Volume 19 Issue 3 MAY/JUNE 2018
TRENDING
OYSTER REVIVAL
Wrasse are creating a new market for marine hatcheries as revealed by the dramatic increase in cleaner-fish production.
Hatchery Manager Natalie Clark checks algae cultures at Hoopers Island facility.
Oyster hatcheries support collaborative effort to increase oyster populations in Chesapeake Bay S
ome 20 non-profits, scientific organizations, community groups and oystermen from Maryland and Virginia are working together as the “Chesapeake 10 Billion Oysters Partnership.” The goal? To bring ten billion new oysters to Chesapeake
Bay by 2025. Tom Zolper, assistant media director for the foundation, confirmed that the success of the program rests in large part on the ability of two oyster hatcheries in the area to provide spat in sufficient quantities.
continued on page 7
RAS RESULTS
Norwegian study shows smaller salmon smolt grow faster in seawater grow-out But bigger smolt grown longer in RAS provide advantages when exposure to sea lice taken into account
BY RUBY GONZALEZ
C O S T I M P L I C AT I O N S
ne hundred and 200-gram salmon smolt grew more quickly when put into seawater for grow-out compared to 600-gram fish. This was one of the results of a study conducted by researchers from the Norwegian Institute of Food, Fisheries and Aquaculture Research (Nofima) which compared performance in terms of growth, survival, health and maturation of salmon produced using different production protocols in RAS. “We do not know the reason for reduced growth during summer in the fish transferred at 600 grams. The trend was the same in all 600 gram-transferred fish, irrespective of photoperiod or salinity in RAS. We are, at the moment, doing analysis of fish composition to see if we can find an explanation,” Nofima scientist Trine Ytrestøyl told Hatchery International.
Ytrestøyl presented the study at the Aquaculture Innovation Workshop (AIW) 2017 in November at Vancouver, Canada. “Since the presentation at AIW, we have done the final sampling, and the 600-gram fish grew very well during the final two months in the sea from September to end of November. But despite their catch-up growth, they were still smaller than the 100 and 200 gramtransferred fish at slaughter in late November,” she said. Cost implications are not covered by the project, she said, because it is very dependent on sea lice situation. “If this is taken into account, it may be more economical to use the larger post-smolts of 600 grams even if they grow a little slower in the seawater phase,” she said. The larger fish, she explained,
O
Trends in European Marine Fish Hatcheries A review based on a paper by Isabel Represas and Alessandro Moretti presented at Larvi 2017 BY DIOGO THOMAZ
At the annual Larvi meeting, held in Ghent, Belgium early last fall Isabel Represas of INVE presented research on the key trends in the European marine fish hatcheries’ industry with a focus on changes between 2013 and 2017. As a recognized reference and innovator in fish hatchery culture, INVE Aquaculture, part of Benchmark, has dedicated special attention to early-stage nutrition to increase survivability and performance of marine fish. It’s owing to this depth of experience in the market that INVE was able to undertake this research on Marine Fish Hatcheries in Europe. highlight of the presentation was information on the creation of a new market for marine hatcheries as revealed by the dramatic increase in cleaner-fish production. Trends in bass and bream hatchery production were also interesting, with a steady increase in numbers produced from the same basic infrastructure. This was achieved through a strategic approach that starts with better dimensioned hatcheries (an increase in the number of large hatcheries), industry integration (as seen in the salmon industry), better protocols and automation. There was also a call for hatcheries to look at
A
continued on page 10 Nofima scientist Trine Ytrestøyl
can reduce grow-out times in open sea cages by 2.5 months, which saves one to two delousing operations, compared to stocking with 100- and 200-gram fish. There are also health benefits, she added, because delousing is tough on the fish and leads both to reduced growth and some mortality. It is a common procedure these days to produce salmon smolt to a larger size before they are put in seawater for grow-out. continued on page 36
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