UK waters are home again to the bluefin tuna


Bluefin tuna Credit: Tom Horton

Atlantic bluefin tuna have returned to UK waters and might as soon as again be seen throughout the summer season and autumn months.

Their numbers seem to be rising, following a protracted interval of absence linked to inhabitants decline, in accordance to analysis led by Cefas and the University of Exeter.

Marine scientists in the UK and Ireland have analyzed a number of datasets, spanning a 16-year interval, to doc the improve in bluefin, which arrive into the waters of the Celtic Seas and off South West England, the Scilly Isles, and North West Ireland to feed in late summer season and autumn.

The analysis is a part of the Defra-funded “Thunnus UK” analysis venture.

Thunnus UK was established to enhance information of this species, as a necessary first step in guaranteeing a optimistic future for Atlantic bluefin tuna round the UK.

Central to the venture’s success has been a concerted effort to share and mix necessary knowledge on the place individuals have noticed Atlantic bluefin tuna.

This will assist to determine the place and when these fish are present in UK waters.

Nearly 1,000 distinctive observations have been recorded between 2013 and 2018 by citizen scientists, scientists, fishers and eco-tour leaders.

Researchers discovered that Atlantic bluefin tuna start to arrive in May and keep as late as January.

UK waters are home again to the bluefin tuna
Bluefin tuna Credit: Tom Horton

However, peak numbers have been recorded between August and October annually.

The analysis attracts on 5 key knowledge sources:

  • The normal public: A complete of 80 sightings recorded by the public and submitted to
  • Eco-tourism: three eco-tourism vessels accumulating knowledge on greater than 1600 boat excursions off the SW coast of England between 2008 and 2018.
  • Opportunistic scientific surveys: 40 days of surveys with >2500 km of effort carried out by Cefas and University of Exeter specialists off the Northwest Coast of Ireland and SW England in 2016 and 2018.
  • Fisheries impartial surveys: (1) knowledge collected by MarineLife throughout the Peltic survey by Cefas between 2013 and 2015, and (2) knowledge collected by the Irish Whale and Dolphin Group throughout the Irish Marine Institute’s Celtic Sea Herring Acoustic Survey between 2014 and 2018
  • Bycatch in business fisheries: Bluefin tuna have been by chance caught (bycatch) in the Irish business fishery for albacore tuna between 2003 and 2017.

Lead writer Tom Horton, of the University of Exeter, stated: “Atlantic bluefin tuna are as soon as again a function in nearshore waters off the UK and Ireland.

“We’ve been in a position to doc this story through the use of knowledge from all kinds of sources.

“We want to work collectively to guarantee a future for Atlantic bluefin tuna, each in the UK and Ireland and extra broadly all through their vary in the Atlantic Ocean.

“This is a really exciting study and the return of these fish suggest an important role in the UK’s ecosystem.”

Jeroen van der Kooij, Principal scientist and Peltic Survey Lead, Cefas, stated: “The distinctive knowledge collected throughout our annual pelagic ecosystem survey of SW English waters is key to this analysis.

“Marine animal observers from MARINELife on board our analysis vessel recorded not solely the arrival, but additionally a subsequent year-on-year improve in sightings of bluefin tuna in the space.

“We will continue to collect this information, which, in combination with data on their prey fish and habitat collected during the same survey, will hopefully increase our knowledge of these exciting yet enigmatic animals.”

Experts staff up to research bluefin tuna and make sure return to UK waters

More info:
Thomas W Horton et al, Evidence of elevated prevalence of Atlantic bluefin tuna in territorial waters of the United Kingdom and Ireland, ICES Journal of Marine Science (2021). DOI: 10.1093/icesjms/fsab039

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University of Exeter

UK waters are home again to the bluefin tuna (2021, April 19)
retrieved 19 April 2021

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