Life of the intertidal zones and tide pools
Marine habitats and intertidal zonation
Tim Hall Life zones of the sea Of the life zones of the sea the intertidal is very small- and a tide pool- even smaller Rosario Beach intertidal life zones
Zone designation Upper limit Lower limit Supralittoral Splash 1 7.0 ft + Upper midlittoral High intertidal 2 7.0ft 4.0 ft Lower midlittoral Mid intertidal 3 4.0 ft 0.0 ft Infralittoral Low intertidal 4 0.0 ft -3.5 ft Sublittoral Subtidal -3.5 ft
More than 100 species of intertidal animals live on the Rosario Beach rocks/tide pools Intertidal organisms are primarily marine plants and animals but may spend a great deal of time out of water
616 hrs/month (85% of the time) 290 hrs/month (40% of the time) 116 hrs/month (16% of the time) Hazards of living in the intertidal zone
Desiccation Extreme temperatures
Altered salinity Reduced feeding opportunities
Predators Factors influencing intertidal zonation Wave shock:
Adaptations-
A strong means of attachment
Either really hard or flexible bodies Hard (or flexible) bodies Strong attachment mechanisms
Rosario Beach rocks on a calm summer like day
Rosario Beach rocks on a February day with strong westerly winds Factors influencing intertidal zonation
Type of substrate:
Refuge and protection from predators
Habitat and colonization substrate
Food source
Disruptive force on high energy beaches
Factors influencing intertidal zonation
Competition for limited space and food
Adjacent colonies of the aggregating anemone may use their nematocysts on each other
The larger acorn barnacle grows faster, smothers, undercuts or crushes the smaller little brown barnacle Microhabitats
Areas downstream of tidepools and in crevices provide protection from desiccation and increased feeding opportunities
Different rock exposures provide protection from sun and wave shock Nooks and crannies provide nice homes and protection from predators
Some organisms (e.g. mussel beds) provide protective habitat for others animals Splash zone- > +7.0 ft
Lichens Checkered and Sitka periwinkle Littorina scutulata and L. sitkana
Little brown and acorn barnacles Chthamalus dalli and Balanus glandula Finger limpet Lottia digitalis Organisms adapted to living more in the air than in seawater- they may be high and dry for several days in a row Life style notes on periwinkles
Move up or down with the What do they eat? tide - more active at night or on foggy days Algae scraped from rocks with radula
Shells used by hermit crabs
Who eats them? How do they reproduce?
Dogwinkle Gelatinous egg masses
Six legged star
Rock crab How long do they live?
5 to 10 years Rosario beach barnacles
Little brown barnacle h Acorn barnacle m
(C. dalli) (B. glandula)
Giant barnacle l,s Haystack barnacle m,l,s
(Semibalanus cariosus) (B. nubilus) H= high tide zone, M= mid tide zone, L= low tide zone, S= sub tide zone “gooseneck” barnacle from the outer coast High intertidal plant life- 7 to 4 ft ~9 species
Green tuft h,m,l Sea moss h,m Turkish towel h,m,l
Cladophora columbiana (G) Endocladia muricata (R) Mastocarpus sp. (R)
Laver h,m,l Rockweed h,m,l Increasing numbers of plant species:
Greater food supply for animals
Increased habitat diversity Porphyra sp. (R) Fucus distichus (B)
G= green algae R= red algae B= brown algae High intertidal animal life- 7 to 4 ft ~12 species
Striped Haystack Everything dogwinkle from the barnacle splash zone plus:
Channeled (S. cariosus) (N. ostrina)
dogwinkle Shield limpet Finger limpet
(Lottia pelta) (Nucella canaliculata) (Tectura scutum) Mid Intertidal plant life- 4 to 0 ft ~35 species
m,l Green rope m,l Encrusting Sea cauliflower codium m,l
Arcosiphonia sp. (G) Codium setchellii (G) Leathesia difformis (B)
Black pine h,m Sea lace m,l Plus many of the species from the splash zone and lower tide levels
Endocladia muricata (R) Neorhodomela larix (R) (G= green algae, B= Brown algae, R= Red algae) Some notes on marine algae
Green algae Brown algae
Chlorophyll pigment Fucoxanthin pigment Varied forms More and more abundant at lower tide levels Red algae Kelps Phycoerythrin pigment Diatoms Largest number of species Golden brown pigment Can grow in deeper water Silica cell walls Some calcareous Film on plants, shells, etc. “coralline” forms Important in plankton Mid intertidal animal life- 4 to 0 ft ~ 40 species
Mussels Aggregating Chitons anemone Dogwinkles
Barnacles
Crabs Starfish Fish Sea anemones of Rosario Beach
Aggregating Giant green Brooding anemone m,l,s anemone l,s anemone l,s
Anthopleura elegantissima A. xanththogrammica Epiactis sp.
