Killing whales for science

Australia has taken Japan to the International Court of Justice over Japan's whaling in the Southern Ocean. There is an interesting series of articles on the Conversation that summarise the court case (in chronological order they are here, here, here, here and here). Australia has argued that Japan is in violation of the International Convention for the Regulation of Whaling and also that Japan's whaling is in contrary to their obligations under the Convention on the International Trade of Endangered Species and the Convention on Biological Diversity.

Japan insists that its whaling activities are for scientific research, which is allowed under the rules set out in the Whaling Convention. Australia case will primarily try to establish that the activities are really a commercial harvest in breach of the International Whaling Commission's moratorium. New Zealand, while not bringing a case against Japan, is set to provide evidence in support of Australia's case. 

It's the worst kept secret in the Universe that Japan is actually engaging in commercial whaling, but establishing it legally seems a bit more tricky. The scientific basis for the hunt has repeatedly been criticised for failing to meet the minimum standards required for science. The major concerns are that very little of the data is published in the scientific literature and most of the hypotheses they claim to be testing are already well established or can be tested without killing whales.

The Institute of Cetacean Research (ICR) is the organisation the undertakes the supposed scientific research involving the lethal sampling of whales. The International Fund for Animal Welfare (IFAW) has recently estimated that the Japanese Government has provided 387 million dollars to the ICR since scientific whaling began in 1988. Since then the ICR has published 150 papers in the literature (according to Web of Science), which is extremely poor output for the amount of money put in (2.58 million per paper!). It is, in fact, poor output had they only received 1% of the IFAW figure.

Another thing to consider is that the 150 published papers are not all on whales and those that are often do not require that the whales be killed to collect the data. Only a tiny minority of the ICR papers present data the require the death of whales and the 387 million dollars has been provided specifically to support the killing of whales. No funding agency would normally continue to provide funding for a research program that has so utterly failed to produce valuable science.

The ICR has stated on several occasions that the output would be better if they didn't have to contend with the Sea Shepherd activists because they prevent adequate sample sizes being taken. Despite these claims the sample size is clearly more than high enough to do some interesting science. In a brief literature search*, I found four papers published since January 2012 that required a total of 37 dead whales. In the same period, the ICR has killed 170 whales in the Southern Ocean alone (notably the lowest two catches since its whaling began) and published just one study in a low quality journal.

It is a hard problem to define exactly what constitutes science. Japan has argued that the International Court for Justice "is a court of law, not of scientific truth", claiming that the Court doesn't have the jurisdiction to determine what constitutes science. But, I think this misses the point. The Court is not being asked to define what constitutes science, but whether the research program is legitimate under the Whaling Convention or veiled commercial whaling. That veil is pretty thin in my opinion and I hope the Court sees it that way too.

*The papers I looked at in the literature search were:
1) Ford T. J., Werth A. J. & George J. C. (2013)
An Intraoral Thermoregulatory Organ in the Bowhead Whale (Balaena mysticetus), the Corpus Cavernosum Maxillaris.
The Anatomical Record 296, 701–708 doi:10.1002/ar.22681

2) Werth A. J. (2013)
Flow-dependent porosity and other biomechanical properties of mysticete baleen.
The Journal of Experimental Biology 216, 1152-1159 doi:10.1242/jeb.078931

3) Pyenson N. D., Goldbogen J. A., Vogl A. W., Szathmary G., Drake R. L. & Shadwick R. E. (2012)
Discovery of a sensory organ that coordinates lunge feeding in rorqual whales.
Nature 485, 498–501 doi:10.1038/nature11135

4) Yamato M., Ketten D. R., Arruda J., Cramer S. & Moore K. (2012)
The Auditory Anatomy of the Minke Whale (Balaenoptera acutorostrata): A Potential Fatty Sound Reception Pathway in a Baleen Whale.
The Anatomical Record 295, 991–998 doi:10.1002/ar.22459

Squid family planning

Female southern bottletail squid may be able to influence the paternity and quality of their offspring by eating the sperm of males. This behaviour is likely to be the result of the conflict that arises between males and females because of their competing evolutionary interests in reproduction. Both sexes use a variety of tactics to manipulate the outcome of mating into their favour. In southern bottletail squid, Sepiadarium austrinum, males use aggression to coerce females into copulations that they might otherwise avoid. 

