Intertidal

northern pipefish

closely related to seahorses, but have a long slender shape; common in esturaries where they blend in with grasses

electric eel

more closely related to catfish than other eels, makes electricity like a battery but unlikely to kill a human b/c discharge time is short

brown pelican

have been persecuted b/c seen as competition for fish, populations plummeted b/c habitat destruction, pollution, and disturbance of nests

sea otters

largest of weasel family, live in N. Pacific coasts, are a keystone species b/c they keep urchin populations in check

bull shark

able to survive in marine, estuarine, and freshwater environments; frequent coastal regions, 1 of 3 species of shark responsible for human shark bites

southern flounder

common flounder found in NC, is left-eyed; identified as either left- or right-eyed depending on which eye migrates as the flounder develops

laughing gull

common gull in NC that gets its name for its laughing-like call

saltwater crocodile

largest living reptile, reaches lengths of >20ft, highest recorded bite strength

giant freshwater stingray

not typically fatal to humans, largest stingray species over 6 ft across

algae octopus

found in intertidal environments of S. Pacific; can display bipedal locomotion (walk on two arms)

estuary

partially enclosed area where fresh water and salt water mix

coastal plain estuary

most common type, formed at end of last ice-age; ex) Chesapeake Bay

tectonic estuary

sea reinvades land due to the sinking of the land ex) San Francisco Bay

semienclosed bay

aka lagoon, formed when sand bars build up parallel to the coastline and partially cut off the sea ex) NC Coast

fjords

glacial valleys that have been invaded by the sea

positive estuary

aka salt wedge estuary, strongly stratified water column with highest salinity at/near bottom and lowest at surface

neutral estuary

aka homogenous estuary, complete mixing leading to similar salinities from top to bottom

negative estuary

evaporite estuary, little freshwater input and high evaporation leads to hypersaline surface

major characteristics of estuaries

• salinity

• substrates

• temperature

• turbidity

• oxygen

• wave actions & currents

salinity

dominant feature of estuaries, varies w/ tides and seasons

substrates

most esturaries have soft-muddy substrates

temperature

varies greatly in esturaries but also w/ salinity

turbidity

effects penetration of light

oxygen

usually in high supply due to mixing, but depleted in substrate

wave action & current

controls deposition of sediments and hte mixing between fresh adn salt water

flushing time

amount of time needed for a given mass of freshwater to be discharged from an estuary

stenohaline

marine animals that can’t tolerate salinity changes

euryhaline

marine animals that can tolerate salinity changes down to 15 ppt

aerenchyma

special tissues that supply roots with oxygen in anoxic mud

salt glands

release excess salt for plants

succulence

incorporation of high water content in tissues to reduce loss by osmosis

salt marshes

communities of grasses in soils that are flooded and drained by tides; have halophytes (plants that grow in high salt contents)

salt pans

higher salinity areas where no vegetation can grow

importance of wetlands

• provide food and habitat for fish, birds, etc.

• filter, dilute, and degrade toxic wastes and pollutants

• reduce flooding and erosion

adaptations of intertidal organisms

• resistance to water loss that occurs b/c of evaporation during low tide

• maintain temperature

• resist mechanical stress of crashing waves

• prevent salinity stress due to salt crusting or freshwater influx

• respiration, reproduction and feeding occur at high tide

tidal pools

• temperature

• oxygen

• salinity

occur around rocky shores, overturned with each tidal cycle

factors for beaches

• grain size - finer grains hold water, coarse sand allows drainage

• wave action - controls degree of erosion and sand movement

• slope - controls degree of erosion and sand movement

beaches

deposits of sand or rock fragments along ocean floors and coastlines

berm

raised areas of the beach (higher slopes in winter, shorter in summer)

sand bar

sand carried away from shore by waves

long shore current

runs parallel to coastline transporting sand

barrier islands

isolated former dunes that are offshore

muddy shores

intertidal areas completely restricted from open ocean activity; have very fine partciple sizes that hold water well and lead to anerobic conditions

fish adaptations for areas

• rocky intertidal = small and elongate to navigate

• mud and sand flats = skates, rays, and flatfishes are significant predators

birds

predation is intense during breeding; play an important part in the intertidal community