SEAGRASS SURVIVAL 



of seagrass in controlled environments 

 of that size. 



Little is known about seagrasses, ad- 

 mit researchers who until this century 

 focused little attention on the stringy 

 plants. Losses, too, are hard to docu- 

 ment since few records mapped their 

 growth before the mysterious "wasting 

 disease" of the early 1930s that wiped 

 out 90 percent of seagrasses along 

 the Atlantic shoreline. 



What is known is impressive. 



Eelgrass— along with shoal grass 

 and widgeon grass in North Carolina- 

 curbs underwater erosion through 

 roots that anchor soils to the sound 

 bottom. Since seagrass typically grows 

 in shallow estuarine waters, its destruc- 

 tion can drastically alter the shape of 

 the nearby shorelines. 



Though seagrasses are rarely found 

 in what Burkholder calls "wave-beaten 

 areas," they do flourish along more 

 protected embayments along some 

 coastlines. Throughout Core Sound, 

 however, 88 percent of the three 

 varieties are concentrated along the 

 calmer, inner shores of Core Banks. 



The roots— spaghetti-like strands that 

 dig deep into muddy bottoms— also 

 draw nutrients from the soil, passing 

 that energy along to other plants and 



animals when the seagrass plant dies 

 or exfoliates each season. 



A century ago, long, tough strands 

 of eelgrass were so common along 

 New England shores that residents 

 there scooped up wagonloads of 

 shredded seagrass and thatched roofs 

 with it. 



To this day, seagrasses— largely 

 recovered from the wasting disease— 

 "grow like carpets, like your back 

 yard," Thayer says. 



In the dense, tangled leaves, micro- 

 scopic and more visible plants and 

 animals attach themselves to the plants 

 and hide among their thick mat. 



Outside the calm of seagrass beds, 

 fish and shellfish fend for themselves 

 without cover of the sprawling, protec- 

 tive canopy. Bay scallops search out 

 seagrass beds, where they grow from 

 larvae. 



When wasting disease ravaged so 

 much of the Atlantic Seaboard's 

 seagrass from 1930 to 1933, the im- 

 pact was immediate. Harvests of 

 scallops in the Delmarva Peninsula of 

 Chesapeake Bay that had totaled 

 25,000 pounds in 1930 plummeted to 

 zero by 1933 and '34. 



More recent declines in seagrass in 

 the Chesapeake Bay are blamed on 



pollution and dredging, a deadly com- 

 bination brought about by coastal 

 development that chokes the life from 

 seagrass. Because they are plants 

 dependent on light for photosynthesis, 

 seagrasses suffocate under cover of 

 turbid waters or heavy algae that block 

 the sunlight needed to make food. 



With no light, there is no life— the 

 reason you find most seagrasses in 

 waters 6 feet deep or less. Multilayered 

 meadows thrive in shallow waters 

 along most of the earth's continents, 

 from the Arctic Circle to Tasmania. 



Dredging and filling remain sea- 

 grasses' most direct enemy, though 

 outside influences that alter water 

 temperature, salinity and light also 

 pose a threat. 



Like the Chesapeake, North 

 Carolina's coast has seen drastic 

 development in the past generation, 

 but Thayer and others are not ready to 

 link that buildup with a downturn in 

 seagrass. 



"We don't have a particularly good 

 historic record," he said from his 

 Beaufort office. "There just aren't any 

 historic maps." 



Researchers agree, however, that 

 seagrass in the Beaufort area has 

 waned little over the past 20 years. 



Only in that time have federal and 

 state regulators entered the scene, 

 writing laws to protect seagrasses from 

 potentially destructive activity such as 

 dredging or mechanical harvesting. 



"It's pretty clear that these practices 

 such as clam-kicking are destructive to 

 the bottom," researcher Charles Peter- 

 son says of mechanical methods that 

 use hydraulic dredges or boat motor 

 propellers. 



"You can see those trails for years," 

 Thayer says. 



Add to the equation the wandering 

 nature of seagrass beds, and it's clear 

 why the protection puzzle is a com- 

 plicated one. 



continued next page 



Aerial view of seagrass beds surrounding a duck blind in Core Sound near Davis, N. C. 



