Transplants of tropical seagrasses 

 may ultimately be a useful restoration 

 technique to reclaim damaged areas, but at 

 this time the results are not consistent 

 or dependable, and the costs seem prohibi- 

 tive for any effort other than an experi- 

 mental revegetation, especially when the 

 relative survival of the plants is consid- 

 ered. Sufficient work has not been done 

 to indicate whether tropical plants are 

 really more recalcitrant than temperate 

 ones. It is likely that continued re- 

 search will yield more successful and 

 cost-effective techniques. 



8,6 THE LESSON OF THE WASTING DISEASE 



The information overload that we are 

 subjected to daily as members of modern 

 society has rendered us immune to many of 

 the predictions of doom, destruction, and 

 catastrophe with which we are constantly 

 bombarded. On a global scale, marine 

 scientists recently feared the destruction 

 of a major portion of the reefs and atolls 

 of the Pacific by an unprecedented out- 

 break of the crown-of-thorns starfish 

 ( Acanthaster planci ). The outbreak spread 

 rapidly and the devastation was intense in 

 the regions in which it occurred. Yet, 

 within a few years Acanthaster populations 

 declined. The enormous reef destruction 

 that was feared did not occur and recovery 

 commenced . 



In south Florida in 1972-73 there 

 appeared to be an outbreak of the isopod, 

 Sphaeroma terebrans , which it was feared 

 would devastate the Florida mangroves. 

 This devastation never materialized, and 

 it now appears that the episode repre- 

 sented a minor population excursion (see 

 Odum et al . 1981 for complete treatment). 



These episodic events proved to he 

 short tenr, and probably of little long- 

 range consequence, yet the oceans arc not 

 nearly as immune to perturbations as many 

 have come to think. We witness climatic 

 changes having major effects and causing 

 large-scale famine on land, but few think 

 this can happen in the seemingly infinite 

 seas. However, one such catastrophic dis- 

 turbance has occurred in the seas, and it 

 was in this century and induced by a 

 natural process. 



In the early 1930's, Zostera marina , 

 a widespread northern temperate seagrass 

 disappeared from a large part of its 

 range. In North America, it virtually van- 

 ished from Newfoundland to North Carolina, 

 and in Europe from Norway and Penmark 

 south to Spain and Portugal. The outbreak 

 began on the open marine coasts and spread 

 to the estuarine regions. 



Many changes accompanied this distur- 

 bance. Sandy beaches eroded and were re- 

 placed with rocky rubble. The protective 

 effects of the grass beds were removed. 

 The fisheries changed, although slowly at 

 first, as their detrital base disappeared. 

 Noticeable improvement did not become 

 widespread until after 1945 (Rasmussen 

 1977), and full recovery required 30 to 

 40 years. It should be emphasized that 

 this was a large-scale event. In Denmark 

 alone over 6,300 km- (2,430mi-) of eel- 

 grass beds disappeared (Rasmussen 1977), 

 By comparison, south Florida possesses 

 about 5,000 km- (1,930 mi^) of submerged 

 marine vegetation (Bittaker and Iverson, 

 in press). Originally the wasting disease 

 was attributed to a parasite, Labyrithula . 

 but now it is felt that the cause was 

 likely a climatic temperature fluctuation 

 (Rasmussen 1973). As man's role shifts 

 from that of passive observer to one of 

 responsibility for large-scale environ- 

 mental change, basic understanding of the 

 fundamental processes of ecosystems is 

 necessary to avoid his becoming the cause 

 of associated large-scale disturbance com- 

 parable to the wasting disease. 



8.7 PRESENT, PAST, AND FUTURE 



Increasingly, studies have shown the 

 importance of submerged vegetation to 

 major commercial and forage organisms 

 (Lindall and Saloman 1977; Thayer and 

 Ustach 1981; Peters et al . 1979; Thayer 

 et al. 1978b). Peters et al . (1979) found 

 that in the Gulf States the value of the 

 recreational salt water fish catch exceed- 

 ed $168 million in 1973, which represents 

 about 30% of the total U.S. recreational 

 fishery (Lindall and Saloman 1977). Of 

 this, 59'^ of the organisms caught were 

 dependent on wetlands at some stage of 

 their life cycle. Lindall and Saloman 

 (1977) estimated an even higher dependency 



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