Finding Nemo 4: Aliens Among Us
Finding Nemo 4
Aliens Among Us
|Norfanz vessel, see full image slide show|
To explore deep sea habitats and biodiversity in the Tasman Sea, a joint Australian-New Zealand research voyage carried leading Australian, New Zealand and other international scientists to uncover new marine species and habitats. The NORFANZ research voyage explored deep sea habitats around seamounts and abyssal plains around Lord Howe and Norfolk Islands through to northern New Zealand. The voyage collected biodiversity samples, DNA tissue samples, seabed habitat data, photographs and video on seamounts at depths between 200 meters and 1.2 kilometers, and surveyed free-swimming animals that live in the water masses above and around these seamounts. Australia’s National Oceans Office – the body responsible for developing and implementing Australia’s Oceans Policy – and the New Zealand Ministry of Fisheries supported the four-week voyage between 10 May and 8 June.
With cooperation from the National Oceans Office , the NASA-sponsored Astrobiology Magazine chronicles the scientific notes written by the researchers onboard. As the director of the Hayden Planetarium, Neil Tyson, wrote about the marvels of biodiversity: "I do not know whether biologists walk around every day awestruck by the diversity of life. I certainly do. On this single planet called Earth, there co-exist (among countless other life forms), algae, beetles, sponges, jellyfish, snakes, condors, and giant sequoias. Imagine these seven living organisms lined up next to each other in size-place. If you didn’t know better, you would be hard-pressed to believe that they all came from the same universe, much less the same planet".
The main goal of the summer expedition mirrored that sentiment: to provide baseline information on the, nature and potential vulnerability of these unique habitats and their biodiversity. The results will give scientists interested in biodiversity a much better understanding of the species that live on and around the deep seamounts and ridges throughout the Tasman Sea, many of which were new to science. The information will also enhance and contribute to international collaboration in oceans management.
Day 9: 09.00hrs, 18 May 2003.
By Clive Roberts, Te Papa scientist
Wind SE 33 knots; sea moderate, SW swell 2m. Air temp 20.4 C, sea surface temp 23.2 C.
It is Sunday and we are 150 n miles north of Norfolk Island. I have been up on Watch A since 3.00am. The trawl net is damaged and needs about 2 hours to replace a wire before it can be used. The weather is not good, blowing over 30 knots, torrential tropical rain, with some lightning. We are pitching so much my chair has a mind of its own and is moving around the cabin with me sitting on it as I try and write this. Fortunately I have got used to the vessel movement now. A few of my colleagues are not so lucky.
|Bamboo coral, see full image slide show |
Before breakfast we hauled up the Sherman sledge from over 1000m, in the catch was one tripod fish and some nice invertebrates including sponges. Now that we have spent some time swath mapping the seabed, we have located a few small seamounts that look like volcanoes with small calderas at their summit. Unfortunately these are too steep and hard to sample, so instead we are running a benthic camera over the largest to see directly what is living on its slopes. We can process the colour film on board, so look forward to seeing the results later today.
After the camera tow we shall shoot the beam trawl to 700 m and then the orange roughy trawl across a flattish plane at about 1000 m depth that looks less hostile than most of the sea bed here. I hope that we get some good samples because this site is a critical one for this survey being the most northerly on our voyage. Results from here will help us link our survey with those carried out off New Caledonia.
Happily the bad weather has passed and the sea and sky are easing. Watch A has just finished a 12-hour shift, during which we sorted samples from Sherman, completed a beam trawl to 750 m (sampling 14 fish species), an orange roughy bottom trawl to 1030 m (12 fish species), a benthic camera tow along the sea bed at 400 m, and several hours of swath mapping in this inaccurately charted area.
Among the fish catches were two species not previously recorded in Australian waters, a species of tripodfish and a lanternfish. Both records are supported by preserved specimens. The benthic camera film showed an inclined knobbly rocky seabed with some sponges and a few small fishes, but not a rich invertebrate community as seen on the top and sides of some seamounts. This direct observation supports the level of diversity indicated from the samples collected and also why the gear was so often damaged.
