An aquatic ecosystem is a water-based environment that supports significant biological activity. There are several types of aquatic ecosystems including freshwater systems like lakes and rivers, groundwater, brackish water, and marine environments. Aquatic ecosystems provide important services like water purification, biodiversity, and breeding grounds for many species. Key factors that determine the organisms in an aquatic ecosystem include temperature, sunlight, oxygen, and nutrients. Plankton, nekton, and benthos are the main groups of aquatic organisms. Natural and human-caused changes can impact aquatic ecosystems, such as eutrophication from excess fertilizer runoff.

1. AQUATIC
ECOSYSTEM
Presentation By Group 5

2. WHAT IS AN AQUATIC ECOSYSTEM?
Aquatic ecology is the study of water based
ecosystems. 
They are an area of water, in which ‘significant’
biological activity can occur.
This definition excludes most groundwater systems 
Aquatic ecosystems can involve flowing or still water,
and can be fresh or saline.

3.  Freshwater (Limnology) 
Groundwater 
-Lakes (lentic) 
-Rivers (lotic)
TYPES OF AQUATIC ECOSYSTEM
Brackish water (inter-tidal) 
Marine (Oceanography)
Anthropogenic waters
(i.e drinking water) .

4. Freshwater involves lakes, ponds,
rivers and streams, wetlands,
swamp, bog and temporary pools.
Freshwater habitats are classified
into lotic and lentic habitats. Water
bodies such as lakes, ponds, pools,
bogs, and other reservoirs are
standing water and known as lentic
habitats.
Groundwater ecosystems deliver
services that are of immense
societal and economic value, such
as: 1) purification of water and its
storage in good quality for
decades and centuries, 2) active
biodegradation of anthropogenic
contaminants and inactivation
and elimination of pathogens,
3) nutrient recycling
FRESHWATER
GROUNDWATER

5. A Brackishwater ecosystem is a type
of aquatic ecosystem that is made
up of shallow, partially enclosed
areas. When freshwater joins
seawater, brackish water is found.
Brackish water ecosystems have a
salt level of 5 to 35 parts per million.
Estuaries, salt marshes, mangrove
swamps, and forests are just a few
examples.
Marine ecosystems are aquatic
environments with high levels of
dissolved salt. These include the
open ocean, the deep-sea ocean,
and coastal marine ecosystems,
each of which has different
physical and biological
characteristics.
BRACKISHWATER
MARINE

6. Biodiversity 
 Breeding 
Buffer systems 
Sinks 
Only part of the hydrological cycle 
-Species richness/trophic structure
-Breeding grounds for many species 
-Physical and chemical 
-Resting places for sediments and chemicals
IMPORTANCE OF AQUATIC ECOSYSTEM

7. CHARACTERISTICS OF AQUATIC ECOSYSTEMS
Factors such as temperature, sunlight, oxygen, and nutrients determine which
organisms live in which area of the water
Three groups of aquatic organisms include:
Plankton - mostly microscopic organisms that float or drift freely in the
water, and can be microscopic animals (zooplankton) or microscopic
plants (phytoplankton).
Nekton - are all organisms that swim actively in open water,
independent of currents.
Benthos - are bottom-dwelling organisms of the sea or ocean and are
often attached to hard surfaces

8. • Natural Succession- normal cycle of pond
becoming forest
• Artificial Succession - humans add N P to
water via fertilizer sewage causing
succession to happen faster =
EUTROPHICATION
• Water Pollution
• Excessive use of Fertilizers
• Industries
• Waste Disposal
WHAT FACTORS
CAN ALTER
AQUATIC
ECOSYSTEMS?