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Davide DB

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Everything posted by Davide DB

  1. Davide DB
    On December 30, I took the last dive of the year and ended 2023 on a high note by filming this very special creature swimming under the boat in 10 meters of water. I'm in Tuscany, Italy, in the Mediterranean sea. Initially I had misidentified it by mistaking it for a Siphonophore but then, thanks to the report of a biologist I found out that it is a very rare salp. Helicosalpa virgula. Species within the genus Helicosalpa are pelagic tunicates with keg-shaped solitary zooids and aggregate zooids in chains (not whorls). They are also among the most rarely collected salps, with most observations from subtropic and tropic regions. Pictures and videos of live, aggregate helicosalp species in situ is rare. https://www.researchgate.net/publication/341934517_Encounters_with_the_rare_genus_Helicosalpa_Chordata_Thaliacea_Salpida_using_citizen_science_data Sea temperatures are rising. 2023 was terrible for us, and 2024 does not bode well. The temperature at the bottom is 14 degrees Celsius, which is normal for these places, but in the first few meters we still have a small thermocline of a couple of degrees. As a result, the surface water is murky because of sediment brought in by streams and rains, and there is very good visibility at the bottom, typical of the summer months. However, even in not the best visibility, it was worth filming this alien 😄
  2. Davide DB
    First data of 2024. We're gonna need a bigger Y axis. More than 90 percent of the heat absorbed by our planet ends up in the oceans. This is easily observed by the surface temperature of the oceans, shown in this figure. Shown here is the surface temperature of the oceans measured between latitudes 60 north and 60 south. We note that ocean temperature today is higher than 20 or 40 years ago (lighter lines on the graph). Its variation depends on seasonal phenomena but also on ocean mechanisms that last several years, such as the ENSO (El Niño-Southern Oscillation) oscillation, which, in the two extremes called El Niño and La Niña leads to warmer or colder ocean temperatures, respectively. But annual climate change is leading to more intense El Niño phenomena, as seen in the 2023 line, which is almost half a degree higher than "normal" temperatures (indicated by the gray region around the mean)! Source: https://climatereanalyzer.org/clim/sst_daily/ Text: https://chpdb.it/_climate_dash/index.php#sst_NS60 Some Italian scientists have created this Climate Change dashboard updated daily automatically and in Italian. The data comment on themselves but it is easy to translate the rest with Google.
  3. Davide DB
    That article terrified me. Moisture aside, I keep the lenses to grow mushrooms perfectly 😄 Do any of you use silica gel bags in your lens drawers?
  4. Davide DB
    Yep. IMHO too expensive. I've put a desiderata on Abebooks and I'm confident to find it shortly below 20 euro 😉
  5. Davide DB
    Because of the popularity of blackwater diving, I suggest you this beautiful photo book. Quoting from the author Erich Hoyt website: When people hear the word “migration,” they think of animals that move from a feeding area to a breeding area and back each year. But the greatest migration on Earth happens twice every night. The movement is largely vertical and performed by plankton followed by predatory fish, squid, octopus and other species that have acquired a taste for plankton. The migration starts deep in the waters of the ocean at sunset. As they move, the plankton nibble on plant plankton and other tasty morsels in the water and, eventually, some on each other. The feeding ends just before dawn when the plankton retreat to the depths of the ocean to hide during the day until the next evening, when they migrate back up the water column. In Planktonia, Erich Hoyt invites readers to dive into the dazzling nighttime ocean. Countless microscopic plankton — larval creatures such as ornate ghost pipefish, left-handed hermit crabs and bony-eared assfish — ascend to the upper waters to feed, returning to the depths before sunrise. These tiny planktonic creatures are delicate and beautiful; some look terrifying; and most look nothing like the creatures they will become as adults. This great vertical migration attracts larger adult creatures, too, from the solitary 6-inch (15 cm) bigfin reef squid and the fierce and hungry 6 1/2 foot (2 m) female blanket octopus, which is up to 40,000 times heavier than her male mate. Everyone comes here for the midnight feast, and they are all ravenously hungry. The book can be bought online on many stores.
