Reports

Experimental production of natural zooplankton and the quality of stored eggs

Published:

01/03/2010

Authors:

Jónína Þ. Jóhannsdóttir, Hugrún Lísa Heimisdóttir (student of the University of Akureyri), Friðbjörn Möller, Rannveig Björnsdóttir

Supported by:

Fisheries Project Fund, Student Innovation Fund, University of Akureyri Research Fund

Experimental production of natural zooplankton and the quality of stored eggs

Plankton is the most important food for our juveniles' main fish stocks and redfish is the most common species of plankton in Iceland, but Acartia species can also be found in plankton almost all year round. The aim of the project was to cultivate selected species of natural zooplankton that are common in Iceland (redfish and Acartia) and produce hibernation eggs to ensure its supply all year round. In connection with the project, facilities have been set up for the cultivation of zooplankton and live algae that were used as feed for the plankton. Wild zooplankton has been collected using various methods and breeding experiments performed under different environmental conditions. Experiments have also been performed with the hatching eggs of Acartia tonsa in two separate experiments. The main results indicate that the animals are very sensitive to any kind of treatment as well as temperature changes during collection. There were large losses in the first days after collection and it proved difficult to keep the animals alive for more than a few weeks. Nutrition has a far-reaching effect on animal reproduction, performance and productivity, and the results indicate that the algae concentrate used was not suitable for the cultivation of zooplankton, but much better results were obtained with the use of live algae. The hatching of the laying eggs went well and they managed to get the animals to produce eggs. Subsequently, it is planned to investigate the effects of various factors such as the nutritional content of food, food supply and density on the development, sex ratio and egg production of the animals.

Zooplankton is the food source of our fish stocks, with Calanus finmarchicus being the most abundant species in the marine ecosystem around Iceland in addition to Acartia that may be found in the zooplankton throughout the year. The overall goal of this project was to culture natural zooplankton species (Calanus finmarchicus and Acartia) for production of eggs that is the basis for commercial production of copepods. Facilities for culturing zooplanktonic species and live algae have been set up as part of the project. Natural zooplankton has been collected using various approach and attempts have been made to culture copepods under various conditions. Eggs of Acartia tonsa have furthermore been hatched and cultured in two separate experiments. The main results indicate that zooplankton species are extremely sensitive to handling and temperature changes during collection and transport. Significant losses were observed during the first days following collection and the copepod cultures only survived through a few weeks. Previous studies show that nutrition profoundly affects reproduction, survival and productivity of zooplankton species. The present results indicate that the algae paste used did not fulfill the nutritional requirements of the copepods but improved results were achieved using live algae cultures. Hatching of dormant eggs proved successful and eggs have been collected from the experimental units. Further experiments are planned with the aim to study the effects of nutrition, food supply and copepod densities on the development, sex ratio and productivity of the cultures.

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Reports

Nordic information and communication network regarding safety of seafood products. Final Report

Published:

01/03/2007

Authors:

Helga Gunnlaugsdóttir, Björn Auðunsson

Supported by:

NSK (Strategy Reserve), NEF (Nordic Officials' Committee for Fisheries Policy), IFL

Nordic information and communication network regarding safety of seafood products. Final Report

This report is the final report in the Nordic information and communication network project regarding the safety of seafood products, which began in 2005 and was formally completed at the end of 2006. The project developed a joint Nordic website (www.seafoodnet.info) which gathers in one place relevant links containing information on the chemical content of marine products, both undesirable substances and also nutrients. Iceland (first the Fisheries Research Institute and then Matís ohf) was responsible for developing the website and maintaining it, but each country is responsible for its information and for updating it. The project was formally completed at the end of 2006, when the website had just been moved to a new content management system, Eplica, which simplifies all web management and also makes it easier for visitors to find the content they are looking for. It is hoped that these will enable the web to stay "alive" with little effort and cost.

This report is the final report in a Nordic project called “Nordic information and communication network regarding safety of seafood products and utilization of the resources from the sea”. The report contains a summary of the activities in the projects after the 2nd workshop in the project, which was held in Copenhagen, Denmark on April 21st 2006 until the project formally ended at the end of 2006. During this period the website was transferred into a new web content management system called Eplica product suite, which makes administering much easier than in the earlier version and accessing the website much more user-friendly. This was done in accordance with agreements reached at the workshop in Copenhagen. Although the project has formally ended, it is hoped that the seafoodnet.info website will continue to live for some time to come, as a common database or co-ordination of information and reporting of chemical substances, ie nutrients and undesirable substances in seafood. Furthermore, it was hoped that the project would be a cornerstone for further networking and innovative transnational research with the participation of scientists in the Nordic countries and EU.

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