Marine Ecology Exam #1

What is ecology as a science?

The scientific study of how living things interact with each other (biotic) and their environment (abiotic)

What do the root words of Ecology mean?

Eco = Oikos - means "at home"
Ology = "the study of"

What are some examples of how abiotic and biotic interactions can influence the distribution and abundance of marine organisms?

The pollution and cloudy waters off of the East coast of Florida drastically harmed aquatic plants, resulting in a manatee die off.

What are the levels of Ecology?

Individual, population, community, ecosystem, biome, biosphere

What are some examples of what a marine ecologist might study at each of the levels of ecology?

Individual - an anomalous individual
Population - a pod of orcas
Community - the pod of orcas as well as the prey they eat
Ecosystem - the pod of orcas, their prey, and the environment around them
Biome - the whole portion of the ocean that the orca pod resides in
Biosphere - everything??

Emergent Properties

Properties not found in the component parts of the levels of ecology, but which arise from the interactions and relationships of these parts.

Sargassum

-Type of pelagic brown algae
- two dominant species
-reproduce by fragmentation
- form mats, lines, patches that support a diverse ecosystem
- knowledge gaps exist regarding nursery function and seasonal distribution/movement

What are the major marine topographic features?

continental shelf, continental slope, continental rise, deep-sea floor

Continental Shelf

Shallow, gently sloping section of continental margin that extends from shore to where the slope becomes steep.

Continental Slope

Steep, seaward section of the continental margin.

Continental Rise

Gently sloping area at the base of the continental slope.

Deep Sea Floor

Nearly flat area of the deep-sea floor.

Marine Zones

Benthic, pelagic, deep sea

What are the parts of the Pelagic zone?

neritic and oceanic

What are the parts of the Benthic zone?

Subtidal, shelf break - Deep sea floor - bathyal, abyssal, hadal

What are the parts of the Deep Sea zone?

Epipelagic, Mesopelagic, Bathypelagic, Abyssopelagic

What are the abiotic factors in the marine environment?

salinity, temperature, light, pressure, dissolved oxygen, tides, life in a fluid medium

Why does salinity increase?

Evaporation and formation of sea ice

Why does salinity decrease?

precipitation, freshwater inflow, glacial melt (poles)

Osmoconformers

Maintain internal solutes similar to their environment (ex. invertebrates)

Osmoregulators

Maintain a constant internal solute concentration by controlling water and salt concentrations (ex. sharks and bony fish)

Stenohaline

Species that do not tolerate a wide range of salinities

Euryhaline

tolerate a wide range of salinities

What are the three regions of a temperature-depth profile?

surface layer, intermediate layer, deep layer

Surface Layer

warm waters up to 200m deep, mixed by wind, waves, and currents

Intermediate Layer

Below the surface layer up to 1,000 to 1,500m deep. Defined by a permanent thermocline.

Deep Layer

Below 1,500m deep, uniformly cold water, typically

At what depths does loss of color discrimination appear?

30 - 50 m

Hypoxic Zones

Form when the levels of DO are very low, to the point organisms die or leave the area to survive.

Tides

Caused by the gravitational pull of the moon/sun and rotation of the Earth, Moon, and sun.

Spring Tide

Tides occurring near the times of the full and new moon, when the range of the tide is the greatest.

Neap Tide

Tides occurring near the times of the 1st and 3rd quarters of the moon, when the range of the tide is minimal.

What are some factors that impact different organisms and the way they experience their surroundings depending on their unique circumstances?

Size, shape, location in the water column, geographic location, motility

Scaling Up

this occurs when physical effects on the environment cascade up from individual to population ecosystem-levels

Life History

The pattern of survival and reproduction events of a species

Salinity

Total amount of salt dissolved in seawater. PPT. Open ocean ranges from 33-37

Temperature

Sea surface temp varies with latitude because of differences in solar input. Varies with depth.

Pressure

Increases exponentially with depth. 1 atm for ever 10m depth.

Dissolved Oxygen

The level of free, non compound oxygen present in water.

What are the three types of tides?

Semidiurnal, mixed semidiurnal, diurnal

What is life history theory?

Field in evolutionary ecology that seeks to explain how evolutionary forces (natural selection) select for optimal success in organisms. Selection of traits produces adaptations in response to the environment, but trade offs exist. Optimization of trade-offs between growth, survival, and reproduction.

Fitness

The measure of an organism's ability to survive and reproduce.

Life histories are balances of what?

Energy costs and benefits

What are the four major life history characteristics?

Growth, age of maturity, fecundity, lifespan

Early age of maturity costs and benefits

Benefits: increases the chances of reproducing before mortality.
Costs: reduced growth, reduced quality of progeny, reduced future fecundity.

Late age of maturation costs and benefits

Benefits: invests in growth and grow larger, increased fecundity, increased quality of progeny, increased future fecundity.
Costs: may not survive until maturity.

Fecundity

the physiological maximum potential reproductive output of an individual. Essentially the rate of reproduction.

What are the factors that fecundity is correlated to?

Frequency of reproduction and number of offspring produced

How is fecundity related to the amount of parental care?

Inversely

Semelparous

single reproductive event before mortality. ex: octopus

Iteroparous

Multiple reproductive events over a lifetime. ex: cownose ray

Lack Clutch Size

The clutch size that produces the greatest number of successful young.

