Wednesday 4 June 2014

Dogger's in the Bank!

According to North Sea legend, there exists a merry elf-like creature called a Klabautermann who helps sailors and fishermen with their duties on ship. While none of us here have actually seen one of these good willed sprites, we must surely have had one on board given how smoothly everything has gone on this trip!

Sailing into the sunset (A. Cunha, JNCC)
All in all it’s been a pretty epic survey; we’ve been operating around the clock for 456 hours, collected samples from more than 400 stations over an area roughly a third the size of Wales, sifted our way through around two thousand litres of sediment and captured over 30 hours of video footage of the seabed. The data we’ve collected will now be processed and analysed back on shore, the results will give us plenty to pore over in the next few months. The outputs from our survey will allow us to get a much better understanding of how the biological communities at Dogger Bank respond to anthropogenic pressures and natural processes, how we can monitor these changes and how different sampling gear can affect your results. 

An Ocean Quahog, Arctica Islandica (A. Cunha, JNCC)

We had an exciting end to our penultimate day shift when we found a huge Arctica islandica in our grab. These bivalved behemoths are really rare and can live for hundreds of years (the oldest recorded, nicknamed ‘Ming’, was thought to be over 500 years old!). After recording its measurements, we returned this fella to the ocean, where it will probably live for many decades to come.

The Day Shift, plus 'floaters'! (A. Cunha, JNCC)
The Night Shift, taken by their camera shy shift lead (P. McIlwaine, Cefas)
To sign off, we’d like to say a huge thank you to everyone involved in the survey. It’s been a really successful trip, especially as we’ve managed to meet all our main objectives and more to boot. None of this, of course, would have been possible without the skill and professionalism of the officers and crew of the RV Cefas Endeavour as well as the experience and expertise of our partners at Cefas, including Scientist in Charge Dr Sue Ware. 

Stay tuned for future instalments from our next survey later on in the year!

Tuesday 3 June 2014

Pick a grab, any grab

For 17 days now, we have been grabbing bits of the Dogger Bank seafloor in order to better understand the habitats and communities that live there.

Today we are entering a new phase of the survey in which we’re going to use 5 different grabs to collect samples from a smaller area within this marine protected area.

The reason behind this extra effort is the need to compare our data with data collected in previous studies and by international colleagues using different grab equipment. Analysis of samples collected from different grabs can give different results. This is thought to be due to the differences in the way these grabs operate as well as their specifications.

Mini Hamon grab being deployed (A. Cunha JNCC)

The mini and large Hamon grabs for example, are effective for sampling fine and coarse sediments and have been widely used in the United Kingdom.

A Shipek going into action (A. Cunha JNCC)
The Shipek grab is smaller and used mainly for sediment particle size analysis; it is better suited for coarser sediments. The Day and Van Veen grabs are good for sampling fine and sandy sediments but are prone to getting stones caught in their jaws which can result in part of the samples being lost.

New grab induction day  (A. Cunha JNCC)

Because the Van Veen grab is a new piece of equipment on board of the Cefas Endeavour, a Risk Assessment  protocol has been created and everyone on board that will eventually use or help using this grab had to participate in a full demonstration of all possible hazards and risks.

The Van Veen being inspected by the Master, the Chief Scientist
and the engineers on board (A. Cunha JNCC).

A Van Veen grab being deployed by crew members  (M. Nelson JNCC)
We hope that the findings from this part of the survey will help us gain an insight into how data collected using different grabs vary and allow us to better compare our results with those collected in other studies at Dogger Bank.