Freshwater and Intertidal Ecology Flashcards

A set of vocabulary flashcards covering the fundamental concepts of aquatic ecology, properties of water, primary production, and nutrient dynamics based on the lecture transcript.

Aquatic Ecology

The scientific study of aquatic organisms and their interactions with the environment.

Specific Heat

The amount of heat that must be absorbed or lost for one gram of a substance to change its temperature by $1^{\circ}\text{C}$; water's high specific heat forms a buffer against changing environmental temperatures.

Density

The mass per unit volume, which for pure water reaches a maximum of $1000\,\text{kg\,m}^{-3}$ at a temperature close to $4^{\circ}\text{C}$.

Salinity

The saltiness or dissolved salt content of a body of water; in sea water ($35\,\text{ppt}$), it depresses the freezing point to $-1.91^{\circ}\text{C}$.

Specific Gravity

The ratio of the density of any substance to the density of some other substance taken as a standard, usually water.

Viscosity

A measure of a fluid’s resistance to flowing; it decreases as temperature increases and increases frictional resistance for organisms.

Primary Production

The creation of organic molecules from inorganic components using an external energy source, primarily through photosynthesis.

Photosynthesis

The process where photosynthetic organisms capture light energy through pigments such as chlorophylls to fix $CO_2$ into organic compounds.

Chemosynthesis

A process common in deep sea hydrothermal vents where bacteria fix $CO_2$ using chemical energy from inorganic compounds instead of light.

Photo-oxidation

Destructive reactions caused by exposure to high light intensity at the water surface that inhibit photosynthesis.

Compensation Depth

The depth at which light-supported photosynthesis exactly balances the metabolic losses due to respiration; the lower limit for phytoplankton growth.

Photic Zone

The column of water above the compensation depth where light is sufficient for photosynthesis.

Aphotic Zone

The dark zone of a water body located below the compensation depth.

Eutrophic

Highly productive waters characterized by high nutrient values that support large numbers of microorganisms, algae, and animals.

Oligotrophic

Unproductive waters characterized by low nutrient values and clear water, limiting the lake's ability to support life.

Mesotrophic

Water bodies with nutrient levels and productivity that fall in the middle range between oligotrophic and eutrophic.

Thermocline

The transition layer in a water body between the warmer mixed upper water and the cooler deep water.

Detritus

Dead plant material, such as that from swamps or marshes, which undergoes conditioning by fungi and bacteria to become nutritious.

Hydrography

The science that measures and describes the physical features of bodies of water and the land areas adjacent to them.

Upwelling

The process by which deeper waters move to the surface, delivering substantial amounts of nutrients and resulting in higher primary production.