Ecology Lesson 3 Flashcards
(68 cards)
Salinity
How salty the water is
Levels of salinity
Low: Freshwater
Middle: Estuaries
High: Marine
Osmoregulation
What freshwater has no problem doing. It’s regulating the level of salt in the body. Meaning we can drink the freshwater.
Estuaries
A barrier between freshwater and ocean.
Animals crossing the salinity boarder?
Not many organisms can cross this boarder because you always have to balance the levels of salts in your body, and they all have different ways of doing this depending on what environment you live in. ie. salmon and bull sharks can do this.
Depth affects on ocean structure?
Light levels (no light in deeper)
Temperature (Colder is deeper)
Pressure (higher is deeper)
Intertidal zone
Between low and high tides. Exposed to air and water.
Across ocean zones
Intertidal, neurotic, and oceanic. And continental shelf (it’s shallow).
Vertical ocean zones
Photic, aphotic, abyssal. also mesopelagic.
Photic zone
Where you can see sunlight in the ocean, where photosynthesis occurs. At 200m.
Benthic zone
Anything on the seafloor.
Abyssal Zone
Deep down. Organisms here adapted to intense pressure. It’s very food limited because you can’t photosynthesis.
Important factor in ocean?
Depth and distance to shore
Mesopelagic zone
From 200 to 1000m. The biggest daily migration is the movement from 1000 to 200m to feed in the day.
Benthic vs pelagic
seafloor vs water column
Photic vs aphotic
Sunlight layer vs no light layer
Intertidal vs. neritic vs. oceanic
On shoreline vs close to coastline vs. far out
Differences in ocean vs. lakes
- Has littoral (very close to shoreline) vs. limnetic zone (open lake)
- Photic zone is very shallow.
- They have a lot of sediment so they tend to be quite turbid, so the light attenuates much faster, so it gets darker much faster.
Stratification
How fixed the water column is. Can dictate how much nutrients there are. One water layer sitting on top if another, with no mixing.
Thermocline
Zone of rapid temperature change. Why the layers don’t mix heat gradient.
Photic and Aphotic zones in lakes?
Photic: Warmer (it’s less dense so it floats on the cool water), oxygen-rich (from the photosynthesis), nutrient-poor.
Aphotic: Cooler (more dense), oxygen-poor, nutrient-rich (because there are no organisms using up the nutrients in the same way as the surface).
Lake stratification
In summer the layers don’t mix because the temp differences. Then in fall there is no thermocline because the water is the same density. Then in winter, the thermocline in the opposite direction (warmer at bottom, colder at top). Then in spring there is no thermocline and it mixes, with ramp in productivity. This is in temperate lake, as tropical lakes have different seasons.
Mixing during turnover
Oxygen to bottom, the nutrients to top. Important in terms of recycling the thing needed for photosynthesis. Occurs in fall and spring. The thermocline brakes down.
Open ocean stratification
Photic is 20 degrees and bottom drops to 2 degrees. The saltily affects the density. Has eutrophic and oligotrophic.