FRV Mara 8/64
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | FRV Mara (74MR) |
| Cruise identifier | 8/64 |
| Cruise period | 1964-08-03 — 1964-08-06 |
| Status | Completed |
| Purpose | Research |
| Objectives | 1) North sea counterpart to visibility studies on synthetic fibre drift nets carried out in Malta during the month of May
2) 2 sighting stations were set up 3) 3 different methods of measuring the optical density of water were used to give comparable readings of the beam attenuation coefficient and the diffuse attenuation coefficient. 4) Plankton and water samples were taken to assess the the nature of the turbidity of the water and its possible effect on the realtive visibilty of different colours of net |
| Chief scientist | C C Hemmings (Department of Agriculture and Fisheries for Scotland Aberdeen Marine Laboratory), Colin J Chapman (Department of Agriculture and Fisheries for Scotland Aberdeen Marine Laboratory) |
| Cruise report |  (0.06 MB) |
| Ocean/sea areas | |
| General | North Sea |
| Specific | Cullen Bay |
| Measurements | |
| Biology and fisheries | |
| Gear research | Quantity: number of experiments = 1 Description: At Cullen Bay visibility studies on synthetic fibre driftnets were carried out. Two ranges, and inner and outer range, were set up for testing. They consisted of a buoyed wire frame. |
| Gear research | Quantity: number of experiments = 1 Description: Fibre 1- Melt-dye green 'Ulstron' In the day this net was visible, but seen the same as balck and brown. At night it was fairly visible in luminescence. |
| Gear research | Quantity: number of samples = 2 Description: Plankton and water samples were taken to assess the turbidity of the water and how it may affect the visibility of net colours. |
| Gear research | Quantity: number of experiments = 1 Description: Fibre 3- Orange dyed 'Ulstron' In the day this net was the least visible. At night it was fairly visible in luminescence. |
| Gear research | Quantity: number of experiments = 1 Description: Fibre 4- Tan dyed 'Ulstron' Day refernce not given. At night it was fairly visible in luminescence. |
| Gear research | Quantity: number of experiments = 1 Description: Fibre 2- Natural white 'Ulstron' In the day this net was the most visible. At night it was fairly visible in luminescence. |
