Dolphin Head and North East of Farnes Deep Offshore Survey (Blog #3): Drop Camera footage at Dolphin Head HPMA

Monday, October 9, 2023

By Eilidh Boa

Offshore Survey Marine North East of Farnes Deep HPMA Dolphin Head HPMA

In the third blog post from our offshore survey team on their survey to Dolphin Head and North East of Farnes Deep HPMAs, they tell us about the drop camera footage they've obtained at Dolphin Head HMPA.

JNCC has recently completed the first environmental survey of the new Highly Protected Marine Area (HPMA) Dolphin Head on the RV Tom Crean.

Situated in the eastern English Channel and covering 466 km², Dolphin Head’s marine environment is currently considered to be in a degraded state. To allow the area to recover from the impacts it has historically faced, activities such as fishing are likely to be excluded.

As part of our monitoring survey, two control sites near Dolphin Head were selected to allow a comparison between the HPMA (Dolphin Head) and the control sites over time.

One way to monitor the marine environment is to use a drop-down underwater camera system. These systems allow the survey scientists to record videos and take photos of the seabed to identify the habitat type as well as species that are present in a survey area. Across Dolphin Head and the two control sites, drop-down cameras were used to do just this. Sending the camera down to the seabed revealed some exciting marine life including conger eels, lesser spotted dogfish, nursehounds and cuttlefish.

The coarse and gravelly sediments of Dolphin Head are home to a wide variety of marine species, each with an important role to play in the ecosystem. The nature of the sediment in this area means that there are plenty of hiding places for many organisms to find refuge, meaning that these habitats are teeming with life. Take a look at the photograph below (Image 1) – can you spot the squat lobster? Many other crustaceans are found in Dolphin Head, including edible crabs, hermit crabs and European lobsters (Image 2).

Image 1: Can you spot the squat lobster in this photo? Answer at the end of this blog post.

Image 2: Top – European lobster; bottom left – hermit crab; bottom right – edible crab (© JNCC).

Some animals have adapted to life in this habitat so well that they blend in! The turbot (see Image 3), a species of flatfish, was the perfect example. Turbot have thin, oval-shaped bodies with both eyes on the left side, allowing them to lie flat on the seabed. They imitate the seabed that they lie on by changing their colour, meaning that they can go undetected by both prey and predators.

Image 3: Turbot (© JNCC).

Vast beds of brittlestars cover large areas of the coarse sediments across Dolphin Head and the control sites (see Image 4). Brittlestars are closely related to starfish, with a central oval disc and 5 long thin arms. Like starfish, brittlestars are able to regrow their arms. They can be found in large groups in areas where there is plenty of food and are often associated with a diverse range of species, resulting in a more diverse and resilient ecosystem.

Image 4: Brittlestar bed (© JNCC).

Other species spotted amongst the coarse sediment were the scallops. Unlike other bivalves, scallops can swim quickly to escape predators by ‘clapping’ their shells together to propel themselves through the water and were often seen swimming past the camera (see video clip). Scallops also differ from most other bivalves because they have a ring of simple eyes on the soft tissue at the outer edge of their shell.

It wasn’t only gravel and coarse sediment that was observed throughout the survey areas; occasionally boulders were spotted. The photo below (Image 5) shows just how much life can be found on one boulder! This boulder is partially covered in orange encrusting sponges, soft corals known as dead man’s fingers, sea urchins, topshells and even some egg cases.

Three species of ray were also spotted with our drop-down camera including a thornback ray and an undulate ray (see Images 6 & 7). Undulate rays are listed as endangered species and thornback rays are listed as near threatened. They do not have teeth, but instead have crushing plates which allow them to grind up their prey, which mainly consists of crustaceans and molluscs.

Now that the first survey of the Dolphin Head HPMA is complete, it is time for the JNCC survey team to head to the next site, North East of Farnes Deep HPMA.

If you missed our previous blog posts on this survey, you can catch up at the following links: