IMS 16 - Marine Ecology

Marine Ecology

3 Domains

Archaea

-          Simple microscopic bacteria-like

-          Methane producer & sulphur oxidizers

-          @ deep vents & seeps of extreme temp & press

Bacteria

-          Simple life x nucleus; purple bacteria, green non-sulphur bacteria, cyanobacteria

Eukarya

-          Complex with nucleus; protoctist, fungi, multicellular plant & animal

5 Kingdom

Monera

-          Single cell; x nucleus; cyanobact, heterotrophic bac, archaea

Protoctista

-          Single & multi cell with nucleus; algae, protozoa

Fungi

-          Mold & lichen @ intertidal zone

-          Decomposer; mineralize organic matter

Plantae

-          Multicell plants; surfgrass phyllospadix, eelgrass zostera @ shallow coast, mangrove & marshes

Animalia

-          Multicelled simple sponge to complex vertebrates

Taxonomy (Systematic Classification) by Carolus Linnaeus

-          Kingdom Phylum Class Order Family Genus Species

Marine Organism Classification

-          Based on habitat & mobility

-          Water floater – plankton & bottom dweller – benthos

Plankton

-          Greek planktos means drifting / wandering

-          Swim weakly / move vertically; horizontal oceanic position undetermined

-          Microscopic & multicellular; phytoplankton & zooplankton

-          Macroplankton >200um, microplankton 20 – 200um, nanoplankton 2-20um, picoplankton / ultraplankton <2um (heterobact / cyanobact)

-          Holoplankton (entire life as plankton) & meroplankton (temporary plankton/larva – later become fish)

Nekton

-          Move independent of current

-          Adult fish, squid, marine mammal & reptile

-          Unable to move coz temperature, salinity, pressure, viscosity, nutrients

Benthos

-          Epifauna (On seabed / rocks)

-          Inauna (Buried in sand, shell, mud)

-          Nektobenthos (On seabed & swim/crawl)

-          Shallow: Various physical & nutritive condition, dense attached algae

-          Deep: Constant species number; biomass reduce

-          Deeper: No photosynthesis, feed each other; slow life

Adaptation

-          Species creation to adapt/inhibit varied restricted niches

-          Marine environment more stable; x pressure

-          Stable temperature; Surface –2 °C – 32 °C (Shallow coastal 40 °C)

-          Land temperature –88 °C – 58 °C

-          14% aquatic species of total species; 2% pelagic 98% benthic

-          Rocky, sandy, muddy, flat, sloped, irregular, mixed bottom different habitat

-          Pelagic quite uniform; lack extreme environment variability; x adaptation

-          High temp, low salinity, low viscosity, need extension to maintain in water

-          High frictional resistance if high TSA, x sinking (phytoplankton)

-          Warm water diatom Planktoniella species has clear marginal ring to rise TSA

Stenothermal organism

-          Withstand small temperature change @ open ocean

Eurythermal organism

-          Withstand large temperature change @ shallow coasts

Hypotonic

-          Too little solute; too much water; release water to surrounding, dehydrated

-          Marine fish less saline, fish salinity = 1/3 seawater

Overcome: drink & secrete salt through chloride-releasing cell & concentrated urine


Marine Environment Division

Epipelagic

·         Low oxygen, no photosynthesis >150 m

·         Low nutrient @ 200 m, coz bacteria decomposition

Mesopelagic

·         DO minimum 700 – 1000 m

·         High nutrient, large-eyed fish, bioluminescent organism

Bathypelagic & Abyssalpelagic

·         75% living space of all ocean

·         Fish complete blind, small, bizarre, predaceous

·         Sharp teeth & big mouth, O₂ rise with depth

Euphotic

·         < 100 m enough sunlight

Aphotic

·         X light

Benthic

·         Subneritic (spring high tide shoreline – 200m depth)

·         Suboceanic (Benthic > 200)

Supralittoral zone

·         Transition area (land to springtide shoreline)

Subneritic zone

·         Littoral – between high & low tide

·         Sublittoral – low tide zone to 200m

Sublittoral zone

·         Inner sublittoral – x algae

·         Outer sublittoral –inner sublittoral zone to 200m / shelf break

Suboceanic province

·         Bathyal –200m to 4km (slope)

·         Abyssal – 4km to 6km (>80% of benthic)

Hadal – 6km