- 30th May 2019
- Posted by: Joanne Woodhouse
- Category: Blog
Following our attendance at the 9th Institute of Fisheries Management specialist conference on Fish, Flows and Climate Resilience the team discuss highlights from the day.
Rachelle Ngai comments, ‘As a non-fish expert, the IFM 9th Specialist Conference on Fish, Flows, and Climate Resilience, brought more nuance and detail from the academic and practitioner community of how fisheries are impacted by a changing flows and climate.’
Coarse fish in english rivers
Graeme Peirson’s presentation on Coarse Fish in English Rivers challenged the assumptions that temporal variations in coarse fish recruitment, survival, and growth are driven by temperature and flow. The study found that high summer flows were beneficial for coarse fish, although there was no correlation found between temperature and roach and chub recruitment. This study’s results differed from a number of studies completed in North
America and Graeme’s reflections made salient points. England’s landscapes include modified and shorter watercourses, with high winter precipitation and no classic seasonal flood pulse. On the other hand, North America’s landscapes include snow top mountains, less modified and longer watercourses with functional floodplains and a seasonal flood pulse. The differences in landscapes may not be the only reason for differing results but the research highlighted a common theme of the conference. Habitat connectivity of watercourses and its floodplains is one of the most important aspects of providing fisheries resilience to the inevitable changing flows and climate.
Mark Warren, a Hydroecologist with the Environment Agency, gave a presentation on work the EA is currently undertaking to establish if there are discernible links between environmental baseline and incident data. Information on fish kills extracted from the EA’s National Incident Reporting System is already suggesting that the first half of 2019 has seen more fish kill incidents than the same period in each of the last 5 years. Mark also
highlighted the National Drought Monitoring Network that has been operated by the EA since 2017. This network of salmonid and river habitat monitoring sites aims to provide a long term data set that will allow a better understanding of the response of salmonids to low and droughts, outside the effects of abstraction and flow regulation.
The effect of freshet releases on the spawning migration of Brown Trout
Katie Burnham comments, ‘Over the last two years I have worked on a variety of fisheries projects as a hydroecologist within the hydroecology and catchment management team in the Saltaire office. Attending the IFM 9th Specialist Conference on Fish, Flows and Climate Resilience was a great opportunity for me to discover some of the research and project work that peers within my specialism are involved with.’
Jonathan Bolland discussed the effect of freshet releases on the spawning migration of Brown Trout. Reservoirs can have significant impacts on the natural flow regime within a catchment. Jonathan’s research wanted to understand the impacts of freshet releases (periods of prolonged higher flow) on Brown Trout migration. Jonathan developed a method to distinguish between ‘home range’ movements and those which could be considered as migratory for spawning. A series of freshet flows from two different reservoir sites were released and the movement of individual tagged fish was monitored. Ultimately the study concluded that there was no change in the behaviour of the local Brown Trout populations during the releases, and no increases in what might be considered spawning migration. Jonathan suggested that the population at the sites used have all the habitat they need locally and therefore, don’t need to migrate, so at a different site you might get completely different results