Ecology, Intertidal Zones, and Estuaries

Ecology Ecology – how organisms interact with each other and their environment Ecosystem – all living and nonliving factors in a given area

Factors in an Ecosystem Abiotic Biotic Population size Population density Community types

Competition Living together: Symbiosis – close relationships; 3 types Commensalism +/0 Parasitism +/– Mutualism (cleaner fish) +/+

Flow of Energy in an Ecosystem Autotrophs – producers Heterotrophs – consumers Food chains & Food webs

The Intertidal Zone Intertidal zone (littoral zone) – area between the high and low tides Subtidal zone – region from the end of the continental shelf to the low tide marker; never is exposed to air

Rocky Intertidal Zone

Typical Rocky Shore

Soft Bottom Shore

Substrate Substrate Hard, rocky - (Rocky Shore Intertidal Communities) Sandy – (Soft-Bottom Intertidal Communities) Muddy –

Vertical Zonation on a Rocky Shoreline Vertical Zonation (4 zones): Spray Highest reach of spray & storm waves to high tides Infrequently wetted Organisms: lichens, encrusting algae, sea hair, limpets Upper From upper region of high tides to sea level Organisms: acorn barnacle, shore crab, limpets, rockweed, snails

Vertical Zonation (cont.) Middle Covered & uncovered 2 times per day Semidiurnal tides Organisms: surf grass, sea anemones, mussels, sea stars, barnacles Lower Usually submerged except for a few hours each month Organisms: kelp, sea stars, sea urchins, chitons

Stressors in the Intertidal Zone Water loss (desiccation) Temperature changes Salinity changes Wave shock

Solutions to Dealing with the Stressors Desiccation 3 strategies for dealing with H2O loss “run-and-hide” – (crevices/tide pools) “clam-up” “dry-out” – (seaweeds) Temperature Just Be Tough (like me) Radiating structures colors

Some animals allow themselves to just dry out A chiton has the ability to loose 70 percent of its water and still survive

Light color reflects light Ridges allow heat to escape

Solutions to Dealing with the Stressors Salinity Tough Burrow / “clam-up” Wave shock Holdfasts (seaweeds) Byssal threads (mussels) Muscular foot of snails Low profile Hiding

Estuaries Estuaries – enclosed areas where freshwater & saltwater meet & mix (ex. bays, lagoons, deltas)

Physical Characteristics of Estuaries Salinity – 0% - 35% Extreme salinity changes Salt wedge – salinity changes at different depths due to density differences.

Substrate – deposition of fine particles Commonly soft mud Low 02 due to high organic matter & decomposing bacteria Results: odor (egg smell; sulfur); black Fluctuating temperatures

Types of Estuary Communities Open H2O Fauna: Anchovies, mullets, anadromous & catadromous fishes (Shad, Eels, Striped Bass) Mud flats Very few plants Fauna: fiddler crabs, clams, mussels, oysters, ghost shrimp, pipe fish, silver sides, polychaetes, Predators: birds & fishes

Type of Estuary Communities (cont.) Salt marshes Plants: cord grasses Bacteria Ex. Cape May, New Jersey Mangrove forests [R]: propugules; H2O [B/W]: inland; pneumatophores Fx: habitat / protect shorelines