SciBlogs

Archive 2009

Australian media on a mission to make scientists look dodgy Rebecca McLeod Dec 21

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Yesterday 895,000 Australians (and this one Kiwi) woke up to the headline “HOPES FADE IN COPENHAGEN, RISE ON THE REEF” in a national newspaper. As one who is always up for a bit of optimism I began reading… but by the second line my hopes were somewhat dashed: “Scientists ‘crying wolf’ over coral”.

This front page story reported the views of one (I repeat ONE) scientist, Peter Ridd, a physicist from James Cook University, who believes that ecologists and biologists studying the Great Barrier Reef are guilty of exaggerating threats to the reef, such as increased sedimentation, crown of thorns starfish, pollution, and temperature-induced damage called bleaching. Ridd argues that the reef is still in ‘good health’ despite public attention being drawn to these individual threats over recent years, thus affecting the credibility of marine scientists, particularly with respect to current concerns about the susceptibility of coral reefs to climate change.

It seems to me that The Australian has gone out of its way to turn this scientific debate, which is essentially one marine scientist disagreeing with a score of others, into another example of how ‘dodgy scientists’ are conspiring to delude the public into thinking that climate change is a real phenomenon.

A more in depth article further inside the newspaper “How the reef became blue again” does quite a good job of describing recent research findings by scientists at the Australian Institute of Marine Science, regarding the ability of corals to recover from bleaching events caused by increases in water temperature. However, you have to dig really deep to get to what I think is the part that is deserving of the headline:

“Ocean acidification is another matter, however. This lesser-known product of climate change is a greater danger to the reef by Ridd’s assessment. It happens as the ocean absorbs CO2 from the atmosphere, altering its pH value. Although surface sea temperatures are rising fastest in tropical regions, the threat of acidification comes from the higher latitudes, where the colder water takes in CO2 more easily.

The theory is that when atmospheric CO2 reaches between 480ppm and 500ppm, the warmer water lapping coral reefs will cease to be a barrier to acidification: even a small change is thought to spell trouble for calcifying organisms such as corals, making it more difficult for them to make the skeleton structures that in turn build reefs.”

If you would like to find out more about this incredibly scary phenomenon, I posted a rather thought-provoking film on it a couple of months ago. Even Peter Ridd thinks that ocean acidification is the single greatest threat to the Great Barrier Reef – but only those few of the 895,000 that got close to the end of the 2 page article would be aware of this!

Are the public so supersaturated with climate change stories that the media are having to infer scientific controversy to get the attention of the public? Quite possibly. How sad.

A+ for Australian Marine Scientists Rebecca McLeod Dec 04

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The Marine Climate Change Impacts and Adaptation Report Card Australia 2009 has just been released. Hiding behind the long-winded name is an excellent resource – a website-based state-of-knowledge of how climate change is likely to affect Australia’s marine life, with expert opinions from more than 70 marine scientists across the country.

Whilst the majority of the information presented on the website is available in various scientific papers, having it all combined on a common site, and in plain English is a real leap forward in making marine issues accessible to the public. Through many many many many (you get the drift) hours of careful research, scientists from a large range of disciplines have come to conclude that climate change has, is and will continue to affect marine life.

And these implications seem to reach every kind of marine environment there is – from the open ocean to coastal reefs to estuaries. Particularly concerning are stresses upon species that provide a home for marine animals – for example, kelp forests, among which a multitude of fish and invertebrate species live, are very sensitive to changes in seawater temperature, and so are predicted to disappear from southern Australia if seawater temperatures continue to rise.

Kelp forests are predicted to disappear from Tasmania should the sea temperature continue to rise

Kelp forests are predicted to disappear from Tasmania should the sea temperature continue to rise

Meanwhile in more tropical regions, such as the Great Barrier Reef, corals are suffering from multiple climate change related issues. Increased water temperature can stress corals, causing death of the individual anemone-like creatures that come together to form a coral colony. This occurrence is known as “bleaching”, and is becoming increasingly common and severe. A more recently-discovered phenomenon – ocean acidification – has the potential to devastate corals and other organisms that have skeletons made of calcium carbonate. It isn’t pleasant to think about, but if the corals disappear, so too will all of those who live on and amongst them.

