Marine Biology: Introduction to Marine Environment
Dec 20, 2015
Marine Biology:Introduction to Marine Environment
Marine Environment
• Properties of water
• Basic oceanography
• Ecological principles
• Larval ecology
• Terrestrial vs. Marine ecosystems
• Divisions of marine environment
Oceans: seawater
• 71% surface
• 3.8 km depth
• 1.370 x 106 km3 volume
• Presence of all phyla
Water property
Solvent actions of water
Water property
• Surface tension
• Conduct of heat
• Viscosity
• Latent heat of evaporation
• Heat capacity
• Density (Temp, Salinity, Pressure)
• Dissolving ability
Seawater property
• 96.5% water + 3.5% dissolved compounds (salt)
• Salinity: 34-37 psu
• ppt• %o
• PSU (practical salinity unit)
(Evaporation – Precipitation)
Equator
Seawater constituents: Principle of constant proportions
• Major (99.28%):
Cl (55.04%); Na (30.61%); SO4-2; Mg; Ca; K
• Minor (0.71%):
HCO3; Br; HBO3; Sr (Strontium)
• The remaining 0.01%: (not constant)
Nitrate; phosphate; SiO2; trace metals; organic compounds; gases (O2 and CO2)
Basic oceanography
• Oceans: 4 divisions + marginal seas
Basic oceanography
• Oceans: 4 divisions + marginal seas
• Continental shelf, slope, rise, & abyssal plain
• Seamount & trench
Basic oceanography
• Oceans: 4 divisions + marginal seas
• Continental shelf, slope, rise, & abyssal plain
• Seamount & trench
Basic oceanography
• Oceans: 4 divisions + marginal seas
• Continental shelf, slope, rise, & abyssal plain
• Seamount & trench
• Tectonic plates (板塊 )
Plate Tectonics
• Continental drift
• Seafloor spreading
Plate Tectonics
• Continental drift
• Seafloor spreading
• Subduction
• Hydrothermal vents
Temperature and vertical stratification
• Metabolism: Q10
• Preference & tolerance
• Poikilothermic or ectothermic vs. homeothermic or endothermic
• Thermocline (50-300m)
• Picnocline
• Surface water temperature: SST
T-S diagram: Sigma-t (t) = (density – 1) x 1000
Light: solar radiation
• Photosynthetic Active Radiation
• Euphotic, disphotic, aphotic
• Light extinction coefficientK = (ln I0 – ln Id) / depth (m)
Wave
• Wind wave height: wind speed, distance wind blows, duration wind blows
• Wavelength
Current
• Predominant wind
• Ekman spiral: Corioris effect
Upwelling
• Coastal upwelling
• Equatorial upwelling
Circulation of seawater
• Antarctic convergence: cooling of saline water from equator >>> intermediate water masses
• Antarctic circumpolar: freezing causes cold and saline water sink >>>Antarctic bottom
Atlantic
Pacific
Indian ocean
Ocean conveyor belt
• Thermohaline circulation
• Slowing or shut-down: cooling of Europe
Internal wave
• Flow over tough topography
• Propagate along the picnocline
• Weak surface slick
• Mix deep water in thermocline
• Luzon channel
Ecological principles
• Ecology, Species, community, ecosystem
• Ecosystem components: autotrophic vs. heterotrophic; trophic structure, trophic level, food web vs. food chain
Biomass pyramid
Energy pyramid
Biogeochemical cycles
• Carbon cycle
• Phosphorus cycle
• Nitrogen cycle
Carbon cycle
Phosphorus cycle
Nitrogen cycle
Ecosystem structure
• Niche: fundamental & realized niches
• Habitat
• Dominant
• Species richness, diversity:
species richness not equal to stable environment
• Liebig’s law od the minimum: limiting factor
Ecological control• Competition: competitive exclusion principle
• Predation: predator vs. prey
• Grazing
• Keystone species or key industry species
Benthic invertebrates: distribution & abundance
• Recruitment
• Migration
• Asexual reproduction
• Mortality
Larval types
• Planktotrophic larvae:
mostly in tropics, shallow water
• Lecithotrophic:
more towards polar regions and the deep sea
• Non pelagic (no free-swimming larvae):
as lecithotrophic larvae
Planktotrophic Lecithotrophic
Nonpelagic
Factors affecting larval settlement
K Selection vs. r selection
Opportunistic vs. equilibrium species
• life-history strategy
• Higher frequency of disturbances favors r selective species
• Unequal distribution of disturbance allows coexistence
Terrestrial vs. marine ecosystems
• Carbohydrates vs. proteins
• Vertical distribution
• Large vs. small primary producer
• Carnivores common in marine environment
• More productive on land; more efficient in energy transfer in marine food chains ay lower levels
• Marine food chains much more complicated