A new paper from Ben Wegener, Devi Stuart-Fox, Mark Norman and Bob Wong shows that males don’t have it all their own way. Mating occurs head-to-head and is initiated by the male who lunges at the female and grasps her in his tentacles. The male then transfers packets of sperm, called spermatophores, to the female by sticking them into a cavity just below her mouth where they can survive for up to three weeks. But, the spermatophores often have shorter lives because the females will remove and eat them, sometimes before the male has finished copulating with her.

The authors also determined how females were using the nutrients gained from eating the spermatophores. They fed a group of spermatophore-depleted males on a diet laced with a radioactive marker, which was incorporated into new spermatophores as they produced them. Once the females had eaten the radiolabeled spermatophores it was possible to find where the nutrients were being used by assaying for the marker in tissue samples. 

Levels of the marker were elevated in a number of tissues, including the eggs and reproductive glands. Females, therefore, benefit from consuming spermatophores by gaining some additional nutrition that can be allocated to producing offspring. It’s also possible that spermatophore consumption is a form of cryptic female choice, where the spermatophores of low quality males are eaten preferentially. But, this remains to be demonstrated.

This story is also published on the Australasian Evolution Society website in the Research Highlights section.

Reference

Wegener, B. J., Stuart-Fox, D., Norman, M. D., & Wong, B. B. M. (2013). Spermatophore consumption in a cephalopod Biology Letters, 9 (4) DOI: 10.1098/rsbl.2013.0192

World Oceans Day

Tomorrow is World Oceans Day, but today you can get a live stream from the Great Barrier Reef. Expert marine biologists are apparently on hand (I can't load the website) to answer your questions and you can even talk to SCUBA divers on the Reef. Check you social media too because it'll be on Twitter, G+ and YouTube.

Worm sperm

You may have never thought about what feature distinguishes males from females. After all, in mammals the differences are often clear to us. In other groups too, the differences between male and female traits are often conspicuous. But, there are many species where male and female reproductive organs are both present in the same individual. Even in these species we can tell male parts from female parts.

To distinguish male from female we look at the relative size of the sex cells or gametes. Males produce the smaller gametes (e.g. sperm) and females produce the larger gametes (e.g. eggs). This difference in the size of the gametes is known as anisogamy, which essentially means without ("an") the same ("iso") gametes ("gamy"). 

The converse of anisogamy is isogamy. Species that are isogamous are very rare now, but this is thought to be the ancestral condition. As in anisogamous species where fertilisation only occurs when egg and sperm meet, fertilisation cannot occur in isogamous species unless the gametes of two different mating types meet. In isogamous species mating types are are referred to by various names, such as "+" and "-", in place of male and female.

The origins of anisogamy are unclear, but we have a pretty good explanation for why it evolved. Each gamete an individual produces costs energy and it must be stocked with additional reserves so that the zygote can complete development and start acquiring it's own energy. In isogamy, each member of a pair contributes half the energy to produce a viable offspring. In anisogamy, the cost is overwhelmingly paid by one of the mating types.

Investing almost nothing in individual gametes comes with a huge advantage, vastly more gametes can be produced increasing the number of offspring you can potentially produce. The more gametes an individual has the more fertilisations and individual can potentially achieve. Once one mating type gets far enough down the path of small gametes, its pair can't follow because that is likely to result in a zygote that doesn't have enough resources to survive.

It is relatively clear that fertilisation success has driven the evolution of males that produce more, small sperm. However, there are other aspects of sperm size and shape that appear to contribute to fertilisation success and these are surprisingly variable among and within species. Clear demonstrations that differences in sperm characteristics affect fertilisation success are rare, which makes a new paper in Evolution particularly interesting. 

Darren Johnson of the National Centre for Ecological Analysis and Synthesis, with Keyne Monro and Dustin Marshall of UQ (now both at Monash) looked at sperm traits in the broadcast spawning tubeworm, Galeolaria gemineoa. These worms can occur individually or in huge aggregations, leading to substantial variation in the concentrations of sperm and eggs in the wild. Because they don't leave their tubes, their options for increasing fertilisation success are limited relative to mobile species.

