What is Marine Ecology? Flashcards
What is marine ecology?
A branch of marine science that studies the interactions between organisms and their biotic and abiotic environments, and the effects these interactions have on patterns of distribution and abundance of organisms.
It is studied from the level if individuals up to whole ecosystems and over varying spatial and temporal scales.
What are the two types of evolution?
- Microevolution
2. Macroevolution
What is microevolution?
Change in the genetic composition of a population over multiple generations. This can result in phenotypic change (e.g. colour, morphology, anatomy, behaviour) and/or changes in life history of a population/species (e.g. growth rates, age/size at maturation.
What is macroevolution?
If genetic changes take place over a long enough period of time period (usually many generations), it can result in new species being formed (speciation).
What does evolution also incorporate?
Extinction (loss of all populations and species)
What is the meaning of life history?
An organism’s life history is the sequence of events related to survival and reproduction that occur from birth through death. Populations from different parts of the geographic range that a species inhabits may exhibit marked variations in their life histories.
What is marine ecology and evolution?
The branch of marine science that tests concepts and hypotheses stemming from ecological and evolutionary principles/observations.
What is an example of marine ecology and evolution?
How/why do interactions between organisms and their biotic and abiotic environments affect the genetic composition of marine populations?
Or vice versa….. (sometimes called evolutionary ecology)
What are the abiotic factors in the marine environment?
- Light
- Temperature
- Salinity
- Water depth (pressure)
- Tides (immersion/emersion)
- Waves
- Currents (velocity)
- Density
- Substratum
- Oxygen
- pH
- Nutrients
What are the biotic factors in the marine environment?
+ = increase/benefit pop. / - = decrease/harm pop. / 0 = no effect
- Predation (+/-)
- Parasitism (+/-)
- Competition (+/- or -/-)
- Territoriality (+/- or -/-)
- Commensalism (+/0) - benefit one organisms but won’t effect the other
- Mutualism (+/+) - both organisms benefit)
- Facilitation/succession
- Species richness
- Functional diversity
- Evolutionary history
- Human impact
What are the levels over which marine ecology can be studied?
- Individual
- Population (same species)
- Community (populations of different species)
- Ecosystem (communities in their physical environment)
- Over long evolutionary time scales (Palaeo-marine ecology)
- All of the above can be studied from local to regional and global scales
What is individual level marine ecology?
How organisms survive under varying biotic and abiotic conditions - i.e. how do individuals find shelter, mates and food?
What is an ecological niche?
Range of environments over which a species is able to live
What is an ecological niche dependent on?
- Abiotic factors such as temperature and salinity, which affects the physiology of the organism
- Biotic factors such as predation, parasitism etc.
What are examples of studying marine ecology at individual level?
- Cleaner wrasse picking parasites off reef fish (example of mutualism)
- Owl limpet (Lottia gigantea) shell can be secondary substrate (home) for other organisms e.g. algae (example of commensalism/parasitism)
What is population level marine ecology?
How populations of the same species are distributed, and how they persist in both the current conditions and in response to changing environments
What is population change over time dependent on?
- Species characteristics e.g. life history, growth, survival, emigration/immigration
- Limiting resources affect population growth and dispersal potential
- Genetic characteristics of species affect their ability to adapt to new and changing environments
What is an example of studying marine ecology and population level?
Bloom of coccolithophore Emiliania huxleyi off Cornwall, observed by satellite
What is community level marine ecology?
How populations of different species interact
What is the distribution and abundance of populations of different species in a community determined by?
A combination of:
- Dispersal of larvae & adults to appropriate habitats
- Inter-specific competition (e.g. for food/space)
- Grazing and predation
- Parasitism and disease
- Disturbance (physical and biological)
- Facilitation and succession
What are examples of studying marine ecology at community level?
- Predation by seastars can cause the biological lower limit to disturbance of muscles
- Sponges and other encrusting invertebrates on mangrove roots compete for space
What is ecosystem level marine ecology?
How whole ecological communities are affected by its physical/biotic environment
What range of physical variables are ecosystems influenced and defined by?
- Spatial and seasonal patterns of temperature, depth, salinity, upwelling /downwelling etc.
- Geological forces (tectonics, coastal geomorphology, sediment /substrate types)
- Historical factors such as disturbance/recovery from glacial/inter-glacial cycles (especially for coastal communities)
- Cyclical or sporadic climate processes (El Nino, hurricanes/cyclones)
- Anthropogenic impacts (overfishing, global climate change)
What are examples of studying marine ecology at ecosystem level?
- Different communities / group of organisms between exposed rocky shore and sheltered rocky shore
- Before and after a bleaching event - coral bleaching caused by anomalous warm waters
- Ecosystem-wide effects of fishing
- Biomass is greater inside marine reserve than outside marine reserve
What is palaeo-marine ecology (over long timescales)?
How the abiotic and biotic environment shapes the distribution, abundance, diversity and evolution of life in the oceans over deep time
- Looking backwards to inform the present and future of marine ecology
- Not just studied over contemporary time scales
- Can ecological response to past climate warming events (e.g. Paleocene-Eocene Thermal Maximum (PETM), 55.5 Mya) inform current research on the ecological effects of global climate change?
What are examples of palaeo-marine ecology?
- Hermatypic coral reefs can only form in shallow tropical waters with low levels of sediment input. Reefs do not grow if winter temperatures are below ~20ºC.
- Late Pleistocene = 20ºC winter isotherm (using oxygen isotopes) & mostly northerly fossil coral reefs in the Eastern Pacific - compared to modern 20ºC winter isotherm & most northerly modern coral reef in the Eastern Pacific (see map)
What are patterns of marine diversity over time a function of?
- Mass extinction events
- Evolutionary radiations
- Global climate and geological processes