Cumbrian Derwent Avian Predation Survey
Donation protected
FOREWORD BY GEORGE WOODWARD - retired River Wye Ghillie / EA Special Enforcement Officer
I first met Chris Taylor some thirty years ago when we were both employed as Water Bailiffs for the then National Rivers Authority on a major poaching incident in North Wales , this deployment involved continuous surveillance in appalling weather conditions with long hours of duty. It was during this period that I found Chris had a total dedication to the job in hand and a commitment to '' get the job done. ''
I feel sure that this dedication will show great results in any survey work concerning the predation of fish stocks by Cormorants and Goosanders. It is of great credit to him that he is attempting to take this work in hand and should be given any help and encouragement possible. I for one knowing his feelings for our aquatic environment give him my full endorsement in what will not be an easy or simple task.
George Woodward
ABOUT ME
My name is Chris Taylor and I live in Cockermouth . I developed a love for freshwater environments as a child and have been involved in protecting river catchments going back as far as 1989 , mainly whilst in the employment of the National Rivers Authority / Environment Agency where I acquired years of fishery survey and fishery enforcement experience as well as attaining the Certificate and Diploma of The Institute of Fisheries Management.
THE PROBLEM
Sadly , like many other UK rivers , the River Derwent's wild salmon stocks are now considered At Risk / Severely At Risk by the Environment Agency. Numbers of adult salmon returning to the river from their sea feeding grounds in order to spawn have declined year on year to alarmingly low numbers which could soon not be enough to sustain the river's population and preserve this iconic King of Fish for present and future generations. It is for this reason that all salmon fisherman on the River adhere to a self implemented 100 % catch and release policy in the hope that scientific research can identify the causes of the decline so that measures can be taken to facilitate the re-establishment of the salmon population to numbers that are sustainable.
Many theories as to the reasons for the decline in returning adult salmon have been put forward , however recent scientific work involving the tagging and subsequent monitoring of the annual seaward migration of juvenile salmon smolts ( known as the smolt run which usually occurs around late March to early June ) on a number of rivers in the UK have shown that 70% + of the smolts tagged in some cases do not even make it to the estuary !
The obvious next step is to find out WHY and then to address the cause by implementing SCIENTIFICALY BASED RIVER CATCHMENT MANAGEMENT MEASURES to protect the SMOLTS on their seaward migration.
WHY MONITOR AVIAN PREDATORS
Because despite the River Derwent being categorized as a SPECIAL AREA OF CONSERVATION due in part to it's once healthy and sustainable salmon population , the effects of avian predation have not been scientifically surveyed.
The two avian predators suspected by those concerned with salmon conservation of contributing to the collapse of wild Atlantic salmon stocks in the UK are the EUROPEAN CORMORANT and the GOOSANDER. Neither bird originates from the UK whilst Wild Atlantic Salmon have been swimming in our rivers for over 60 million years ( the Goosander was first recorded as breeding in Scotland in 1871 and the first colonies of breeding European Cormorants ( P. carbo sinensis ) were recorded in South east England in 1981 ). The European Cormorant is a different sub species to our native coastal Cormorant ( P. carbo carbo ) which is not considered to be a threat to our wild salmon stocks.
Both species have increased significantly in numbers in the UK, after being given PROTECTIVE STATUS by The Countryside and Wildlife Act 1981 and the EU Birds Directive. Each bird is a formidable hunter of fish and the Goosander is especially adept at catching fish up to 20 cm in slow to fast flowing , unobstructed rivers like the River Derwent. Both can also hunt their prey at night.
The Diet of Goosanders in the UK has been shown to form up to 93 % by mass of salmon for ducklings and 92% for adults in the summer and 70% by mass in the winter. One Goosander / Cormorant can consume 25 + SALMON SMOLTS a day ( based on an average individual smolt weight of 20g ).
Below is a conservative estimate of the potential cost of avian predation on WILD SALMON SMOLTS if one Goosander / Cormorant was consuming 8 smolts a day.
8 smolts a day equals the loss of 56 smolts a week
A 10-12 week smolt run would cause the loss of 560 - 672 smolts
The above would deny a river of between 17 - 20 returning Wild Atlantic Salmon based on a 3 % return rate. ( present return rates of adult salmon are estimated to be around 2.5 - 5 percent ).
For a number of years , volunteers have carried out a count of Goosanders and Cormorants present on the Derwent system each March. The latest available Avian Predation Bird count on part of the River Derwent was 188 Cormorants and 169 Goosanders but numbers are estimated to be twice as high in the overall catchment.
If we just address the Goosander count using the above conservative calculations we find that 169 Goosanders could be accountable for the seasonal loss of between 2873 - 3380 RETURNING WILD ATLANTIC SALMON.
At present , due to these NON INDIGINOUS PREDATORS being given protective status by the EU and the UK GOVERNMENT , the number of Goosanders and Cormorants that fisheries can cull only allows for a small percentage of the numbers of birds that inhabit a fishery to be reduced despite many now agreeing that culls should be based on numbers determined by science and not politics in order to prevent the extinction of our wild salmon stocks.
In addition other species of fish present in the River Derwent Catchment such as lampreys and eels are also vulnerable to avian predation . Numbers of both species are in decline , especially the common eel which is nearing extinction in the UK , and yet they are given little protection from uncontrolled numbers of invasive avian predators.
THE AVIAN PREDATION SURVEY 2022
The aim of this Survey is to complement and expand upon existing studies to provide more scientific data on the number of Cormorants and Goosanders present in the Cumbrian Derwent system throughout the year. It will provide more data on the bird's diet and analyse the possible effect of this on Salmonid numbers.
Here on the Cumbrian Derwent , we are supporting a 3 year research project involving the tracking of salmon smolts as they travel down the river and out to sea. This is being carried out by Glasgow University and preliminary results from the first year of study indicate that only 9% of smolts tagged in St Johns Beck safely reached the estuary at Workington !
The Avian Predation Survey 2022 will not however be confined just to the smolt run as avian predation will be monitored in the River Derwent's Catchment for a full twelve month period. This is because the loss of pre smolt salmon , particularly Salmon parr , could also be having a significant effect upon returning adult numbers. Limited data on bird populations is available from WEB's surveys carried out by members of the British Ornithological Society , but presently we have no comprehensive data on population trends over a consecutive twelve month period. Data will be gained using a number of methods including high tech photographic techniques as well as manual surveys by volunteers. Natural England has carried out some limited research on the diet of Goosanders and Cormorants on the Derwent system by the genetic analysis of Goosander and Cormorant faeces , the otolith analysis analysis of Cormorant pellets and the analysis of gut contents. The Avian Predation Survey 2022 will expand upon this to provide additional information.
This Survey will be A MAJOR GAME CHANGER not just here on the River Derwent but nationally too , if it provides proof that AVIAN PREDATION is having a damaging effect upon VULNERABLE WILD SALMON POPULATIONS , as this will help to enable those concerned with the protection of NATIVE WILD SALMON to present an overriding case for a change in the law to allow for the pragmatic reduction in numbers of NON INDIDGENOUS AVIAN PREDATORS to levels that do not threaten the very existence of THE KING OF FISH in our waters.
It goes without saying that this survey will need the cooperation of the local community to succeed and in that light I would be grateful to anyone interested in assisting in its execution to contact me as soon as they are able as a significant amount of groundwork needs to be undertaken prior to the 2022 Survey.
All my time in executing this survey including the analysis of otolith samples I give freely, the funds that are needed are solely for equipment , basic running costs such as fuel and insurances and for the cost of the DNA analysis of faeces samples from private Laboratories. Any unused funds will be donated to the Atlantic Salmon Trust.
PLEASE HELP TO SAVE OUR WILD SALMON BY SUPPORTING THIS SURVEY AND DONATING NOW
I first met Chris Taylor some thirty years ago when we were both employed as Water Bailiffs for the then National Rivers Authority on a major poaching incident in North Wales , this deployment involved continuous surveillance in appalling weather conditions with long hours of duty. It was during this period that I found Chris had a total dedication to the job in hand and a commitment to '' get the job done. ''
I feel sure that this dedication will show great results in any survey work concerning the predation of fish stocks by Cormorants and Goosanders. It is of great credit to him that he is attempting to take this work in hand and should be given any help and encouragement possible. I for one knowing his feelings for our aquatic environment give him my full endorsement in what will not be an easy or simple task.
George Woodward
ABOUT ME
My name is Chris Taylor and I live in Cockermouth . I developed a love for freshwater environments as a child and have been involved in protecting river catchments going back as far as 1989 , mainly whilst in the employment of the National Rivers Authority / Environment Agency where I acquired years of fishery survey and fishery enforcement experience as well as attaining the Certificate and Diploma of The Institute of Fisheries Management.
THE PROBLEM
Sadly , like many other UK rivers , the River Derwent's wild salmon stocks are now considered At Risk / Severely At Risk by the Environment Agency. Numbers of adult salmon returning to the river from their sea feeding grounds in order to spawn have declined year on year to alarmingly low numbers which could soon not be enough to sustain the river's population and preserve this iconic King of Fish for present and future generations. It is for this reason that all salmon fisherman on the River adhere to a self implemented 100 % catch and release policy in the hope that scientific research can identify the causes of the decline so that measures can be taken to facilitate the re-establishment of the salmon population to numbers that are sustainable.
Many theories as to the reasons for the decline in returning adult salmon have been put forward , however recent scientific work involving the tagging and subsequent monitoring of the annual seaward migration of juvenile salmon smolts ( known as the smolt run which usually occurs around late March to early June ) on a number of rivers in the UK have shown that 70% + of the smolts tagged in some cases do not even make it to the estuary !
The obvious next step is to find out WHY and then to address the cause by implementing SCIENTIFICALY BASED RIVER CATCHMENT MANAGEMENT MEASURES to protect the SMOLTS on their seaward migration.
WHY MONITOR AVIAN PREDATORS
Because despite the River Derwent being categorized as a SPECIAL AREA OF CONSERVATION due in part to it's once healthy and sustainable salmon population , the effects of avian predation have not been scientifically surveyed.
The two avian predators suspected by those concerned with salmon conservation of contributing to the collapse of wild Atlantic salmon stocks in the UK are the EUROPEAN CORMORANT and the GOOSANDER. Neither bird originates from the UK whilst Wild Atlantic Salmon have been swimming in our rivers for over 60 million years ( the Goosander was first recorded as breeding in Scotland in 1871 and the first colonies of breeding European Cormorants ( P. carbo sinensis ) were recorded in South east England in 1981 ). The European Cormorant is a different sub species to our native coastal Cormorant ( P. carbo carbo ) which is not considered to be a threat to our wild salmon stocks.
Both species have increased significantly in numbers in the UK, after being given PROTECTIVE STATUS by The Countryside and Wildlife Act 1981 and the EU Birds Directive. Each bird is a formidable hunter of fish and the Goosander is especially adept at catching fish up to 20 cm in slow to fast flowing , unobstructed rivers like the River Derwent. Both can also hunt their prey at night.
The Diet of Goosanders in the UK has been shown to form up to 93 % by mass of salmon for ducklings and 92% for adults in the summer and 70% by mass in the winter. One Goosander / Cormorant can consume 25 + SALMON SMOLTS a day ( based on an average individual smolt weight of 20g ).
Below is a conservative estimate of the potential cost of avian predation on WILD SALMON SMOLTS if one Goosander / Cormorant was consuming 8 smolts a day.
