L7 Intertidal BIO 450

Tidal zones

• splash zone

• upper intertidal

• lower intertidal

• subtidal zone

Splash zone

• lichen (upper)

• glue green algae (cyanobacteria)

• brown algal (lower)

lichen

composite organism of 2 or 3 with symbiotic relations

• algae/cyanobateria and fungi

Upper intertidal zone

• cyanobacteria Calothrix spp

• filamentous

• secretes mucus sheath around colony to protect and adhere to rocks

• UV absorbing sheath pigments to prevent photoinhibitation

Fiddler Crab

• major claw to impress females

• submerged periodically

• can breathe air

• major claw lost and feeder claw morphs into new claw

microhabitat selection

when organism chose specific small scale enviornment within larger habitat that suits best need

• fiddler crab retreat into deep moist burrows during hot parts

• avoids lethal temp

Heat Dome

• hot air trapped over an area by high pressure, causing temp to stay high and rise

• sessile organisms could not move to cooler areas and suffered the most

  • got cooked and stayed there

Rough periwinkle

• upper intertidal zone

• breathe air like lungs

• can switch to anaerobic (submerged in water)

• feed on lichen and algae

crustose algae

a way of growing, where it forms crust by adhering to substrate

• middle intertidal zone

• red and brown

• calcium carbonate into cell wall

Cirri

• modified feet that extend in water to bring plankton to mouth

• planktonic → sessile

• acorn barnacle

planktonic larval stage benefits

• wide dispersal

• less competition

• increased genetic diversity

• can find better habitat

planktonic larvae risks

• high mortality (predation)

• random settlement

• energy costly to make larvae

• dependent on currents

No allele effect

• population too small, individuals hardere time surviving/reproducing

• lower fitness

• normal growth

weak allele effect

• fitness decreases at low population

• but still survives

strong allele effect

• population drops below a threshold

• extinction risk

• if population small can be negative growth rate

allele effect

• population size has extra effect

• dN/dt

population growth vs density

• dN / dt

• population growth depends on density

• measure of fitness

• low density → low fitness → low growth

• hard to find mates, less survival

Barnacles allele effect

• strong allele effect

• low population density → barnacles too far apart

• cannot reproduce effectively (no neighbors)

• fitness drops SHARP → negative growth

blue mussels

• middle intertidal zone

• filter feeders

• attach to rocks using byssal threads

dog whelks

• middle intertidal zone

• respires through gills

• feed on organisms under shells through hole

sea stars

• wide range reproduction strats

• simultaneous hermaphrodite (male + female) self fertilize

foundation species

• species that create habitat

• support other organisms

• keystone predator (controls dominant species)

purple sea star and sun stars

• keystone predator

• eats mussels and prevents them from taking over

• controls biodiversity

fragmentation

habitat broken into smaller isolated pieces

fewer species close together → harder to reproduce → allele effect

• red sea stars

chlorophyta

• green algae

• shallow water

• need light

ochrophyta

brown algae

• absorbs more light than green

• mid intertidal

rhodophyta

red algae

• lower intertidal

• red light disappears first

• deep low light

macroalgae

• not vascular plants

• no roots stem

• holdfast

holdfast

• anchors algae to substrate

• not used for nutrient uptake

• ONLY for attachment

stipe

• central stem like structure

• no true vascular tissue

blade

• thin flat leaf like

• macroalgae photosynthetic cells on both sides of leaf (constant movement and flipping in water)

pneumatocysts

• gas bladders

• help float in water

• sessile

bladder wrack

• brown algae

• lower intertidal zone

• specific pneumatocysts

• source of iodine to treat goiters

• uses carbolic acids (phenols) to deter predators

  • mullocks and sea urchins

costal estuaries

• transition from fresh to salt water

coastal plain

• drowned river valleys

• flat land adjacent to seacoast

• form as glaciers receded

• sea levels rose to flood low lying valleys

• decrease in topography

bar built

• trapped water → unstable conditions

• separated from ocean by island barriers

• limited water exchange

eutrophication risks

• susceptible to nutrient run off

• leads to algal blooms

wind driven mixing

• shallow protectd from waves

• mixed by winds not tides

• mixes fresh water + sea

extreme saline fluctuations

• inlet close → freshwater (low saline)

