Unraveling mysteries 

 of the marsh ecosystem 



In North Carolina three teams of scientists are 

 conducting research aimed at understanding the 

 relationship between coastal grass and fish pro- 

 duction. Although they share this common long- 

 term goal, their current efforts are directed at un- 

 earthing the secrets of different, and very specific, 

 aspects of the marsh-estuarine ecosystem. 



Briefly, one group of scientists is studying the 

 relationship between grasses and animals growing 

 in the marsh. Another is examining the importance 

 of eel grass, an underwater grass, to aquatic 

 animal life. The third is determining how micro- 

 organisms, such as bacteria, increase the food or 

 nutrient value of detritus, decaying particles of 

 marsh and eel grasses. All three projects promise 

 to yield important information toward a more 

 complete understanding of the marsh-estuarine 

 ecosystem. 



The work of UNC ecologists A. E. Stiven and 

 E. J. Kuenzler, supported by Sea Grant, centers 



Energy from marsh grasses 

 eventually is fuel for you 



(Continued from page 1) 

 and attach themselves to the detritus. Larger 

 marine organisms, including some species of fish, 

 feed on the tiny decaying grass particles. Bigger 

 animals consume smaller ones until the food chain 

 reaches man. 



While farmers have reliable estimates on how 

 many pounds of grain their hogs and cattle must 

 eat to grow one pound of meat, no one has yet 

 related the amount of grass growing in the marsh 

 and estuaries to the amount of seafood produced. 

 Scientists believe that before sound decisions can 

 be made on how we will use marshes in the future, 

 more information is needed to determine how 

 changes in the marsh might affect our fishery re- 

 sources. Ideally, researchers would like to be able 

 to predict what the destruction of one acre of 

 marsh might mean in terms of lost fish production. 



North Carolina has nearly three million acres 

 of marsh and estuarine waters. If the belief proves 

 true that marsh and fish production are related, 

 protection of our estuaries and wetlands is es- 

 sential to a continued healthy fishing industry. 



As more people choose to work and play in the 

 coastal area, planning how marsh ana estuarine 

 resources will or won't be used becomes critical 

 to the future of the fishing industry and to one of 

 man's major food resources. 



But before we can plan, we need answers to 

 questions about the importance of marsh grasses 

 to seafoods. The intricacies of the food chain that 

 begins in the marsh need to be better understood. 



in the salt marshes. In attempting to determine 

 the dynamics of that system, they are looking at 

 the number and kinds of animals that feed on the 

 detritus of Spartina alterniflora, North Carolina's 

 dominant marsh grass. They aim to develop models 

 that will show mathematically how productivity of 

 marsh grass and detritus compares to the amount 

 of detritus eaten and animal-life produced. This 

 part of their research will help determine if marsh 

 animals are dependent on detritus for their energy. 

 In better establishing the importance of marsh 

 grass to fish productivity, Stiven and Kuenzler 

 are studying the amounts of detritus transported 

 to the open estuaries from salt marsh. 



Results from this work may help man determine 

 whether he can manipulate the marsh environment 

 and thus, the production of fish. With this data, 

 scientists hope to be able to predict, for instance, 

 how fertilization of marshes with sewage would 

 affect fishery production. 



Research at the Atlantic Estuarine Fisheries 

 Center supported by the National Marine Fisheries 

 Service and led by Dr. G. W. Thayer, a task leader 

 in the Center's ecology division, focuses on phyto- 

 plankton, marsh and sea grasses (particularly eel 

 grass) growing in the estuarine waters and their 

 importance to fish and shellfish in the aquatic 

 environment. Scientists at the Beaufort lab are 

 seeking to determine the rate at which energy in 

 detritus moves into and through components of 

 the estuarine ecosystem, the routes energy follows 

 and the speed at which it is used by marine 

 animals, including fish. 



The NMFS researchers hope to be able to predict 

 how environmental change, such as an increase in 

 water temperature caused by the discharge of 

 nuclear power plant cooling waters, would increase 

 or decrease fishery resources. If they are successful, 

 their work should furnish environmental managers 

 a valuable tool for predicting the impact of man's 

 activities in the coastal area. 



Dr. John Hobbie, North Carolina State Univer- 

 sity ecologist, is working with Sea Grant support 

 to get the facts on the role bacteria play in the 

 detritus -based food chain. Microbes, it is believed, 

 (See "A study," page U) 



Smooth cordgrass, a dominant N.C. marsh grass. 



