Finding Nemo 5: Diving The Abyss
Finding Nemo 5
Diving The Abyss
|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 13: 11.00hrs, 22 May 2003.
By Clive Roberts, Te Papa scientist
At Lord Howe Island
Wind W 13 knots; sea slight, NW swell 2m. Air temp 20.5 C, sea surface temp 22.1 C.
We arrived at Lord Howe Island at about 08.30 hours. The is no harbour here. With a vessel draft of nearly 7m it took a couple of hours of careful and slow steaming through shallow reefs to arrive at a safe anchorage. Ships master, Andrew Leachman, officers and crew all did a skilled job that they made look easy. We anchored off Ned’s Beach, which was sheltered but still rolling with the ocean swell as it moved over the shallow water.
|Stone Crab, see full image slide show|
Most of the morning was spent making arrangements to transfer scientists, including arranging customs clearance and pick up from the vessel. Procedures ran smoothly without mishap. We said goodbye to several colleagues and welcomed aboard their replacements.
Lord Howe Island is a spectacular place with its two high mountains. The highest, Mount Gower (874m at the top), made me think of the seamounts we are surveying. Both where produced by the same geological forces, and are just as rugged.
Now we have left our anchorage and are heading south to Ball’s Pyramid. We shall swath map the southern end of the Lord Howe Island plateau, ready to sample the slope fauna in our next stations later tonight.
Day 14, 23 May 2003.
by Mark Norman, Museum Victoria
Low swell (~2-3 m), 15 knot wind, 20 ° C
Yesterday was the changeover day and a group of 10 of us swapped with departing scientists. New arrivals included specialists in sharks (Dr Peter Last and Daniel Gledhill, CSIRO; Dr Bernard Seret, Institute for Research and Development, Paris), other fishes (Dr Martin Gomon, Museum Victoria; Kerryn Parkinson, Australian Museum), crabs (Dr Peter Davie, Queensland Museum), other crustaceans (Dr Penny Berents, Australian Museum), brittle stars (Dr Tim O’Hara, Museum Victoria), octopus and squid (me) and a deep-sea camera specialist Bruce Barker (CSIRO).
Everybody on board was very welcoming to the new crew and we were shown round the ship and assigned cabins. We’ve also been assigned shifts. I’m on "Day Shift", 3am to 3pm . Our shift emerged bleary eyed at 3am to find an orange roughy trawl net down, sampling the seafloor at around 700 metres deep between Lord Howe Island and a pinnacle of rock known as Ball’s Pyramid.
|Orange Roughy, see full image slide show|
The seafloor mapping team (SWATH mappers) spent several hours last night mapping the uncharted seafloor around Ball’s Pyramid and choosing appropriate locations to trawl. Again, lots of rough rocky ground. The mapping was followed by two hauls using the Sherman sled in shallow waters (around 90 m deep). It brought up about 15 species of fish including boxfish, flounders and a new moray eel record for the area. Many small invertebrates were also collected.
This morning we’ve had two orange roughy trawls so far at 700 m and 570 m, which have brought up some interesting critters. Both trawls caught the bizarre Coffinfish (genus Chaunax ). They also caught a range of rattail fishes, dragonfish and tripodfish. The second haul also contained two small sharks and an electric ray (Torpedo macneilli). Some of the invertebrates captured include long armed crabs (genus Platymaia), a bush of black coral, some squid and a huge soft-bodied red prawn (Plesiopanaeus edwardsianus).
The sun is rising now and hitting Ball’s Pyramid and Lord Howe Island in the distance. Short-tailed shearwaters are foraging low over the water around the ship.
Around 10am, the benthos drop camera was lowered to take photographs of the seafloor. We’ll report the findings tomorrow.
Just after lunch, the Sherman sled came up from sampling 600-900 m deep. It came up with lots of rubble including many dead shells and coral pieces. Orange Lamp Shells (brachiopods) were very common, along with scallops, lace corals and sea urchin parts. Amongst this rubble was some small shrimps, bits of brittlestars and two large deflated sea urchins. More tomorrow.
Day 15, 24 May 2003.
