Aquaculture and Water Resources
Aquaculture
A) Subsistence
Breeding of a few specimens, usually trout or carp, in ponds or artificial waterways, ponds, or seawater. It is traditional in many rural areas.
B) Extended
Is the breeding of aquatic animals in their natural environment. It provides a suitable and secure environment for its development, but the rearing and fattening are made naturally. The production is great with good environmental conditions. Example: In Galicia, they perform extensive aquaculture production of mussels in large rafts (rafts floating).
C) Intensive
This is an activity equivalent to intensive livestock applied to aquatic animals, mainly fish, molluscs, and crustaceans.
Impacts of Aquaculture
- Impacts on water bodies, pollution of aquatic ecosystems
- Impacts on coastal areas: habitat destruction
- Impacts on marine species, fishing pressure exerted on certain fish species
- Impacts on human health
- Impacts on the economy
Water as a Resource
Human society needs a constant supply of large quantities of water as it is irreplaceable as a basic need and directly involved in almost all production processes; therefore, it is the most precious natural resource. Considered as a whole, it is a resource rather than sufficient to meet the demands; however, there are factors that make water a limited and scarce resource in many areas. These factors are:
1. Uneven Distribution
The spatial and temporal distribution is very uneven, as is the center of increased consumption, such as large cities and industrial areas. This makes water a resource that is not always available naturally in the place and time it is needed.
2. Exponential Growth in Requirements
The exponential growth in requirements is due to population growth and diversification and increased per capita consumption as a result of increased living standards.
3. Pollution
The losses from pollution contribute greatly to water being a rather limited and scarce resource in many regions.
4. Water Management
Generally, water management is done by following strategies that consider it an unlimited resource.
5. Recycling and Reuse
Water has great potential to be recycled and reused for new applications, and this feature is generally poorly utilized.
Traditional Sources of Water Production
a. Surface Water
It is water from rain and snowmelt that runs quickly on the ground and feeds streams, ponds, and rivers. This water is surface runoff, which provides most of the water used.
b. Groundwater
The water of precipitation is infiltrated into the ground to escape evapotranspiration and drops down to an impermeable layer that retains it. It builds up and saturates the holes in the ground, forming an aquifer.
Human Influence on the Hydrological Cycle
The available water to cover the needs of human beings is located mainly on the continents in the liquid state. By regulating the amount of runoff and precipitation, by accumulating it in dams and reservoirs, we may face water shortage periods (temporary imbalance). With the intake of water resources available, such as the proper use of irrigation systems, imbalances in the spatial distribution can be resolved. Human actions currently outstanding in this regard are:
- The construction of dams and reservoirs by rolling waterways (dams, concrete walls) to regulate and retain water.
- The exploitation and replenishment of aquifers.
- The collection of spray by means of ramps and channels that flow into underground deposits.
- The transfers or transfers of water from one river basin to another.
- The desalination or treatment of seawater or brackish water to remove its salt content.
In the future, among others, the following interventions will arise:
- The coverage of major dams to prevent water loss through evaporation.
- The formation of artificial rain through structures such as the “hydrological accelerator” (a long and wide tube filled with helium and anchored in a coastal area; when moist air rises through it, it condenses and causes rain) or the use of aircraft to “seed the clouds” with silver salts to lead cores that allow water vapor to condense on them and generate rain.
Water Uses
- Consumptive uses of water are those that reduce the quantity or quality.
- Non-consumptive uses are those that do not reduce the quantity or quality and allow it to be used for other purposes.
a. Consumptive Uses of Water
Farm Applications
The farm sector is increasing the demand for this resource. 70-80% of the demand for water worldwide is consumed in agriculture. In Spain, it reaches 3/4 of the total, so it is a crucial sector in the problems of water deficit. Agriculture uses both surface water and groundwater for irrigation. Under irrigation, it is necessary to note that its efficiency worldwide is less than 40% as much water is lost by evaporation or by pipelines in poor condition.
Urban or Domestic Uses
This is the water supply to the population, trade, and services. City water usually comes from reservoirs. A feature of this provision is that it needs prior treatment to ensure public health. Consumption is variable and depends on population size and level of life. While the percentage of its use worldwide is just over 7%, in Spain, it is just over 15%.