Abiotic Factors Shaping Ocean Ecosystems Marine Bio Unit 1

Question-and-answer flashcards covering the key abiotic factors shaping ocean ecosystems based on the provided notes.

What are abiotic factors?

The non-living components of an ecosystem that influence survival.

How do abiotic factors influence which organisms can survive?

They are physical and chemical conditions that determine survival and distribution of organisms.

How does temperature function as the ocean's thermostat?

It affects metabolic rates, reproduction, and species distribution; temperature structure forms thermoclines.

What is a thermocline?

A transition layer between warmer surface water and cooler deep water, creating distinct vertical communities.

What is the photic zone?

The upper ~200 meters of water where sunlight supports photosynthesis.

Why does light intensity decrease with depth?

Because light is absorbed and scattered as it travels through water.

Which light color disappears first with depth?

Red light is absorbed first, while blue light penetrates deepest.

What is the average ocean salinity?

About 35 parts per thousand (3.5%).

How does salinity affect seawater properties?

It influences density, freezing point, and organism physiology.

What are estuaries?

Coastal areas where rivers meet the ocean with variable salinity.

How does pressure change with depth?

Pressure increases by about 1 atmosphere for every 10 meters of depth.

How does pressure affect gas-filled organs?

High pressure can compress gas-filled structures like swim bladders; deep-sea organisms have adaptations to cope.

What drives surface ocean currents?

Wind patterns and Earth's rotation (Coriolis effect).

What drives deep ocean currents?

Differences in temperature and salinity (density-driven).

What do ocean currents transport?

Nutrients, heat, and marine organisms.

How is oxygen added to seawater?

From air-water surface exchange and photosynthesis.

Which water holds more dissolved oxygen: warm or cold?

Colder water holds more dissolved oxygen than warm water.

What are oxygen minimum zones?

Mid-depth regions where dissolved oxygen is at its lowest.

What is upwelling?

The process that brings nutrient-rich but often oxygen-poor water from depth to the surface.

What is the typical ocean pH?

Approximately 8.1, slightly basic.

What is ocean acidification?

The lowering of pH due to CO2 absorption from the atmosphere.

Why is carbonate chemistry crucial for marine life?

It governs shell and skeleton formation in corals, mollusks, and other organisms.

What are key nutrients in the ocean?

Nitrogen, phosphorus, and silica.

Why are nutrients often limiting factors for marine production?

Availability of essential nutrients limits primary production.

How do upwelling zones affect productivity?

They bring deep, nutrient-rich water to the surface, boosting productivity.

How does wave action influence coastal ecosystems?

Wave energy shapes habitats and drives adaptations; affects feeding, reproduction, and dispersal.

How might organisms adapt to constant wave action?

Through strong attachments, flexible structures, and timing of activities to withstand waves.

Name three abiotic factors most important for marine life.

Temperature, light (photic zone), and salinity (with other factors like pressure, nutrients, pH, and currents also influential).