RV Cefas Endeavour 10/12
Cruise summary report
|Ship name (ship code)||RV Cefas Endeavour (74E9)|
|Cruise period||2012-07-02 — 2012-07-16|
|Port of departure||Lowestoft, United Kingdom|
|Port of return||Lowestoft, United Kingdom|
1. To gather full coverage multibeam data between the two rock outcrops within Haig Fras (HF) Site of Community Importance (SCI) and collect ground-truth samples using grabs and underwater cameras to characterise the seabed (for Defra / JNCC).
2. To conduct site verification surveys at the Greater Haig Fras, North West of Jones Bank and South of the Scilly Isles rMCZ (recommended Marine Conservation Zone) sites. Sampling to include acoustic survey in 'corridors' (single lines) and full coverage 'nested blocks', complemented by ground truth sampling with Hamon grab underwater cameras at an array of stations based on a 5 km triangular grid (for Defra / JNCC).
3. To survey a 1 x 5 km area of seabed to provide a data set for comparing the survey capabilities of Cefas Endeavour and Autosub (an Autonomous Underwater Vehicle belonging to the National Oceanographic Centre, Southampton). Full coverage acoustic survey using multibeam and sidescan sonar. Ground truth sampling with grabs and underwater cameras (for Defra / NERC).
4. To carrying out a multibeam survey of an area of seabed, previously unsurveyed, between Start Point and West Rutts in the Start Point to Plymouth Sound and Eddystone Reefs cSAC (candidate Special Area of Conservation) to complement acoustic surveys undertaken in 2011 (for Defra / Natural England)
All times recorded in this report are in British Summer Time (BST). All times recorded in survey data and metadata are in GMT, as taken from the ship's GPS system. BST = GMT + 1 hour.
RV Cefas Endeavour departed Lowestoft at 09:00 on Tues 3rd July and motored to a location near the Innwer Gabbard where a full test deployment was made of the sampling gear, namely a 0.1 m2 Hamon grab with video camera attached (known as a HamCam), a camera sledge and a drop camera frame. All test were successful, and both video and stills images downloaded from both camera rigs. Opportunity was taken to cover health and safety aspects of sampling work, and to demonstrate and train staff in the use of equipment and processing of samples. A muster drill was held at 15:30 hrs followed by a security exercise. A cruise briefing was held at 18:00 hrs for scientists and crew.
Passage continued to a site southeast of the Isle of Wight where at 02:30 on Weds 4th July a calibration (patch) test was completed on the EM2040 multibeam system. Science staff spent the day familiarising newcomers with data recording procedures, covering the use of the Tower Navigation system, completing metadata recording sheets and entering the data into DigiLog (a metadata database). Details of the survey plan and requirements were finalised with JNCC and Cefas headquarters. The internal clocks of the cameras on the sledge and drop camera frame were synchronised with GPS time and test shots taken of a clock set to GPS time. Examination of the time stamp in the EXIF data encoded in the digital images showed the clock in the sledge camera to be lagging GPS time by 1 second (Figure 2), while that used on the drop frame was in advance of GPS time by 1 min 36 seconds. The vessel continued passage to the Haig Fras area, and was ready to begin survey at 08:00 on Thursday 5th July.
|Chief scientist||Roger A Coggan (Centre for Environment, Fisheries and Aquaculture Science Lowestoft Laboratory)|
|Cruise report||(0.80 MB)|
|Specific||Western Channel & Western Approaches|