Of course, with environmental science, and science in general, it is difficult to “prove” things beyond all doubt. To reflect such uncertainty, the observations, predictions and forecasts are rated with high, medium or low confidence, and I think that this is a really worthwhile addition to the site. Also included are sections on things that aren’t yet known, and require further research.

This site does make for some scary reading, and I wonder whether a section along the lines of “what you can do”, or “alternative pathways” section might lessen the blow. But then, it could be argued that individual efforts from the public would not be enough to stop the processes that are already in motion – what is needed are global-scale changes introduced by world leaders.

In the meantime, marine scientists will keep working to document our rapidly changing marine environments…

How resilient are coral reefs to tsunamis? Rebecca McLeod Nov 24

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The September 29th tsunami waves left widespread destruction across the Pacific nations of Samoa, American Samoa and Tonga, evidenced by devastated villages, and multiple fatalities and injuries. But what about the natural environment? Was there paralleled damage under the sea, on the coral reefs that fringe these islands? Not only is this question of interest from an ecological perspective, but also from a social perspective: communities rely heavily upon these reefs for food, tourism and social wellbeing. As these communities begin to rebuild, and eventually encourage tourists to come back, the state of the coral reefs could be a factor in a tourism market that relies heavily on water-based activities.

The potential for damage to coral reefs following major storm surges and tsunamis is two-fold: the initial force of the waves hitting the reef, and the subsequent delivery of huge amounts of sediment and debris onto the reef as the wave retreats and during rainfall in the following weeks.

Using field tests, scientists at the ARC Centre for Excellence in Coral Reef Studies have demonstrated that the shape of the coral influences how vulnerable it is to damage by large waves. For example, table-topped corals (those with a broad top and attached to the reef by a stalk) are more prone to being overturned by a large wave than those that are mounded or branched. Location matters too, with corals on the front and crest of the reef where the waves break being more prone to damage by large waves than those situated on the top and back sides of the reef.

Arguably the greatest tsunami-associated threat to corals is posed by sediment and debris that is carried from the land as the waves retreat. Sediment can smother and even bury corals, leading to suffocation of the coral polyps. Extensive mechanical damage and scouring can result from debris such as building materials, machinery and cars getting pounded onto the reef.

Initial surveys of coral reefs along the west coast of Thailand following the Boxing Day tsunami in 2004 recorded mass destruction of corals. However, despite these initial concerns, repeat surveys in the following months found that the damage, although severe in small patches, was generally not as bad as first feared. This anomaly was due to much of the coral initially recorded as dead having in fact recovered. On the Island of Banda Aceh at the northern tip of Sumatara, scientists were in a unique position of being able to make before and after comparisons of reef health, as they had surveyed the reefs prior to the tsunami. The research team, led by Dr Andrew Baird at the ARC Centre for Excellence in Coral Reef Studies reported a remarkable resilience of coral communities to the tsunami waves. The damage observed was considerably less than that caused by destructive fishing practices (e.g. dynamite fishing) and coral harvesting, and was also considered to be significantly less than that resulting from hurricanes, due to differences in the distribution of wave energy in the water column.

I am not aware of any similar surveys being carried out in areas affected by the most recent tsunami (if you know of any please tell me!), but these experiences from the 2004 tsunami seem to suggest that the long-term impacts of the tsunami waves on coral reefs may not be all that bad. It seems plausible that those reefs in good health prior to the tsunami may experience a faster recovery than those already suffering from bleaching, grazing crown of thorns starfish, or destructive fishing practises.

