At the surface, it is home to white sharks, southern bluefin tuna, and marine mammals including blue whales and sealions – the images that make the Great Australian Bight a vast and iconic Australian ocean region.
Down deep there’s another lesser known world – and a frontier area for marine science, plus oil and gas exploration. Although we know that more than 85 per cent of shallow Bight species (such as those mentioned above) can be found nowhere else in the world, very little is known about their deep water counterparts.
We recently returned from 20 days exploring deep waters of the Bight – the first voyage supporting our recently announced science collaboration with BP and Marine Innovation Southern Australia (MISA, a consortium of South Australia’s major marine research institutions, including the South Australian Research and Development Institute, University of Adelaide, Flinders University and the South Australian Museum); a collaboration aimed at gaining a greater scientific understanding of the Bight.
In the video below meet CSIRO’s Mark Lewis and see our research in action.
In one of only a few whole-of-ecosystem studies undertaken in Australia, CSIRO and MISA are providing information to decision makers in industry and government to support sustainable development in the Bight and monitor possible future impacts.
Aboard Australia’s Marine National Facility research vessel, the Southern Surveyor (check out a virtual tour of the ship), we surveyed the Bight in depths of 200 to 2000 metres – collecting the deepest set of samples ever taken from the area.
Using a range of equipment, we collected samples of fauna from the seabed and the water column such as fishes, crustaceans (shrimp and crabs) and echinoderms (sea stars, sea urchins and sea cucumbers) and phytoplankton (single-celled plants). These included unusual species like the bizarre amphipod Phronima (see picture above) and this deep sea crab (below).
We also collected a great variety of environmental information, including acoustic data that will help map the seabed and determine if oil seeps are present. We used what’s called an integrated coring platform (ICP), pictured below, which collects sediment cores from the seabed plus acoustic measurements (we recently blogged about this piece of gear).
There is a reason that we’re collecting all of these wonderful critters, samples and data – it will help us understand the composition, distribution and number of species in the Bight, and the ways in which they are influenced by the environment around them. This will be vital information for any potential development in the Bight.
All of this information contributes to an ecosystem model, which will help CSIRO, MISA and BP understand how the ecosystem could change with, for example, future development or exploration (for oil and gas for example), allowing industry and government to plan for future activities in the region in an informed way.
Survey results will be made available to decision makers in industry and government – to help evaluate the needs for future ecological monitoring as oil and gas activities accelerate and expand in Australia’s deep ocean.
Read more about our Great Australian Bight collaboration with BP and MISA.
Moon Jellyfish: It is rare for these to live more than six months in the wild but they are really interesting.
All species in the genus are closely related and is hard to pick them apart except by genetic sampling.
They grow to about 25–40cm in diameter and can be recognized by its four horseshoe-shaped gonads, easily seen through the top.
It is not really a strong swimmer and it mainly drifts with the current feeding on plankton, fish eggs, small organisms and molluscs. It captures food with its tentacles and scoops it into its body for digestion.
Moon Jellyfish are found throughout most of the world’s oceans, from the tropics to as far north as latitude 70°N (runs through the middle of the US and Spain) and as far south as 40°S (runs through Tasmania).
It has also been found in waters as cool as 6C to as warm as 31C.
They do not have any respiratory parts such as gills, lungs, or trachea so it respires by diffusing oxygen from water through the thin membrane covering its body.
Climate scientists studying the impact of changing wave behaviour on the world’s coastlines are reporting a likely decrease in average wave heights across 25 per cent of the global ocean.
In some of the first climate simulations of modelled wave conditions they also found a likely increase in wave height across seven per cent of the global ocean, predominantly in the Southern Ocean.
Lead author, Dr Mark Hemer, said that 20 per cent of the world’s coastlines are sandy beaches which are prone to natural or man-made changes. It is estimated that 10 per cent of these sandy coasts are becoming wider as they build seawards, 70 per cent are eroding and the remaining 20 per cent are stable. Around 50 per cent of Australia’s coast is sand.
“Waves are dominant drivers of coastal change in these sandy environments, and variability and change in the characteristics of surface ocean waves (sea and swell) can far exceed the influences of sea-level rise in such environments.
“If we wish to understand how our coasts might respond to future changes in climate then we need to try and understand how waves might respond to the projected changes in global atmospheric circulation seen as shifts in storm frequency, storm intensity and storm tracks,” Dr Hemer stated.
