Institute of

SF Sea Fisheries

Project

Studies on ichthyoplankton (fish eggs and larvae)

Lead Institute SF Institute of Sea Fisheries

Plaice eggs from catches as part of the International Herring Larval Survey (IHLS)

Studies on fish eggs and larvae

What additional insights can we gain from our exploratory surveys? We are addressing this question in the context of fish eggs and larvae.

Background and Objective

Almost all marine research expeditions, known as surveys, focus on specific target species and are adapted in time and space according to the objective. Our research vessel operations are complex and expensive. We therefore have a strong interest in gathering as much data and knowledge as possible during the cruise.

For example, the target species of the International Herring Larval Survey (IHLS) are newly hatched herring larvae. However, other species are also caught, some of which are poorly understood in their early life stages. Many of these species are not commercially important and are therefore rarely studied scientifically. However, we also determine the species composition of this associated fauna, produce distribution maps and so on, and thus increase the benefit of the survey time spent.

Target Group

Scientific purposes /basic scientific research

Approach

In addition to the target species, other fish larvae and eggs are sorted out during the processing of survey catches. These are identified and measured where possible. Species communities are recorded and species distribution maps are regularly updated.

Larva of the visceral fish (Echiodon drummondii). Its adult form lives as a commensal (= organism that feeds on the food of a (foreign) host organism without harming it) in the intestines of sea cucumbers.

diverse developmental stages of the Limande — Early (bottom) and late (top) developmental stages of the Limande (Microstomus kitt).

Our Research Questions

What can we learn about species that have been little studied?
How can we maximise the benefits of surveys?

Preliminary Results

While for some species, even after years, we only have isolated specimens, for others we can produce very detailed distribution maps. These can, for example, provide information on important nursery areas for these species.

In winter, for example, in addition to the herring larvae that are the focus of the survey, plaice eggs are regularly caught, sorted by stage and counted in the English Channel. The results are made available to our Dutch colleagues who analyse the year classes of plaice larvae.

For many fish species, in addition to collecting samples, we have also produced photo series of the different developmental stages of the larvae. This material is mainly used at the Institute of Sea Fisheries for larval identification and is constantly being added to. It is also used for external training courses and public relations.

Distribution of sardine larvae — Total number of sardine (Sardina pilchardus) larvae in the southern North Sea and the English Channel as a sum over the years 2009-2018. The legend shows the circle diameter for each 1- 4 - 9 larvae.

Distribution of plaice larvae — Total number of plaice larvae (Pleuronectes platessa) in the southern North Sea and the English Channel in 2009-2018. The larvae hatch in the eastern part of the English Channel and drift with the current into the North Sea. The circle diameter for 16 - 64 - 143 larvae is shown in the legend.

Links and Downloads

ICES data portal: eggs and larvae surveys

ICES Working Group on Surveys on Ichthyoplankton in the North Sea and adjacent Seas (WGSINS)

Our research survey website: Herring larvae in the North Sea (IHLS)

Thünen-Contact

Dr. Norbert Rohlf

Telephone

+49 471 94460 331

norbert.rohlf@thuenen.de

SF Institute of Sea Fisheries

Funding Body

EU - European Maritime and Fisheries Fund (EMFF)
(international, öffentlich)
European Union (EU)
(international, öffentlich)

Duration

1.2009 - 12.2027

More Information

Project status: ongoing

Publikationen

0
Costas G, O'Hea B, Alvarez P, Blom E, Burns F, dos Santos Schmidt T, Farrell E, Garabana D, Holah H, Huwer B, Eliasen SK, Korta M, Angelico MM, Nash R, Nunes C, Núñez-Riboni I, Politis SN, Riveiro I, Thorsen A, Ulleweit J, et al (2023) Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS). Copenhagen: ICES, 118 p, ICES Sci Rep 5(81), DOI:10.17895/ices.pub.23790201
https://literatur.thuenen.de/digbib_extern/dn066643.pdf
1
Costas G, Kloppmann MHF, Alvarez P, Angelico MM, Burns F, dos Santos Schmidt T, Garabana D, Korta M, Nunes C, O'Hea B, Riveiro I, Sampedro P, Solla A, Thorsen A, Ulleweit J, Damme CJG van (2021) ICES Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS: outputs from 2020 meeting). Copenhagen: ICES, 88 p, ICES Sci Rep 3(11), DOI:10.17895/ices.pub.7899
https://literatur.thuenen.de/digbib_extern/dn063402.pdf
2
Costas G, O'Hea B, Alvarez P, Angelico MM, Burns F, dos Santos Schmidt T, Huwer B, Garabana D, Kloppmann MHF, Korta M, Nash RDM, Nunes C, Núñez-Riboni I, Riveiro I, Sampedro P, Solla A, Thorsen A, Ulleweit J, Damme CJG van (2021) Working Group on Mackerel and Horse Mackerel Egg Surveys (WGMEGS). Copenhagen: ICES, 40 p, ICES Sci Rep 3(82), DOI:10.17895/ices.pub.8249
https://literatur.thuenen.de/digbib_extern/dn064012.pdf
3
Burns F, Damme CJG van, Ulleweit J, Fonn M, Thorsen A, Franco C (2013) 2013 International mackerel and horse mackerel egg survey : preliminary results ; Working Document / Survey Report, ICES WGWIDE 2013. Copenhagen: ICES, 36 p
4
Tiedemann M, Kloppmann MHF, Ulleweit J, Gröger JP, Hagen W (2013) A spatial analysis of larval fish assemblages in the Celtic Sea off Great Britain (47° to 51° N): implications of bathymetry and ocean warming. Mar Biol Res 10(5):482-493, doi:10.1080/17451000.2013.819983
5
Ulleweit J, Burns F, Damme CJG van, Fonn M, Kloppmann MHF, Milligan SA, Thorsen A (2010) Survey report: 2010 International mackerel and horse mackerel egg survey : preliminary results. 36 p Working Doc ICES WGWIDE 2010/1
6
Kloppmann MHF, Ulleweit J, Damme CJG van (2008) Distribution of Snake Pipefish during the 2007 MEGS : working document presented at the Working Group for the Mackerel Egg Survey.
7
Kloppmann MHF, Ulleweit J (2007) Off-shelf distribution of pelagic snake pipefish, Entelurus aequoreus (Linnaeus, 1758), west of the British Isles. Mar Biol 151(1):271-275, DOI:10.1007/s00227-006-0480-4

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