Taxonomy

Coregonus autumnalis | Pollan

Distribution

Status

Conservation status

HABITATS DIRECTIVE ARTICLE 17 REPORTING
Range
Favourable
Population
Bad
Habitat
Inadequate
Future Prospects
Inadequate
Overal Assessment of Conservation Status
Bad
Overal trend in Conservation Status
Unknown

Source: NPWS 2013.


IUCN Conservation Status
Ireland (1)
Vulnerable  [B2ab(iii,v), D2]
Europe (2)
* Endangered [B1ab(iii)+2ab(iii)]
Global (2)
*Endangered B1ab(iii)+2ab(iii)

Sources: (1) King, J.L. et al 2011; (2) Freyhof, J. & Kottelat, M. 2008.

* Assessed as Coregonus pollan Thompson 1835. See 'Additional Comments' below regarding taxonomy.



Legal status

Protected by the following legal instruments:

  • Habitats Directive Annex V

  • Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention) Appendix III

  • Fisheries Acts 1959 to 2006
  • Fisheries Act (Northern Ireland) 1966.
Sources: King, J.L. et al, 2011; Maitland, Peter S., 2004.

Native status

Native.

Species Biology

Identification

  • One dorsal and one adipose fin.
  • No barbels present on head.
  • No large bony plates present on body.
  • Lateral line extends almost entire length from head to tail.

  • Small dagger shaped 'pelvic axillary process' found just above the pelvic fin.

  • Teeth not present.
  • Dorsal fin ordinarily with less than 20 rays.
  • When lowered, dorsal fin less than or equal to head length.

  • Upper and lower jaws level i.e. neither upper or lower jaw extends beyond the other.
  • Colouration; Greenish-brown dorsally, to silvery-green laterally fading to silver-white ventrally. Dorsal and caudal (tail) fins mid- to dark grey, pectoral, pelvic and anal fins mid- to light grey.
  • Head relatively small, eyes relatively large.
  • Length at maturity; 30-35cm.
  • Adult weight; c. 450gm.
  • Normal life span 5-7 years.

Sources: Maitland, Peter S., 2004; Greenhalgh, Malcom, 2001.


Habitat

On the island of Ireland this species occurs in lakes. So far populations have been identified in Lough Neagh, Lower Lough Erne, Lough Allen, Lough Ree and Lough Derg. The species is anadramous in North America and nothern Eurasia where it also occurs. The Irish and Northern Irish populations are considered to be land locked relicts of post-glacial colonization.

Source: Harrison, A.J. et al 2012.

Habitats include but are not necessarily limited to;

  • Mesotrophic Lakes (FL4)
  • Eutrophic Lakes (FL5)

Sources: Harrison, A.J. et al, 2010; NPWS 2013; Fossitt, J.A., 2001.

Reproduction

Based on Lough Neagh population:

  • Spawning takes place in Winter (December), with eggs being deposited on rocky or gravelly, shallow areas of lake beds.
  • Hatching is after approximately two months.
  • Maturity reached after 2nd year.
  • Lifespan is 5-7 years.
Source: Rosell, R. et al, 2004.

Threats faced

THREAT
ARTICLE 17 CODE
RANKING
Invasive non-native species*
I01
High
Pollution to surface waters (limnic & terrestrial,  marine & brackish)**
H01
High
Water abstractions from surface waters
J02.06
Medium

* competition for resources with alien invasives Zebra Mussel (Dreisenna polymorpha) and Asian Clam (Corbicula fluminea) and with introduced coarse fish species.

** bth can lead to eutrophication which can impact on the Pollan itself as well as one of its main prey items.

Source: NPWS 2013.


The 2011 Irish Red Data Book assessment also identified as a threat to the species.;

  • Lack of gene flow for individual lake populations.

Source:King, J.L. et al 2011.



Conservation actions

In the Article 17 Habitats Directive reporting for the period 2007-2012  no Conservation Actions in place or being implemented during the period are listed.

A 2005 All Ireland Species Action Plan for Coregonus autumnalis identified four main action plan targets;

  • Maintain the existing pollan stocks and prevent further decline in any of the populations.
  • Create ‘back-up’ stocks of all four pollan sub-populations by 2010.
  • Restore the Lower Lough Erne and Shannon lakes populations to demonstrably sustainable levels by 2015.
  • Restore pollan to sites where they have become extinct e.g. Upper Lough Erne by 2015.
Source: Anon., 2005.


