October 2023

Carcinus maenas er en almindelig strandkrabbe og en vigtig invasiv art, der er opført blandt de 100 ”verdens værste fremmede invasive arter”. (Foto: Hans Hillewaert/Wikimedia/CC BY-SA 4.0 DEED)

Forsuring af havet kan føre flere invasive arter til danske farvande

Havforsuring påvirker biologiske processer i en bred vifte af marine taxa (grupperinger af arter – red.). En ny undersøgelse, som er offentliggjort i Research and Reports in Biodiversity Studies, viser, at specielt koralrevene i troperne står over for en lang række indbyrdes forbundne problemer (blegning, korrosion, sygdom, spredning af tang, invasive arter), som alle er forårsaget af stigende CO2-niveauer.

UV-Foto Galleri: David Holland

Dave Holland er en britisk undervandsfotograf, som har dykket siden 2005 og været dykkerinstruktør siden 2006. Han underviser i dykning hos ScubaGear i Ringsted og leder dykkerture for klubbens medlemmer. Tidligere har han arbejdet som dykkerinstruktør i både Wales og Egypten i en årrække. Her deler han nogle af sine foretrukne undervandsfotografier fra Danmark og udlandet.

Master Liveaboards introduce 3 new vessels and 2 new destinations

From Tuesday October 31 onwards, Master Liveaboards will be taking over both operations and sales of Blue Horizon and Blue Melody in the Egyptian Red Sea, as well as Blue Voyager in the Maldives.

Blue O Two has been operating these award winning vessels for many years and on the ground, the same great team will be waiting for customers, both old and new.

Ryukyuan Pygmy Squid, photographed in the wild.

Meet two new species of pygmy squid

The deep, emerald waters surrounding Japan's Okinawa Islands are a haven for marine life, and is one of the most biodiverse ecosystems on the planet. Within this vast biodiverse haven, scientists have discovered two new species of pygmy squid lurking beneath the surface: the Ryukyuan Pygmy Squid and Hannan's Pygmy Squid.

These two species have now been described and catalogued, with names that connect them to Japan's cultural heritage. Findings have been published in the Marine Biology journal. 

DAN announces DEMA party, seminar schedule and more

As your dive safety organization, we’ll raise a glass to all who work tirelessly to promote safe diving. We hope you’ll join us on Tuesday, November 14, 6:00 p.m. – 9:00 p.m. at the Sugar Mill (right across the street from the convention center).

Meet With DAN

If you’re planning to be at the show, make an appointment to meet with us and learn what DAN can do for your dive business.

Förkonditionering: Träning minskar risken för tryckfallssjuka

Denna kolumn är anpassad från ett kapitel i min bok, Scuba Physiological - Tror du att du vet allt om dykmedicin? Tänk om! Kapitlen i denna bok skrevs ursprungligen av forskare inom dekompressionsforskning som en del av ett treårigt projekt som heter PHYPODE (Physiology of Decompression). Min (självutnämnda) uppgift var att skriva om deras ibland komplicerade forskning i en form som är tillgänglig för alla dykare.

Marinarkæologisk sportsdykkerdag i Årøsund

Dagen var arrangeret af det genstartede Marinarkæologiske Udvalg (MAU) under Dansksportsdykker Forbund på opfordring og i samarbejde med Museum Sønderjyllands arkæologiske afdeling i Haderslev og Langelands Museum. Dagen blev afviklet takket været gode frivillige hjælpere og logistikstøtte fra Haderslev Dykkerklub i samarbejde med de frivillige medlemmer af MAU.

Southern Resident killer whale holding in its mouth a harbour porpoise calf that was eventually drowned

Why are orcas killing porpoises?

A comprehensive study published in the journal Marine Mammal Science analysed over 60 years of recorded interactions between Southern Resident killer whales (SRKW) and porpoises in the Salish Sea. This endangered population of orcas, known for their fish-based diet, particularly Chinook salmon, has been involved in numerous incidents of porpoise harassment, leading to the deaths of many porpoises.

Possible explanations

The study proposes three main reasons for this behaviour: