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 x 10 6 km 3 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: 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%); SO 4 -2 ; Mg; Ca; K Minor (0.71%): HCO 3 ; Br; HBO 3 ; Sr (Strontium) The remaining 0.01%: (not constant) Nitrate; phosphate; SiO 2 ; trace metals; organic compounds; gases (O 2 and CO 2 )

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 coefficient K = (ln I 0 – ln I d ) / 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

PlanktotrophicLecithotrophic 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