Eulogy for a seastar, Australia’s first recorded marine extinction



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The Derwent River Sea Star was only documented for 25 years before its extinction.
Blair Patulo, Museums Victoria, CC BY-NC

Tim O’Hara, Museums Victoria

We see the surface of the sea: the rock pools, the waves, the horizon. But there is so much more going on underneath, hidden from view.

The sea’s surface conceals human impact as well. Today, I am writing a eulogy to the Derwent River Seastar (or starfish), that formerly inhabited the shores near the Tasman Bridge in Hobart, Tasmania. It is Australia’s first documented marine animal extinction and one of the few recorded anywhere in the world.




Read more:
Extinction is a natural process, but it’s happening at 1,000 times the normal speed


https://giphy.com/embed/TgFkyRxbZCTLx8OEqF

The Derwent River Seastar, preserved in the Tasmanian Museum and Art Gallery, Hobart. Credit: Christy Hipsley, Museums Victoria/University of Melbourne

Scientists only knew the Derwent River Seastar for about 25 years. It was first described in 1969 by Alan Dartnall, a former curator of the Tasmanian Museum and Art Gallery. It was found on and off until the early 1990s but scientists noted a decline in numbers. Targeted surveys in 1993 and 2010 failed to find a single individual.

It was listed as critically endangered by the Tasmanian and Australian governments. But now, like a long-lost missing person, it is time to call it: the Derwent River Seastar appears extinct.

It is actually quite hard to document the extinction of marine animals. There is always hope that it will turn up in some unusual spot, somewhere in that hidden world. Australia has an ambitious plan to create high-resolution maps of 50% of our marine environment by 2025. This is a formidable task. But it is a reflection of our lack of knowledge about the oceans that, 20 years after the launch of Google Maps and despite an enormous effort in the interim, much of Australia’s seafloor in 2025 will be still largely known from the occasional 19th-century depth sounding, or imprecise gravity measurements from satellites.

We do notice when big animals go. There used to be a gigantic dugong-like creature called Steller’s Sea Cow, which lived in the North Pacific Ocean until it was hunted to oblivion by 1768. There is no mistaking that loss.

Steller’s Sea Cow, which grew up to 10 metres long and weighed between five and ten tonnes, was hunted to extinction in 1768.
Paul K/Flickr, CC BY

But the vast majority of the estimated 1 million to 2 million marine animals are invertebrates, animals without backbones such as shells, crabs, corals and seastars. We just don’t monitor those enough to observe their decline.

We noticed the Derwent River Seastar because it was only found at a few sites near a major city. Its story is intertwined with the usual developments that happen near many large ports. The Derwent River became silty and was at times heavily polluted by industrial and residential waste. The construction of the Tasman Bridge in the early 1960s cannot have helped.

From the 1920s a series of marine pests were accidentally introduced by live oysters imported from New Zealand, or by hitching a ride on ships. Some of these pests are now abundant in southeast Tasmanian waters and eat or compete with local species.




Read more:
Australia relies on volunteers to monitor its endangered species


The Derwent River Seastar has been a bit of an enigma. From the start, it was mistakenly classified as belonging to group of seastars (poranids) otherwise known from deep or polar habitats. Some people wondered whether it was an introduced species as well, one that couldn’t cope with the Derwent environment.

However, we used a CT scanner at the School of Earth Sciences, University of Melbourne, to look at the internal skeleton of one of the few museum specimens. Sure enough, it has internal struts to strengthen the body, which are characteristic of a different group of seastars (asterinids) that have adapted to coastal environments and are sometimes restricted to very small areas.

https://giphy.com/embed/3ksOMV7xcoVKhOXVE2

CT scan showing the internal structure of the seastar. Source: Christy Hipsley, Museums Victoria/University of Melbourne

Is this seastar like a canary in a coal mine, a warning of a wave of marine extinctions? Sea levels are rising with global warming, and that is going to be a big problem for life adapted to living along the shoreline. Mangroves, salt marsh, seagrass beds, mud flats, beaches and rock platforms only form at specific water depths. They are going to need to follow rising sea levels and reform higher up the shoreline.

Coastal life can take hundreds to thousands of years to adjust to these sorts of changes. But in many places we don’t have a natural environment anymore. Humans will increasingly protect coastal property by building seawalls and other infrastructure, especially around towns and bays. This will mean far less space for marine animals and plants.




Read more:
Rising seas will displace millions of people – and Australia must be ready


We need to start planning new places for our shore life to go – areas they can migrate to with rising sea levels. Otherwise, the Derwent River Seastar won’t be the last human-induced extinction from these environments.The Conversation

Tim O’Hara, Senior Curator of Marine Invertebrates, Museums Victoria

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Sweden: World’s First Electrified Road


The link below is to an article that takes a look at the world’s first electrified road, an experimental road that charges the batteries of electric cars as they drive.

For more visit:
https://e360.yale.edu/digest/worlds-first-electrified-road-opens-in-sweden

Iraq: First National Park – the Central Marshes of Iraq


The links below are to articles reporting on the naming of Iraq’a first national park – the Central Marshes of Iraq.

