The main objectives are :

- to build up time series of abundance indices for the main commercial species in the North Sea (assessment of the main commercial fish stocks in the North Sea: whiting, cod, haddock, Norway pout, herring, sprat, mackerel, plaice).

- calculation of the larval index for herring and sprat.

The complementary objectives are :

- egg sampling with CUFES (Continuous Underwater Fish Eggs Sampling) in the North Sea.

- study of the distribution and relative winter abundance of marine mammals and birds in the North Sea.

-Recording of acoustic data (for later analysis).

The associated project is "International Bottom Trawl Survey - Assessments of EU and non-EU managed fisheries. Fisheries Information System".

01-01-1960 : The first cruises to monitor juvenile herring are set up by the Netherlands and Germany. These IYHS (International Young Herring Survey) cruises are coordinated by the ICES (International Council for the Exploitation of the Sea).

01-01-1962 : Gradually, the other riparian countries join this programme and the study area is extended to the entire North Sea. Other species are included in the monitoring and the surveys are renamed IYFS (International Bottom Trawl Survey).

01-01-1976 : France joins this programme and covers two important areas for the French fishery in the first quarter of each year, one in the southern North Sea and the other in Western Scotland.

01-01-1980 : A working group in charge of coordinating the North Sea surveys and analysing the data is created. This is the official start of this series of monitoring campaigns.

01-01-1992 : In order to ensure a better coordination of all the campaigns set up by the countries at different periods of the year, both in the North Sea and in the North-West Atlantic, it was decided to create a common working group in charge of analysing the data.

01-01-1996 : The results of this bi-annual sampling in the North Sea are analysed and ICES concludes to continue the two annual campaigns by redistributing the effort of the participating countries which keep a campaign either in the first quarter like France, or in the second quarter like France.

01-01-1997 : From this year onwards, the French cruise takes place once a year during the winter period. It is responsible for sampling the southern North Sea.

01-01-2007 : The sampling area allocated to France and the Netherlands is extended to the Eastern Channel.

01-01-2015 : Replacement of the vessel 'Gwen Drez' by the vessel 'Thalassa II'.

01-01-2017: Reduction in the number of days at sea (23 days compared to 30 previously)

For the collection of data on waste: analysis of data by category, mapping and trends according to a protocol harmonised at European level :

- Protocol validated since 1994 (MEDITS) and 1995 (IBTS/EVHOE)

- Protocol harmonised at European level (mesh size, protocol, trawls)

- Protocol adopted for the implementation of the DCSMM at European level

Limitations : system to be completed locally for shallow waters (0-20 metres)

• Sampling plan(s) :

Random, stratified

• Specification of data type :

- For fauna:

Melanogrammus aeglefinus; Merlangius merlangus; Gadus morhua; Trisopterus esmarki; Clupea harengus; sprattus sprattus; scomber scombrus; Pleuronectes platessa

Seabirds

Zooplankton; benthic invertebrates; fish

Marine mammals

- For litter :

Inventory of different types of waste (plastics, glass, metal, plastic bottles, leather and fabrics, fishing gear, miscellaneous)

• Parameter(s) observed or measured:

- For fauna :

Counting of juveniles. Otolith sampling

Observation on board the vessel

Presence in the zooplankton sample since 2008; presence and determination of benthic invertebrate fish

- For litter :

Density

• Resolution of parameter(s) :

- For fauna :

Per fishing operation, systematic analysis of scientific fishing catches

- For litter :

Density per hectare

• Format(s):

The available data exist in the format: csv