Tonight we steam for about 40 hours to the Lord Howe Rise.
Day 10: 09.00hrs, 19 May 2003.
Wind NW 8 knots; sea slight, SW swell 2m. Air temp 22.0 C, sea surface temp 22.4 C.
We have passed over the deep Norfolk Basin (over 3000m) and are now steaming across the Lord Howe slope. In order to sample the biodiversity of this deep area we are going to shoot a bottom trawl called the "ratcatcher" which has full wings and small mesh, so is good for sampling fishes and invertebrates on smooth bottoms. Target depth is at least 1500m. This is much deeper than it has been shot previously, so it will be interesting to see how well it performs.
|Finned Octopus, see full image slide show|
The weather greatly improved overnight and the wind dropped, so now we are enjoying a gentle 2m high swell with just wind ripple on top. Due to the improved weather and the long steam west, both watches are catching up on some well earned rest and taking the opportunity to cross-check our records and clean up any errors in the database.
Our colleague Phil Alderslade, a bamboo coral specialist, gives an update on his group below. So far on the NORFANZ voyage several new discoveries have been made about gorgonians, including two genera and species new to science and major range extensions for known species.
Watch A comment
By Phil Alderslade, Northern Territories Museum scientist
"Bamboo corals" are a common sight amongst bottom living animals sampled from seamounts. They are the sea fans or sea whips, a form of soft coral that are technically known as gorgonians of the family Isididae.
The most striking feature of these corals is that their axis (the stem and branches) is segmented and resembles bamboo. Although bamboo corals can grow very large, attaining 30cm thick at the base and up to 10m tall, only relatively small colonies have been found in our samples. The largest bamboo coral was a whip about 2m long and as thick as a pencil; the smallest, only 15mm in length, and little thicker than a needle.
This small colony, and another that was somewhat larger, proved to be very unusual. Both of them are species of Primnoisis, and not only are they the first to be identified from this part of the world, but they also represent major northward range extensions for the group. Up until now, Primnoisis has mainly been found in Antarctic and Subantarctic waters, predominantly below South America.
One colony was found on the seamounts just to the north of New Zealand. Another was found attached to a rock collected from the bottom near Norfolk Island. These two samples substantially extend the known geographic range of this genus.
There are two other range extensions of note. First we have some fragments of a very rare sea fan called Isidoides. This has only been recorded once before from deep water off Indonesia.
Second, we have found a particular type of sea pen where it has never been collected before. It is known scientifically as Gyrophyllum sibogae, and until now it has only been found in the deep waters of Madagascar, Indonesia and Tasmania. But we have managed to collect five colonies from near Norfolk Island.
Two important new discoveries are a couple of very small soft corals that are new to science. These are not just new species, these are so different from their nearest relatives that they are new genera as well.
The first looks like small, bright purple spots on some fragments of sponge. Under magnification it can be seen that the spots are actually minute coral polyps; the white sclerites (the microscopic skeletal granules) can be seen scattered on the brightly coloured tissue.
The second new find consists of strands of gray tissue forming a maze over a couple of small rocks. Most of the polyps have been worn off due to abrasion, but a few remain. They are about 5mm tall and 1mm thick. Under a microscope, the skeletal sclerites, which are made of calcium carbonate, show that this coral is very similar to only two other types of soft coral, and both of these have only been found in the North Atlantic Ocean and the Mediterranean Sea. This is the first record for the Pacific Ocean.
Day 11: 11.00hrs, 20 May 2003.
Wind NW 20 knots; sea moderate, N swell 2m. Air temp 23.2 C, sea surface temp 22.3 C.
Early this morning the ratcatcher trawl was operated at 1530m depth on a soft, flat seabed for about 60 minutes. It took another 35 minutes to haul and was on deck at 04.00hrs.