For more visit:
http://news.mongabay.com/2013/0819-hance-iraq-national-park.html
http://newswatch.nationalgeographic.com/2013/07/31/new-iraqi-national-park-may-be-a-game-changer/

Tokelau: The World’s First Solar-Powered Country


It may be small, but it’s a start. Tokelau is about to be the world’s first solar-powered country.

For more visit the article linked to below:
http://grist.org/list/the-worlds-about-to-get-its-first-entirely-solar-powered-country/

Article: John Dean and the Franklin River


The link below is to an article on the Australian Geographic website about John Dean. He was the first person to paddle down the Franklin River in Tasmania, Australia.

For more visit:
http://www.australiangeographic.com.au/outdoor/pioneer-adventurer-john-dean-and-the-franklin-river.htm

Article & Video: Tube-Lipped Nectar Bat


The link below is to an article with an embedded video showing the rare Tube-Lipped Nectar Bat, which was first discovered in Ecuador in 2005.

For more visit:
Super-tongue Bat Caught on Camera (With Video)

Australia: Victoria – Otway Ranges


Tiger Quoll Spotted for First Time in Ten Years

The link below is to an article reporting on the first sighting of a Tiger Quoll in the Otway Ranges of Victoria in ten years.

For more visit:
http://grist.org/list/weird-adorable-animal-spotted-for-the-first-time-in-over-a-decade/
http://www.geelongadvertiser.com.au/article/2012/05/08/324541_news.html

Greenland: Global Warming May Remove Ice Quicker Than First Thought


Climate change may change Greenland sooner rather than later according to the article linked to below.

See also:
http://www.treehugger.com/climate-change/greenlands-ice-cover-more-sensitive-warming-once-thought.html

Australian Wilderness Adventures: Episode 001 – Cathedral Rock National Park


Today I have uploaded the first episode in what will be a growing series of documentary-like videos for my YouTube channel (Kevin’s Wilderness Journeys). This series of videos will focus on national parks and reserves in Australia (especially New South Wales), with a view to providing useful information for people who may be interested in visiting the national park being considered in any particular episode. I am hoping to provide a preview of the main attractions in each national park and the facilities available for visitors. Hopefully these will whet the appetite for those who view the videos and provoke a desire to actually visit the national parks under consideration.

This first episode focuses on the Cathedral Rock National Park, with a look at the Cathedral Rock Track and the Woolpack Rocks Track. There will be more episodes to come, including episodes on Dorrigo National Park, Bongil Bongil National Park and Myall Lakes National Park – among others. Hopefully in time better equipment will improve the quality of videos available – but none-the-less, I do think the videos are useful to some degree as they are.

The actual size of the video I have in my archives for the first video is 2.85 GB, so there is a fair reduction in file size (and therefore quality) to get the videos online and within the limits of YouTube file sizes and length.

 

Check In: Day 2 of Holiday


I have had a most interesting couple of days on the road and in the bush. Currently I’m in a motel room at Woolgoolga, near Coffs Harbour on the mid-north coast of New South Wales, Australia. ‘Hardly the wild,’ I hear you say, and you’re quite right – it isn’t. The weather was beginning to change I noticed on the final leg of my day’s itinerary, so I decided to hide out in a motel room for the night – good decision, it’s pouring outside.

I won’t give all away – I’ll leave the main description of the holiday to the website – but just some of the ‘downlights’ of the first couple of days for this post.

I didn’t arrive at Cathedral Rock National Park until just on dark, but did get the tent up prior to darkness arriving – when it did, it was dark! The campfire took an eternity to get going as all of the timber was damp and by the time I got it started it was time for bed – all-be-it an early night (7.30pm). I had decided to not spend the money on replacing all of the gear I needed to replace for camping, following the loss of a lot of gear over the years due to storage, etc. I hadn’t done much in the way of bushwalking or camping for years due to injuries sustained in my car crash and a bad ankle injury, so I left it all a bit late. I figured that for this holiday I’d make do and replace the gear with quality gear before the next trip. In short, I’ll get by – but it would have been nice to have some good gear just the same. It was a very cold night let me tell you – and long.

When I reached the heights of my first walk today, standing on top of Cathedral Rock National Park, my digital camera decided to die on me. I knew there was something wrong with it during the ascent as it was really chugging away taking pictures. I did get a couple of reasonable panoramic shots on the top of Cathedral Rock before it died, so that was good. I took stills with the video camera I was using, so it wasn’t a complete loss. When I completed the Woolpack Rocks walk I made the trip to Coffs Harbour to seek a replacement and got one for a reasonable price. It’s just another compact and so I will also buy a digital SLR prior to my next trip I hope. My previous SLR was basically destroyed when the camera cap came off during a multiple day bushwalk and all manner of stuff got into it. It wasn’t digital so I didn’t bother repairing it.

So tomorrow – off to Dorrigo National Park I hope and several lengthy walks I haven’t done before. Hopefully the rain will clear.