News & Events
Bacteria linked to mortality in aquaculture hatchery systems
Speaker(s): A/Prof. Jennifer Cobcroft, James Cook University (Singapore)
When: 26 April 2017 (3:00 - 4:00pm)
Where: SBS CR3 (Level 1)
Type: Seminars


Marine fish larvae are susceptible to mortality caused by bacterial infection during larval rearing within aquaculture systems. This study examined the performance of fish larvae, striped trumpeter (Latris lineata), and the cultivable bacteria associated with larval culture to 15 days post-hatch (dph) in clearwater or greenwater. The greenwater source was either live microalgae, Nannochloropsis oculata, or a concentrated algal paste (instant). The growth of larvae was higher in live algae than in clearwater or instant algae. However, survival was higher in both live algae and clearwater than in instant algae. Mortality of larvae reared in instant algae coincided with significantly higher cultivable bacteria in the larvae and in larval culture tanks. There was a correlation between bacterial flora of the larvae and the culture environment, demonstrated by a more complex flora associated with larvae held in live algae. Live microalgae is recommended for greenwater culture of striped trumpeter, while concentrated algal paste products should be used with caution as greenwater for marine fish larval rearing. Several techniques exist for managing potentially harmful bacteria and overall bacterial load in fish hatchery systems. However, more research is needed to understand the direct and indirect effects of bacteria on larval mortality in order to inform management practices that support sustainable aquaculture.


Jennifer Cobcroft received her PhD from the University of Tasmania, Australia, in 2002, for research into the development and feeding behaviour of the larvae of the marine finfish species striped trumpeter. She has over 20 years’ experience in aquaculture, largely focusing on solving challenges in the hatchery production of marine fish species. Her research has spanned larval visual development, tank environmental conditions to optimise feeding, water treatment systems to reduce parasites and pathogens in the hatchery, and finding solutions to skeletal deformities that impact commercially cultured fish. She was a research scientist at the Institute for Marine and Antarctic Studies, University of Tasmania, until June 2015, securing research funds of AU$3.9M. Recently, she has consulted in the strategic planning of emerging aquaculture research opportunities, marine fish hatchery trouble-shooting, and in aquaculture development in a number of countries. She is the current Secretary of the World Aquaculture Society (WAS), a former Board member of the Asian Pacific Chapter of WAS, and recently commenced as Associate Professor Aquaculture at JCU Singapore.