• drought evaporation → hypersaline (very salty)

  • fiddler crabs can tolerate rapid changes

delta

• form at the mouth of large rivers

• sediments accumulate to make complex set of channels and marshes

tectonic estuaries

• tectonic activity causes piece of land to sink

• forms costal depression → fills w water

  • more rare

fjords

• long narrow valleys

• steep sides

• created by advancing glaciers that flood when glaciers retreat

• glaciers = ice scrapers

sill effect

• pushing land from ice scraping glaciers (deposits)

• barrier between fjord and ocean

• good at blue carbon (storage)

blue carbon

• carbon stored in marine ecosystem

• removal of carbon bc organisms settle to bottom

flushing time

• time take to turnover (replace) freshwater into estuary

tidal prism

• the difference in volume of water in estuary between mean high tide and mean low tide

salt wedge

• most stratified

• less dense freshwater on top

• salt water underneath (wedge)

isohaline

• contour that joins points of equal salinity in aquatic sys

• lines that show salt pattern

vertical mixing

• least stratified

• occurs when river flow low and tidal currents strong

  • range from no stratification (well mixed) to partial

partially mixed

• some stratification

• deep esturaries with strong turbulence

well mixed

• no stratification

• shallow estuaries

• more turbulent

highly stratified

• deep water estuaries fjords

• strong layers (little mixing)

• surface → freshwater runoff

• deep → cold, dense seawater

halophytes

• salt tolerant plant species

• grow in salt contaiminated soil or water

recretion

secretion of salt ions by glands or salt hairs

• 15% of all halophytes

pickleweeds

• succulent stores water in fleshy leaves

• halophytes stores excess salt in leaves

euhalophyte

dilutes salt within leaves/stem

recretohalophye

excrete using salt glands/hair

pseudohalophyte

• intercept ions in roots and minimize transport of ions

west indian manatee

• order sirenia

• herbivours = seagrass

• heavy bones

• lots of blubber

• can tolerate brackish water

salt marshes

threats

• algal bloom

• fragmentation

• pollutioin

• boats

carbon sequestration

• salt marshes store carbon long term

• remove CO2 from atmosphere

• HUGE effect

• anoxic sediments preventing decomp

• plant sinks down further with no oxygen

carbon sequestation steps

1. plant photosynthesize → take in CO2

2. produce OM

3. dead material falls into mud

4. gets trapped in anoxic sediments (carbon trapped)

marsh loss

• sea level rise

• storms

• less sequestration + more CO2

• thermal expansion

phragmites australis

• invasive species

• drys out system

• release toxins to surpress growth of competitors

• marsh loss

european green crab

• invasive

• eat clams, oysters, other crabs

genetic paradox of species invasions

founder effects and small population size result in invasive populations w lower genetic diversity

• how invasive species so successful if they should have low genetic diversity

• low diversity but high success = paradox

chromosomal inversion + gametic disequilibrium

• genes locked together

• gets flipped and no longer cross over

  • good combination for invasion success

inundation

• flooding by water (sea level rising)

• if water rises slow → marsh adapts

• if water rises too fast → marsh dies

  • overwhelm salt tolerance, anoxic conditions

nutrient loading

• threat to marshes

• excess nuitrients from: runoff, agricultiure, precipiation

• more nitrogen enters marsh

• fast growth BUT weak structure

mudflats

• tidal surface exposed to air at low tides

• exposed at lowtide, covered at high tide

• soft sediment, low oxygen, high nutrients

  • burrowing animals pacifi

pacific razor clam

• lives in mud

• escape adverse conditions at low tide by burying themselves

• filter feeders

• switch to anaerobic respiration when tide is out