Available online
Description
As the British herring fishery has declined, so has the plaice fishery increased. In 1976 two thirds of the plaice landed in the UK came ashore at Lowestoft. It is a very important port. Plaice fis...hing is also important to the Netherlands, Denmark, Belgium and Germany. In order to exploit the plaice fishery properly it is thus important to know as much as possible about the plaice populations that inhabit the North Sea. this programme describes how the plaice life cycle is exploited by fishermen and how the latest fisheries research is telling us more about the plaice, particularly how we think its migratory behaviour is organised. This latest knowledge is being obtained using a selection of highly sophisticated electronic techniques in addition to already well established techniques of population study such as fish tagging and monitoring catches.
As the British herring fishery has declined, so has the plaice fishery increased. In 1976 two thirds of the plaice landed in the UK came ashore at Lowestoft. It is a very important port. Plaice fis...hing is also important to the Netherlands, Denmark, Belgium and Germany. In order to exploit the plaice fishery properly it is thus important to know as much as possible about the plaice populations that inhabit the North Sea. this programme describes how the plaice life cycle is exploited by fishermen and how the latest fisheries research is telling us more about the plaice, particularly how we think its migratory behaviour is organised. This latest knowledge is being obtained using a selection of highly sophisticated electronic techniques in addition to already well established techniques of population study such as fish tagging and monitoring catches.
| Module code and title: | S334, Oceanography |
|---|---|
| Item code: | S334; 10 |
| First transmission date: | 29-06-1978 |
| Published: | 1978 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:00 |
| + Show more... | |
| Producer: | Roger Jones |
| Contributor: | Roy Harden-Jones |
| Publisher: | BBC Open University |
| Keyword(s): | Fish migration; Ground water seepage; Plaice; Sector scanning sonar; Selective tidal stream transport |
| Footage description: | Underwater film of plaice being caught in a trawl. Shots of catch at Lowestoft harbour. Roy Harden Jones introduces the programme. Jones picks up and examines a plaice pointing out some of its characteristics. He cuts open the head of the fish and explains a method for determining the age of the fish by examining its bony otolith. With the aid of an animated diagram, Jones discusses the migratory patterns of the plaice. Jones goes on, with the aid of an animated map to discuss how the migratory triangle of plaice is modified for their particular geographical area of the North Sea. Jones briefly lists the lines of evidence on which this migratory pattern for North Sea plaice is based. Jones holds up a tagged plaice as he talks. Jones, on board the research trawler 'Clione', explains how sector scanning sonar is used to track individual tagged fish during their migration. Shots of scanning equipment being launched and of the tracking screen. Film shots of plaice being tagged in preparation for sonar scanning. Commentary by Jones. Shots of the main sector scanner display showing the tagged plaice being tracked during its migration. Commentary by Jones. With the aid of an animated map, Jones discusses the track of the plaice as determined by sector scanning sonar. He goes on to examine a vertical scan which shows the depth of the fish at any time during its migration. An animated diagram helps to illustrate his points. Jones explains how these techniques led to the formulation of the selective tidal screen transport hypothesis. He points to a map of the North Sea as he talks. Jones discusses possible local factors which set off plaice migration and which tell the fish when it has arrived at its spawning grounds. He points to a map and diagrams as he talks. Jones discusses, particularly, the possibility that fresh water springs in the North Sea may act as markers for the plaice. Jones sums up the programme. |
| Master spool number: | 6HT/72639 |
| Production number: | 00525_1302 |
| Videofinder number: | 880 |
| Available to public: | no |