Dr Hemer explained that coastal impacts of climate change studies have predominantly focused on the influence of sea-level rise and, until now, not focussed on how changing wave conditions will impact the coastal zone in a changing climate.
He said sea-level rise is likely to have considerable influence along much of the world’s coastlines. However, with such poor understanding of how changes in waves and other coastal processes will also influence shoreline position, it is difficult to attribute a level of future risk to the coast under a warmer climate.
The study compared results from five research groups from Australia, the United States, Japan, Europe and Canada. Each group used different modelling approaches to develop future wave-climate scenarios.
“While we find agreement in projected change in some parts of the world’s oceans, considerable uncertainty remains. We’re continuing to quantify the dominant sources of variation with the latest generation of climate models which will be used in the up-coming Intergovernmental Panel on Climate Change reports,” Dr Hemer said.
He said climate is one of several mostly human-driven factors influencing coastline change. These findings are derived from a study which seeks to understand potential impacts on coasts from climate change driven wind-wave conditions. The study will be published in the print edition of the journal Nature Climate Change on 25 April.
Media: Craig Macaulay P: 03 6232 5219 M: 0419 966 465 Email: Craig.Macaulay@csiro.au
As it is Good Friday I thought I would look into the association of fish with Christianity and religion in general. However, that turned out to be way too hard and full of potholes I just could not be bothered navigating around – and I’m trying to pack the swag for camping.
So, rather that concentrate on one fish I have “researched” Wikipedia for a description of all fish.
Here you go:
A fish is any member of a paraphyletic group of organisms that consist of all gill-bearing aquatic craniate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups. Most fish are ectothermic (“cold-blooded”), allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature.
Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams (e.g., char and gudgeon) to the abyssal and even hadal depths of the deepest oceans (e.g., gulpers and anglerfish). At 32,000 species, fish exhibit greater species diversity than any other group of vertebrates.
The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods.
By Peter McIntosh, Principal Research Scientist, Marine and Atmospheric Research.
Tea-leaves, entrails, cockatoos: we all want to forecast the future. Weather forecasts have become so commonplace we rarely think about the technology, research, computing power and millions of observations behind those couple of words: “mostly sunny”.
It’s not just the family BBQ that is at stake here. Farmers make decisions about planting, fertilising and harvesting worth many hundreds of thousands of dollars based on weather forecasts. Emergency services rally resources on high flood or fire risk days. Energy companies crank up the power if the forecast is hot or cold.
But that’s not enough. They all need to see further into the future than a weather forecast allows, and that’s where a seasonal climate forecast comes in.
Lewis Fry Richardson came up with the idea of numerical weather forecasting in 1922. Back then, his computers were real people in a large room scribbling parts of the calculation on notepads and passing them to messengers and an overall coordinator. A weather forecast starts with Newton’s laws of motion as they apply to gases (the atmosphere) and throws in some basic thermodynamics and the “ideal gas” law. These days, digital computers synthesise millions of observations with Richardson’s mathematical equations on a fine grid covering the entire planet to produce 10-day weather forecasts before morning tea.
But are they any good? In short, yes, and improving all the time. The skill of a seven-day forecast today is equal to the skill of a three-day weather forecast 30 years ago. Put that down to faster computers, more observations, and better techniques for using the observations to start the forecast.
However, beyond ten days, there is a problem. The ability to forecast individual weather systems rapidly decreases due to chaos. What this means is that very small errors in the starting conditions for the model (a butterfly flapping its wings in Brazil) can amplify over time and cause large errors. That’s where the ocean comes in.
Water has a much higher heat capacity than air, so the ocean changes its temperature slowly relative to the overlying atmosphere. Once a large patch of ocean becomes warm, it stays warm for many months, influencing weather systems all the while.
A recent example is the 2010-2011 La Niña, where warmer-than-normal ocean temperatures north of Australia contributed to increased rainfall, particularly in Queensland. More generally, ocean surface temperatures in the Pacific and Indian oceans can be linked to rainfall in different parts of the country. The link is made by analysing data going back to 1950 to determine how ocean temperature changes affect rainfall for the following season. This has been the basis of statistical seasonal forecast models such as the Bureau of Meteorology’s Seasonal Climate Outlook.
However, there is an emerging problem. The observations make it clear that the climate is changing and the oceans are warming. The Indian Ocean has warmed by more than half a degree since 1970, and it’s likely that this is affecting its relationship with Australian rainfall.
The past is becoming less of a guide to the future. Statistical models based on these past relationships are gradually losing accuracy and need to be replaced.
