Ecology of Aquatic Systems: Abiotic and Biotic Factors

Ecology

The study of interactions among organisms and their environment.

Abiotic factors

Non-living chemical and physical parts of the environment that affect living organisms.

Biotic factors

Living components of an ecosystem that affect the organisms within it.

Aquatic biomes

Biomes that are primarily water-based, characterized by specific abiotic factors.

Energy source in ecosystems

Solar energy for terrestrial and aquatic ecosystems, with a food chain starting from plants to grazers to carnivores.

Dark environments energy source

Chemical energy from deep ocean vents supporting bacteria and grazers.

Temperature range for life

Narrow range of 0°C - 45°C due to physical constraints like ice crystal formation and protein denaturing.

Water balance in organisms

Aquatic organisms must balance solute concentration, with hypotonic (freshwater) and hypertonic (saltwater) osmosis.

Nutrients in aquatic systems

Availability of inorganic nutrients such as Nitrogen and Phosphorus.

Dissolved O2

Amount of dissolved oxygen in water, which is temperature dependent.

Solar radiation

Varies with latitude and seasons, affecting climate and ecosystems.

Global air circulation

Patterns that influence precipitation and climate across the globe.

Impact of oceans

Oceans affect local climate through their heat and moisture.

Impact of landforms

Mountains can affect precipitation patterns in regions like southern British Columbia.

Species evolution

Species evolved from ancestors in specific locations or dispersed and survived in new locations.

Natural selection

The process by which organisms adapt to abiotic and biotic factors to survive and reproduce.

Positive biotic factors

Factors that benefit organisms, such as plants needing pollinators.

Negative biotic factors

Factors that harm organisms, such as predation.

Field research

A method of studying ecology by observing organisms in their natural environment.

Laboratory experiments

Controlled experiments conducted to study ecological interactions in a regulated setting.

Sea urchin

A possible predator in studies analyzing the impact on seaweed cover.

Limpet

A grazer whose removal showed no significant impact on seaweed cover in studies.

Seaweed cover

Percentage of seaweed cover affected by the presence or absence of grazers.

Ecology

Interactions of natural organisms with their environments.

Organizational levels of ecology

Four primary levels: Organism/individual, populations, communities, ecosystems.

Abiotic factors

Non-living environmental factors such as temperature, rainfall, nutrients, CO2, and solar radiation.

Biotic factors

Living environmental factors such as predation, competition, and insect & fungal parasites.

Environmental science methods

Three kinds: field, experimental, and modelled.

Global change impact on ecology

Both abiotic and biotic vectors are changing.

Aquatic biomes

Include saltwater, freshwater, and transitional areas.

Freshwater aquatic environments

Often have a strong seasonal component.

Saltwater environments

Strongly structured by depth, with conditions and biodiversity highly variable by depth.

Transition environments

Highly productive areas between different ecosystems.

Light attenuation in water

Limits productivity in aquatic systems.

Salt exposure ability

Affects community ecology in aquatic environments.

Migration and dispersal in aquatic systems

Can be passive and over long distances.

Gigantism in aquatic systems

A niche adaptation observed in some aquatic organisms.

Oxygen concentrations in water

Inversely proportional to temperature.

Lakes & ponds

Seasonal mixing redistributes O2 and nutrients.

Rivers & streams near source

Colder, clear, and lower in nutrients.

Rivers & streams downstream

Warmer, slower, and more sediment.

Estuary

Transition between freshwater and ocean, with variable saltiness.

Wetlands

Transition between aquatic (usually freshwater) and terrestrial, typically rich in biodiversity.

Oak Hammock Marsh

A wetland in Manitoba that improves water quality by removing contaminants.