Biome Located at the junction of the atmosphere, hydrosphere, and lithosphere Zone between high tide and low tide where an abundance of marine life thrives Complex marine ecosystem found along coastlines worldwide Rich in nutrients and oxygen, making it “home” to a variety of organisms

The intertidal zone is further divided into four key sub-zones: Splash/ Spray zone - "desert" of the intertidal zone, survives on the mist and spray of the ocean Upper intertidal zone - covered by water during high tide so it experiences dry periods daily Middle intertidal zone - regularly covered with sea water Lower intertidal zone - dry only during the lowest tides and contains the highest biodiversity within the intertidal zone

Located above the spring high tide Line Covered by water only during unusually high tides and storms Sprayed with salt water during high tide (hence the name spray zone) Size of spray zone depends on slope, splash, climate, and amount of shade Organisms common to this area: Algae, barnacles, isopods, lichens, lice, limpets, periwinkles, snails & whelks Little vegetation

Flooded during High tide only Highly saline environment Very extreme temperatures due to exposure of land to air and then to water Organisms common to this area: anemones, barnacles, brittle stars, chitons, crabs (including hermit crabs), Fucus, green algae, isopods, limpets, muscles, sea stars, snails, & whelks Some marine vegetation Also contains tide/ rock pools which can be inhabited by small fish and larger seaweeds

residents have many special adaptations. Tide pools differ from each other depending on depth and height in the intertidal zone. Anemones, barnacles, dog whelks, sculpins, and sea urchins create intricate interactions in these tiny, isolated micro-habitats. Each tide pool is a unique environment formed in rocky depressions by the receding tide. Tide pool organisms face large and sudden changes in salinity, temperature, pH and other factors due to tidal movements. As a result,

Almost equal periods Covered and uncovered by water throughout day depending on tide Temperatures less extreme due to shorter periods of exposure to the sun Lower salinity levels Organisms are larger and more complex & life is more diverse Major biological factor is competition for space Organisms common to this area: anemones, barnacles, chitons, crabs, green algae, isopods, limpets, muscles, sea lettuce, sea palms, sea stars, snails, sponges, & whelks Higher inhabitant of marine vegetation, especially seaweeds Also contains Tide/ rock pools which can be inhabited by small fish, shrimp, krill, sea urchins, and zoo plankton

Almost always flooded Only exposed at Low tide & exposed for longer amounts of time at extremely low tides Great biodiversity & larger animals organisms not well adapted to periods of dryness or extreme temperatures Organisms common to this area: abalone, anemones, brown seaweed chitons, crabs, green algae, hydroids, isopods, limpets, muscles, nudibranchs, sculpin, sea cucumber, sea lettuce, sea palms, sea stars, sea urchins, shrimp, snail, sponges, surf grass, tube worms, & whelks Normal salinity levels and shallow waters to allow photosynthesis account for larger more abundant vegetation (such as seaweeds)

In the intertidal zone the most common organisms are small and most are relatively uncomplicated organisms. Reasons include: intermittent supply of water which marine organisms require to survive wave action around shore can wash away or dislodge poorly suited or ill-adapted organisms high exposure to sun causes temperature range to be extreme salinity is much higher because salt water trapped in rock pools evaporates leaving salt deposits

The littoral zone is covered with salt water at high tides, and it is exposed to the air at low tides; the height of the tide exposes more or less land to this daily tide cycle. Organisms must be adapted to both very wet and very dry conditions.

The turbulence of the water is another reason that this area can be very difficult one in which to survive - the rough waves can dislodge or carry away poorly-adapted organisms. Many intertidal animals burrow into the sand (like clams), live under rocks, or attach themselves to rocks (like barnacles and mussels).

The temperature ranges from the moderate temperature of the water to air temperatures that vary from below freezing to scorching.

Depressions on the shores sometimes form tide pools although they are not long-lasting features. The salinity of tidepools varies from the salinity of the sea to much less salty, when rainwater or runoff dilutes it. When salt water left in tide pools evaporates, all that is left is salt deposits. the are Animals that must adapt their systems to these variations. Some fish, like sculpin and blennies, live in tide pools.

A lthough well-protected against the forces of nature, the plants and animals of the intertidal zone are not entirely protected from man. M an's impact on the intertidal zone can easily disturb the balance within an intertidal community. H azardous chemicals from waste disposal can harm species that feed on the ocean's bottom. M anmade or natural oil seepage can clog tidepool animals so they are unable to live or avoid being eaten. C areless tidepool explorers can crush animals and leave others exposed. U nfortunately, the intertidal zone is a place where changes to the climate and human impact can have their greatest impact.