One step closer to harvesting kelp Rebecca McLeod Nov 09

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On Friday the Fisheries Minister Phil Heatley announced that giant kelp (Macrocystis pyrifera) will be introduced to the Quota Management System (QMS). This decision marks the first step of a process to “manage” the species, which forms extensive forests around much of New Zealand’s coastline. The second step will involve the setting of a Total Allowable Catch limit for the species. I posted a few weeks ago about the scientific arguments against kelp harvesting (“Is it wise to ‘mow’ our kelp forests?”), where kelp specialists Drs Chris Hepburn and Nick Shears gave their responses to the proposal to enter kelp into the QMS.

The Ministry received 26 submissions from stakeholders, most representing large organizations such as the NZ Marine Sciences Society (270+ scientists), the NZ Recreational Fishing Council and multiple iwi. In very general terms, the submissions from those in the fishing industry supported the introduction of the species to the QMS. And the majority of submissions from scientists, environmental and other groups were in agreement with them – perhaps not a huge surprise given that the alternative to QMS introduction was the creation of an open-access fishery! Where these two sides differed in opinion was in size of the future Total Allowable Catch. Industry argued for “a sustainable level”. Nearly everyone else argued that with a complete lack of scientific information, the only guaranteed sustainable level is zero. And the masses raise a very valid point – after all, the overall objective of the QMS is to help ensure the sustainable utilisation of fisheries resources…

Could kelp harvesters like this soon be working along our coasts? Image: http://w3.shorecrest.org

Could kelp harvesters like this soon be working along our coasts? Image: http://w3.shorecrest.org

The Ministry will begin a process of stakeholder consultation early next year before setting Total Allowable Catch limits for attached giant kelp in fisheries management areas 3 (East Coast of the South Island) and 4 (extending out to the Chatham Islands). It will be a very interesting process to observe – given the lack of biomass estimates, location-specific growth rates and knowledge about the ability of kelp to recover from canopy removal, it is difficult to imagine just how the Ministry will go about calculating a “sustainable level of harvest”.

Solved: the problem of the cross-dressing frogs Rebecca McLeod Nov 03

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The global plight of amphibians received a lot of attention last year – the official Year of the Frog. Just in case you missed it, amphibians are currently undergoing a worldwide extinction crisis, with 32% of all species threatened with extinction. The reasons for this sorry state of affairs are believed to be many – loss of habitat, increased incidence of disease, competitive exclusion from introduced species, climate change, increased UV radiation, pollution, predation, and overexploitation.

But I don’t want this to be yet another story documenting the alarming state of our global ecosystem. Recently I attended a very inspiring seminar given by Jen Germano – and it gave me hope that innovative approaches to conservation might just lead to some species recovering to healthy levels. Germano is a doctoral student at Otago University who is about to submit her PhD thesis under the supervision of Drs Phil Bishop and Alison Cree, and in collaboration with Landcare Research scientist Dr Frank Molinia.

A Maud Island frog (Leiopelma pakeka)

A Maud Island frog (Leiopelma pakeka)

Germano has spent the past 5 years focusing on ways to improve the success of conservation efforts for New Zealand native frogs (genus Leiopelma). New Zealand currently has 4 species of native frog – all classified as endangered – and 3 species that are believed to be extinct. Our frogs are from an archaic lineage and have a few traits that set them apart from those inhabiting other parts of the globe. Most notably, New Zealand native frogs do not have external eardrums, and therefore do not croak, instead communicating with chemical signals. There is also no easy way to tell males and females apart – there are no colour, size, or other morphological differences between sexes (hence the crass but attention-grabbing headline!), and this has posed problems for those trying to save them.

Jen Germano with some Maud Island froglets (babies)

Jen Germano with some Maud Island froglets (babies)

A proactive approach is being taken to frog conservation in this country, and many organizations are involved with efforts to breed and translocate frogs, to encourage sustainable populations. With other endangered species captive breeding populations have provided a form of “insurance”, but one major problem has arisen for NZ frogs – whilst our zoos have put a great deal of effort into starting captive frog colonies, they haven’t been able to successful breed any of the native frogs. This setback led Germano to develop a method for telling apart males and females based on hormone levels in their urine. The method is relatively non-invasive, and has allowed Germano and her colleagues to sex Maud Island frogs with 94% certainty. The ability to identify the sex of our native frogs is a big leap forward for captive breeding and translocation programs, as now they will be able to provide even sex ratios, which will hopefully lead to higher breeding success. Germano has been passing on her skills to staff at Auckland Zoo and Orana Park, where captive breeding programs are underway.