Broadcast Spawning

Release millions of eggs and sperm into the water for fertilization; survival rate is low.

"Rate of Living" Theory

Suggests that aging is caused by the accumulation of damage to cells and tissues.

How does metabolic rate correlate with body size?

Has a negative correlation with body size, and typically lifespan

R-Selected Species

Reproduce rapidly in selected habitats, produce large numbers of offspring, which individually have a low probability of survival. Tend to be good colonizers.

K-Selected Species

Have traits associated with living at densities close to carrying capacity, invest more heavily in fewer offspring with higher chances of survival. Tend to be better competitors.

Dispersal

Net-movement or spread of organisms from one location to another; often larval stages.

Migration

Directed movement of an organism between specific areas, usually for specific purposes.

Plankton

Organisms that live suspended in the water whose movements are largely dictated by currents.

Phytoplankton

Plankton that performs photosynthesis. Ex. diatoms and dinoflagellates

Zooplankton

Plankton consisting of heterotrophs. Ex. animals and protozoans

What are the dispersal types?

Planktotrophic, lecithotrophic, direct release, teleplanic

Planktotrophic

Many small eggs. (10^3 - 10^6) larvae feed on plankton, long dispersal time (weeks)

Lecithotrophic

Fewer eggs (10^2 - 10^3) larger larvae live on yolk sac, short dispersal time (hours-days)

Direct Release

Female lays eggs or broods young, juveniles released and crawl/swim away.

Teleplanic

Larvae that utilize transoceanic currents - always planktotrophic.

What are some factors that larvae use to select settlement sites?

Chemical, environmental (light), and biological cues

Gregarious Settling

When larvae settle on adults of their own species. ex. bivalves, barnacles, sand dollars

What are the types of larvae?

lecithotrophic, planktotrophic, teleplanic

Lecithotrophic Larvae

Swimming larvae that depend on nourishment from a yolk sac provided, no feeding or digestive structures. Typically spend only a few hours to a day in the plankton. Development is quick and dispersal is limited to 100s of meters. Most bony fish and some invertebrates.

Planktotrophic Larvae

Have specialized larval feeding structures and digestive systems and actively feed while they are in the plankton. Spend a longer duration of time in the plankton and are therefore capable of dispersing over long distance.

Teleplanic Larvae

Live in the open ocean on major transoceanic surface currents. Some can delay metamorphosis if suitable habitat is not found. Competent to settle and metamorphose for more than 100 days. Very wide distribution. Common in benthic invertebrates.

Why have larval dispersal?

Mortality is very high during larval phases.
Benefit must be substantial:
-spread young over a variety of habitats
-young will be in a habitat away from adults
-avoid overcrowding
-reduces competiton
-dispersal!

Why have planktonic dispersal?

The geographic range of inverts with it is usually greater than those without.

What are some cues that contribute to the precise timing of larval dispersal?

lunar cycles, tides, and daylight

What are some mechanics that species have evolved to reduce the mortality rate of planktonic larvae?

estuary retention
export to continental shelf

Estuary Retention

The larvae of some estuarine species remain in the surface waters on the incoming tides, being retained in the estuary, where habitat is suitable.

Export to Continental Shelf

Larvae could potentially return to estuary (or nearby) on an incoming tide, although it may also be lost to sea.

What are some things that can influence population dynamics?

larval strategy, reproductive success, and recruitment

Autonomous Drifting

Benthic adults can detach from the bottom and drift or be moved by wind and waves at the water's surface or by currents along the sea floor, to a new area.

Rafting

Some marine organisms can complete their life cycles on floating substrata and be carried thousands of kilometers.

Hitchhiking

On boat hulls, in ballast water or on another organism (whales, sea turtles)

Hopping

Intergenerational stepping-stone dispersal

Creeping

Organisms extending their distribution incrementally along continental shelves where habitat and environmental conditions are sufficiently similar for long distances.

What is a population?

A group of organisms of the same species occupying a particular space at a particular time.

What are the different types of distribution patterns?

clumped, uniformed, random

Clumped

Wide variety - typically find when species is localized around a resource (nutrients, water, food). Closer you are to one another - higher reproductive success. Animals foten travel in schools, packs, etc. If prey, being in groups gives better protection. Predators have better chance of catching prey in groups as well.

Uniformed

Competition for resources such as space, food water, territory

Random

Typically observed where there are an abundance of resources

What effects the size of a population?

Births, immigration, deaths, emigration

What are the components of life history?

age at sexual maturity, when and how often it reproduces, number and size of offspring, chances of survival - all of these are related to the survivability of a species and their possible extinction.

What factors control population?

density dependent factors
density independent factors

Density Dependent Factors

Conditions whose effect increased as population grows. ex. competition for space, nutrients/food, light - predator/prey relationships

Density Independent Factors

Exerts effects unrelated to population density. Ex. severe weather, flood, industrial accidents

What are the three factors that influence the probability of a species going extinct?

size of geographic range, degree of habitat tolerance, size of local population

Population Genetics

A field of genetics that focuses on genetic differences within and between populations

Locus

A fixed position on a chromosome

Allele

One or more alternative forms of a gene that arise by mutation and are found at the same locus on a chromosome

Allele Frequency

The relative frequency of an allele at a particular locus in a population; used to describe the amount of variation at a particular locus