Microorganisms in Aquaculture

Genetic Resources for Microorganisms in Aquaculture

• Aquaculture involves farming aquatic organisms from microbes to shellfish and finfish.
• Aquaculture's increasing production has led to substantial growth in fish production for human consumption.
• Aquaculture contributed more than wild-caught fisheries for the first time in 2014.
• In 2014, global aquaculture production accounted for 44.1% of total global fish production.
• To feed the growing population, fish consumption (especially from aquaculture) plays an important role.
• Fish consumption is key to meeting the nutritional needs of a growing population.

Microbes' Role

• Microbes play a crucial role in cycling nutrients in terrestrial and aquatic ecosystems.
• Marine microbes are responsible for about half of global primary production.
• Microbes in natural marine and freshwater ecosystems are key components of food webs and nutrient cycling.
• They are used as live feeds, probiotics, and filtration systems in aquaculture.
• Microbes are indispensable resources for the growth of shellfish and finfish in aquatic ecosystems.
• Microbes can substitute for fishmeal and fish oil, which is growing more expensive.
• Meeting the nutritional needs of aquaculture species includes microbes.
• 30.8% of world fish production by aquaculture consists of non-fed species, notably carp, and bivalve molluscs like clams, oysters and mussels.
• Genomic approaches now let you rapidly determine the composition of natural microbial communities.

Study Overview

• This will provide information about the genetic resources of key microorganisms on which aquaculture depends.
• These microorganisms such as microalgae enhance the nutritional quality of Artemia and rotifers.
• Bacteria are used for human diet supplements and include species that improve fish and shellfish survival and growth.
• Bacteria also play an important role in filtration systems needed in recirculating aquaculture systems.
• Zooplankton (Artemia spp. and rotifers) is widely used as feed for the aquaculture industry.
• China is the world's biggest aquaculture producer making up over 80 percent of world aquaculture production with other countries including Indonesia, India, Viet Nam and the Philippines.

Microorganisms in Aquaculture

• Microalgae uses are divided into green water approaches, direct feeding, indirect feeding, and pigment production.
• Green water is water in which microalgae grow naturally, or are added.
• Green water is an important sector in aquaculture because of the freshwater fish aquaculture that it supports.
• The fish and shrimp are raised without additional aquaculture feed.
• Microalgae used for green water production are Nannochloropsis spp., Chlorella vulgaris, Isochrysis spp. and Tetraselmis spp.
• Microalgae species such as Nannochloropsis spp., Pavlova spp., Isochrysis spp., Tetraselmis spp., Thalassiosira weissflogii, Dunaliella spp. and Chaetoceros spp. are commercially used.
• Thraustochytrids are marine microorganisms considered as microalgae that are rich sources of long-chain polyunsaturated fatty acids
  • This has potential as feed additives in aquaculture. The genus Schizochytrium is the most commonly used in aquaculture.

Bacteria in Aquaculture

• They are increasingly used to reduce pathogen effects being extensively used in China and South America.
• Probiotic application improves disease resistance or growth of aquaculture species.
• Many species of Gram-negative bacteria and Gram- positive bacteria are considered for use in aquaculture.
• Their modes of action includes competitive exclusion or immunostimulation as well as improvement in appetite or feed conversion that leads to better growth

Zooplankton in Aquaculture

• It is used as live feed.
• The Artemia spp. comprises both zygogenetic and parthenogenetic groups.
• It is found in the Americas being the most important
• Several strains of Artemia are used for aquaculture
• They are a resource for selection of characteristics desirable in aquaculture ( in particular nutritional value)
• Rotifers are used in aquaculture, with the Brachionus being the most important genus and other genus used by farmers in Asia