By 05.00hrs we had collected all the specimens of invertebrates and fishes from the nets and cod-end, and taken them to their respective laboratories for sorting, identification, registration, photography and preservation. Although not a large catch in terms of weight, there was a good range of both bottom-living and pelagic species that took us another 5-6 hours to process.
Our invertebrate scientists were happy with some good samples of prawns, blind lobsters, sea cucumbers, soft corals, glass sponge, jellyfish, octopods, squid and prawns. Some of which were new records.
|Jewel Squid, see full image slide show|
The presence of bottom-living species, such as sponges, soft corals and sea cucumbers, indicated that the net was effectively sampling the seabed. Often at these depths the sampling gear may not operate correctly because the electronic sensors cut out making it difficult to know if the gear is on the bottom or flying above it. Clearly, the trawl worked correctly at this station.
A total of about 30 species of fishes were collected, including several species appear to be new records for the area. Two of these are possibly new to science and await confirmation from further research back on shore. Bottom living fishes sampled included rattails, basketwork eels, tripodfish, slickheads, a deepsea skate, and a ghost shark. Midwater, or pelagic, fishes sampled included exotic dragonfishes, lanternfishes, gulper eels, snaggletooth, anglers, loosejaws, and viperfishes. One particular specimen had a lanternfish in its stomach that was half its own size.
Life at these depths occurs in complete darkness, except for the flashing of light organs (photophores) on the bodies of the inhabitants. Different species have rows or patches of photophores that emit light of different colours (red, purple, yellow, green, blue) that flash at different frequencies peculiar to that type of fish, prawn or squid.
It is thought that deep-sea animals communicate with each other using particular combinations of colour and pulsing frequencies. Also, light is often used in combination with a lure on the end of a barbel to entice prey within striking range. Food can be scarce at these depths, so mouths are often big to engulf very large prey and are festooned with long sharp teeth to help keep hold of the meal. A combination of these adaptive features plus a jet black or dark red body often results in some amazing life forms.
"Alien" has nothing on these wonderful creatures.
Day 12: 11.00hrs, 21 May 2003.
Wind S 13 knots; sea slight, NW swell 2m. Air temp 22.1 C, sea surface temp 21.7 C.
Today we have been attempting to sample a seamount that rises from about 1500 m to a peak of just under 300m deep. This feature gives a brick red image on the colour sounder indicating that it is comprised of very hard rock. Despite using our strongest sledges we have come fast several times. However the gear is designed to break free, so has been retrieved intact each time. Close contact with the seabed gives the metal a shiny polish and many solid parts are chipped and bent from the encounter.
After coming fast last tow we broke free, but retained a sizable lump of the bottom. This large piece of rock was so heavy that it had to be broken into smaller pieces to be moved. It was very dense, fine-grained larva and caused great interest because of the marine life attached to its surface (see photos).
Samples of invertebrates are very rich and our scientists are busy sorting, identifying, photographing and preserving a wide range of sponges, corals, bryozoa, hydroids, molluscs, worms, and crabs.
The sledge samples have contained a few fishes. Although lacking in quantity these have been quality specimens, comprising some new records and new species.
We shall continue to swath map and sample this seamount until about 20.00 hours, then we are heading off to Lord Howe Island to change over some scientists. It is hard to imagine that we have been at sea for nearly two weeks and the first leg of the voyage is over.
|Long-arm Crab, see full image slide show|
The Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the New Zealand National Institute of Water and Atmospheric Research Ltd (NIWA) are providing scientific support for the voyage. The NORFANZ voyage will use NIWA deep-sea research vessel, the R.V. Tangaroa (NORFANZ).
The expedition received considerable interest from scientists worldwide. Twenty four scientists from more than eleven research organisations will be represented onboard, including staff of CSIRO, Hobart; Museum Victoria; the University of Tasmania; Australian Museum; Queensland Museum; Northern Territory Museum; NSW State Fisheries; Te Papa, Wellington; National Institute of Water and Atmospheric Research, New Zealand; Institute de Recherche pour le Développement, Noumea; Natural History Museum, Paris; and California Academy of Sciences, San Francisco.