Moon jellyfishes and sea gooseberry in Sandvik 1

Description:

Description: English: Two moon jellyfishes (Aurelia aurita) and a sea gooseberry (Pleurobrachia pileus) in Sandvik, Lysekil Municipality, Sweden. The jellies are disturbing the top water layer of the fjord. The photo was taken on a calm, sunny morning after a rain, so it's likely that the layer is warmer water with some freshwater added. In this case that would make a thermocline coincide with a halocline and resulting in a very thin but visible pycnocline. This difference in density and the altered refractive index is what makes the water look "oily". The jellies are quite small and young, about 5–6 cm (2.0–2.4 in) in diameter, and since the are just below the surface and stirring up the pycnocline beneath them, that would make the layer of warmer freshwater on the fjord about 6–8 cm (2.4–3.1 in) thick at the time. The gray dots in the photo are daphnias, the fjord was full of them at the time. Date: 2 May 2020, 09:51:11. Source: Own work. Author: W.carter. Camera location58° 23′ 18.2″ N, 11° 27′ 13.18″ E View all coordinates using: OpenStreetMap 58.388388; 11.453660. : This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: Some debris in the water, mostly plant parts, and surface bubbles have been removed.