8 smolts a day equals the loss of 56 smolts a week
A 10-12 week smolt run would cause the loss of 560 - 672 smolts
The above would deny a river of between 17 - 20 returning Wild Atlantic Salmon based on a 3 % return rate. ( present return rates of adult salmon are estimated to be around 2.5 - 5 percent ).
For a number of years , volunteers have carried out a count of Goosanders and Cormorants present on the Derwent system each March. The latest available Avian Predation Bird count on part of the River Derwent was 188 Cormorants and 169 Goosanders but numbers are estimated to be twice as high in the overall catchment.
If we just address the Goosander count using the above conservative calculations we find that 169 Goosanders could be accountable for the seasonal loss of between 2873 - 3380 RETURNING WILD ATLANTIC SALMON.
At present , due to these NON INDIGINOUS PREDATORS being given protective status by the EU and the UK GOVERNMENT , the number of Goosanders and Cormorants that fisheries can cull only allows for a small percentage of the numbers of birds that inhabit a fishery to be reduced despite many now agreeing that culls should be based on numbers determined by science and not politics in order to prevent the extinction of our wild salmon stocks.
In addition other species of fish present in the River Derwent Catchment such as lampreys and eels are also vulnerable to avian predation . Numbers of both species are in decline , especially the common eel which is nearing extinction in the UK , and yet they are given little protection from uncontrolled numbers of invasive avian predators.
THE AVIAN PREDATION SURVEY 2022
The aim of this Survey is to complement and expand upon existing studies to provide more scientific data on the number of Cormorants and Goosanders present in the Cumbrian Derwent system throughout the year. It will provide more data on the bird's diet and analyse the possible effect of this on Salmonid numbers.
Here on the Cumbrian Derwent , we are supporting a 3 year research project involving the tracking of salmon smolts as they travel down the river and out to sea. This is being carried out by Glasgow University and preliminary results from the first year of study indicate that only 9% of smolts tagged in St Johns Beck safely reached the estuary at Workington !
The Avian Predation Survey 2022 will not however be confined just to the smolt run as avian predation will be monitored in the River Derwent's Catchment for a full twelve month period. This is because the loss of pre smolt salmon , particularly Salmon parr , could also be having a significant effect upon returning adult numbers. Limited data on bird populations is available from WEB's surveys carried out by members of the British Ornithological Society , but presently we have no comprehensive data on population trends over a consecutive twelve month period. Data will be gained using a number of methods including high tech photographic techniques as well as manual surveys by volunteers. Natural England has carried out some limited research on the diet of Goosanders and Cormorants on the Derwent system by the genetic analysis of Goosander and Cormorant faeces , the otolith analysis analysis of Cormorant pellets and the analysis of gut contents. The Avian Predation Survey 2022 will expand upon this to provide additional information.
This Survey will be A MAJOR GAME CHANGER not just here on the River Derwent but nationally too , if it provides proof that AVIAN PREDATION is having a damaging effect upon VULNERABLE WILD SALMON POPULATIONS , as this will help to enable those concerned with the protection of NATIVE WILD SALMON to present an overriding case for a change in the law to allow for the pragmatic reduction in numbers of NON INDIDGENOUS AVIAN PREDATORS to levels that do not threaten the very existence of THE KING OF FISH in our waters.
It goes without saying that this survey will need the cooperation of the local community to succeed and in that light I would be grateful to anyone interested in assisting in its execution to contact me as soon as they are able as a significant amount of groundwork needs to be undertaken prior to the 2022 Survey.
All my time in executing this survey including the analysis of otolith samples I give freely, the funds that are needed are solely for equipment , basic running costs such as fuel and insurances and for the cost of the DNA analysis of faeces samples from private Laboratories. Any unused funds will be donated to the Atlantic Salmon Trust.
PLEASE HELP TO SAVE OUR WILD SALMON BY SUPPORTING THIS SURVEY AND DONATING NOW
Organizer
Chris Taylor
Organizer
England
