Roles of environmental factors in the recruitment of the European grayling Thymallus thymallus, near its southern range limit in England

Event Abstract Back to Event Roles of environmental factors in the recruitment of the European grayling Thymallus thymallus, near its southern range limit in England Tea Basic1, 2, 3*, Robert Britton2, Richard Cove4, Anton Ibbotson3 and Stephen Gregory3 1 Centre for Environment, Fisheries and Aquaculture Science (CEFAS), United Kingdom 2 Bournemouth University, United Kingdom 3 Game & Wildlife Conservation Trust, United Kingdom 4 Natural Resources Wales, United Kingdom Density-dependent and independent factors are driving the recruitment of salmonids, with conspecific density, discharge and temperature especially important. Major drivers of the Atlantic salmon Salmo salar and brown trout Salmo trutta recruitment are well known, however there is a paucity of knowledge on the potamodromous salmonid European grayling Thymallus thymallus, whose post-emergence time coincide with period of increasing temperature and low discharge. Consequently, this study assessed the importance of different density-dependent and independent parameters for grayling survival during incubation and emergence period in a southern chalk stream. Linear and non-linear stock recruitment models were fitted to derive residuals from the “best” performing model and use in mixed effect models as a response variable. River temperature and discharge derived variables, conspecific and heterospecific densities were used as explanatory variables in a set of mixed effect models, with river site as a random effect on the intercept. The final mixed effect model revealed the significant effect of both the incubation and post-incubation temperature anomaly, number of days with low flow post-incubation and 0+ brown trout densities on 0+ grayling densities. The relationship with incubation temperature anomaly and 0+ brown trout abundance was positive, while increasing the number of days with low flow following incubation period negatively affected their survival. In addition, post-incubation temperature anomaly had a concave quadratic relationship with 0+ grayling densities, with threshold set at 13.5 °C. These outcomes are discussed in relation to future population persistence and management in a changing climate. Keywords: salmonids, recruitment, temperatur, discharge, Chalk streams Conference: XVI European Congress of Ichthyology, Lausanne, Switzerland, 2 Sep - 6 Sep, 2019. Presentation Type: Oral Topic: GRAYLING (GENUS THYMALLUS): EVOLUTION, SYSTEMATICS, MANAGEMENT AND CONSERVATION Citation: Basic T, Britton R, Cove R, Ibbotson A and Gregory S (2019). Roles of environmental factors in the recruitment of the European grayling Thymallus thymallus, near its southern range limit in England. Front. Mar. Sci. Conference Abstract: XVI European Congress of Ichthyology. doi: 10.3389/conf.fmars.2019.07.00071 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 24 Jun 2019; Published Online: 14 Aug 2019. * Correspondence: Dr. Tea Basic, Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Lowestoft, United Kingdom, Tea.basic@cefas.co.uk Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Tea Basic Robert Britton Richard Cove Anton Ibbotson Stephen Gregory Google Tea Basic Robert Britton Richard Cove Anton Ibbotson Stephen Gregory Google Scholar Tea Basic Robert Britton Richard Cove Anton Ibbotson Stephen Gregory PubMed Tea Basic Robert Britton Richard Cove Anton Ibbotson Stephen Gregory Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.