| Title | When and how? Freshwater mussel recolonization in Lake Orta |
| Abstract | Thanks to a video posted on a social network, live mussels of Unio elongatulus, have been recorded from Lake Orta (Italy) over one
century after the last (and only) report. With its long and well documented history of pollution, Lake Orta offers the opportunity to document
the post-extirpation recovery of freshwater unionid mussels. This case evidences that recovery/recolonization is possible despite
a high devastation in the past, and permits to evaluate how fast recolonization may occur, in which way, and in what conditions. The
answer to the how fast was sought by estimating the age of the larger and seemingly older individuals of the population. To address the
in which way we compared the haplotypes of Lake Orta specimens of Unio elongatulus (the only species present) with those of surrounding
populations. We concluded that, since Lake Orta lacks a direct connection with the putative source populations, colonizing
mussels were almost certainly transported by fish carrying glochidia that were used for lake restocking after liming. Data from the
long-term monitoring of water chemistry and sediments have allowed defining what conditions proved to be suitable for survival making
possible the start of mussels recovery. But not only water and sediment quality matters for mussels recovery, which was delayed by
nearly ten years after the reappearance of fish. This delay reflects the need of the whole trophic chain to be reestablished to allow the
survival of the suitable and healthy host-fish populations necessary for mussels reproduction. |
| Source | Journal of limnology (Testo stamp.) 75 (2s), pp. 120–130 |
| Keywords | Mussel recolonization; Unio elongatulus; molecular analysis; age estimation; population structure. |
| Journal | Journal of limnology (Testo stamp.) |
| Editor | Istituto per lo Studio degli Ecosistemi., Verbania Pallanza, Italia |
| Year | 2016 |
| Type | Articolo in rivista |
| DOI | 10.4081/jlimnol.2016.1286 |
| Authors | Riccardi Nicoletta(1), Froufe Elsa(2), Lopes-Lima Manuel(2,3), Mazzoli Claudio(4) |
| Text | 350719 2016 10.4081/jlimnol.2016.1286 Scopus 2 s2.0 84964809833 Mussel recolonization; Unio elongatulus; molecular analysis; age estimation; population structure. When and how Freshwater mussel recolonization in Lake Orta Riccardi Nicoletta 1 , Froufe Elsa 2 , Lopes Lima Manuel 2,3 , Mazzoli Claudio 4 1 CNR Institute for Ecosystems Study, L. Tonolli 50, 28922 Verbania Pallanza, Italy; 2 Interdisciplinary Centre of Marine and Environmental Research CIIMAR/CIMAR , University of Porto, Rua dos Bragas 289, 4050 123 Porto, Portugal; 3 IUCN/SSC Mollusc Specialist Group, c/o IUCN, Pembroke St, Cambridge CB2 3QZ, UK; 4 Department of Geosciences, University of Padua, Via Gradenigo 6, 35131 Padova, Italy Thanks to a video posted on a social network, live mussels of Unio elongatulus, have been recorded from Lake Orta Italy over one century after the last and only report. With its long and well documented history of pollution, Lake Orta offers the opportunity to document the post extirpation recovery of freshwater unionid mussels. This case evidences that recovery/recolonization is possible despite a high devastation in the past, and permits to evaluate how fast recolonization may occur, in which way, and in what conditions. The answer to the how fast was sought by estimating the age of the larger and seemingly older individuals of the population. To address the in which way we compared the haplotypes of Lake Orta specimens of Unio elongatulus the only species present with those of surrounding populations. We concluded that, since Lake Orta lacks a direct connection with the putative source populations, colonizing mussels were almost certainly transported by fish carrying glochidia that were used for lake restocking after liming. Data from the long term monitoring of water chemistry and sediments have allowed defining what conditions proved to be suitable for survival making possible the start of mussels recovery. But not only water and sediment quality matters for mussels recovery, which was delayed by nearly ten years after the reappearance of fish. This delay reflects the need of the whole trophic chain to be reestablished to allow the survival of the suitable and healthy host fish populations necessary for mussels reproduction. 75 Preprint 01/10/2015 When and how Freshwater mussel recolonization in Lake Orta pdf articolo Riccardi et al.2016_Orta recolonization.pdf Articolo in rivista Istituto per lo Studio degli Ecosistemi. 1129 5767 Journal of limnology Testo stamp. Journal of limnology Testo stamp. J. limnol. Testo stamp. Journal of limnology. Testo stamp. nicolettarita.riccardi RICCARDI NICOLETTA RITA |
