Mearns Rock in 1993

Mearns Rock 1993   1993 Enlarged Quadrat

What You See

Fucus now covers about 20% of the boulder's surface. Large, older plants are gone; they seem to have been replaced by young plants. Mussels are growing on the front face of the boulder (black regions). Although the barnacle areas are difficult to see in the photo, the barnacles have died back considerably.
1993 Quadrat

In this photograph, dark patches of mussels have taken hold on the boulder. Also visible are whitish patches of barnacles and, in the upper section of the photo, young, gold-brown Fucus plants.

What's Happening

The young seaweed from the 1990 photo has matured, died back, and has almost entirely left the boulder. The patches of mussels probably began as young animals in 1992, but were too small to be seen in the 1992 photo. Now that they are larger, they are more visible. NOAA biologists aren't sure why the barnacles have died back. Have you any ideas why?