The ingredients for a better seasonal forecast are simple: take one weather model, add global models of the ocean, land-surface and sea-ice, add a healthy dash of observations to start it all off and blend at high speed in a supercomputer.
The weather model cannot accurately predict individual weather systems beyond about ten days, but the ocean model ensures that the average behaviour of the individual weather systems is about right for many months into the future. These individual weather systems in turn change the slow-to-respond ocean in a realistic way. The result is a useful forecast of average temperature, rainfall and winds for the next few seasons.
These so-called “coupled ocean-atmosphere global models” are the future of seasonal forecasting. They do not depend on a long history of observations, but instead start from present-day conditions and use physics to divine the future.
As the climate changes, these models adapt because they start from recent observations. Even without the effect of climate change, global coupled models now outperform their simpler statistical counterparts. The seasonal climate outlook has entered the digital age.
Seasonal climate forecasts will never be perfect; there are just too many butterflies out there. But they don’t have to be perfect. In the same way that you can make money betting on dice that you know are loaded, a seasonal forecast can shift the odds in a farmer’s favour. The new breed of seasonal climate forecast will give farmers and others who depend on seasonal climate outlooks the best chance to cope with an uncertain future. And maybe some time to simply sit back and enjoy that cuppa.
Peter McIntosh receives funding from the Australian Government and the Managing Climate Variability Program of the Grains Research and Development Corporation.
By Sarah Wilson
Today is World Water Day. In the spirit of this day I would like to pay homage to all things freshwater. In particular I would like to draw your attention to a peculiar fish found in the depths of the largest freshwater lake in the world : behold the Golomyanka.
OK, I admit it is a rather unassuming looking fish, but looks can be deceiving. Golomyankas, also known as Baikal oilfish, are only found in one place in the world – Lake Baikal . This UNESCO World Heritage Listed Lake is located in nippy Siberia. It is 25 million years old, contains one fifth of the world’s unfrozen freshwater, and is home to a staggering number of plant and animal species found nowhere else in the world. Earning it the nickname of ‘the Galapagos of Russia’.
As for the fish, it’s pretty amazing too:
Amazing fact No. 1: They are the world’s most abyssal fish. This means they live in the entire range of depths found in Lake Baikal. That’s a span of up to 1700m below the surface of the water. The pressure of going to these depths would easily crush a human.
No. 2: They rapidly melt in sunlight leaving only oil, fat and bones. (Imagine that!)
No. 3: It is one of only a few viviparous fish in the world. Viviparous means that it doesn’t lay eggs, but gives birth to live young . It gives birth to up to 3000 larvae at a time.
No. 4: They are a primary food source for the Lake Baikal’s nerpa seal. One of the few exclusively freshwater seal species found in the world.
No 5: They have a high fat content (over a third of their body weight is made up of fat). Native Siberians have been known to use them as fuel for their lamps.
Bareskin Dogfish: I have an affinity with this dogfish. Little is known about how it works or the environment it inhabits. It is actually a shark and has so far only been found near Japan, along the Australian coast from about Brisbane to Hobart and in a relatively small area from Perth to the north.
Apparently they are dark in color with white-tipped fins, which suggest the pictured specimen above is either an albino or just a very crook sample.
According to what I could find out about them they have no anal fin (who would want one) and has grooved dorsal spines with the second larger than the first. It has a blunt nose, large eyes and large nostrils. It grows to a a maximum of about 45cm.
They are found in a depth range of 500m to 1200m.
It has litters of three to 22 pups.
And that is about where the information on this thing ends: No information on the reproductive cycle, no information on annual fecundity, gestation period, age at maturity or longevity.
From ugly ducklings like the Rough Dreamer to the kiss-me-I’m-really-a-prince Clown Triggerfish, Australia’s marine fishes are now at your fingertips thanks to FishMap.
FishMap is a free online mapping tool that anyone can use to find out which fishes occur at any location or depth in the waters of Australia’s continental shelf and slope. You can create species lists for any region that include photographs and illustrations, distribution maps and current scientific and common names.
FishMap has a million and one uses for everyday fish lovers, such as finding out which fishes occur at your local fishing spot, creating a personalised pictorial guide or identifying the fish you spotted during a dive. Researchers can examine the range of a threatened species, or figure out what occurs in a marine reserve. Commercial fishers can find out what fishes occur at different depths in the areas they fish, or even determine the possible species composition for catches of any fishery in the waters of Australia’s continental shelf and slope.
