Please enable JavaScript.

Coggle requires JavaScript to display documents.

Y1 FINAL (FIELD TRIP) - Coggle Diagram

- - - - Not always the same height because of Earth's inclination results in mixed tides: HH,LL,HL,LH)
    - - Takes 28 days for the moon to circle the Earth which does a rotattion every 24h
    - - Moon's orbit around the earth is elliptical
      - Greater when moon is closer = perigee
      - Smaller when moon is farther away = apogee
      - Tide ranges greater during
        Full & New moon
        
        Sun has less grav effect because is further than the moon
        
        But when sun & moon are in line
        (Full & New moon) there is a compound
        effect which results in HIGHER HIGH
        & LOWER LOW
        
        Spring
        
        Neap
  - - - Grav pull on water by moon creates a tidal bulge -> H
      - Withdrawal of water in areas away from the tidal bulge -> L
      - Earth rotates (24h) under the tidal bulges so that one location will experience both H&L
      - 2 tidal bulges are equal&opposite = semi-diurnal tides
  - - - Race Rocks ~ 7 knots
      - World : Saltstraumen Norway ~ 20 knots
  - - - Lowest Normal Tide (LNT) : average of the lowest low water, one for the 19 years of the predictions.. Average of each of the 19 lowest tides of the year
      - USA: mean lower low water (MLLW) of each day of the 19 years
      - Datum to which levels on a nautical chart & tides predictions are refered
      - 19 years = one lunar cycle (metonic cycle)
      - Negative tides -> below the established chart datum
  - - - Predictable
      - Clean
      - Reliable
    - - Harsh environment (water movement, saltwater, fouling organisms)
      - Expensive to setup & hard to maintain
      - Environmental impacts
- - - - Abiotic
        
        Food & Oxygen availability
        
        Obtain oxygen from water
        
        Organisms in high IT have limited time to feed & oxygen
        
        Most marine organisms get food from water or plankton so can only feed underwater
        
        Adaptations
        
        Low activity levels at low tide
        
        Feed/oxygen the whole time underwater -> mussels, barnacles
        
        Scaleless fish can absorb O2 across body -> Northern clingfish
        
        Modified O2 absorption -> tube feet of blood stars
        
        Temperature
        
        Water temp varies only slightly over year (7~12*)
        
        Air temp can vary drastically (0~30*)
        
        Organisms out of water are subject to more variations of temp
        
        Adaptations
        
        Eurythermal enzymes in barnacles but not in sea urchins or sea stars
        
        Evaporative cooling in mussels & gooseneck barnacles
        
        UV light
        
        Marine organisms can sunburn, especially out of water
        
        Adaptations
        
        Sunscreen - natural compounds that absorbs UV
        
        Protective shells
        
        Under rocks & overhangs
        
        Desiccation
        Water loss, drying out, dehydration
        
        Adaptations
        
        Lose water then rehydrate -> Porphyra
        
        Live in tidepool
        
        Mucus -> anemones, Fucus
        
        Close up or clamp down -> mussels, barnacles, limpets
        
        Conserve water -> aggregating anemone attaching shells & pulling in tentacles ( help keep the water instead)
        
        Some species are more tolerant to being in the air (e.g. periwinkles, limpets) & can live in high IT
        
        Can increase with wind & temperature
        
        Occurs during low tides due to air exposure
        
        Wave exposure
        
        Some rocky IT are very high energy ecosystems
        
        Organisms waves exposed are adapted to hang on
        
        e.g. mussels have byssal threads
        
        e.g. some algae/seaweeds are very flexible
        
        Salinity
        
        Variation (especially at low tides)
        
        Euryhaline - tolerant to wide variations (e.g. mussels, barnacles)
        
        Stenohaline - tolerate only a narrow range (e.g. sea stars)
        
