RV Lough Foyle LF/18/92
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RV Lough Foyle (74LG) |
| Cruise identifier | LF/18/92 |
| Cruise period | 1992-07-19 — 1992-07-31 |
| Status | Completed |
| Port of departure | Belfast, United Kingdom |
| Port of return | Belfast, United Kingdom |
| Purpose | Fisheries |
| Objectives | Pelagic fish acoustic survey
1. To estimate the biomass and age-compostion of the mixed Manx and Mourne stocks of herring in the northern Irish Sea. 2. To dertermine the distribution and biomass of sprat. 3. To further improve acoustic survey methods on Lough Foyle. |
| Chief scientist | Mike Armstrong (Department of Agriculture for Northern Ireland) |
| Cruise report |  (0.24 MB) |
| Ocean/sea areas | |
| General | Irish Sea and St. George's Channel |
| Specific | North Irish Sea |
| Track charts | (0.04 MB) |
| Measurements | |
| Biology and fisheries | |
| Zooplankton | Quantity: number of measurements = 2 Description: Near the Targets on tow 23 adult and young herring were caught. On tow 24 a catch of sprats and jellyfish. The transducers were successfully calibrated. |
| Pelagic fish | Quantity: number of measurements = 4 Description: 4 trawl samples tows 1-4 were taken during the day. |
| Pelagic fish | Quantity: number of measurements = 1 Description: Tow 25 was to fish a mixture of herring and sprat. |
| Pelagic fish | Quantity: number of measurements = 2 Description: Near the Targets on tow 23 adult and young herring were caught. On tow 24 a catch of sprats and jellyfish. The transducers were successfully calibrated. |
| Pelagic fish | Quantity: number of measurements = 4 Description: Tows 19-22 were completed mainly containing sprats and herring. Tow 22 was unsucessful as the target was probably plankton. |
| Pelagic fish | Quantity: number of measurements = 4 Description: Tows 15-17 were aimed at catching adult herring. Tow 16 was unsuccessful. Tow 18 was to catch sprats and young herring. |
| Pelagic fish | Quantity: number of measurements = 1 Description: Tow 12 was taken, the haul being sprats again. The echosounder was also calibrated. |
| Pelagic fish | Quantity: number of measurements = 3 Description: Tows 9, 10 and 11 contained mainly spats again. |
| Pelagic fish | Quantity: number of measurements = 4 Description: Tows 5-8 were taken from Dundalk Bay to Lambay Island, trawl consisted mainly of sprats. |
| Demersal fish | Quantity: number of measurements = 1 Description: A grid of transect was surveyed between the Calf of Man and Douglas. Herring targets were found to have risen from the seabed after dark and were fairly abundant. |
| Demersal fish | Quantity: number of measurements = 2 Description: Near the Targets on tow 23 adult and young herring were caught. On tow 24 a catch of sprats and jellyfish. The transducers were successfully calibrated. |
| Demersal fish | Quantity: number of measurements = 4 Description: Tows 15-17 were aimed at catching adult herring. Tow 16 was unsuccessful. Tow 18 was to catch sprats and young herring. |
| Demersal fish | Quantity: number of measurements = 3 Description: They followed transect 26, deviating to investigate the ''herring peaks'' before finally reaching transect 30. |
| Demersal fish | Quantity: number of measurements = 4 Description: Tows 19-22 were completed mainly containing sprats and herring. Tow 22 was unsucessful as the target was probably plankton. |
| Demersal fish | Quantity: number of measurements = 1 Description: Tow 25 was to fish a mixture of herring and sprat. |
| Demersal fish | Quantity: number of measurements = 3 Description: Tows 9, 10 and 11 contained mainly spats again. |
| Demersal fish | Quantity: number of measurements = 4 Description: Tows 5-8 were taken from Dundalk Bay to Lambay Island, trawl consisted mainly of sprats. |
| Demersal fish | Quantity: number of measurements = 1 Description: Transects were surveyed and it was noted that concentrations of herring were found at the Targets. |
| Demersal fish | Quantity: number of measurements = 4 Description: 4 trawl samples tows 1-4 were taken during the day. |
| Acoustic reflection on marine organisms. | Quantity: activity duration in days = 10 Description: Acoustic surveys. 25 midwater trawls also completed |