  6. Davide DB
    We are happy to have you among us. Welcome!
  7. Davide DB
    Looking forward to see some video from your partner. Judging by social media, it seems that blackwater has become a real fashion. By now, photographs are everywhere. Given the number of people practising them around the world, their contribution to science by identifying new species or unknown larval forms should not be overlooked.
  8. Davide DB
    Hi Ann, Welcome aboard!
  9. Davide DB
    I'm happy you join us!
  10. Davide DB
    Hi Andy, welcome onboard! North UK dive sites? Tell us more. Is it seasonal diving?
  11. Davide DB
    It seems perfect for the intended use and good for blackwater too. Really good price.
  12. Davide DB
    Were you tethered?
  13. Davide DB
    I don't know how exactly they do it in places where blackwater is a business. I've read several reports but devil is in the details. If I were to do one with friends, I would hang the line with lights from a large, well-marked floating buoy and leave the boat free to follow the buoy. Or if I wanted to hang the lighted line from the boat, I would have to use a floating anchor that would hold it to travel with the current.
  14. Davide DB
    And this thread has also been derailed.... 🤣 Joking aside, it would be interesting to get some reports from someone who has shot video in blackwater. Also photos at this point... 😇 Speaking of technique. In blackwaters, are divers always tethered? Regardless of video or photos I'm interested in learning more about the logistics. Years ago some guys organised one among friends which turned out to be a failure. They hung the line with lights from the boat and leftathe boat in the current. Unfortunately the wind was pushing the boat faster than the divers who spent the whole time chasing the boat. Game over.
  15. Davide DB
    and a knife on the calf...
  16. Davide DB
    Imagine being caught with your DIY readers and the camera mounted on a laundry basket... at night! Not a pretty sight 🤣
  17. Davide DB
    If you like, there's a DIY - Tutorial section waiting for you 😇
  18. Davide DB
    WWL stands for? Wide Wet lens?
  19. Davide DB
    Interesting thread Ben! While it is easy to see lots of blackwater photos, it is difficult to see good videos and almost impossible to get information on the techniques used. The most beautiful blackwater video is this one shot on the island of Ponza a few years ago by Alexander Semenov for his Aquatilis project. IIRC his footage was also used by the BBC. If you look on his channel there are several videos taken at the same location. He used a Panasonic S1 and a GH5 with lenses that are anything but macro (the animals filmed are large). I've always been intrigued by the 'strange' technique used to stabilize the camera: a plastic basket that increases the volume of the kit and makes everything more stable. This reminds us that no matter how powerful, our cameras do not have the ideal ergonomics for shooting video. Technique aside, I would like to add one more consideration: it is usually thought that blackwater requires abysmal depths in which major migrations of plankton and larval-stage animals down the water column take place... This video proves otherwise. I am familiar with the island of Ponza and you can clearly see that they are on a small shoal almost outcropping not far from the harbour. It is true, however, that the island is very far from the coast. Evidently, in this case, more seasonal factors (spring) and currents count.
  20. Davide DB
    Wow
  21. Davide DB
    It seems in the same ballpark of a WWL
  22. Davide DB
    Wow I didn't notice it! Thanks A lot of options. Right now I prefer the cheapest solution: I'm using it on a river in 50 cm of water (three of them) to film trouts so if i can avoid to buy a housing...
  23. Davide DB
    Thanks the Ulanzi adapter is not going to work because attach on the top/back of the GoPro housing and the Digipower adds a frame around the camera while the Puluz is interesting and could work. The AOI has an optional 52 mm adapter
  24. Davide DB
    I cannot use T-housing either. I'm using the Digipower extended battery with that enclosure so I need a special adapter
  25. Davide DB
    I'm testing this one and I cannot use the GoPro housing
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