EXCLUSIVE
WE REVEAL THE SCIENCE ON HOW TO CATCH MORE ESTUARY FLOUNDER
Retired research scientist Dr Roger Munro explains the relationship between harbour ragworm and flounders, using data collected on flounder catches from the Loughor Estuary to help you catch more and bigger flounder this autumn
Although lugworm, king ragworm and white ragworm are regarded as good baits when targeting flounder, there is little doubt that in an estuary environment, harbour ragworm, or ‘maddies’, are widely considered the ‘steak and chips’ of the flounder’s diet. One hundred and sixty eight all-round sea anglers across South Wales were asked to consider the following question: “Forget the age-old saying “lugworm in winter and ragworm in summer” – if you had to pick just one species of worm to use exclusively for the rest of your fishing career, which one would you choose?” Their responses were as follows: 10 per cent chose harbour ragworm; 12 per cent chose lugworm and 78 per cent chose king ragworm. Shore and boat anglers in different regions of the UK may or may not agree with these responses because different types of worm species may be more effective in their respective areas and types of venues.
The data, shown in the box below, suggests that to win a flounder competition for the heaviest bag, we should use harbour rag as bait but lugworm will probably win us the prize for the heaviest fish. Why then is harbour rag so effective at catching flounder in the relatively sheltered tidal pills (creeks) in the middle regions of an estuary? This is because in most estuaries the greatest population of harbour rag normally occurs in the middle regions, with their numbers decreasing both towards the upper end and towards the mouth of the estuary.
Sandbanks in the entrances of the estuaries are particularly mobile making it difficult for worm beds to become established. Furthermore, the greatest number of harbour rag are found in the stretch of the estuary with the greatest variation in salt concentration: that is the middle region, and beds of harbour rag are normally established where the tidal strength is very weak and where the exposure to waves is extremely sheltered.
