Limnology Chapters 1 and 2

Definition of limnology

The oceanography of lakes- also includes inland waters.

Physical science with large biological component

Where is the world's water?

- Ocean (97.3%)

- Ice (2.19%)

- Soil moisture (0.005%)

- Atmospheric water vapor (0.001%)

- Inland freshwater lakes (0.009%)

- Inland saline lakes (0.008%)

- Rivers (0.001%)

How is limnology interdisciplinary?

Innvolves thing such as geology in terms of erosion and sedimentation

- questions physical dimensions

- questions the climate which involves meteorology/climatology

Where is most freshwater stored?

In lakes and rivers

what are edaphic factors?

properties of soil, basically asks, "what is the soil like?"

Allochthonous vs. autochthonous materials

Allochthonous: Pertaining to materials, particularly rock masses, that formed somewhere other than their present location, and were transported by fault movements, large-scale gravity sliding, or similar processes

Autochthonous: a large block or mass of rock which is in the place of its original formation relative to its basement or foundation rock

- It can be described as rooted to its basement rock as opposed to an allochthonous block or nappe which has been relocated from its site of formation

What sets up the lake continuum?

geology, physical dimensions, and climate

What are some examples of lake continuum?

- Oligotrophy (good visual but poor nutrients) to eutrophy (high nutrients like algal blooms-swamp visuals)

- mesotrophy; which is a bit of everything

What are the levels of temperature and oxygen stratification?

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Top surface: Epilimnion

Middle surface: Metalimnion

Lower depth: Hypolimnon

What is the continuum quantitatively

amt of inorganic carbon fixed by photosynthetic producers

Characteristics of eutrophic lakes and organisms living in them

shallow broad littoral zone with dirtyish water (brown or greenish brown), full of nutrients.

- oxygen depleted in summer hypolimnion

Organisms living in there ex: Chironomus sp. (MIDGE FLY)

- larvae lookd like bright red worm (bloodworm)... seen before in ecology when doing lake study @ UTA pond

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Characteristics of oligotrophic lakes and organisms living in them

deep and steep bankes with epilimnon volume usually small compared to hypolimnon

- low sediments and organic matter, intolerant of low oxygen

ex organisms: Tanytarsus midge larvae, Deep water salmonid or coregonid fishes present

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What is paleolimnology?

Study of inland water sediments

What is dystrophy?

Deficient in calcium-usually bogs or bog lakes

think of cranberry bogs

-acidic

-stained water color

What is Palynology?

Study of fossilized spores and pollen

What's typically the first thing a limnologist studies?

water chemistry

such as nitrogen which comes with studying ammonia (via fish piss)

How is biology connected to limnology?

aquatic biology is rooted in the physical science of limnology

ecological concepts developed from study of freshwater organisms... such as the trophic cascade and top down and bottom up regulation

What is trophic cascade?

Altering abundance at one trophic level

changes the ecosystem at other levels

What is the littoral zone?

Near shore which means subject to high erosion via wave action and grinding of ice

- Has large sediments and shallow water but often well lit

-highest levels of aquatic plants

- high biodiversity

What is the sublittoral zone?

-finer sediments and well oxygenated

-known as the "shell zone"

What is the profundal zone?

Cold deep layer- Forms in any lake deep enough for

temperature stratification

- low oxygen and pH

-fine sediments

-lowest biodiveristy

what is the benthic zone?

touching or close to the bottom of any other zone

- any organisms living on or near the bottom is part of benthos

ex) round goby and zebra clam/mussel

What is the pelagic zone?

Open water, where shore and bottom lose

influence

-Where most plankton species occur

describe photosynthesis in lakes

-Trophogenic (photic) zone - where synthesis

of carbon compounds occurs

- Tropholytic zone (aphotic) - respiration and

decomposition predominate

- The boundary between these two layers is a

function of light penetration: light intensity and turbidity

How can freshwater be challenging?

Freshwater is always diluting body fluids>> causes freshwater fish to have evolved kidney structure>>> osomoregulators

what are some physical and chemical factors of freshwater?

There is no tides due to them not having an effect on the moon

pH: usually 4-11 unlike the ocean

What are some adaptions organisms have to living in freshwater?

taxa have desiccation resistant phases (ability of an organism to reduce or prevent water loss when exposed to dry air or drought)

- often ecloses and protects the organism

ex) sponges

-Many freshwater taxa lack a larval stage

What is metagenomics?

the study of the structure and function of entire nucleotide sequences isolated and analyzed from all the organisms

Is domain archaea a real bacteria?

NO

- but it is the most important group to limnology are methanogens that decompose

Characteristics of Domain Eubacteria

"Blue green algae"- Cyanobacteria

important to limnology when affect water quality

- photosynthetic using chlorophyll a

- almost all obligately photosynthetic

-most oxygen providing

ex) spirulina is good bacteria cyanobacteria>>> incredible productivity

What are dinoflagellates?

Phylum dinoflagellata

- two flagella

- cause bioluminescence

have multiple types of chlorophyll

ex of organism) Pfiesteria causes fish kills and can be toxic ti humans

mostly diatoms

What is responsible for carrying most photosynthesis on earth?

Golden Brown Algae

-many potential phyla

- glass shells

What amkes Macrophytes different from others?

they use biocarbonate ion instead of CO2

-big plants

ex) amazon lily pads

What are Ciliates-Phylum Ciliophora?

common part of plankton community

-mostly feed on prokaryotes

-classic protozoa

What are rotifers-phylum rotifera?

-mostly freshwater

-complex life cycles

-can reproduce asexually or sexually

-this is due to having a horizontal gene transfer "genomic shattering" >>> can live in challenging environments

Annelids - Phylum Annelida

- Leeches, mostly freshwater, mostly

scavengers, a taxonomic mess

- Polychaetes, hairy worms, very few in

freshwater

- Oligochaetes, real worms, most important in

limnology, thousands of species

Crustacea - Branchiopoda

Two big groups, Anostraca and Notostraca

Crustacea - Copepoda

- More than 14,000 described species

- May exhibit cyclomorphosis, seasonal changes in body form

what are the orders of obligately aquatic insects, beetles, and flies?

- Ephemoptera >>> mayflies

- Odonata >>> dragonflies and damselfies

- Plecoptera >>> stoneflies

- Trichoptera >>>> caddisflies

- Megaloptera >>>> dobsonflies, alderflies

- Coleoptera >>> beetles

- Diptera >>> flies