Resources

FRV Clupea 0806C

Cruise summary report

Cruise Info. 
Ship name (ship code)FRV Clupea (74CU)
Cruise identifier0806C
Cruise period2006-06-15 — 2006-06-28
StatusCompleted
Port of departureFraserburgh, United Kingdom
Port of returnFraserburgh, United Kingdom
PurposeResearch
ObjectivesObjectives

1. To carry out an acoustic survey to determine an abundance estimate for sandeels in the in the water column. Three frequencies, 38, 120, and 200 kH will be used to aid species recognition. This acoustic survey will also produce abundance estimates for herring and sprats. Concentrations of fish will be sampled using the pelagic trawl. Species composition and length frequency distributions of fish caught will be determined. Sub samples will be weighed and their otoliths removed to establish length-weight relationships and age composition.

2. To carry out a demersal trawl survey to determine an abundance index for sandeels in the seabed sediment. This demersal trawl survey will also produce abundance indices for herring and sprats, the two other main "prey" species as well as the major piscivorous fish predators in the area, whiting, haddock and cod. At each trawl station the length frequency of all fish species caught will be determined. Sub-samples of sandeels, herring, sprats, cod, haddock, and whiting will be weighed to determine length-weight relationships. Otoliths will be taken to determine age composition. Sub-samples of the gadoid predators will be retained and frozen for subsequent dietary analysis.

3. Simultaneously with the demersal trawl survey, a hydrographic survey will be undertaken using a Seabird 19 CTD sampler fitted with fluorometer and transmissometer to determine spatial variation in water temperature, salinity fluoroescence and turbidity across the study area. Approximately 44 vertical dip stations will be sampled. These data are required to inform the analysis of the demersal trawl and acoustic survey data to derive an overall sandeel abundance estimate.

4. Simultaneously with the acoustic survey, a survey of seabirds at sea within the study area will be undertaken using standard census methods. Protection of local breeding seabirds was one of the principal motives underpinning the sandeel fishery closure.

5. Whilst c
Chief scientistSimon Greenstreet (Fisheries Research Services Aberdeen Marine Laboratory)
ProjectMFO7n
Coordinating bodyFRS
Cruise reportFRV Clupea 0806C cruise report 0806c.pdf (0.13 MB) 
Ocean/sea areas 
GeneralNorth Sea
Specificoff Firth of Forth
Measurements 
Physical oceanography 
CTD stationsQuantity: number of stations = 45
Description: Hydrographic sampling stations, work undertaken between 0400h and 1600 BST. A grid of hydrographic stations, utilising the demersal trawl stations along with additional stations, was sampled. At each station CTD deployed. The hydrogrpahic stations in the hydro transect were re-sampled to assess changes in hydrographic conditions over the course of the cruise. Water samples were collected at a hydro transect of stations for subsequent chlorophyll analysis to calibrate the flurometer.
Biology and fisheries 
BirdsQuantity: activity duration in days = 3
Description: Sea bird survey. Work conducted between 0400h and 1500 BST. Data were aggregated over the same 5 minute periods of acoustic integration to allow direct comparison of predator abundance and prey density.
Mammals and reptilesQuantity: number of observations = 8
Description: Grey seal sightings. The numbers, identity and locations of all marine mammals observed at sea recorded.
Demersal fishQuantity: number of stations = 19
Description: Demersal trawl stations, work undertaken between 0400h and 1600 BST. At each station A Jackson Rockhopper demersal trawl gear (BT158) with 10mm codend mesh was deployed. The total numbers at length of all species in the catch was determined. Samples of herring, sprats and sandeels were weighed to determine length-weight relationships and otoliths were collected to determine age at length keys. Samples of whiting and haddock were retained and frozen for dietary analysis at the laboratory
Acoustic reflection on marine organisms.Quantity: activity duration in days = 3
Description: Acoustic survey. Work conducted between 0400h and 1500 BST when sandeels were most likely to be active in the water column. Acoustic data integrated over 5 minute periods. RoxAnn data were routinely collected throughout the entire duration of the acoustic survey including additional track between transects and whilst steaming to and from anchorages.
Data held at BODC Get data
Series/Profiles 
53  CTD/STD cast
Transmittance and attenuance of the water column
Salinity of the water column
Temperature of the water column
Vertical spatial coordinates
Density of the water column
Electrical conductivity of the water column
Chlorophyll pigment concentrations in water bodies
Transmittance and attenuance of the water column
Salinity of the water column
Temperature of the water column
Vertical spatial coordinates
Density of the water column
Electrical conductivity of the water column
Chlorophyll pigment concentrations in water bodies

