What You See
The boulder is now about 50% covered with larger, older seaweed (mainly Fucus). Barnacles are filling in spaces left by dying seaweed. The beach face is heavily covered with seaweed.
1992 Quadrat
Larger, older seaweed (mainly Fucus) is dying off. Light-colored barnacles are filling in spaces left by dying seaweed. The mussels appear larger now.
What's Happening
The Fucus that was young in the 1990 photo has aged and is now dying off. Why is it dying off?