Germano explains that until recently, very little was known about the basic life history of our native frog species. “While I was working on frog translocations for my Masters project, I saw many of the problems that other scientists were facing when working with these frogs and it was obvious that there were huge gaps in the knowledge that we had for the basic biology of our endemic species and in the information that managers and scientists needed to conserve them.” A large part of Germano’s thesis involved determining the breeding season of Maud Island frogs – and surprisingly she found it is likely to occur in mid winter. Germano has also discovered that Maud Island frogs have incredibly low sperm counts, which may also help to explain why their numbers are so low.

With her PhD thesis soon to be submitted, Germano will be heading to Memphis Zoo in the USA to begin a position as a postdoctoral researcher in amphibian reproductive biology. But she can leave with the satisfaction of knowing that the Maud Island frogs and those working to save them in a much better position than when she began her studies.

The largest remaining population of native frogs in NZ exists on Maud Island, a predator-free island in the Marlborough Sounds.

The largest remaining population of native frogs in NZ exists on Maud Island, a predator-free island in the Marlborough Sounds.

Orokonui Ecosanctuary to open Rebecca McLeod Oct 29

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After more than 20 years of dreaming, planning and pure hard work the Orokonui Ecosanctuary will be officially opened this Friday. The 307 hectare block of land is situated near Waitati in the Blueskin Bay catchment, just a short drive from Dunedin. The opening marks the completion of the Visitor and Education Centre – a fine demonstration of eco-building. Much of the timber was milled from exotic pines that once resided within the sanctuary, the building is positioned to capture and retain sun and warmth, shipping containers have been recycled into administration areas, and waste water is treated onsite.

I was lucky enough to get a guided tour around the sanctuary a couple of weeks ago, and was incredibly impressed. There are few examples of remnant forest on the East Coast of the South Island, but here is one of them – towering broadleaves, podocarps and kanuka – these forest types are within close proximity of each other. A 2 million dollar, 10 km long pest exclusion fence was completed in 2007, and an ongoing eradication program since then has seen exotic mammals including possums, rats and stoats reduced to undetectable levels. And so enter the stars! Kaka, saddlebacks and jeweled geckos introduced since the completion of the fence have been flourishing, as have resident tomtit, brown creeper and  rifleman. The hope is that, in years to come Kiwi, Kakariki and Tuatara will be established within the sanctuary. It should only be a matter of time until Otago has a southern equivalent of the Karori Wildlife Sanctuary! I highly recommend going on a tour of this incredible place – the guides are so passionate and knowledgeable, and will no doubt have more to show us as the forest ecosystem recovers in years to come.

This viewing platform was constructed from exotic wood that was milled from within the sanctuary

This viewing platform was constructed from exotic wood that was milled from within the sanctuary

10% by 2010? Yeah Right! Rebecca McLeod Oct 20

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In 2005 an ambitious goal was set by the then Ministers of Conservation and Fisheries – 10% of the marine environment around New Zealand would be under some form of protection by 2010. This announcement was met with much celebration by marine scientists and environmentalists throughout the country and the wheels were set in motion to take a regional approach to marine protection. Going off the recent success of the implementation of a network of marine reserves in Fiordland, the Department of Conservation and the Ministry of Fisheries put together a structure under which local groups of stakeholders would propose networks of marine protected areas in their region. These networks would encompass a variety of habitat types (such as estuarine, offshore reefs, soft sediment etc.) and protection measures (marine reserves, zones with specific fishing restrictions etc.). But despite this initial flurry of activity, the Government has been unnervingly quiet on this issue of late. I am aware of two regional proposals – for the sub-Antarctic Islands, and for the West Coast of the South Island – that are currently at the public consultation stage, but yet to be put forward to the Government. Whilst the fact that these proposals are undergoing consultation is evidence that things are happening at a regional level, I am skeptical that the final proposals will move through parliamentary channels in a timely manner. As we race towards 2010, I am left with considerable doubt as to the ability, or will, of the Government to meet the target of 10% by 2010.

