In order to improve the habitat of the Rivers Ribble and Hodder in the north west of England it is necessary to assess existing fish stocks. 

To assist the Ribble Fisheries Association a test census of stock has been made on the rivers Hodder and Ribble. The fish have been taken by electro fishing techniques. The following fish were collected over six days in September 1965: dace, chub, grayling, eel, salmon and trout. This short report summarises the findings of the survey

Stewart, L.

English

Aquatic Commons


JUDICIOUS FISHERY MANAGEMENT CAN BE LIKENED TO A TOOL,, THE 
SOLE PURPOSE OF WHICH IS TO PROVIDE BETTER ENVIRONMENTAL CONDITIONS 
FOR A DESIRED SPECIES OF FISH, BUT IN SAYING THIS NO HARD AND FAST 
RULES CAN BE LAID DOWN FOR IMPROVING ANY FISHERY. THE ULTIMATE 
OBJECTIVE IN FISHERY MANAGEMENT PRACTICE IS THE PRODUCTION OF 
BETTER FISHING AND MAINTENANCE OF STOCK, 
IN THE I930'S FISHERY WORKERS IN AMERICA BEGAN TO REALISE 
AS MORE AND MORE EVIDENCE ACCUMULATED FROM THEIR RESEARCHES THAT 
THE ARTIFICIAL PROPAGATION AND RE-STOCKJNG OF RIVERS WITH VARIOUS 
TYPES OF FISH WAS NOT A MIRACLE CURE FOR DECLINING FISHERIES. 
IN THE LANCASHIRE RIVER AUTHORITY AREA IT CAN BE SAID THAT THE 
FINDINGS IN AMERICA ARE SOMEWHAT CONFIRMED BY THE WORK DONE HERE. 
WHERE WATERS HAVE TO PROVIDE FISHING FOR THE EVER INCREASING 
NUMBERS OF ANGLERS, IT IS ESSENTIAL FOR THEM TO ADOPT A REALISTIC 
POLICY OF ATTEMPTING TO HELP NATURE, FOR WITH A REASONABLE DEGREE 
OF FREEDOM FROM INTERFERENCE GY ANGLERS, BIOLOGISTS ARE IN 
GENERAL ACCORD THAT HABITAT IMPROVEMENT, JUDICIOUSLY PLANNED AND 
CARRIED OUT, CAN IMPROVE FISHING BUT, AS A GENERAL STATEMENT NO 
SET CONDITIONS CAN BE PROPOUNDED FOR ANY STREAM IMPROVEMENT SCHEME. 
THE DANGER OF APPLYING THE SAME TECHNIQUES TO ALL BODIES OF WATER 
IS FRAUGHT WITH DANGER. CONDITIONS VARY FROM ONE STREAM TO 
ANOTHER AND ANY IMPROVEMENT OBTAINED IN ONE PARTICULAR RIVER MAY 
NOT GIVE THE DESIRED RESULT IN ANOTHER. 
VARIOUS WORKS CAN, HOWEVER, BE CARRIED OUT IN AN ATTEMPT TO 
IMPROVE AN ENVIRONMENT AND THE FIRST INVESTIGATION SHOULD CENTRE 
UPON DIVIDING THE FISH INTO SIZE GROUPS, RATIOS AND SPECIES PRESENT. 
WHEN THIS IS KNOWN THEN SHOULD COME A DECISION AS TO WHAT SPECIE 
IS TO BE PREDOMINANT AND WHAT WORKS ARE NECESSARY TO ENSURE THIS 
OBJECTIVE. IT IS KNOWN THAT FOR TROUT TO THRIVE A GOOD STEADY 
FLOW OF CLEAN WATER IS NECESSARY AND THAT THERE SHOULD BE PLENTY 
OF RIFFLED AREAS„ SOME OF THESE WILL SERVE AS (A) SPAWNING 
GROUNDS, ( B ) SOURCES OF FOOD, AND (c) NURSERY GROUNDS FOR THE 
YOUNG THAT ARE PRODUCED, ALTHOUGH MANY LARGE TROUT FEED IN THE 
SOMEWHAT DEEPER RIFFLED AREAS, AND MOST FISHERMEN KNOW THAT 
LARGER FISH WILL LIE IN POOLS, THERE SHOULD BE APPROXIMATELY AS 
MANY POOLS IN A RIVER AS THERE ARE RIFFLED AREAS. IF A 
PRELIMINARY SURVEY SHOWS THAT A STREAM UNDER SCRUTINY IS LACKING 
IN POOL AVAILABILITY, HAVING REGARD TO THE RATIO OF RIFFLED AREAS, 
THEN THE CONSTRUCTION OF REMEDIAL WORKS THAT WILL PRODUCE A 
BALANCE OF ONE OR OTHER OF THE TWO ABOVE-MENTIONED FACTORS MAY 
BE NECESSARY. 
A PROBLEM THAT USUALLY ARISES IN THE DETERMINATION OF ONE 
OR OTHER OF THE ABOVE FACTORS IS THE CARE THAT MUST BE GIVEN TO 
THE LOCATION ADOPTED FOR ANY WORKS IN ANY RIVER. UNLESS CARE 
IS EXERCISED IT IS LIKELY THAT THE WORKS, AS A RESULT OF EROSION 
AND SILTATION, MAY RENDER SOME OF THEM QUITE VALUELESS, ONE 
OF THE MOST UNFORTUNATE FEATURES OF HABJTAT IMPROVEMENT HAS BEEN 
THE ALMOST COMPLETE LACK OF QUANTIT1VE EVIDENCE UPON WHICH TO 
BASE CONCLUSIONS AS TO WHAT THE ULTIMATE RESULT OF ANY REMEDIAL 
WORK IS LIKELY TO BE, IN SHORT, HOW DO WE KNOW WHETHER A 
HABITAT WILL BE IMPROVED OR NOT. IT IS UNFORTUNATE, AT THE 
PRESENT, THAT LITTLE INFORMATION AS TO THE NUMBERS OF F[SH IN 
THE RIVERS HODDER AND RIBBLE AND THEIR TYPES, IS AVAILABLE 
UPON WHICH TO BASE SOUND CONCLUSIONS, THE INFORMATION 
GIVEN BY ANGLERS AS TO THE FISH CAUGHT AND THEIR TYPES |S FAR 
FROM BEING ACCURATE OR INDEED TRUTHFUL. 
R E P 0 R T 
RIVERS RIBBLE AND HODDER- HABITAT IMPROVEMENT 
MANY PERSONS ARE PRONE TO CONSIDER THAT CHECK WEIRS, DAMS, 
DEFLECTORS AND OTHER STREAM WORKS ARE ESSENTIAL FOR IMPROVING 
FISHING. THE BROAD DEFINITION OF HABITAT IMPROVEMENT IS SURELY 
TO PROVIDE A BETTER ENVIRONMENT FOR THAT SPECIE FISH THAT ANGLERS 
DESIRE, AND THIS ENCOMPASSES MANY DIFFERENT TYPES OF ACTION AND 
ANY ACTION IN THE RIVERS HODDER AND RLBBLE CAN ONLY BE DEALT WITH 
ON A LONG-TERM BASIS . AS BEFORE MENTIONED. THE FIRST STEP SHOULD 
BE AN ESTIMATION OF THE FISH STOCKS IN THE RIVERS, THEN CAN IT 
BE DECIDED WHAT STEPS SHOULD BE TAKEN TO REDUCE THE NUMBERS OF 
FISH PREDATING ON OTHER FISH OR ON THE FOOD AVAILABILITY IN THE 
RIVER, IN THE ELIMINATION OF ANY COMPETITORS FROM ANY WATER 
A DECISION MUST BE MADE AS TO WHICH TYPE OF FISH IS FAVOURED 
