1. 1 ROCKY INTERTIDAL ZONE Western US rocky intertidal zones – less seasonal changes. The greatest limiting factor is space. Eastern US soft-bottomed intertidal zones - temperature changes cause seasonal population changes. The greatest limiting factor is climate.

2. 2 Rocky coasts are characterized by: - abundant food supply with good light - tides produce hours of flooding in cool water followed by desiccation (drying out) and high temperatures - tidal pools are created and emptied - temperature and salinity fluctuate - very distinct zonation worldwide - wave shock http://www.youtube.com/watch?v=6pZ0PZBNgU4 http://www.youtube.com/watch?v=6pZ0PZBNgU4 - competition for space fierce (limiting factor)

3. 3 COPING STRATEGIES / ADAPTATIONS: - WATER LOSS: - run & hide, clam up, tolerate - allow drying out - find tide pools - http://www.youtube.com/watch?v=6QaMA5S1E1E http://www.youtube.com/watch?v=6QaMA5S1E1E - http://www.youtube.com/watch?v=IyNEG-PvZmM http://www.youtube.com/watch?v=IyNEG-PvZmM - TEMPERATURE - tolerate - move to moist areas - light color - SALINITY - clam up - tolerate - RESTRICTED FEEDING (MOST ARE FILTER FEEDERS) - only feed when tide is high - tide height determines where they can live

4. 4 COPING STRATEGIES / ADAPTATIONS: - WAVE SHOCK: - attach (holdfasts, byssal threads, glue) - cling (suction cups) - fish lack swim bladders - find shelter - thicker shells - compact shape - low profile - go with the flow / flexible

5. 5 Wave action cuts rocks into sea caves, cliffs and sea stacks that provide shelter. Competition for these limited living spaces is high. Inhabitants must find a place to attach or hide or be crushed between waves and rocks. Methods of attachment include cement, byssal threads, holdfasts, muscular and tube feet, and boring.

6. 6 Adaptations also include symbiosis and reproductive strategies, like hermaphrodites and organisms that change sex. The rocky coastal communities’ succession has a predictable pattern that is often controlled by sea urchins. Grazing urchins remove algae from rocks. NOAA

7. 7 New communities can then begin because one group doesn’t over populate the area. Pioneer stage - bacteria and algae Juvenile - protozoa and worms Mature - barnacles, rockweed, mussels, seastars and sea urchins Collectively these animals became known as fouling communities because of their harmful effects on ship’s hulls, docks, pilings, and the smell they create at low tide.

8. 8 THE BATTLE FOR SPACE - AVAILIBILITY OF SPACE LIMITS POPULATIONS IN INTERTIDAL - COMPETITION FOR SPACE DOMINANT BIOLOGICAL FACTOR - HOW TO COMPETE - be first to get to open space - effective dispersal - reproduce rapidly - take over - grow over

9. 9 VERTICAL ZONATION - UPPER, MIDDLE & LOWER ZONES - UPPER LIMIT SET BY PHYSICAL FACTORS - LOWER LIMIT SET BY BIOLOGICAL FACTORS (predation & competition)