Southern right whale population on the rebound Rebecca McLeod Oct 14

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Southern right whales, hunted perilously close to extinction last century, appear to be making a remarkable recovery in New Zealand according to recent research. For the past four years a group of scientists from Auckland and Otago Universities, the Department of Conservation and the Australian Antarctic Division have been sailing south to the Auckland Islands to count and identify individual whales that go there to breed and calve. Recent DNA matches of whales recorded in both the Auckland Islands and mainland New Zealand have shown that the animals migrate between these two areas and likely form one intermingling population. Certain individuals have also been seen at the Auckland Islands, Campbell Island, mainland New Zealand and South Australia – these animals certainly get around!

The research group sails to the Auckland Islands on the R.V. Evohe, and then conducts surveys from small boats. Here they are in Port Ross.

The research group sails to the Auckland Islands on the R.V. Evohe, and then conducts surveys from small boats. Here they are in Port Ross.

Individual whales are able to be identified by unique markings on their skin. These white patches are aggregations of crustaceans, called cyamids, which cluster around skin calluses.

Individual whales are able to be identified by unique markings on their skin. These white patches are aggregations of crustaceans, called cyamids, which cluster around skin calluses.

These patches of cyamids remain remarkably consistent year on year.

These patches of cyamids remain remarkably consistent year on year.

Results of genetic analyses by Professor Scott Baker and his team at Auckland and Oregon State Universities indicate that the New Zealand population of southern rights was reduced to as few as 50 reproductive females following years of hunting in the 1800s and early 1900s, and further illegal whaling of the species by the Soviet Union in the 1950s and 60s. Since the 1960s the population appears to have been steadily increasing. Ten years ago the population was estimated to include about 900 whales, and the preliminary findings of the latest surveys, indicate that numbers have likely doubled since then. According to Dr Simon Childerhouse, the leader of the most recent expeditions, the rate of recovery of New Zealand southern right whales appears to be at least as high as that seen for populations in Australia and South Africa. In contrast, populations of northern right whales are incredibly depleted, and do not appear to be recovering. Despite right whales being protected in the northern hemisphere, mortality from ship strike and entanglement in fishing gear appears to be outweighing natural population increase. In this sense, southern right whales are fortunate – their natural home range around the Southern Ocean and coastal and offshore New Zealand, has relatively low volumes of shipping traffic.

Southern rights are baleen whales, and feed upon zooplankton such as copepods and euphausids.

Southern rights are baleen whales, and feed upon zooplankton such as copepods and euphausids.

Although, as Dr Will Rayment from the University of Otago explains, as the species starts to recolonise mainland New Zealand, it is possible that they will be more at risk of such threats. “Historically, southern right whales have aggregated in sheltered bays, including Otago and Wellington Harbours, to breed and calve. As this species makes a resurgence around the mainland, it is expected that they will again tend to spend time in these areas – although of course since they were last here the intensity of human use of harbours has changed somewhat. Their tendency to spend time in coastal areas means that they could possibly be affected by human activities such as shipping, fishing, aquaculture, and even tidal power generation. It will be interesting to see how the species and human activity interact in coming years. Here we have a unique opportunity for proactive management of an endangered species – as opposed to reactive management, which is more often the case.”

Two southern right whales, with the R.V. Evohe anchored in the background.

Two southern right whales, with the R.V. Evohe anchored in the background.

