1. Intertidal Communities Rocky Shores  Distance from low water is correlated with variations in physical and biological stresses, resulting in distinct horizontal bands of zonation.

2. Intertidal Zone The area that lies between the highest high tides and the lowest low tides

3. Figure 10.22

4. Intertidal Communities Rocky Shores  The middle intertidal is more densely populated with species more troubled by competition for food and space than physical limitations of the environment.

5. Intertidal Communities Magnified cross-section of a lichen with algae cells (dark spots) embedded in fungal filaments. Snails and limpets grazing on sparsely distributed algae growing along the edge of a tidal pool. Rocky Shores © Wildlife Pictures/age fotostock

6. Intertidal Communities Rocky Shores  The upper intertidal of rocky shorelines hosts organisms that suffer with frequent desiccation and punctuated food supplies. Stunted acorn barnacles, Chthamalus, survive in the shallow depression of carved letters.

7. Intertidal Communities Rocky Shores The aggregate sea anemone, Anthopleura elegantissima. Exposed individuals (upper right) have retracted their tentacles to avoid dessication. © Danita Delimont/Alamy Images

8. Rocky Intertidal Communities Close-up view of mussels, Mytilus, attached to rocks in the middle intertidal. Algal species exposed during low tides use thickened cell walls to prevent water loss. © Carsten Medom Madsen/ShutterStock, Inc.

9. Rocky Intertidal Communities Tightly packed barnacles compete for space along the intertidal. Photo by Dave Cowles, Rosario Marine Invertebrates website http://rosario.wallawalla.edu/inverts

10. Rocky Intertidal Communities Sea stars, Pisaster, aggregating near the low tide line to avoid dessication. © Charles A. Blakeslee/age fotostock

11. Intertidal Communities Rocky Shores  The lower intertidal hosts a diversified assemblage of plants and animals that are exposed to air for only a short period of time each day. Surf grass covers rocks and helps to keep intertidal organisms moist during low tide. © Weldon Schloneger/ShutterStock, Inc.

12. Rocky Intertidal Communities The green anemone, Anthopleura xanthogrammica. An eolid nudibranch with long finger-like cerata projecting from its dorsal surface. © Weldon Schloneger/ShutterStock, Inc. © Kerry L. Werry/ShutterStock, Inc.

13. Rocky Intertidal Communities A scallop flaps its valves (shells) vigorously to jet away from a predatory sea star. © Marevision/age fotostock

14. MORE SPECIFICALLY Rocky Intertidal Zone Have hard rocky bottoms On shores without much sediment Found in New England and the west coast Locally here – “Montauk Bluffs” and the LI (North Shore) coastline

16. Rocky Intertidal Zone Problems of living in intertidal zone:  Exposure to air  Wave shock

17. Exposure to Air Varies along the intertidal zone  High intertidal zone is exposed longer

18. Exposure to Air Water Loss = Dessication Prevention:

19. Exposure to Air Water Loss = Dessication Prevention:  Move – tide pools  Hide – in moist areas  Close up

20. Figure 11.5 Seaweed Dessi- cation

21. Figure 11.2 Littorina

22. Exposure to Air Water Loss = Dessication Prevention:  Move – tide pools  Hide – in moist areas  Close up Withstand Drying out – seaweed, chitons

23. Exposure to Air Temperature Fluctuations  More extreme in air Solutions: tolerance or hiding

24. Figure 11.3

25. Exposure to Air Salinity Fluctuations  Fresh water from rain  High salinity in tide pools from evaporation Solutions: tolerance, close up, hide or death

26. Exposure to Air Restricts Feeding  Most sessile animals are filter feeders  Others are busy avoiding stress Animals in high intertidal grow slowly

27. Figure 11.4 (CA) Mussel

28. Wave Shock A problem even when the tide is high varies along coastlines

29. Wave Shock Adaptations to reduce the impact:  Thicker shells  Compact bodies  Flexibility

30. Wave Shock Many organisms must anchor themselves  Mussels- byssal threads  Seaweeds – holdfast  Barnacles – glue Others move to sheltered areas

34. Flexible kelp – withstands wave action

35. Figure 11.10

36. Grow taller and shorter per wave action

37. Figure 11.26

38. Sunflower Sea Star, California. Credit: © Brandon Cole/Visuals Unlimited 416530 1 more Intertidal Organism… Holds on!

39. Adaptations… Because of all of these adaptations, you see a distinct vertical ZONATION on rocky shorelines. Resultant (from competition)

40. Figure 11.9 Zonation in seaweeds

42. Rocky Intertidal Communities Vertical zonation patterns on a 3- m-high rock on the coast of Oregon.

43. Vertical Zonation All rocky intertidal communities are divided into distinct bands or zones Each species is only found in one specific vertical range

44. Vertical Zonation Results from biological and physical factors Upper limit – physical factors Lower limit – biological factors

45. Because of Zonation, there is Competition For Space Open space on the rock usually limits populations Food is plentiful

46. How to Win the Competition For Space Be the first to get there  Good dispersal Undercut or grow over your neighbors  Barnacles  “Competition example!!!”

48. Figure 11.14 Space – newly settled barnacles (arrow); w/ 2 mussels, 2 barnacles Limpets…anemones (oh my…)

49. Zonation Zonation causes there to be very distinct biotic communities in a rocky intertidal zone: Upper (Intertidal) Middle (Intertidal) Lower (Intertidal)

50. Upper Intertidal Splash zone – above the high tide line Lichens, cyanobacteria, periwinkles (snails) Mostly land predators

51. Middle Intertidal May have many zones within this zone – due to tidal differences Barnacles Mussels, other barnacles and rockweed Sea stars = predators

53. Figure 11.18 Bands/zones between organisms on rocks

54. Zonation in Bonaire: Limpets

57. Keystone Predator Sea stars can dramatically affect the community structure “Intermediate Disturbance Hypothesis” – increases diversity (will be in competition lecture too)

59. Local… A few pictures from your local “rocky intertidal” habitat

60. Long Island Sound (Bluff View)

61. “Rocky Intertidal” (LIS)

62. “Rocky” Shoreline (North Shore of LI)

63. <-- “Wrack Line”

64. “Wrack” Weed (dead)

65. Wrack Weed (alive) “Fucus sp.)

66. LONG ISLAND SOUND, LI, NY

67. “Gull” (Larus)

68. “Sandpiper” (Calidris)

69. Now -- Our 1 st “Main” Habitat -- part of the Rocky (hard bottom) ecosystem -- KELP FOREST (go to new lecture)