A colony of Galeolaria caespitosa, which are nearly identical to G. gemineoa (photo D. Semmens).

Groups of eggs from multiple females were exposed to the sperm of a single male at six different concentrations and two different ages. Fertilisation success was measured at the proportion of eggs that were undergoing normal development within each treatment. This is not a direct measure of fertilisation success because some embryos may have died very early due to genetic incompatibilities rather than the absence of fertilisation. However, it is a reasonable and practical proxy.

At high sperm concentrations, males that produced sperm with longer average tail length and smaller average head size achieved greater fertilisation success. In contrast, males that produced sperm with longer than average heads were favored at low sperm concentrations and older age. The results suggest that variation in sperm size and shape within a species may be preserved because different fertilisation environments favor contrasting sperm characteristics. 

The logistics of genetically assigning paternity prevented the authors from varying sperm competition environments. Had the sperm of multiple males been in competition to fertilise the eggs, different traits or trait combinations could have been favoured. While it is probably more realistic to pit the sperm of several males against each other, single male experiments still provide useful insights into selection on sperm traits.

An abbreviated version of this post also appears in the Research Highlights on the Australasian Evolution Society website.

References:

Johnson, D., Monro, K., & Marshall, D. (2013). The maintenance of sperm variability: Context-dependent selection on sperm morphology in a broadcast spawning invertebrate Evolution, 67 (5), 1383-1395 DOI: 10.1111/evo.12022

The resilience of coral reefs

Many people are justifiably concerned with the potential impacts of climate change and ocean acidification on coral reefs. But, coral reefs have been declining for at least the last 25 years and probably much longer, overwhelmingly due to threats that are unrelated to climate change. If we do not address these impacts we will continue to lose coral cover and reefs will be more vulnerable to climate change and ocean acidification.

A coral outcrop on the Great Barrier Reef (photo Wikipedia)

A new paper serves as an illustration of how resilient coral reefs are to climate impacts when they are isolated from other anthropogenic impacts, such as overfishing and agricultural runoff. James Gilmour and other researchers from the Australian Institute of Marine Science and some from the Centre of Excellence for Coral Reef Studies followed the recovery of the Scott Reef system after a catastrophic bleaching event in 1998 that reduced coral cover from 50% to 10%. There was great concern for the reef system because it was isolated from other reefs that could supply coral larvae to fuel recovery.

The Scott Reef system. The crescent shaped reef at the bottom is Scott Reef South, the small reef above the left arm of the crescent is Scott Reef and the pear shaped reef is Scott Reef North (photo Wikipedia).

It turns out that, on balance, the isolation was a good thing. The supply of coral larvae reaching the reef was less than 6% of what it was prior to the bleaching event for six years. But, the reef was also isolated from chronic anthropogenic pressures, particularly overfishing. The number of herbivorous fish was already high at the time of the bleaching and jumped afterwards. As coral cover increased the numbers of herbivorous fish declined back to what they were prior to the bleaching.

The daisy parrotfish, Chlorurus sordidus, is an important herbivore on coral reefs (photo Dennis Polack, EOL).

The herbivorous fish kept seaweed and other organisms that compete with coral from taking over. Remnant corals that survived the bleaching were able to grow quickly and the small numbers of coral larvae reaching the reef had unexpectedly high survival. The fast growth of existing coral drove the initial recovery of the reef. Once young corals became established and began reproducing the supply of larvae increased and the recovery of coral cover accelerated.

Ten years after the bleaching event the supply of coral larvae had returned to the levels seen before the bleaching. Two years later the amount of coral cover and community structure on the reef had largely been restored. The rate of recovery is made more remarkable by the occurrence of a second more moderate bleaching event, two cyclones and a disease outbreak.

The study highlights just how resilient coral reefs can be to the effects of climate change and other disturbances if chronic anthropogenic stress is low. Overfishing, sedimentation and pollution are causing severe declines in coral cover right now. If we can control these threats, coral reefs might be able to survive in a warmer, more acidic ocean.