These days, Port Ross at the northern end of the Auckland Islands, is the main breeding area for New Zealand southern rights. The whales congregate there in large numbers throughout the winter months. Dr Rayment says that there may be up to 200 individuals in the harbour at any one time, and all evidence points towards the species being highly promiscuous. During the latest trip to the Auckland Islands, it was common to see several males pursuing a female, with the female often rolling on her back in an effort to stop males from mating with her. Following a one year gestation period, females tend to return to the harbour to calve, and then spend a year nursing their calf before conceiving again – resulting in most females producing one calf every three or four years. The increase in whale numbers appears to be following a typical exponential population growth often seen in recovering populations. And the increase is starting to be noticeable in mainland New Zealand – numbers of annual whale sightings recorded by the Department of Conservation are trending upwards around Otago. The current population is estimated to be only 10% of the pre-whaling numbers, suggesting that we may well be visited by a lot more southern rights in the future. In these times of doom and gloom for the marine environment (think depleted fish stocks, marine pollution, ocean acidification…), it is uplifting to see a species making a comeback.

Southern right whales often approached the research vessels during surveys.

Southern right whales often approached the research vessels during surveys.

Last year the expedition was joined by a journalist and a photographer from National Geographic – the resulting underwater photographs are truly awesome.

Environmental negotiations ??!!?? Rebecca McLeod Oct 05

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Well here we go again – the stage is being set for another battle of “the environmentalists” versus “the developers”. This time, the battle grounds are numerous, and share one thing in common – conservation land status. As the Government prepares to conduct a stock take of the mineral deposits in conservation land around the country, mining companies and those wanting continued protection of our conservation estate are shaping up for a fight.

Last night on the current affairs show Sunday, “the developers” stated that they were prepared to negotiate with “the environmentalists”, so that everyone could come out a winner. In my opinion, this argument is complete nonsense – how can there possibly be negotiation when the two sides are dealing in completely different currencies? The developers are dealing in dollars, as developers tend to do. But what currency are the environmentalists dealing in? Do they even have  a currency? Well, I don’t believe that they do – apart from a sense of guardianship, the environmentalists are not set to personally gain from protecting our conservation land from development. This might seem like an obvious point to make, but therein lies the difference.

It heartens me to see such battles being waged around the country – where big, well-funded developers who set to gain financially from environmental exploitation are going into battle with small community groups, Iwi and environmental organizations that are fighting to protect our environments and the ecosystems they support. These groups typically do not have the large pool of resources required for a fair battle with the developers, and so rely on the generosity of volunteers (including scientists) to put together cases for environmental protection. It has a distinct David and Goliath feel about it – and has me wondering what can be done to make these fights more even. Often what these small environmental groups need is scientific advice, and better yet, research to support their arguments – but they can’t afford to fork out for consultants. I am aware of a number of situations where environmental scientists are giving their time and expertise to advise and support these small environmentally-focused groups. The community groups obviously benefit enormously from this interaction, and I believe that the scientists do too – what better way to gauge that the science you are doing is relevant?!

Unfortunately, when it comes to the possibility of mining conservation land, the environmentalists have more than just the developers to deal with: in this case it seems likely that they will be going head to head with the National Government – and that seems like a lopsided battle indeed.

Antarctic sea spiders Rebecca McLeod Oct 02

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Whilst I often see sea spiders (Pycnogonids) in kelp forests around the South Island, it wasn’t until I visited Antarctica that I got a little creeped out by them. Like many marine invertebrate taxa, sea spiders in Antarctica display gigantism – the largest species can have a leg span of half a meter, and bodies up to 5 cm long! It turns out I didn’t have any reason to fear for my life… these “spiders” don’t have killer venom, or spin human-sized webs. Instead they suck the juices of soft-bodied invertebrates like anemones and ascidians (sea squirts), or eat small hydroids and bryozoans. At last count there were 264 different species of pycnogonids in Antarctic and sub-Antarctic waters  – here are a few pictures to whet your appetite.

Colossendeis sp. Photo: Dale Stokes

Colossendeis sp. Photo: Dale Stokes

Pycnogonid loving - all legs... the males carry the fertilized eggs around until they hatch. Pycnogonids don't have a pelagic larval stage, so don't spread very far. Photo: Dale Stokes

Pycnogonid loving - all legs... the males carry the fertilized eggs around until they hatch. Pycnogonids don't have a pelagic larval stage, so don't spread very far. Photo: Dale Stokes

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