ABOVE THE OTHERS, WHEN THIS IS DONE RIVER WORKS COULD BE 
ARRANGED AND ATTEMPTS MADE TO IMPROVE THE FEED IN THE RIVER,, 
TO ASSIST THE RLBBLE FISHERIES ASSOCIATION A TEST CENSUS 
OF STOCK HAS BEEN MADE ON THE RIVERS HODDER AND RLBBLE. THE 
FISH HAVE BEEN TAKEN BY ELECTRO FISHING TECHNIQUES AND THE 
OPERATIONS WERE CARRIED OUT FROM DUNMOW SYKE TO DUNSOP BRIDGE, 
A DISTANCE OF APPROXIMATELY 4.5 MILES. THE FOLLOWING FISH WERE 
COLLECTED OVER SIX DAYS FROM 7TH TO 24-TH SEPTEMBER, 1965 
THE WEIGHTS OF THE FISH VARIED BETWEEN 3.5 LBS. AND 4 OZS. 
ANALYSING THE TOTAL NUMBERS OF FISH (10,078) INTO A LENGTH OF 
RIVER OF APPROXIMATELY 7,400 YDS. A POPULATION DENSITY OCCURS 
OF 1.6 FISH PER YARD WIDTH OF RIVER. 
THESE ACTUAL FIGURES DO NOT TAKE INTO ACCOUNT THE ESCAPE-
MENT OF FiSH FROM THE ELECTRO FISHING GEAR, ALTHOUGH IT IS 
LIKELY THAT 80% OF THE TOTAL RIVER STOCK WAS RECOVERED, THE 
FjSH POPULATION IN THE REACH UNDER REVIEW IS LIKELY TO BE THAT 
WHICH THE RIVER WOULD SUPPORT. INVESTIGATIONS HAVE BEEN 
CARRIED OUT INTO POPULATION DENSITIES FOR SALMON P A R R / S M O L T S 
(TWO YEARS OLD FISH) AND IT HAS BEEN FOUND THAT A POPULATION 
DENSITY PER 100 YDS. OF STREAM TWO YARDS WIDE SUPPORTS ONE 
FISH PER FOUR YARDS OF SURFACE AREA, PREDATION BEING NON-EXISTANT. 
THIS SEEMS TO INDICATE THAT THE AVAILABILITY OF FOOD IN THE 
UPPER REACHES OF THE HODDER UNDER EXAMINATION WOULD BE SUCH AS 
TO SUPPORT A POPULATION OF PROBABLY TWO FISH PER YARD OF RIVER 
WIDTH. THE WEIGHT OF FISH SO SUPPORTED MIGHT BE IN THE REGION 
• .:i •*- - G . I \ : . . .• .- i i _ .. • 
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OF 3/4 LB, ALTHOUGH THIS IS AN EMPIRICAL ASSESSMENT. IT IS 
NOW SUGGESTED THAT THE RlBBLE FISHERIES ASSOCIATION AND ITS 
AFFILIATED MEMBERS SHOULD DECIDE WHAT FISH COULD BE REMOVED, 
AT THE SAME TIME AS A MAJOR SURVEY IS BEING CONDUCTED THROUGH-
OUT THE WHOLE OF THE RIVER, SUCH A SURVEY WOULD NECESSITATE 
TAKING SAMPLES OF FISH OF ALL TYPES FOR SCALE READING TO 
DETERMINE THEIR GROWTH RATES AND THE STOMACH CONTENTS. AFTER 
TWO YEARS INTENSIVE WORK FACTUAL INFORMATION SHOULD THEN BE 
AVAILABLE TO ENABLE AM ACCURATE ASSESSMENT OF (A) THE STOCKS 
OF FISH PRESENT, (B) WHAT THE RIVER CAN REASONABLY SUPPORT, 
(c) THE AMOUNT OF FOOD THAT IS CONSUMED, AND ( D ) THE DEGREE 
OF COMPETITION FOR THE FOOD THAT IS AVAILABLE. 
FROM THE BIOLOGICAL SURVEY CARRIED OUT ON THE RIVER 
