under an established Fucus canopy. However, if an area of the 

 mid-intertidal is cleared (e.g., by ice-scour), Fucus germlings settle 

 and grow into a new canopy (Keser and Larson 1984) . As individual 

 plants age, they become more susceptible to epiphytism (Menge 1975), 

 storm damage and ice-scouring (Mathieson et al. 1982; Chock and 

 Mathieson 1983) ; their removal makes space available for settlement and 

 growth of new germlings to continue the cycle of abundance (Schonbeck 

 and Norton 1980) . The entire cycle generally takes 2-4 years in the 

 Millstone Point area, but different stations may become out of phase, 

 because of different settlement patterns, growth rates, or exposure to 

 clearing processes. 



As reported last year, from 1979 to 1981 there had been a general 

 decline in mean annual percent cover of fucoids in Zone 11. Through the 

 past two years, however, the trend appears to be reversing. The 

 re-establishment of a fucoid canopy was seen most clearly at Fox 

 Island-Sheltered, where Fucus cover Increased steadily from a low of 7% 

 in April 1981, to ca. 60% by September 1982, to almost 75% by September 

 1983. Giants Neck, White Point and Seaside Exposed have all shown 

 increasing fucoid cover through this report year. More temporal 

 patterns in fucoid canopy will be presented in a later section. 



Zone III was characterized by dense coverage of Chondrus crispus , 

 sometimes obscured by a canopy of Fucus vesiculosus . Recovery of 

 Chondrus and Fucus at most stations, beyond that reported last year 

 (NUSCo 1983), again points to the occurrence of long-term cycles in 

 abundance of these perennial algae. At Seaside Sheltered, the decrease 

 in Chondrus (from over 16% in 1982 to less than 7% this year) was 

 attributed to competition for space with mussels, whose coverage 

 increased from ca. 16% to 30%. Mussel coverage also increased at 

 Seaside Exposed; this may cause future loss of Chondrus . 



Fox Island-Sheltered also had low coverage of Chondrus in Zone III 

 (more than last year, but still <7%); this was not attributed to 

 competition by Mytilus , as it has been consistent since 1979. The 

 relatively high abundance of Fucus and free space in Zone III of Fox 

 Island-Sheltered has also been consistent. At all stations, barnacle 

 coverage in Zone III was lower than in Zone II, and those individuals 

 that did settle were mostly removed before autumn as a result of predation. 



15 



