Oceans 11 – Dalesandro
Notes – The Epipelagic Zone
-The epipelagic (or sunlit) subzone is the top layer of the ocean zones. It consists of
the first 200-300 metres of the photic area.
-About 90 percent of all ocean life lives in this region because of its warm
temperatures and strong sunlight. This is the only zone able to support plant life
because it has the light needed for photosynthesis.
-Though plants are abundant, there aren’t very many places for organisms to hide.
Therefore some species have developed a camouflage called counter shading.
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Counter shading is when an organism is dark on the top of their bodies, and
light on the bottom. From below, they will blend in with the light above and
from above they will blend in with the darker water below.
-The epipelagic zone only accounts for 9% of the water in the world’s oceans.
-There are three producers found in the epipelagic zone:
1) Free-floating algae.

Red algae (Rhodophyta) Exs: porphyra, dulse, ceramium, and maerl.
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Green algae (Chlorophyta) Exs: thongweed and sea lettuce.
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Brown algae (Phaeophyta) Exs: kelp, sargassum, turbinaria, and wrack.
2) Phytoplankton.

Tiny, one-celled photosynthetic plankton like diatoms and dinoflagellates.
3) Plants.

Flowering plants (angiosperms) Exs: seagrasses like eelgrass and
thalassia.
-This abundance in producers leads to complex and varied food chains in the epipelagic
zone.
-Shallow-water fish include: all coral reef species, gobies, groupers, seahorses,
snappers, and flatfish.
-Other shallow-water organisms include: cephalopods, sea lions, whelks, and crabs.