Australia’s marine biodiversity is among the richest in world, but before FishMap there was no easy way to generate illustrated species lists for any location you choose within Australia’s marine waters. It’s the only resource of its kind in the world that covers virtually all species of fish found in the marine waters of an entire continent.
The tool provides the scientifically known geographical and depth ranges of over 4500 Australian marine fishes – including our 320 sharks and rays. Searches reveal illustrated lists of fishes by area, depth, family or ecosystem. These lists can be printed to create simple guides or, if you really want to get serious about it, data can be downloaded into a spreadsheet for research.
FishMap is built on the Atlas of Living Australia’s open infrastructure, which is bringing Australia’s plants, animals and fungi from Australia’s biological collections to everyone.
The Atlas of Living Australia is an initiative of Australia’s museums, herbaria and other biological collections and is supported by the Australian Government through the National Collaborative Research Infrastructure Strategy, the Super Science Initiative and the Collaborative Research Infrastructure Scheme.
FishMap will be officially launched on Tuesday 26 February 2013 and is available on the Atlas of Living Australia website:
Media: Bryony Bennett. Ph: +61 3 6232 5261 MB: 0438 175 268 E: firstname.lastname@example.org
Lanternfish are generally the most abundant group of fishes caught during trawls of the mid-water (mesopelagic) and deep (bathypelagic) regions of the ocean.
They are some of the most widely distributed, populous, and diverse of all vertebrates. Therefore, lanternfish play an important ecological role as prey for larger organisms.
Kapala lanternfish are usually between 35mm – 67 mm in length and are found in the southwestern Pacific Ocean.
The image above was posted on our Facebook page last week for users to comment on what the fish was thinking. You can read the great responses we got here.
These images were taken for a photographic guide produced by CSIRO scientists to identify the mid-water fish of the southern Tasman Sea. Here are some more great images from the guide.
Mid-water fishes are notoriously difficult to identify and this guide was developed to help researchers, students, commercial fishers and fisheries observers to identify fishes, encourage standardisation in data collection and foster data sharing. The guide shows both striking images of specimens collected in a good condition while also showing normal specimen quality collected during trawls.
Find out more about the Kapala Lanternfish and other mid-water fish of the southern Tasman Sea by checking out the guide!
We’ve got a special FFT for you today- a feature article by Rich Hillary on the Southern Bluefin Tuna and why we should be concerned that the current biomass is between 3−8% of the tuna’s unfished level.
Laying the track for a road to recovery for the iconic southern bluefin tuna
Southern Bluefin Tuna are majestic, temperate ocean dwellers, roaming across the oceans of the southern hemisphere, from the tropics to the sub-Antarctic. They grow to two metres and 200 kilograms, mature between eight and 20 years of age, and can live to 40.
Southern Bluefin eggs are spawned in warm waters off Java and north-western Australia. As larvae and small juveniles they ride the Leeuwin Current down the coast of Western Australia to spend their first summer in south-western WA and the Great Australian Bight. They continue to summer in the Bight, wintering in either the south-east Indian Ocean or Tasman Sea until about five. Then they stop returning to the Bight. Instead they move between feeding grounds, areas of high productivity spread between New Zealand and South Africa. Later as mature adults they join the spawning migration to the tropics below Indonesia.
Southern Bluefin are highly prized on the Japanese sashimi market, where the overwhelming majority of the global catch is sold. They have been heavily fished since the 1950s by high-seas long-line vessels and purse seine. They have also been grown in pens in Port Lincoln South Australia since the 1990s.
The current best scientific advice is that mature biomass is between 3−8% of the tuna’s unfished level. This is well below accepted national and international sustainable levels. Due to its low spawning biomass and, until recently, high levels of fishing mortality Southern Bluefin are classified as conservation dependent under Australia’s Environment Protection and Biodiversity Conservation Act and Critically Endangered by the IUCN.
Overfishing is the greatest recognised threat to Southern Bluefin. With low numbers of spawning adults, natural variation means there is a high risk of further declines. Several years of low juvenile survival, even with little or no change in fishing, can result in rapid decline. There is no buffer of long-lived adults that exists when populations are higher.
Management of Southern Bluefin is via international agreements on quotas, which can often lead to decision paralysis and status quo management. This management system can be slow to respond to problem signals such as low numbers, leaving the population ill-equipped to deal with the vagaries of juvenile survival.
