jackkkkkkk Flashcards
Q: What are some factors that might lead to suboptimal harvest in salmon farming?
- high mortality rates, often due to infections,
- high lice levels necessitating treatment,
- and the presence of very infectious diseases in an area that may require early harvesting.
Q: How does the sea lice situation affect salmon farming?
A: Sea lice are a significant problem in salmon farming. They can cause high levels of stress and mortality in the fish, leading to early harvests or reduced biomass. The industry uses various methods to combat sea lice, including chemicals, medicine, non-medicinal treatments, and new technologies.
Q: What is the “traffic-light” system in Norway, and how does it relate to salmon farming?
A: In Norway, the traffic-light system is a management system used to regulate the maximum allowable biomass (MAB) in salmon farming based on lice situations in each region. Depending on the lice situation, the MAB can increase (green), stay the same (yellow), or decrease (red).
Q: What are the main constraints and considerations when deciding the optimal harvest time in salmon farming?
A: The decision on the optimal harvest time in salmon farming is influenced by various factors, including biological constraints like fish growth and release times, government regulations such as maximum allowable biomass and fallowing periods, market conditions like market price and sales contracts, and operational constraints like labor, harvest capacity, and processing capacity. There may also be ad-hoc reasons leading to suboptimal harvests such as high mortality and lice levels.
Q: How is the challenge of sea lice currently being tackled in the salmon farming industry?
A: The industry has adopted various measures to tackle the problem of sea lice. These include the use of chemicals and medicines, non-medicinal treatments, and the development of new preventative technologies. However, reliance on medicinal lice treatment has been decreasing due to concerns about chemotherapeutic resistance in sea lice.
Q: Why might ad-hoc reasons cause suboptimal harvest in salmon farming?
A: Ad-hoc reasons such as unexpectedly high mortality rates, high lice levels leading to the fish being too weak for treatment, or the presence of highly infectious diseases in an area can lead to early or late harvests, thus making them suboptimal. In some cases, biomass might need to be reduced before treatment due to capacity limitations.
Q: What is the impact of sea lice on wild salmonid populations?
A: Sea lice are a serious threat to wild salmonid populations. They can potentially exterminate entire stocks if not properly managed. Sea lice release eggs into the water that develop into larvae, which then attach to salmonids and feed on their mucus and skin cells.
Q: How does sea lice affect aquaculture operations?
A: The presence of sea lice can force operators to harvest fish earlier than ideal, leading to suboptimal yields. Additionally, lice treatment can be a significant operational expense, with both direct costs for treatment methods and indirect costs related to reduced fish health and growth.
Q: How does the surveillance programme for resistance to chemotherapeutants in salmon lice work in Norway?
A: The surveillance programme is designed to monitor the efficacy of chemical treatments against sea lice and to detect any emerging resistance. The number of lice in a farm must be counted weekly when the temperature is 4C or above, and every other week when the temperature is below 4C. The programme helps inform the development and implementation of lice management strategies.
Q: What are some non-medicine treatments for sea lice?
A: Non-medicine treatments for sea lice include mechanical treatments like Thermolicer and Flusher, which use heat and water pressure, respectively, to remove sea lice from the fish. These methods have been increasingly adopted as the industry looks to reduce reliance on chemicals and medicines.
Q: What is the role of government regulations in influencing harvest decisions?
Government regulations play a significant role in harvest decisions. Regulations may set limits on maximum allowable biomass, require periods of fallowing (not farming fish) to reduce disease risks, and impose measures to control sea lice levels. Regulations can also dictate response measures in the event of infectious disease outbreaks.
Q: What are some preventative tools being used against sea lice in the industry?
The industry is exploring new technologies as preventative tools against sea lice, such as protective clothing for fish and innovative cage designs that prevent lice from reaching the fish. Further information specific to the presentation would be required for more detailed insights.
Q: What is Infeksiøs lakseanemi (ILA), and how does it affect harvest decisions?
Infeksiøs lakseanemi (ILA) or Infectious Salmon Anaemia is a highly infectious disease that can significantly affect salmon farming. When ILA is found in an area, authorities might require all neighboring sites to harvest early to prevent the spread of the disease, leading to potentially suboptimal harvests.
