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Prosjektnummer: 900049
Status: Avsluttet
Startdato: 01.01.2008
Sluttdato: 31.12.2009

Coordinated Action: Lice International (Canada (USA), Scotland, Ireland and Norway)

Prosjektet har vært finansiert gjennom Norges forskningsråd med delfinansiering fra FHF. Førstnevnte har hatt ansvaret for å kvalitetssikre prosjektet faglig og administrativt. Prosjektet har egen nettside hos Forskningsrådet (prosjektnr. 184992) med supplerende informasjon.

Resultatene fra dette prosjektet leses best på de tilhørende plakat (poster)-presentasjonene. Nedenfor følger det engelske rapportsammendraget.
Results achieved
This project brought together key institutes in the development of dispersal models for sea lice and the methods used to validate these. The collaboration between these institutes, in particular co-ordination of the work to ensure that outcomes from the regions are comparable and hence supportive of each other has been valuable.

Two methods have been used in the field, sentinel cages and hydrodynamic modelling.

Sentinel cages
From the trials carried out in Scotland, Norway, Ireland and Canada the initial findings suggest that while the design and size of the various national cages differ slightly, observed louse settlement on fish is sufficiently similar to allow data comparisons among participating countries to be carried out. While further data collection and statistical analysis should be carried out, the CALI program has demonstrated that standardising methodology across nations allows datasets to be combined and examined resulting in more robust conclusions to be drawn and effect advice on future integrated sea lice management strategies.

Hydrodynamic modelling
The systems modelled vary in scale, complexity, climate and ecology. The modelling and parameterisations have benefited from the extensive international collaboration between these countries including novel hydrodynamic modelling to cope with the complex geography of fjordic systems, modelling of wind forcing and models of lice biology. A general finding across these differing systems is the weather and/or flow-dependent formation of concentrations of larval lice at locations that are distant from their source.

Vertical migration of free swimming salmon lice larvae
During the second meeting (Ørlandet 12–13 August 2009) behavior of free swimming larvae were defined as one of the important areas for further research and was put on the short list. From contacts in Canada the project was able to borrow a 10m long plankton mesh column designed to stand in the water. The column could be partitioned of for each meter and planktonic sub samples could be taken from the column. By stocking the column with salmon lice nauplii and copepodids an idea of vertical position and migration could be elucidated. In November 2009 one was able to do a short preliminary test and found that both nauplii and copepodids aggregated at the surface at day. The same results were also shown for dark conditions. This was not in line with older research. Since one only was able to do one test the experiments needs to be duplicated in a full set design.
Increased levels of farmed salmonid hosts for parasitic sea lice have raised the question of transfer between farmed and wild sources. The study of distribution and dispersal of sea lice has thus become more important over the last years and key institute s from several countries are currently doing research in this field. Comparative experimental field work and coordinated action on both methods and publishing results will potentially give large synergetic results.
To do comparative experimental studies on methods used in one or several of the participating countries (sentinel cages, trawling for sea lice larvae and development of dispersal models for sea lice) and coordinate other research efforts done individually through workshops.
Expected project impact
The project will contribute to the development of a robust understanding of lice biology, which also may help in predicting responses to climate change.

Standardised approaches allowing comparison of methods and results across a larger range of environments than found in any one country will allow for development of robust understanding of lice biology, and may help in predicting responses to climate change. Further, collaboration on systems with as different scales and environment as in this project could also bring benefits beyond sea lice studies.
Project design and implementation
The combination of so different fields as physical oceanography and sea lice biology are being refined into particle transport models to simulate dispersal of sea lice as indicated below.

Modelling dispersal in different geographical areas
The key participants proposed here have played central parts in the present knowledge of dispersal of larvae for their specific regions (Norway, Scotland and Canadian west coast). The methods used are of similar character but considerable benefits would come from comparing results and refining methods together.

Larvae surveys
Fisheries Research Service are the first to report on successful direct sampling of sea lice larvae. The transfer of the practical knowledge to the other participants is of large interest.

Sentinel cages
Sentinel cages can be used to verify results from particle transport models of sea lice dispersal. The method has been used in Norway and Scotland and is under development as a method in this context.
Dissemination of project results
Final results will be published in a final report and as a poster.