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DISPLAYING POSTS TAGGED: port phillip bay (6)

Filming our underwater backyard

Author
by Kate C
Publish date
23 October 2014
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Comments (0)

What do you know of the Vampire Squid? How about the Dragonfish, the Sea Mouse and the Fangtooth? These bizarre animals live kilometres – yes, kilometres – beneath the ocean’s surface. We’ve brought them up to sea level for you to meet at the exhibition Deep Oceans, which opens this weekend at Scienceworks.

Anglerfish exhibit Deep Oceans Anglerfish exhibit
Image: Australian Museum
Source: Australian Museum
 

This exhibition comes to us from the Australian Museum and we’ve added some local characters to the mix. Parks Victoria tells us that nearly half of Port Phillip is less than eight metres deep, and its greatest depth is only 24 metres. It’s just a puddle compared to the true deep oceans. This means we can see a huge diversity of our marine life just by heading out into the bay with a mask and snorkel.

 

Over the past months, Dr Julian Finn has filmed seals, fish, crabs and others in our local marine parks with a fish-eye lens. This footage will be projected inside the Underwater Backyard virtual aquarium dome, where you can stand right beside the bay’s residents without getting wet.

Deep Oceans is at Scienceworks 25 October 2014 to 12 April 2015.

Here’s looking at you

Author
by Blair
Publish date
23 May 2013
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Comments (3)

There are round ones, black ones, orange ones, blue ones. Compound, stalked and spots. Some animals have two, others eight or perhaps 100. Eyes see amazing things and they’re amazing to look at.

I’ve spied many a curious eye looking back at me underwater. Here are 19 fishes, three octopuses, three squid, two rays, a scallop, a seahorse, a shark and a shrimp. Thirty-one belong to marine species, one lives in freshwater. See how many species you can recognise.

An array of marine animal eyes. An array of marine animal eyes.
Image: all photos by Julian Finn
Source: Museum Victoria
 

Find more information on the species behind the eyes on our Port Phillip Bay Marine Life website.

Editor's note: This will be Blair's last blog post (for now) as he's leaving the museum for other adventures. Now's a good moment to revisit his many posts, or you can just remember him as his colleagues choose to - wearing a silly hat and making anatomical models out of balloons.

Blair's ballon demonstration Blair demonstrating odd genitalia of the animal world using balloons at the Melbourne Museum SmartBar event, January 2013.
Image: Jon Augier
Source: Museum Victoria

Orange army on the sea floor

Author
by Kate C
Publish date
23 May 2012
Comments
Comments (1)

Every year, thousands of Giant Spider Crabs (Leptomithrax gaimardii) congregate in Port Phillip Bay ahead of their annual winter moult.

When solitary, these crabs are often hard to spot; algae, sponges and sea squirts set up shop on their shells and provide excellent camouflage. However when the crabs aggregate and march, this hungry army is easy to spot. They scavenge whatever food they can find, including the wildlife on the shells of one another. The spectacle of hundreds of large orange crabs against the bare, sandy sea floor is an amazing sight.


It’s still a bit of a mystery what the aggregations are all about but senior curator Dr Julian Finn has some ideas from several years of observation.

Like many crustaceans, Giant Spider Crabs are protected by their hard body shell, rather like a suit of armour. The trouble is that a hard shell doesn’t allow room for growth. Crabs must shed their old skin to get bigger; they can expand their size in the brief window before the new skin hardens. The process of moulting takes up to an hour and all the crabs in an aggregation moult almost simultaneously.

Spider crab emerging Spider crab emerging from its old shell. The new shell is a vivid orange colour.
Image: Julian Finn
Source: Museum Victoria
 

Newly-moulted Giant Spider Crab Newly-moulted Giant Spider Crab in its fresh orange shell.
Image: Julian Finn
Source: Museum Victoria
 

A soft, freshly-moulted crab is irresistible to predators such as rays, seals and birds. By aggregating in the thousands an individual crab reduces its chance of being eaten, much the same way as mammals in herds find protection in numbers. Movement into shallow waters may help the crabs, usually dispersed throughout Port Phillip Bay, aggregate in a single mass and gain refuge from the strong tidal currents that scour the deep channels.

An earlier explanation that the annual aggregations were related to mating has thus far proved unlikely, as following the moulting of tens of thousands of crabs, only the odd couple has been observed to mate. We still don’t know however what happens when they disperse back into deep water. Julian believes this sudden influx of tender crab meat is an important part of the Port Phillip Bay food chain.

Spider crab moults Hundreds of cast-off spider crab moults on the sandy seabed.
Image: Julian Finn
Source: Museum Victoria
 

If you'd like to see some Giant Spider Crabs without the need for SCUBA gear, have a look at the entrance of the Marine Life exhibition at Melbourne Museum.

Port Phillip Taxonomic Toolkit

Author
by Blair
Publish date
15 March 2012
Comments
Comments (5)

Hey check out www.portphillipmarinelife.net.au – the new Port Phillip Taxonomic Toolkit website we launched this week! It's a joint initiative between the Department of Sustainability and Environment, and us at the museum.

Juvenile Scalyfin, jellyfish and biscuit stars in Port Phillip Bay. Left to right: Juvenile Scalyfin, jellyfish and biscuit stars in Port Phillip Bay.
Image: Julian Finn | Mark Norman
Source: Museum Victoria
 

There is a spectacular gallery of over 2,000 photographs that make it the site to surf if you don't want to get wet this dive season. And if you do get wet, then it's the one place to learn about the cool stuff you've seen underwater.