In 2006, the revelation of significant under-reporting of catches from the long-line vessels further increased the uncertainty in stock status and the risk of future tuna declines. In response, the Commission for the Conservation of Southern Bluefin Tuna (CCSBT) substantially reduced the global quota (in 2006 and 2009). An international body of major fishing nations, the CCSBT renewed its commitment to developing a formal rebuilding plan for the Southern Bluefin. Monitoring of the population has shown that the initial quota reductions have stopped the overfishing.
Member scientists of CCSBT instigated a process of developing a robust rebuilding strategy in the early 2000s. This strategy, called a Management Procedure, differs to more common (and problematic) ad hoc quotas. The specific objectives to be achieved are agreed beforehand.
Quota setting decisions are largely automatic – key data is fed into the procedure and a total allowable catch is produced. No negotiation is permitted and no lengthy stock assessment process is required.
The procedure is then extensively tested through investigation of a wide range of “what if” scenarios. Stakeholders can be satisfied the procedure will rebuild stock under a wide range of potential future conditions.
CSIRO scientists were heavily engaged with the international team that developed the Management Procedure, adopted and used to set the global quota by CCSBT in 2012. This is the first such outcome for an international tuna fishery.
An important benefit of the Management Procedure approach is that it gives scientists more time to explore the remaining uncertainties in our understanding of the Southern Bluefin. CSIRO scientists have recently completed electronic tagging and genetic abundance estimation projects to better understand the migration patterns and breeding capacity of the stock.
It is expected that, even with the rebuilding strategy in place, recovery of the tuna will take a number of years. Southern Bluefin are long-lived and mature late, so the implementation of the Management Procedure is the start of a process, not the conclusion of one.
The next challenges for Southern Bluefin are for members of the CCSBT to maintain the accurate reporting of data from the fishery, to ensure that recommendations coming from the Management Procedure are adhered to, and for the scientists to continue integrating the latest research into the management framework so that future decisions are made on the best available scientific advice.
Rich Hillary received funding from the Fisheries Research and Development Council (FRDC).
By Keirissa Lawson
We have developed a hydrocarbon sensor array system that can detect different types of hydrocarbons in marine waters at varying sensitivities and in real time.
The sensors were originally used to explore for oil and gas resources, but are also being applied to study ocean changes, monitor our marine environments and measure the human impact on them.
The hydrocarbon sensor array has been deployed in a number of surveys, including to help monitor the extent of the Deepwater Horizon oil spill in the Gulf of Mexico, study natural oil and gas seeps, and for petroleum exploration in the Perth Basin.
Here are some great pics of our work in this field.
Leaning toward a Banded Sweep but not really sure. Anyway, sweeps are grey, often with a tinge of blue, green, or sometimes brown. They both like to get together in schools and are found from the southern coast of New South Wales, around the south of the country and north to the central coast of Western Australia.
The Sea Sweep can grow to about 61cm in length (the one above is just a bit shy of that….) while the Banded Sweep is a bit smaller.
They are found on rocky reefs in coastal waters. Young sweeps hang out in small schools inshore, and the larger adults school in small groups in open waters, often in turbulent areas on coastal reefs to 25m deep.
An innovative global observing system based on drifting sensors cycling from the surface to the ocean mid-depths is being celebrated by scientists today after reaching a major milestone – one million incredibly valuable ocean observations.
From 10 drifting robotic sensors deployed by Australia in the Indian Ocean in late 1999, the international research program has been quietly building up a global array which is now enabling new insights into the ocean’s central influence on global climate and marine ecosystems.
The initial objective was to maintain a network of 3000 sensors, in ice-free open ocean areas, providing both real-time data and higher quality delayed mode data and analyses to underpin a new generation of ocean and climate services. The program is called Argo.
“We’re still about 50 years behind the space community and its mission to reach the moon,” says Argo co-Chair and CSIRO Wealth from Oceans Flagship scientist, Dr Susan Wijffels.
“The world’s deep ocean environment is as hostile as that in space, but because it holds so many clues to our climate future exploring it with the Argo observing network is a real turning point for science.
“In its short life the Argo data set has become an essential mainstay of climate and ocean researchers complementing information from earth observing satellites and uniquely providing subsurface information giving new insights into changes in the earth’s hydrological warming rates and opening the possibility of longer term climate forecasting,” Dr Wijffels said.
Although the one millionth profile of the upper ocean, measured from the surface to a depth of two kilometres, was achieved in early November, oceanographers around the world are today celebrating this critical benchmark in ocean monitoring which delivers data to a scientist’s desk within 24 hours of sampling.
Celebrations included a series of high-level international presentations by senior scientists involving Dr Wijffels, her Argo co-Chair Prof Dean Roemmich from Scripps Institution of Oceanography, oceanographer Dr Josh Willis from the NASA Jet Propulsion Laboratory, and Dr Jim Cummings from the US Naval Research Laboratory.
The Argo array has risen to now number more than 3500 sensors, the largest there has ever been. The average lifetime of the floats has improved in the past decade greatly increasing the efficiency of the operation.
Presently 28 countries contribute to the annual A$25M cost of operating the program. The US is the largest provider of sensors to the network, with Australia, led by CSIRO with the Integrated Marine Observing System and the Bureau of Meteorology, maintaining more than 300 profilers for deployment mainly in the Indian and Southern Oceans, and Tasman Sea.
The 1.5 metre tall robotic sensors cycle vertically every 10 days, sampling temperature and salinity. At the surface, the sensors despatches its data via satellite to national centres across the globe, where analysts then check it, package it and send it to synchronous assembly centres in France and the US. The sensor’s ascent and descent is regulated by a hydraulic pump, powered with lithium batteries. Their life expectancy is between 4-9 years, averaging more than 200 profiles per sensor as they drift with the currents and eddies.
Data are collected at the impressive rate of one profile approximately every four minutes, (360 profiles per day or 11000 per month) and on 4 November 2012 Argo passed the symbolic milestone of collecting its one millionth profile. To put this achievement in context, since the start of deep sea oceanography in the late 19th century, ships have collected just over half a million temperature and salinity profiles to a depth of 1km and only 200000 to 2km. At the present rate of data collection Argo will take only eight years to collect its next million profiles.
Dr Wijffels said almost 1200 scientific papers based on or incorporating Argo data have been generated since the start of the program. Prominent findings include:
- Analysis of ocean salinity patterns that suggests a substantial (16 to 24%) intensification of the global water cycle will occur in a future 2° to 3° warmer world.
- A more detailed view of the world’s largest ocean current, the Antarctic Circumpolar Current.
- An insight into changing bodies of water in the Southern Ocean and the way in which carbon dioxide is removed from the atmosphere.
- Isolating the effect of ocean warming and thermal expansion on the global energy and sea level budget.
Dr Wijffels said Argo data is now also being widely used in operational services for the community, including weather and climate prediction and ocean forecasting for environmental emergency response, shipping, defence, and safety at sea.
Media: Craig Macaulay Ph: +61 3 6232 5219 Mb: 04199 966 465 E: Craig.Macaulay@csiro.au
Orange Roughy: Can’t believe it has taken FFT over a year to come to this important fish of the sea. Mind you, I still use a typewriter and a Teledex.
Anyway, they are also know as the slimehead or deep sea perch and, as the last name suggests, are found in deep waters between 180m and about 1800m. They are found around Australia and New Zealand, in the Western Pacific Ocean, Atlantic Ocean, and in the Eastern Pacific off Chile.
The orange roughy is slow growing and long lived – usually about 145 year but apparently there is one in the Australian National Fish Collection in Hobart that is about 160 years old.
The orange roughy grows to about 75cm and a maximum weight of 7kg.
Because it is so slow growing and late to mature, the species is extremely susceptible to overfishing and stocks especially those off New Zealand and Australia collapsed in the 1980s and there is debate if they have recovered.
The information below is from Wikipedia and I think is another reason (to go along with the fact the fish have had a bloody hard time over the years) to exclude them from your diet.
Due to its longevity, the Orange Roughy accumulates large amounts of mercury in its tissues, having a range of 0.30 – 0.86 ppm compared with an average mercury level of 0.086 ppm for other edible fish. Based on average consumption and the recommendations of a National Marine Fisheries Service study, in 1976, the FDA set the maximum safe mercury level for fish at 1 ppm. Regular consumption of Orange Roughy can have adverse effects on health.
Red Handfish: The red handfish is found on shallow rocky reefs in only a few locations in south- eastern Tasmania. They grow to about 100 mm in length. Handfish are small, bottom-dwelling fishes that would rather ‘walk’ on their pectoral and pelvic fins than swim. They are native to Australia and five of the eight identified handfish species are found only in Tasmania and Bass Strait. The spotted handfish is endemic to Tasmania’s lower Derwent River estuary. In 1996, the spotted handfish became the first Australian marine fish to be listed as endangered. Scientists, government and the community are involved in a federally-funded recovery plan for the spotted handfish led by CSIRO Marine Research.