JBL Expedition South Seas I and II 2023

zpět na přehled světové mapy

Perfect hard corals but hardly any soft corals

The stony coral formations were quite sensational! There were fields of Acropora table corals at a depth of 30 metres, stretching over 150 m and extending from the steep edge at 20 m down to a depth of 40 m. What was interesting was not only the size of the field, but the fact that there were NO other corals between them! The only organisms that had made it between the corals were black sponges.

These black sponges also appeared in large numbers at another location: Exactly where reef damage was visible on the outer reef, presumably caused by storms. The sponges appear to have an ecological advantage due to their lack of species or coral growth.

Although the species richness of the stony corals was large, we had seen more elsewhere. It was more the quantity of the corals and their intactness that impressed us. There was no sign of climate-induced coral bleaching anywhere (!). Whenever we spotted any white coral fragments, we usually found the culprits not far away.

The culprits were always the crown-of-thorns starfish (Acanthaster planci), whose feeding marks caused the white colour on the coral. At night, even more crown-of-thorns came out of their hiding places and went on their raids. However, we were unable to confirm it was a crown-of-thorns plague, as known from other oceans.

This may be because we also sighted some of their natural predators, such as the Triton's trumpets.

The largest soft corals were leather corals, which were found in a few places like patches in the stony coral reef. But then only ever ONE species had spread there. In addition to leather corals, we also sighted fields of coral anemones and some occasional black wire corals. The reason for this could be that there is simply not enough plankton, which many soft coral species feed on. Only those species that can also feed on light are to be found there.

Fidži, Bligh-Water (Vatu-i-Ra)

We never saw any Nephthea soft corals, not even on steep slopes with strong currents, where they are often sighted in Fiji (Bligh passage/Vatu-I-Ra), and other places. But then Fiji is 4400 kilometres away.

Anemones and their inhabitants were also a rarity! Even though there weren’t many anemones, we identified three species. Amphiprion chrysopterus usually inhabited the anemones. But we also found Dascyllus trimaculatus there.

At the oceanic threshold of the northern passage of Fakarava we photographed an anemone at a depth of 40 m (!). At this depth, anemones are normally no longer to be found, as the zooxanthellae (algae) living in their tissue are dependent on sunlight. But the clear water, which allows the sun's rays to penetrate to great depths, made it possible.

Information and consent to cookies & third-party content

We use technically necessary cookies/tools to offer, operate and secure this service. Furthermore ,with your express consent , we use cookies/tools for marketing, tracking, creating personalised content on third-party sites and for displaying third-party content on our website. You can revoke your consent at any time with effect for the future via the menu item ‘Cookie settings’.
By clicking on ‘Allow all’, you give us your express consent to the use of cookies/tools to improve the quality and performance of our service, for functional and personalised performance optimisation, to measure the effectiveness of our ads or campaigns, for personalised content for marketing purposes, including outside our website. This enables us to provide personalised online ads and extended analysis options about your user behaviour. This also includes accessing and storing data on your device. You can revoke your consent at any time with effect for the future via the menu item ‘Cookie settings’.
You can use the ‘Change settings’ button to grant and revoke individual consent to the cookies/tools and receive further information on the cookies/tools we use, their purposes and duration.
By clicking on ‘Only absolutely necessary’, only technically necessary cookies/tools are used.

V našem Prohlášení o ochraně osobních údajů se dozvíte, jak zpracováváme osobní údaje a k jakým účelům je používáme.

Zvolte nastavení cookies

Oznámení PUSH od společnosti JBL

Co jsou zprávy PUSH? Webová oznámení jako součást standardu W3C definují rozhraní API pro oznámení koncovým uživatelům, která jsou zasílána na počítač a/nebo mobilní zařízení uživatele prostřednictvím prohlížeče. Oznámení se na koncových zařízeních zobrazují tak, jak je koncový uživatel zná z aplikací nainstalovaných v zařízení (např. e-maily). Na koncových zařízeních se zobrazují oznámení, která koncový uživatel zná z aplikací nainstalovaných v zařízení (např. e-maily).

Oznámení umožňuje informovat uživatele o události mimo kontext webové stránky, například o novém příspěvku na blogu, soutěži nebo poukázce.

Tato oznámení umožňují provozovateli webových stránek kontaktovat uživatele po celou dobu, kdy mají uživatelé otevřený prohlížeč – bez ohledu na to, zda uživatel právě navštěvuje webové stránky, či nikoli.

Abyste mohli odesílat webová oznámení push, potřebujete pouze webovou stránku s nainstalovaným kódem web push. To znamená, že i značky bez aplikací mohou využívat mnoho výhod push oznámení (personalizovaná komunikace v reálném čase a přesně ve správný okamžik).

Webová oznámení jsou součástí standardu W3C a definují rozhraní API pro oznámení koncovým uživatelům. Oznámení umožňuje upozornit uživatele na událost mimo kontext webové stránky, například na nový příspěvek na blogu.

Tuto službu poskytuje společnost JBL GmbH & Co. zdarma. KG poskytuje tuto službu bezplatně a lze ji stejně snadno aktivovat i deaktivovat.