There will now be a 90 day consultation period, which will close on 24 February 2012. Further information is at: www.environment.gov.au/coasts/mbp/coralsea/index.html.

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Prof Terry Hughes is Director of the ARC Centre of Excellence for Coral Reef Studies at James Cook University, Queensland

“The announcement today of the proposed reserve is a welcome step in protecting the Coral Sea, one of the last remaining wild places in the sea. It cements Australia’s reputation as a world leader in marine resource management.

The proposed level of no-take area is 51%, compared to 33% in the Great Barrier Reef Marine Park which was re-zoned in 2004.

I would like to have seen more protection for coral reefs – more than 20 of them would be outside the no-take area and vulnerable to catch-and-release fishing under the proposed plan. This should really be called “catch-and-release-and then die” fishing. The survival rate of released fish in an area full of sharks is very uncertain.

The proposed Coral Sea no-take area is hundreds of kilometres offshore, and will have no impact on recreational fishing. There is very, very little commercial fishing currently operating legally in the Coral Sea today.

The proposal should consider more regulation of long-lining (connected lines up to many kilometres long), which will continue in the proposed multiple-use zone. The by-catch from long-lines is a major threat to seabirds, turtles and pelagic sharks.”

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Professor Shaun Collin is WA Premiers Research Fellow and Professor of Neuroecology in the School of Animal Biology and UWA Oceans Institute at the University of Western Australia

“The recent deaths attributed to the great white shark attacks in WA are most distressing and a terrible loss for the families of the victims. However, the culling of any species of sharks is not the solution. Not only will this be indiscriminate killing of a protected Australian species (under both the EPBC Act and state legislation), there is no way of being sure the sharks caught will be those responsible for the attacks. At present, there is no data to suggest that shark numbers are increasing off WA’s coastline and shark attacks in Australia have remained relatively constant over time, occurring at a rate of approximately one per year for the last 50 years. Sharks are apex predators and they play a critical role in the complex balance of oceanic ecosystems and their removal can have major impacts on other marine species. Education and surveillance are the best prevention of human fatalities off the WA coast until better repellent devices are developed. Non-lethal shark protection measures such as spotter planes and patrol boats should substantially improve the ability to identify large sharks and enable swimmers and divers to avoid them. Australia (and especially WA) has one of the highest levels of biodiversity in the world. Culling sharks will upset the important role these apex predators play. Our Neuroecology Laboratory at The University of Western Australia is currently working on various methods to repel sharks based on their battery of senses.”

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Dr Charlie Huveneers is a Shark Ecologist within the Marine Environment and Ecology Program at the South Australian Research and Development Institute (SARDI Aquatic Sciences) and lecturer in the School of Biological Sciences at Flinders University, Adelaide

“There is no scientific evidence to suggest that the short time period between the recent attacks is a reflection of an increased population size of white sharks. It could simply be related to the seasonal fluctuation of the number of white sharks within specific areas and that white sharks might naturally be more often occurring around the populated Western Australian coastline at this time of the year. Unfortunately, we currently have no reliable measure of the population size of white sharks. However, we do have some evidence of large variations in the number of white sharks from year to year within specific locations such as the Neptune Islands off South Australia. A below average number of white sharks one year does not necessarily mean that the white shark population is decreasing. Similarly, an above than average number of white sharks the following year does not necessarily mean that the white shark population has dramatically increased compared to the previous year. It is more likely dependent on the distribution of white sharks and the various and complex factors influencing the movements and migrations of these sharks.

Although shark attacks are tragic events and are often highly mediatised, they are still very rare events with a low probability of occurrence. White sharks are also known to undertake very large migrations between South Australia and Ningaloo Reef on the west coast and off Rockhampton on the east coast. As a result, the culling of a few specimens within one location is unlikely to significantly reduce a risk of shark attack which is already extremely low.

Around the world, several means of mitigating shark attacks have been put in place with variable level of success, but it is unlikely that one method can be considered the best way to reduce shark attacks. A combination of techniques selected depending on the characteristics of each location frequented by potentially dangerous sharks is likely to be the most efficient. For example, the City of Cape Town has put in place a Shark Spotter program in combination with research aimed to understand the movement patterns of white sharks around seal colonies and populated beaches. The efficiency of the Shark Spotter program relies on the topography of Cape Town with mountains in close proximity to the beaches allowing the spotters to be on a high vantage point and monitor for the dark silhouette of sharks on the sandy background.”

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The discovery of 50 beached sperm whales in the northwest of Tasmania, sparked rescue attempts by Wildlife officials this morning. The Australian Science Media Centre has gathered comments from experts as to why this strange behaviour occurs.

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Dr Catherine Kemper is a marine mammal expert from the Australian Antarctic Division

“The word ‘stranding’ means many things. To most people, it means live animals on the beach but to a scientist is encompasses anything from a carcass washing up to ‘mass strandings’ of many live animals. Whale and dolphin strandings have been happening for thousands of years. We have evidence of 2000-year-old strandings of sperm whales just north of Adelaide. Aboriginal people used to take advantage of stranded whales for food.

Mass strandings do not occur in all species of whales and dolphins, just the ones that are highly social and that live in the open ocean. The reasons for this is probably that these species are not used to being near shore and their social behaviour involves ‘following the leader’ even if it means to their death. (This is putting a human context on the situation, I know, but it helps the lay person to understand a complex system.) Some of the species that tend to mass strand are; sperm whales, common dolphins, offshore bottlenose dolphins, pilot whales.