        Adaptations
        
        Close up -> barnacles, mussels, anemones
        
        Ion pumps in gills -> crabs
        
        Can increase with evaporation or decrease with fresh water input
      - Biotic
        
        Predation
        Animals eating other animals
        
        SPECIALISTS : ear a single prey type
        
        Adaptations
        
        Camouflage / e.g. tidepool sculpins, gumboot chitons
        
        Chemical defense / nudibranchs
        
        Protective shells / e.g. hermit crabs
        
        Escape responses
        
        Mutualistic adaptations / keyhole limpet, scale worm
        
        GENERALISTS : eat a wide range of food types
        
        Refuges
        
        Height in IT / e.g. mussels interactions - Pisaster
        
        Size / e.g. some mussels too big to be eaten by Pisaster
        
        Space / e.g. limpets living on vertical surfaces to avoid predations by birds Black oystercatchers
        
        Herbivory
        Animals eating plants/seaweeds
        (Similar to predation)
        
        Adaptations/Refuges
        
        Physical defense / e.g. calcium carbonate in coralline algae
        
        Chemical defense / e.g. sulfuric acid in acid algae - dissolves calcium teeth - or bromine in Prionitis
        
        Height in IT (above predators)
        
        Competition
        
        EXPLOITATIVE -> differential use of resource
        
        INTERSPECIFIC -> between species
        
        INTERFERENCE -> direct interaction
        
        INTRASPECIFIC -> between individuals of the same species
        
        barnacles compete for space
        
        hermit crabs compete for shells
        
        anemones compete for space
        
        Use or defense of a resource (food, space, mate) that reduce its availability to other individuals
    - - Physical
        
        Substrate: rock
        
        Intertidal: exposed to air & covered by water -> twice a day
        
        Temperature: wide variation with interactions with air
        
        Light: lots in air, but in water varies with depth
        
        Energy (variable with location) : amount of waves & wind hitting the ecosystem
        ex: Pedder Bay = low
        Race Rocks = high
      - Chemical
        
        Oxygen: variation in tidepools ; not very accessible to most intertidal organisms in air
        
        Salinity: wide variation in air & in tidepools, precipitation & evaporation influence it
        
        Nutrients: moderate to high due to proximity to land ; run-off & upwelling
      - Location
        
        Cosmopolitan ecosystem - all over the planet
        
        In all locations where there is bedrock & large boulders that are exposed at low tide (intertidal)
      - Tides create partly aquatic & partly aerial enviro
        
        Distribution of organisms in horizontal bands
        
        Caused by differing tolerances of organisms to stresses, both biotic & abiotic
        
        Banding pattern as a result of rise & fall of tides
        
        Pattern is similar worldwide -> intertidal zonation
      - Limits of organisms
        
        LOWER LIMIT : set by BIOTIC factors
        
        Exceptions
        
        Light setting the lower limit of seaweeds
        
        Predation by terrestrial predators from above
        
        UPPER LIMIT : set by ABIOTIC factors
- - - - The temperature decreases as one approaches the head of the bay. As one enters the bay, the water becomes shallower. Therefore, the water has more interactions with the air. Since the air temperature is cold (~7.5), it will impact the water temperature in the same way, ie it cools it off. For instance, the mouth of the bay with a depth of 25m is 9.1, and the head of the bay, 3m deep, has a surface temperature of 7.8*
    - - The temperature usually decreases with depth. However, my experiences do not depict that. My graphs show an increase in temperature with depth. This is due to the influence of cold air temperature on the surface temperature. As seen on the 1st and 3rd graphs, the water temperature at the surface was colder due to its large interactions with air (which was around 7.5*) and the temperature increased afterwards with the loss of the air's influence)
        +mixing
  - - - The salinity increases with depth because of the density. Saltier water has a bigger density and tends to move to the bottom, explaining why the salinity is higher as depth increases. Also, the surface has a lower salinity since it gets the freshwater inputs of precipitation, which dilutes the salinity
        +mixing makes salinity constant at station #1
    - - As one enters the bay, the salinity decreases. The head of the bay has more freshwater influx (due to the run off precipitations), diluting the salinity and bringing it down, than the mouth of the bay. Also, the salinity decreases when one enters the bay since the distance with the ocean - source of salt - increases and therefore has a smaller impact on salinity