Distribution

World distribution(GBIF)

Outside of North America and northern Eurasia (hence the common name Arctic Cisco) the lake populations in Ireland are the only significant western European populations.

Source: Maitland, Peter S., 2004.

Most records are from arctic regions of North America and Russia. Records also from Ireland. Records from Lake Baikal may be for C. lavaretus (Sukhanova, L. V. et al, 2004).

Accuracy of world distribution shown in the Global Biodiversity Information Facility (GBIF) map below will be constrained by, amongst other factors, data held but not shared by countries and organizations not participating in the GBIF.

Irish distribution

Lough Neagh, Lower Lough Erne, Lough Allen, Lough Ree and Lough Derg.

Temporal change

Records submitted to Data Centre in 2021

The following map is interactive. If you would prefer to view it full screen then click here.

How can you help

The National Biodiversity Data Centre is trying to improve our knowledge on the distribution of Coregonus autumnalis in Ireland. Should you observe the species, please submit sightings to add to the database. Detailed observations will assist us gaining a better insight into where the species is most abundant in Ireland and we might also be able to detect regional variations. Please submit any sightings and photographs at:

http://records.biodiversityireland.ie/index.php

All records submitted on line can be viewed on Google Maps – once checked and validated these will be added to the database and made available for conservation and research.

Further information

For further information contact Dr. Liam Lysaght llysaght@biodiversityireland.ie

References

Publications

Freyhof, J. & Kottelat, M. 2008. Coregonus pollan. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 17 December 2014.

Greenhalgh, Malcom, 2001. The Pocket Guide to the Freshwater Fish of Britain and Europe. Octopus Publishing, England.

Harrison, A.J., Kelly, F.L., Rosell, R.S., Champ, T.W.S., Connor, L. and Girvan, J.R. 2010. First record and initial hydroacoustic stock assessment of pollan Coregonus autumnalis Pallas in Lough Allen,Ireland.  Biology and Environment: Proceedings of the Royal Irish Academy 110B,69–74. DOI: 10.3318/BIOE.2010.110.1.69.

Harrison, A.J., Connor, L., Morrissey, E. and Kelly, F.L. 2012. Current status of pollan Coregonus autumnalis pollan in Lough Ree, Ireland. Biology and Environment: Proceedings of the Royal Irish Academy 2012. DOI: 10.3318/ BIOE.2012.09.

Maitland, Peter S., 2004. Keys to the Freshwater Fish of Britain and Ireland With Notes on Their Distribution and Ecology. The Freshwater Biological Society, Cumbria.

NPWS, 2013. The Status of EU Protected Habitats and Species in Ireland.  Species Assessments Volume 3. Version 1.0. Unpublished Report, National Parks & Wildlife Services. Department of Arts, Heritage and the Gaeltacht, Dublin, Ireland.

Rosell, R.,Harrod C. , Griffiths David and McCarthy, T.K. 2004. Conservation of the Irish Populations of the Pollan, Coregonus autumnalis. Biology and Environment: Proceedings of The Royal Irish Academy, Vol. 104b, No. 3, 67-72

Sukhanova, L. V., Smirnov, V. V., Smirnova-Zalumi, N. S., Kirilchik, S. V. & Shimizu, I. 2004: Grouping of Baikal omul Coregonus autumnalis migratorius Georgi within the C. lavaretus complex confirmed by using a nuclear DNA marker. Ann. Zool. Fennici 41: 41–49

Additional comments

In Annex V of the Habitats Directive 'Coregonus spp. (except Coregonus oxyrhynchus anadromous populations in certain sectors of the North Sea)' is listed. Note that C. oxyrhynchus is listed in Annex II but is not present on the island of Ireland.

In guidance documents for Article 17 reporting, for both Ireland and the U.K. the Annex IV Coregonus spp. suggested taxa has a reference to Coregonus pollan. IUCN Red List assessments for Irish populations European and Global level use Coregonus pollan Thompson, 1835.

From literature, workers in Ireland tend to use either C. autumnalis pollan Thompson or C. autumnalis Pallas 1776. See Rosell, R. et al 2004 for more on the taxonomy of C. autumnalis Pallas 1776 in Ireland.

This species account is based on National Biodiversity Data Centre records for C. autumnalis Pallas 1776 .

Note that IUCN Global assessments uses C. autumnalis for populations outside Ireland.

Variation in the use of taxonomic nomenclature can lead to issues with mapping of species. Guidance notes on Habitats Directive Article 17 reporting indicate that there are issues with the taxonomy for this taxon in Ireland.

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