BODC idDate/TimeLocationDoc.
7227952006-06-20 07:45 56° 17' 23" N  1° 46' 38" W  View metadata report for BODC series reference number 722795
7228512006-06-20 12:55 56° 7' 35" N  2° 39' 46" W  View metadata report for BODC series reference number 722851
7232032006-06-25 10:08 56° 22' 34" N  2° 0' 34" W  View metadata report for BODC series reference number 723203
7232392006-06-25 12:45 56° 22' 19" N  2° 29' 47" W  View metadata report for BODC series reference number 723239
7233562006-06-26 13:15 56° 17' 27" N  2° 20' 7" W  View metadata report for BODC series reference number 723356
7229672006-06-23 06:28 56° 2' 30" N  1° 30' 0" W  View metadata report for BODC series reference number 722967
7230062006-06-23 10:45 56° 12' 28" N  1° 30' 1" W  View metadata report for BODC series reference number 723006
7231352006-06-24 12:20 56° 26' 57" N  1° 48' 46" W  View metadata report for BODC series reference number 723135
7231722006-06-25 07:17 56° 27' 39" N  2° 6' 46" W  View metadata report for BODC series reference number 723172
7232402006-06-25 13:20 56° 17' 26" N  2° 29' 57" W  View metadata report for BODC series reference number 723240
7232762006-06-26 05:36 56° 7' 30" N  2° 19' 58" W  View metadata report for BODC series reference number 723276
7228872006-06-22 09:05 56° 2' 26" N  2° 30' 3" W  View metadata report for BODC series reference number 722887
7229182006-06-22 11:30 56° 8' 13" N  2° 8' 34" W  View metadata report for BODC series reference number 722918
7229922006-06-23 10:00 56° 6' 44" N  1° 31' 28" W  View metadata report for BODC series reference number 722992
7230312006-06-23 12:51 56° 7' 27" N  1° 39' 58" W  View metadata report for BODC series reference number 723031
7230802006-06-24 08:06 56° 17' 34" N  1° 40' 5" W  View metadata report for BODC series reference number 723080
7227832006-06-20 06:45 56° 17' 32" N  1° 39' 59" W  View metadata report for BODC series reference number 722783
7228992006-06-22 09:30 56° 2' 22" N  2° 17' 46" W  View metadata report for BODC series reference number 722899
7229062006-06-22 10:00 56° 2' 27" N  2° 10' 11" W  View metadata report for BODC series reference number 722906
7229312006-06-22 12:05 56° 7' 21" N  2° 0' 0" W  View metadata report for BODC series reference number 722931
7230792006-06-24 07:36 56° 17' 48" N  1° 46' 39" W  View metadata report for BODC series reference number 723079
7231472006-06-25 03:45 56° 25' 5" N  2° 35' 59" W  View metadata report for BODC series reference number 723147
7228382006-06-20 11:30 56° 17' 21" N  2° 29' 58" W  View metadata report for BODC series reference number 722838
7228022006-06-20 09:05 56° 17' 26" N  1° 59' 57" W  View metadata report for BODC series reference number 722802
7229432006-06-22 13:35 56° 1' 57" N  2° 2' 10" W  View metadata report for BODC series reference number 722943
7230922006-06-24 09:29 56° 17' 3" N  1° 31' 13" W  View metadata report for BODC series reference number 723092
7232882006-06-26 06:35 56° 12' 34" N  2° 10' 9" W  View metadata report for BODC series reference number 723288
7233322006-06-26 10:45 56° 17' 31" N  1° 59' 54" W  View metadata report for BODC series reference number 723332
7233202006-06-26 09:30 56° 12' 31" N  1° 40' 0" W  View metadata report for BODC series reference number 723320
7233442006-06-26 12:43 56° 17' 35" N  2° 13' 29" W  View metadata report for BODC series reference number 723344
7231962006-06-25 08:45 56° 22' 29" N  1° 49' 57" W  View metadata report for BODC series reference number 723196
7232152006-06-25 10:45 56° 22' 27" N  2° 10' 0" W  View metadata report for BODC series reference number 723215
7228142006-06-20 09:55 56° 17' 25" N  2° 9' 47" W  View metadata report for BODC series reference number 722814
7228632006-06-22 05:40 56° 7' 27" N  2° 39' 56" W  View metadata report for BODC series reference number 722863
7229792006-06-23 07:50 56° 1' 48" N  1° 20' 39" W  View metadata report for BODC series reference number 722979
7230182006-06-23 12:20 56° 11' 1" N  1° 40' 24" W  View metadata report for BODC series reference number 723018
7230552006-06-24 05:41 56° 9' 5" N  1° 50' 50" W  View metadata report for BODC series reference number 723055
7231112006-06-24 10:22 56° 22' 28" N  1° 40' 0" W  View metadata report for BODC series reference number 723111
7231842006-06-25 07:45 56° 27' 29" N  2° 0' 19" W  View metadata report for BODC series reference number 723184
7232522006-06-25 13:56 56° 12' 33" N  2° 30' 9" W  View metadata report for BODC series reference number 723252
7232642006-06-26 04:58 56° 13' 7" N  2° 20' 32" W  View metadata report for BODC series reference number 723264
7233072006-06-26 08:09 56° 12' 27" N  1° 57' 13" W  View metadata report for BODC series reference number 723307
7228262006-06-20 10:42 56° 17' 25" N  2° 19' 52" W  View metadata report for BODC series reference number 722826
7228752006-06-22 07:15 56° 7' 17" N  2° 29' 59" W  View metadata report for BODC series reference number 722875
7229552006-06-23 05:40 56° 2' 16" N  1° 39' 24" W  View metadata report for BODC series reference number 722955
7229802006-06-23 08:30 56° 7' 31" N  1° 20' 1" W  View metadata report for BODC series reference number 722980
7230432006-06-23 13:44 56° 2' 29" N  1° 49' 58" W  View metadata report for BODC series reference number 723043
7230672006-06-24 06:08 56° 12' 29" N  1° 49' 58" W  View metadata report for BODC series reference number 723067
7231232006-06-24 11:00 56° 27' 22" N  1° 40' 7" W  View metadata report for BODC series reference number 723123
7231592006-06-25 05:04 56° 27' 37" N  2° 28' 23" W  View metadata report for BODC series reference number 723159
7231602006-06-25 05:35 56° 27' 30" N  2° 19' 59" W  View metadata report for BODC series reference number 723160
7232272006-06-25 12:22 56° 21' 25" N  2° 23' 53" W  View metadata report for BODC series reference number 723227
7233192006-06-26 08:40 56° 12' 32" N  1° 50' 8" W  View metadata report for BODC series reference number 723319