The cause of most strandings of live animals is usually not known. There is some evidence that the earth’s magnetic fields may disrupt the navigation ability of some whales in some places. Tasmania and New Zealand have many mass strandings because the open ocean species live close to the coast (ie. the continental shelf is very narrow) and the coast is complex with many bays and inlets. South Australia has few mass strandings (thank goodness) because the shelf is very broad and the coast rather simple.

Recent evidence from some strandings, particularly the deep-diving beaked whales, shows that low-frequency and powerful underwater sounds can result in animals stranding. The theory is that they surface too quickly, probably having become seriously disturbed by the sounds. US naval operations have been implicated in these events. These sounds can also cause physical damage to the inner ear. There is no evidence of this in Australia but then little work has been done here.

South Australia has anything from 50 to 80 reported strandings each year so these events are not unusual. The cause of death of these animals is usually unknown but we investigate as many as possible and find disease, birthing problems, old age, entanglement in fishing gear, boat collisions, intentional killing by humans and others are the major causes. I have summarised the data for South Australia (no one else has done this in Australia) and found that 50 % were unknown cause of death, 20% were unintentional human-related (eg. entanglement, boat collisions etc.) and 5% were intentional killings (illegal, of course)”

Dr Nick Gales is a marine mammal expert from the Australian Antarctic Division

“We know that sperm whales live predominantly in the waters off the shelf break, in the deep sloping waters offshore and they feed in those waters. When you get events like that very low pressure system passing to the south of Tasmania that we had over the last 2 days, with storm force winds, where those waves reach the shallow waters, it becomes incredibly mixed up with sediments. This becomes incredibly confusing for animals that use sound in the water column to navigate in the shallower waters. On those occasions, animals that are bound together very tightly by social bonds like this predominantly female group of sperm whales and their young, tend to move as one organism virtually, and if navigation is confused, on occasion a mistake will be made where they end up on shore. I think this is just what happened on this occasion.

There is no real way of predicting these except maybe a slightly higher incidence in some areas through confusing the symmetry or on stormy events when whales happen to be in close and their prey is in close. The main advances in science have been in trying to deal with those animals once they are ashore, understanding a lot more about the animals from access to them and most recently in actually tracking animals that are able to be refloated and pushed out to sea to look at survival, the movement of these animals and to improve our knowledge of their offshore habitat. Refloating sperm whales is almost impossible, it has been done on a few occasions, in Tasmania mainly, but they are so large and so difficult to refloat that actually returning sperm whales is quite a rare event.”

Associate Professor Rob Harcourt is Director of Marine Science and a Senior Lecturer at Macquarie University

“Sperm whales are deep-diving pelagic social whales, they swim in groups of females, many of which are related, and they are deep-divers that hunt mainly squid, but they do eat fish and a few other things as well. Therefore they are usually found far offshore, except in areas where the water is really deep close to shore.

But in particular years, the line of productive waters, which a combination of large-scale weather systems and weather frontal systems, is closer to the Australian Coast, and in those years there is a greater frequency of strandings, of all sorts of Pelagic cetaceans.

The thing about these animals is that they are large, highly-social animals, that stay together for decades and normally the only encounters they have with firm substances like the ocean floor is when they are diving deep down to feed. So they can get confused and they tend to stick together so if one of ends up coming in too close to shore, they all tend to do the same thing. A normal response to stress at sea, if they are being predated by killer whales for example, is to flee, so that’s why they tend to strand.

It is very sad but we get a huge amount of information as a result of these strandings, a lot of information about how long they live, what they eat, and their relationships within the pods comes from these stranding events. So even though it’s a tragedy for individual whales, its opened up a window into how we understand these animals.”

Dr Karen Evans is part of the Pelagic Fisheries and Ecosystems Stream of CSIRO Marine & Atmospheric Research and is a Research Associate with the University of Tasmania. She has conducted research looking at why whales beach themselves.

“Strandings of whales, both single and mass, have occurred for centuries. Ascertaining the causes of whale strandings has perplexed both the general community and scientists for many years. Why should an animal completely adapted to the marine environment end up on the beach? For some animals we can determine the cause: old age, disease, injury, chase or harassment; but for many the question as to why they stranded remains unanswered. Theories as to why whales strand abound, but little quantitative research has been conducted into this, one of the most puzzling of biological mysteries, and to date no research have identified causes common across all unanswered cases.

We analysed a long term data set of whale strandings in south-east Australia (Tasmania and Victoria) and observed a clear circa-10 year periodicity in the number of whales that stranded each year. When aspects of the regions climate were investigated, this quasi-decadal cycle in the number of whales that strand was found to coincide with the regional persistence of both zonal (westerly) and meridional (southerly) winds. Periods of maximum whale strandings occurred during times of persistent westerly and southerly winds. During periods of persistent westerly and southerly winds colder, nutrient rich waters are driven closer to the south-east region of Australia, potentially enhancing biological activity in the water column and the abundance of prey in coastal regions. These findings suggest that climate, and its links to higher coastal productivity in years of strong winds, may provide a powerful distal influence on whale strandings by re-distributing whales into coastal regions (as a result of a change of prey distributions), increasing the number of whales available to strand in the region. Our study provides the first clear test of existing hypotheses for this mysterious behaviour, and provides managers with a powerful predictive tool to enable them to prepare for years of peak stranding activity.”