Oxygen depletion is a concern on both dry land and in aquatic environments.
Dissolved oxygen is present in water and comes from the atmosphere and also photosynthesis by aquatic plants.
Dissolved oxygen is necessary to many forms of life including fish, invertebrates, bacteria and plants. Fish and crustaceans obtain oxygen for respiration through their gills, while plant life and phytoplankton require dissolved oxygen for respiration when there is no light for photosynthesis.
The level of oxygen in water depends on temperature, pond depth, productivity and fertility, and water movement.
Microorganisms that live in water feed on biodegradable substances and when too much biodegradable material is added to water, the number of microorganisms increase and use up the available oxygen.
If oxygen levels drop below 4mg/l, fish may stop feeding, become stressed, suffer electrolyte loss and begin to die.
This can affect the yield of those cultivating fish for food retail and recreational fishing as well as the supplementation of a species from overfishing.
Oxygen depletion is most common during the summer months or in countries with warm climates throughout the entire year. This is because warm water holds less oxygen than cool water. Higher temperatures also increase the metabolic rate of the fish resulting in the need for more oxygen.
Pure oxygen can be injected into water and dissolved into tanks and sea cages using different methods such as ceramic diffusers and high-velocity venture. Whilst the use of oxygen offers significant benefits to the crop it also creates a risk of fire and hyperoxia.
This is why it is important to check and monitor for leaks in the process so if a problem does arise someone will be notified immediately and they can take the necessary steps to ensure it is resolved quickly.
Analox offer a range of products that can be used to monitor oxygen enrichment and oxygen depletion, with three specifically designed for aquaculture within the agriculture industry.
The LC Commercial and 3000SI O2 sensor combination provides complete multi-point monitoring, ideal for larger aquaculture sites. It allows the user to view the readings and status of all sensors from a single point.
The Aspida is a portable oxygen monitor for ensuring safety where gas is piped or stored in the aquaculture industry.
The Safe-Ox+ is a simple to use oxygen enrichment and depletion monitor – ideal for ensuring the health and well-being of fish, crustaceans, aquatic plants and other aquatic life.