Solent and South Downs: Fish Monitoring Report 2016 We are the Environment Agency. We protect and improve the environment. Acting to reduce the impacts of a changing climate on people and wildlife is at the heart of everything we do. We reduce the risks to people, properties and businesses from flooding and coastal erosion. We protect and improve the quality of water, making sure there is enough for people, businesses, agriculture and the environment. Our work helps to ensure people can enjoy the water environment through angling and navigation. We look after land quality, promote sustainable land management and help protect and enhance wildlife habitats. And we work closely with businesses to help them comply with environmental regulations. We can’t do this alone. We work with government, local councils, businesses, civil society groups and communities to make our environment a better place for people and wildlife. Authors: Georgina Busst & Dom Longley Published by: Environment Agency Further copies of this report are available Horizon House, Deanery Road, from our publications catalogue: Bristol BS1 5AH www.gov.uk/government/publications Email: [email protected] or our National Customer Contact Centre: www.gov.uk/environment-agency T: 03708 506506 Email: [email protected]. © Environment Agency 2017 All rights reserved. This document may be reproduced with prior permission of the Environment Agency. 2 of 78 Foreword Welcome to the 2016 annual fish report for Solent and South Downs. This report covers all of the fisheries surveys carried out by the Environment Agency in Hampshire and East and West Sussex in 2016. This is the tenth annual report we have produced. Our fisheries monitoring programme mainly focussed on spatial monitoring for salmon parr on the River Test in 2016. This work is scheduled every 6 years so we can now directly compare the data with that collected in 2010. The spatial monitoring provides information on how the distribution of salmon parr is changing over time, from 23 surveys that cover a large proportion of the Test. This is complemented by the parr temporal monitoring programme, which occurs biennially, and reveals changes in parr abundance at 6 sites. Together the spatial and temporal monitoring provide us with a fuller picture, allowing us to gain a greater understanding of the Test's salmon population and its variability over time. We also carried out Principal Coarse Fishery (PCF) surveys on several rivers in East and West Sussex, in locations where coarse angling takes place. As well as these we surveyed various waters for the Water Framework Directive and carried out our annual Transitional and Coastal Waters (TraC) surveys in Southampton Water and the River Adur estuary. We now report all our Principal Coarse Fishery surveys in a nationally consistent way, so that anglers, fishing clubs, landowners and others can see the publication ahead of this annual report. Consequently, the PCF survey results are freely available as separate reports. However, as this is the first year of this new style of reporting, we've included the information from the PCF reports for convenience. Weather and climate have a large influence on our fish populations and 2016 was generally warmer than usual. The average temperature over the summer months was the warmest since 2006, increasing from last year by over 1.5°C. Degree days over 12°C (a figure used to demonstrate favourable growth conditions for coarse fish) were the second highest recorded, a stark contrast to 2015 where it was the lowest figure since 1999. Winter was also warm, being the warmest since 2007. 3 of 78 Executive Summary In 2016 we carried out a total of 77 fish surveys throughout the Solent and South Downs area, which included 26 on the River Test and 12 autumn estuarine surveys. • The salmon parr surveys on the River Test revealed that 59% fewer parr were recorded in 2016 compared to the same sites surveyed in 2010. There were 7 sites where we caught no salmon parr in 2016 where we'd previously found them. Conversely, 2 other sites yielded more parr in 2016. Low salmon parr abundance in general was noted across the UK and also in France in 2016. This was attributed to a record high average temperature in December 2015, which probably had a negative impact on spawning and egg development. • Based on data from our salmon counters, we estimate that the number of adult salmon migrating into the River Test was 1,454 and into the River Itchen was 361 between May and December 2016. These figures represent 91% and 45%, respectively, of each river's salmon management target. • Principal Coarse Fishery surveys were carried out on the Pevensey Levels, the Sussex Ouse and the Western Rother. This year, the Environment Agency has started producing individual reports for all PCF surveys, using a standard format - these are freely available upon request, but we've also included the information within this annual report. • 19 Water Framework Directive surveys were carried out across the area on the Pevensey Levels, the Sussex Ouse, and rivers Arun, Hamble and Test. These surveys provide us with the opportunity to assess some stretches of river that are rarely surveyed. The results were varied and are reported in detail in this report. • Estuarine Transitional and Coastal (TraC) surveys were carried out in the autumn of 2016 in both Southampton Water and the Adur estuary. We caught 26 species of fish in Southampton Water and 13 species in the Adur estuary. Autumn juvenile bass numbers were the highest ever recorded in Southampton Water, but bass numbers have slightly declined in the Adur estuary. Overall, the numbers of fish caught in both estuaries were higher than average for autumn, but species diversity was lower than usual. 4 of 78 Rivers of Solent and South Downs East: West: 5 of 78 Contents Foreword ....................................................................................................................................... 3 Executive Summary ...................................................................................................................... 4 Rivers of Solent and South Downs .............................................................................................. 5 Temperature and Rainfall ............................................................................................................. 7 Interpreting Results ...................................................................................................................... 9 Fish survey methods ................................................................................................................... 9 Electric Fishing .................................................................................................................................................... 9 Estuarine Transitional and Coastal (TraC) Surveys ............................................................................................. 10 Fish Counters.................................................................................................................................................... 10 Fish survey results .................................................................................................................... 10 Water Framework Directive surveys .......................................................................................... 10 1. East Sussex ............................................................................................................................. 11 1.1. Pevensey Levels ................................................................................................................ 11 1.2. Sussex Ouse ...................................................................................................................... 21 2. West Sussex ............................................................................................................................ 23 2.1. Arun.................................................................................................................................... 23 2.2. Western Rother .................................................................................................................. 31 3. Hampshire ............................................................................................................................... 37 3.1. East Hampshire .................................................................................................................. 37 3.2. Test: Full Catchment Report ............................................................................................... 40 3.3. Test and Itchen Fish Counters ............................................................................................ 59 4.1. New Forest ......................................................................................................................... 64 5. Estuarine Fish Monitoring ...................................................................................................... 66 5.1. Southampton Water ............................................................................................................ 66 5.2. Adur Estuary ....................................................................................................................... 72 Looking Forward ......................................................................................................................... 77 Acknowledgements ...................................................................................................................