Mark Norman , Museum Victoria
Smooth seas, low slow swell (1-2 m), no wind, 20 ° C
Busy day yesterday finishing with several very productive trawls in shallower water around the Lord Howe region. Many interesting fish and invertebrate species were collected including some rare species. The most interest was sparked by a small colorful fish, known as the Ballina Butterflyfish.
|Prickly Shark, see full image slide show|
Other findings included a new species related to nannygai or redfish (genus Centroberyx), many pelagic cowfish (which are rare elsewhere), about twenty Galapagos sharks (returned live to the sea), a large ray (also returned live to the sea), large leatherjackets, a flutemouth and a pipe horse. Reports from divers in this region suggest that it has one of the highest concentrations of Galapagos sharks of any region of the world. Soft and black corals were also collected, as were many sea urchins of several species.
This was followed last night by a very deep trawl around 1900 metres as we steamed away east from Lord Howe Rise (the seamount chain from which Lord Howe Island and Ball’s Pyramid emerge). This trawl used the "ratcatcher" net, a bottom net that samples smaller creatures than the orange roughy net. This depth is at the edge of the "abyssal" zone. The sea is divided into four major depth zones: littoral (0-200 m), bathyal (200 m-2 km), abyssal (2-6 km) and hadal (after hades or hell, >6 km). The deepest sea is 11 km deep off the Philippines.
Although our catches were not large (usually only 3-5 fish bins) they included many exciting animals. The most dramatic was a large red Stone Crab covered in very sharp spikes. Other invertebrates included a large sea spider, many brittlestars and stalked grazing sea cucumber. Amongst the fishes, the most common were the slickheads (family Alepocephalidae), including one possible new genus.
Slickheads are thought to make up most of the fish biomass in these deeper waters. Other fishes included halosaurs, the fangtooth, deep-sea lizardfish, morid cods, a few grenadiers (also known as rattails) and a deep-sea catshark (genus Apristurus ). One of the strangest fish was a small blind jelly-like fish called Aphyonus, a rare deep mid-water fish. They are rarely captured because they are so fragile. They are probably so soft and gelatinous to help them stay buoyant in the water and save energy. The bones are reduced and their transparency probably helps them avoid detection by predators. The trawl net also captured some other pelagic fishes on its long trek back to the surface. These included small lightfishes and a Gulper Eel.
|Slipper Lobster, see full image slide show|
After every sample, all fish and invertebrates are sorted, identified to lowest level possible, labelled, recorded and preserved in three different ways: in ethanol for DNA studies, in formalin for long term preservation in reference collections (like museums) or frozen for fixation and treatment after the voyage. Any new species or first captures for this voyage are photographed, logged and their images placed in reference folders for the different groups. This speeds identifications in subsequent trawls and provides a constantly updated record of the diversity encountered.
For photography, fish specimens need to be carefully prepared. As so many species are identified by fin colour and form, the fins must be flared to show these features. Other structures such as chin barbels or anglerfish lures must also be arranged to show their structure. As a consequence, each fish to be photographed must be carefully pinned out and have formalin brushed on to the fins and other structures. The formalin helps stiffen these up so that they remain flared when the pins are removed. The time consuming task of preparing and pinning out the fish is done by Al Graham and Dan Gledhill, both of CSIRO Marine Research in Hobart . Once set, the fish are photographed on a raised lightbox of glass to prevent loss of detail caused by shadows. This high-resolution digital photography is done by Robin McPhee of Te Papa, New Zealand and Kerryn Parkinson of the Australian Museum, Sydney.
At around 9am this morning we brought up another ratcatcher trawl from 1400 metres. It was a good fish catch for diversity including two large chimaeras (ghost sharks), two small deep-sea catsharks, lots of slickheads, basket eels, halosaurs and rattails. It also included some of the more interesting small fishes such as another fangtooth, another deepsea lizardfish, a slingjaw and viperfish. The chimaeras turned out to be a species described by one of the shark experts on board. Dr Bernard Seret (from the Institute for Research and Development in Paris) described this species from specimens collected on this same ship, the Tangaroa , in a survey near New Caledonia in 1997.
As I send this off, we are about to put down another deep trawl.
|Scaled Stargazer, 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.