Identify the dominant zones and biomes in aquatic systems and their principal biologic attributes
The correct answer and explanation is:
The dominant zones and biomes in aquatic systems are broadly categorized into Marine and Freshwater environments, each with distinct subdivisions based on factors like depth, light penetration, proximity to shore, and water flow.
Marine Systems:
Open Ocean (Pelagic & Benthic Zones):
Pelagic (Water Column): Divided by light (photic/euphotic where light penetrates for photosynthesis, disphotic/twilight, aphotic/dark). Biologic Attributes: Photic zone dominated by phytoplankton (primary producers), zooplankton, and diverse nekton (fish, whales, etc.). Aphotic zone hosts life adapted to darkness, pressure, and scarce food (bioluminescence, detritivores).
Benthic (Seabed): Extends from shore to the deepest trenches. Biologic Attributes: Life adapted to substrate, pressure, cold, and lack of light (except near hydrothermal vents where chemosynthetic bacteria form the base of the food web). Dominated by detritivores and sessile organisms.
Coastal/Nearshore (Intertidal, Estuarine, Neritic Zones):
Biologic Attributes: Highly dynamic due to tides, waves, and mixing of fresh/salt water (in estuaries). High productivity often based on algae, seagrasses, or detritus. Supports diverse invertebrates, fish nurseries (estuaries), birds, and mammals adapted to variable conditions. Coral reefs and kelp forests are highly productive, biodiverse biomes within this zone, based on symbiotic algae or kelp as primary producers.
Freshwater Systems:
Lentic (Standing Water: Lakes, Ponds): Divided into zones based on light and depth (littoral, limnetic, profundal). Biologic Attributes: Littoral zone (shallow, near shore) has rooted plants, diverse insects, fish. Limnetic zone (open water) has phytoplankton, zooplankton, and fish. Profundal zone (deep, dark) is dominated by decomposers. Productivity varies greatly.
Lotic (Flowing Water: Rivers, Streams): Zoned by flow speed and substrate. Biologic Attributes: Organisms adapted to current (streamlined shapes, attachment mechanisms). Food webs often rely on detritus input from land upstream, or photosynthesis by algae downstream. Supports insects, fish, amphibians, and riparian vegetation.
Wetlands (Marshes, Swamps, Bogs): Areas saturated with water. Biologic Attributes: Dominated by hydrophytic (water-tolerant) vegetation. High productivity, rich in organic matter, crucial habitat for birds, amphibians, insects, and fish, and act as natural filters.