Christmas Rose anemone Plumose anemone l,s l,s anemone l,s
Metridium sp.
Urticina crassicornis U. lofotensis Life style notes on starfish
What do they eat? How do they reproduce?
Clams, mussels, and Sexual reproduction snails Smaller starfish Sponges How do they eat? Asexual reproduction Pry open shell Insert stomach
Who eats them? How long do they live? Glaucus winged gull Several years to >30 Red rock crab
Rosario Beach starfish relatives
Purple sea Green sea Red sea urchin l,s urchin l,s cucumber l,s
(Strongylocentrotus (S. droebachiensis) (Cucumaria miniata) purpuratus) Giant sea Armored sea Brittle star l,s cucumber l,s cucumber l,s
(Ophiopholis aculeata)
(Parastichopus californicus) (Psolus chitinoides) Common features of “echinoderms”
Spiny skin Hydraulic tube feet for locomotion
Radial symmetry Planktonic larvae Chitons of Rosario Beach
Leather chiton Mossy chiton Hairy chiton m,l,s m,l,s m,l
(Katharina tunicata) (Mopalia muscosa) (M. ciliata)
Woody chiton Lined chiton Gumboot chiton m,l,s m,l,s l,s
(Tonicella lineata) (M. lignose) (Cryptochiton stelleri) Life style notes on chitons
What do they eat? How do they reproduce?
Algae Sexual reproduction (males and females) Diatoms Eggs/larvae free swimming or Bacteria brooded by adult
Who eats them? How long do they live? Seagulls Starfish 20 years (or more) Crabs Who are they related to?
These are all related members of the largest marine phylum- mollusca
Mussels and
Octopus clams Snails and limpets
Chitons Common Sea slugs “mollusc” features
Embryology Radula Nervous system Mantle Sea slugs of Rosario Beach
Clown Barnacle eating Opalescent nudibranch l,s nudibranch m,l nudibranch l,s
(Triopha catalinae) (Onchidoris bilamellata) (Hermissenda crassicornis)
l,s Hudson's dorid Shaggy mouse Sea lemon l,s nudibranch l,s
(Acanthodoris hudsoni) (Archidoria montereyensis) (Aeolidia papillosa)
Nudibranchs are carnivores! Blue mussel m
What does it eat? How does it reproduce?
Detritus filter feeder Spawns in spring Planktonic larvae (4-7 Who eats it? weeks) Starfish Settles with byssal threads Dogwinkle How long does it live? Birds 2 to 3 years Larger crabs Otters
(Mytilus trossulus) The larger California mussel is more common on the wave swept outer coast Rosario Beach Crabs
Purple shore Red rock crab Decorator crab m,l,s m,l,s crab m,l
Hemigrapsus nudus (Cancer productus) (Oregonia gracilis)
Kelp crab l,s Porcelain crab m,l Hairy hermit crab h,m
Petrolisthes sp. (Pugettia producta) (Pagurus hirsutiusculius) Life style notes on crabs
What do they eat? How do they reproduce?
Algae Male and female crabs Clams/snails Eggs brooded by female Crustaceans Larvae are planktonic Dead and dying animals Organic detritus
Who eats them?
Birds Crabs
Octopus How long do they live?
Dogfish 1 to 2 years (maybe as Halibut many as 20) People Crab and crustacean growth- molting
Calcium resorbed- shell softens
Body swells with water
Shell is shed
New shell hardens
Benefits
Allows for growth Re-growth of lost legs Sheds barnacles and parasites
Same process of shrimp Not a dead crab! and barnacles
Some other Rosario Beach crustaceans
Rockweed isopod m,l,s Pill bug isopod m,l,s
(Idotea wosnesenskii) (Gnorimosphaeroma oregonense)
Broken back shrimp m,l,s Dock shrimp l,s
(Heptacarpus sp.) (Pandalus danae)
Shrimp= carnivores Isopods= herbivores/detritivores Low intertidal
“a frustratingly rich Increasing fauna and flora” Competition for food and space Predator/prey
Overlap of species interactions from upper and subtidal zones A study at Alki Point
The number of species Larger rocks support more begins to decrease at lower species because of tide zones because of greater habitat availability greater prey interaction “Signature” algae of the low tide zone
Codium Coralline Seersucker algae
(Codium fragile) (Costaria costata) Feather boa Winged kelp Bull kelp
(Nereocystis luetkeana) (Alaria marginata) (Egregia menziesii) Rosario Beach low intertidal sponges (that might also be found in tidepools)
Purple Breadcrumb Red encrusting encrusting sponge l,s sponge l,s sponge l,s
(Halichondria sp.) (Ophlitaspongia pennata) (Haliclona sp.) Rosario Beach low intertidal tube worms
Feather duster tube Calcareous tube worm m,l,s worm m,l,s The favorite tidepool fish – The tidepool sculpin
Tidepool sculpin The subtidal