Have a click around and find your favourite pretty fin or an awesome octopus!

albatross, isopod and Moray Eel from Port Phillip Bay. Left to right: albatross, isopod and moray eel from Port Phillip Bay.
Image: Julian Finn
Source: Museum Victoria
 

The site has 1,001 species from Port Phillip Bay with more to come in 2012. There are frowning faces of stargazers to picture-perfect blue devils, fish that walk instead of swim, cannibalistic sea cucumbers, and seahorses that eat lunch like sucking a hotdog out of a roll. They're all part of our truly amazing local marine life.

The Port Phillip Taxonomic Toolkit is primarily an identification and information resource for scientists and marine enthusiasts, but the images provide some fun and education for all audiences. There are also interactive menus to identify selected species as well as descriptions of characters that make the animals unique.

The project is funded by the Department of Sustainability and Environment's Seagrass and Reefs Program for Port Phillip Bay and will be completed later this year.

New shrimp in Port Phillip Bay

Author
by Kate C
Publish date
8 April 2011
Comments
Comments (1)

MV marine biologist Dr Jo Taylor has reported a tropical stowaway in the warm waters around the Newport Power Station - the Sand Shrimp, Crangon uritai.

Sand Shrimp Sand Shrimp Crangon uritai blends in perfectly with the sandy habitats in which it lives.
Image: John Eichler
Source: Museum Victoria
 

This little crustacean with its cunning camouflage is common in East Asian coastal regions and is not native to Australia. Although other species belonging to the same family (Crangonidae) are common in Australian waters, including Port Phillip Bay, this is the first occurrence of this species anywhere in the Southern Hemisphere.

Reported this week in the online scientific journal, Marine Biodiversity Records, Jo and her co-author Dr Tomoyuki Komai suspect the shrimp was accidentally introduced to Port Phillip Bay. This new sand shrimp probably hitch-hiked in ship ballast while in its tiny larval form. It's only the second confirmed introduction of a shrimp to Australia.

Dorsal and lateral view of the Sand Shrimp. Dorsal and lateral view of the Sand Shrimp.
Image: David Staples
Source: Museum Victoria
 

Three specimens were found in 2008 by members of the Marine Research Group and were identified after comparisons with specimens at the Natural History Museum and Institute in Chiba, Japan. Jo has alerted local biologists and ecologists to keep an eye out for the newcomer so we can track its movement, if any, in local waters.

Links:

Article in Marine Biodiversity Records (abstract only)

Infosheet: Introduced marine organisms in Port Phillip Bay

Sand Shrimp on PaDIL

Blue Groper sightings

Author
by Blair
Publish date
1 March 2011
Comments
Comments (9)

Just like Melbourne loves to steal big sporting events, musicals and exhibitions from other Australian capital cities, now it seems we'd also steal a big fish!

For years I have been sitting in my office in the marine biology area of the museum discretely listening in to my office buddy’s phone calls. There is always something going on but this past week things have gotten more interesting than usual.

“...Another one? ... Where this time? ... Did they give you a photo?... Wow-ee!”

Apparently there have been a number of sightings of Blue Gropers in waters in and around Port Phillip Bay. Once a popular target for spearfishers in the mid 1900s, they are now considered one of the more elusive fish in our waters.

Eastern Blue Groper Eastern Blue Groper, Achoerodus viridis.
Image: Saspotato
Source: Used under Creative Commons CC BY-NC-SA 2.0 from Saspotato
 

We are thought to have only the Eastern Blue Groper in Victoria (Achoerodus viridis), but that is where the mystery widens.

If the western sightings turn out to be the Western Blue Groper (Achoerodus gouldii), then that would be exciting, because even though some guide books list the species in western Victoria, the museum has no verified records that I could find. Effectively, it would be the first offical indication that we have of the Western Blue Groper extending its range from Western Australia and South Australia into Victorian waters.

Being passionate about all things mariney, I have listened to these recent phone calls more keenly than most because regardless of the exact species, Eastern or Western, they suggest that this iconic giant is back in significant numbers. Perhaps this means marine parks and sanctuaries are helping blue groper populations to increase.

Anyway, I’m heading out next weekend to get wet and see if I can further fuel the enthusiasm in here. Join me and get diving or snorkelling, if you see a groper emerge out of the bay haze, snap a photo and help us solve this mystery.

Eastern Blue Groper A male Eastern Blue Groper (Achoerodus viridis) escorted by juvenile Silver Trevally (Pseudocaranx dentex). Shelly Beach, Manly, NSW.
Image: Richard Ling
Source: Used under Creative Commons CC BY-NC-SA 2.0 from rling
 

Oh and if you’re interested...

Blue Gropers are large, slow-growing fishes, that reach a metre or thereabouts – gentle giants if you like. They hang around rocky reefs. Funnily enough, their name is misleading because they are not always blue. Sometimes they are green, sometimes grey, sometimes inbetween. They start life as females and turn into males when about half a metre long, about a ten-year wait to manhood. They are more closely related to wrasses and parrotfishes than to the tropical groper commonly seen by divers on reefs in northern Australia. They are now more sought after for viewing on a spectacular dive rather than for dinner. Reef Watch Victoria monitors blue gropers and other marine life along our coasts.

Links:

Australian Museum Eastern Blue Groper video

Fishes of Australia's Southern Coast

Coastlinks Victoria - marine reserves, parks and sanctuaries

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Updates on what's happening at Melbourne Museum, the Immigration Museum, Scienceworks, the Royal Exhibition Building, and beyond.

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