molecules that capture light 

 energy and make it available 

 for photosynthesis. 



COASTWATCH 1 3 