HODDER TWO YEARS AGO, THE REACH FROM DUMMOW SYKE DOWN TO 
DUNSOP BRIDGE IS NOT A HIGH ZONE OF FOOD POTENTIAL, BUT AS 
MORE INFORMATION COMES TO HAND IT MAY WELL BE THAT THIS AND 
OTHER ZONES OF RIVER COULD WITH ADVANTAGE HAVE RIVER WORKS 
(OF A NOMINAL NATURE) INSTALLED., ONCE A DECISION HAS BEEN 
REACHED REGARDING THE REMOVAL OF UNWANTED SPECIES, I WOULD 
RECOMMEND THAT SURVEYS BE CARRIED OUT WIDESPREAD THROUGHOUT 
THE RIVER SYSTEMS, THAT SAMPLES OF FISH OF ALL SIZES AND 
SPECIES BE TAKEN, THAT THEIR SCALES BE READ FOR GROWTH 
PATTERN, THAT STOMACH CONTENTS BE ANALYSED, AND DURING THIS 
WORK SOME OF THW UNWANTED SPECIES SHOULD BE REMOVED ON 
A PERCENTAGE BASIS PENDING A COMPLETE REPORT UPON THE 
WHOLE BIOLOGICAL FACTORS AS APPLICABLE TO THE RIVER 
UNDER REVIEW. 
IN THE TIME THAT HAS BEEN AVAILABLE IT HAS NOT BEEN 
POSSIBLE TO GO DEEPLY INTO THE SCALE PATTERNS AND GROWTH RATES 
OR STOMACH CONTENTS OF THE FISH OBTAINED. IT IS FITTING TO 
REPORT THAT THERE IS AN IMBALANCE OF STOCK, THAT THE DACE ARE 
FAR TOO NUMEROUS AND AS A GENERAL STATEMENT SHOULD BE REMOVED 
FORTHWITH, RUTHLESSLY AND COMPLETELY. LIKEWISE THE CHUB 
SHOULD BE REMOVED AND ALSO A PERCENTAGE OF THE GRAYLING. SINCE 
THE WORK HAS BEEN CARRIED OUT IN THE DUNMOW SYKE AND DUNSOP 
BRIDGE STRETCH THE RIVER HAS BECOME RE-POPULATED AND A 
FURTHER ELECTRO FISHING EXERCISE WILL BE SET IN MOTION TO 
DETERMINE THE EXTENT OF THIS RE-POPULATION, AND THE SPECIES 
OF FISH AND NUMBERS INVOLVED. 
TO ASSIST IN THIS WORK THE RIVER AUTHORITY HAS GIVEN 
APPROVAL TO THE ACQUISITION OF ELECTRO FISHING GEAR SUITABLE 
FOR REMOVING FISH FROM LARGE RIVERS AND THIS SHOULD BE TO HAND 
EARLY IN JANUARY. 
WHEN THIS 5/6 KVA GENERATOR IS IN USE THE ASSOCIATION 
SHOULD BE UNDER NO ILLUSION WHATEVER THAT THIS ELECTRO 
FISHING EQUIPMENT WILL REMOVE ALL UNWANTED SPECIES. THERE 
BROWN 
WILL ALWAYS BE AN ESCAPEMENT, AND ALSO/TROUT STOCKS WILL BE 
HARMED, ALTHOUGH IT IS LIKELY THAT THE MORTALITY WILL NOT BE 
HIGHER THAN 3%, 
WITH THESE APPRECIATIONS BEFORE YOU IT IS HOPED THAT A 
POLICY FOR THE FUTURE WILL EVOLVE. ONE THAT WILL PREVENT 
OBJECTIONS FROM ANGLERS, ASSOCIATIONS, AND RIPARIAN OWNERS 
TO THE WORK BEING DONE. 
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Rivers Ribble and Hodder - habitat improvement

http://aquaticcommons.org/8078/1/128_Stewart.pdf

Rivers Ribble and Hodder - habitat improvement

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