14.14: Divisions in the Marine Environment

Divisions in the Marine Environment

The Pelagic (open sea) environment is divided into the Neritic and Oceanic Provinces.
Neritic (nearshore zone): Extends from shore with water less than 200 meters. It is subdivided into two zones:

• Littoral (intertidal) zone: Interval between high and low tides
• Sub-littoral zone: Below the littoral zone to a depth of 200 meters.

Figure 14.23. Coral reef in the neritic zone.

Oceanic Provinces (based on depth)

• Epipelagic: Water less than 200 meters
• Mesopelagic: Water between 200 and 1000meters
• Bathypelagic: Water between 1000 and 4000meters
• Abyssopelagic: Water deeper than 4000 meters
• Hadal: Depths below 6000 meters in deep sea trenches

Sunlight penetration has its own divisions (Figure 14.25):

• Photic zone: The upper part of the ocean where sunlight penetrates
• Euphotic Zone: upper ½ of photic zone (usually to about 100 meters)
• Dysphotic Zone: lower ½ of photic zone
• Aphotic Zone: No light penetrates

Figure 14.24. Depth zones

Figure 14.25. Photic Zones