Aquatic Biomes & Primary Productivity

Dissolved oxygen (DO)

Oxygen gas mixed in water that aquatic organisms need; influenced by temperature (cold water holds more DO) and by decomposition/oxygen demand.

Estuary

A highly productive coastal ecosystem where freshwater mixes with ocean water (brackish), with strong nutrient input and tidal mixing; often serves as nursery habitat.

Upwelling

The rise of deep, cold, nutrient-rich water to the surface, fueling phytoplankton growth and supporting productive fisheries.

Eutrophication

Nutrient enrichment (often nitrogen and/or phosphorus) that increases algal growth; when algae die, decomposition raises oxygen demand and can lead to low-oxygen “dead zones” or fish kills.

net primary productivity

the rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances, representing the energy available for growth and reproduction in an ecosystem

gross primary productivity

The total rate of photosynthesis in an ecosystem, representing the overall energy captured before subtracting energy used for respiration. It indicates the amount of organic matter produced by autotrophs, essential for assessing ecosystem health and energy flow.

net primary productivity equation

NPP = Gross Primary Productivity (GPP) - Respiration (R) (cellular respiration)

turbidity

the cloudiness or haziness in water caused by large numbers of tiny particles, such as sediment, algae, or pollutants, which can affect light penetration and aquatic life

What do aquatic producers need?

sunlight, carbon dioxide, and nitrogen and phosphorous to perform photosynthesis and produce organic matter.

littoral zone

the nearshore area of a body of water where sunlight penetrates to the bottom and nutrients runoff into the water, has a high biodiversity