The Marine Biome

The Marine Biome - the circle of life in the oceans consisting of the biota (living things) and the abiota (non-living factors) What does it mean to be living?

Ocean Zonation There are 2 main groups: Pelagic – referring to water column (open ocean) Benthic – referring to the sea floor These groups are subdivided based on depth.

Pelagic Zone: Epipelagic Epipelagic (0-200 m), referred to as sunlight zone. uppermost layer At low latitudes (around equator) can be up to 200 meters deep. At high latitides (around poles) only around 100 meters deep. Why do you think there is a difference in the depths? all photosynthesis takes place here because light penetrates this layer In general, the clearer the water, the deeper the epipelagic layer at that location. This layer has the most marine life. Why?

Pelagic Zone: Mesopelagic Mesopelagic (200-1000 m): often referred to as twilight zone. It is very dim, not enough light for plants to carry out photosynthesis. Temperatures are much colder here and pressure increases dramatically with depth. Home to many bioluminescence organisms. Most mesopelagic organisms migrate to the surface to feed at night, or live off the detritus(waste) from the epipelagic zone.

Pelagic Zone: Bathypelagic Bathypelagic (1000-4000 m): no sunlight penetrates at all it is dark and cold. There is little food available and the pressures are immense. Abundance and diversity of life decreases with depth in this zone and lower zones.

Pelagic Zone: Abyssopelagic Abyssopelagic (4000-bottom) same as bathypelagic except there is more food here. Why? Ranges in temperature from 4 to 10 degrees Celsius. Complete darkness here Life forms in these zones contain tube worms, lantern fish, angler fish, etc.

Benthic Zones Benthic means “bottom” The Benthic Zone is along the seafloor ranging from tidal zones to deep ocean trenches.

Benthic Zone Littoral: the intertidal zone that is alternately covered and uncovered by the tides. Bathyl: covers the continental shelf. Abyssal: covers the continental slope down to deep ocean basins Hadal: the bottom of the deep sea trenches

Ocean Zonation

Marine Biota Living things in the ocean are classified into three main categories: 1) Plankton – cannot swim against a current Phytoplankton – plant plankton Zooplankton – animal plankton 2) Nekton – can swim against a current 3) Benthos – live on, in, or near the bottom of the sea floor