Report of ten years of Mollusca collection in Icelandic waters by the Marine and Freshwater Research Institute. HV 2024-06

Ágrip

Á 10 ára tímabili (október 2013 – mars 2022) var einökum af lindýrum safnað af fiski- og botndýrafræðingum Hafrannsóknastofnunar úr meðafla við togveiðar við mat á fiskistofnum við Ísland. Söfnun fór fyrst og fremst fram við rannsóknir á djúpslóð í haustralli, sem og á grynnri miðum norðvestur af Íslandi í vorralli. Einnig var safnað úr nokkrum leiðöngrum við stofnmat humars (Nephrops norvegicus) í maí og úr flatfiskaralli í ágúst. Stærð möskva trollanna leyfði aðallega söfnun stærri eintaka. Minni lindýr (< 10 mm) söfnuðust í maga og þörmum fangaðra fiska, aðallega ýsu (Melanogrammus aeglefinus) og skrápflúru (Hippoglossoides platessoides). Skoðuð voru steinar, skeljarusl, draugaveiðinet, svampar, kórallar, þang og þarafestur sem komu í netin til að kanna hvort þar leyndust lindýr. Í öllum tilfellum er greint frá ástandi lindýranna, hvort þau voru lifandi eða dauð (tóm skel).

Abstract

Over a period of 10 years (October 2013 – March 2022) sampling effort was operated by the Fisheries and Benthic scientists of the Marine and Freshwater Research Institute (MFRI) to keep molluscs specimens collected as by-catch when trawling during fish stock assessment around Iceland.

These trawls were primarily made during deep-sea surveys (autumn campaign), as well as on shallower fishing grounds north-west of Iceland (March campaign). Some campaigns in May for stock evaluation of lobster (Nephrops norvegicus) and in August for flat fish surveys also contributed with samples.

The size of the mesh of the trawls allowed mainly collection of macro-molluscs. Smaller molluscs (< 10 mm) were collected in the stomach and gut of captured fish, mainly haddock (Melanogrammus aeglefinus) and long rough dab (Hippoglossoides platessoides). By-catches from different origins (stones, shell debris, ghost fishing nets, sponges, corals, seaweeds, kelp holdfast, sweep ups) were photographed and analysed to isolate eventual hidden molluscs. The state of the sampled molluscs, alive or dead (empty shells), is reported in all cases.