Reference:

Gilmour, J., Smith, L., Heyward, A., Baird, A., & Pratchett, M. (2013). Recovery of an Isolated Coral Reef System Following Severe Disturbance Science, 340 (6128), 69-71 DOI: 10.1126/science.1232310

Research Highlights from the Australasian Evolution Society

I have been asked by the Australasian Evolution Society to provide some 'Research Highlights' for their newly launched website. The Research Highlights promote interesting recent research by evolutionary biologists in Australasia. To get more diversity in the types of research covered there will be two or three others writing too. My stories will go up every few weeks and I will endeavor to publish them here as well, probably with some additional comments. My first piece went up a few weeks ago and I've submitted my second, which should go up shortly. I'll post here as soon as it is.

Plastic waste and seabirds

Plastic waste is an important issue for marine conservation. Globally, a greater mass of human waste goes into the ocean than the mass of fish we take out and much of the waste is plastics. And, because plastics breakdown very slowly in the environment they can accumulate in the ocean forming garbage patches. 

Many animals eat or are entangled by plastic debris, which effects animals from very large things like whales to microscopic crustaceans. Photographs of the plastic filled skeletons of albatross chicks on Midway Atoll have placed seabirds among the most recognised victims of plastic pollution. Jennifer Lavers has an interesting article on The Conversation about the problem of plastic pollution for the flesh-footed shearwater and the failure of the Australian Government to place the it on the threatened species list despite significant population declines.

Seaweek!

Seaweek is coming up fast. It's organised by the Marine Education Society of Australia and running from the 2nd to the 10th of March. I've been invited to participate in a day of activities at Rickets Point Marine Sanctuary on the 7th. I'll be talking to primary and high school students about marine introduced species. The day will bring together marine experts from MESA, Parks Victoria, Melbourne Aquarium, Monash University, the Earth Watch Institute, the Ocean Ark Alliance, the Gould League, Marine Care Ricketts Point, Pelican Expeditions, Nautilus Educational and the Australian Youth Climate Coalition (and me, who is not from any of those organisations).

The theme for Seaweek 13 is ‘Sustainable Seas’. The theme provides a focus for students in schools and for communities to inform and inspire them about the diversity of our marine and coastal environments and how, through good management and individual action, we can all contribute towards the sustainability of these environments.

Aims

• Highlight the sustainable management of Australia’s marine environment;
• Identify factors that threaten the sustainability of marine and coastal ecosystems;
• Facilitate the communication of sustainable marine management projects to the education community;
• Initiate interest and actions for supporting sustainable marine management that help us learn more about and contribute towards the sustainability of our marine and coastal environments; and
• Provide schools with educational resources available on the MESA website for school’s classroom based activities.

Find out more about Seaweek here.

The anti-science, anti-environment Victorian Government

The Victorian Government is at it again. They've allowed a "scientific trial" of cattle grazing in Victoria's Alpine National Park against all scientific advice (why conduct a trial when you've already got a robust answer?). They've provided funding to find the Victorian panther, the Australian version of Bigfoot. They've decided to allow private tourist developments in National Parks, when the best thing that National Parks do for the environment is to limit access to people. Now they've decided to redraw the boundaries of the Alpine National Park to allow business at the Falls Creek ski resort to expand. You'd probably be surprised to know that the Victorian Premier is a former director of a real estate company...

Waterfall climbing fish

Diadromous fish are those that live part of their lives at sea and part of their lives if freshwater. Some of these fish reproduce in the upper parts of rivers above barriers like waterfalls, which they must scale in order to make it to the breeding sites. A newly published paper looks at how the Nopili goby, Sicyopterus stimpsoni, manages to climb waterfalls. The researchers found that the way the goby feeds and the way it climbs are very similar.

The Nopili goby, Sicyopterus stimpsoni (photo Takashi Maie)

During feeding the Nopili goby extends its upper jaw out much further and its lower jaw much less than other gobies. In climbing the basic motion is the same except the upper jaw maintains closer contact with the rock. Climbing is also assisted by pelvic fins fused into a sucker, a feature of all gobies. Because no other goby feeds in the same way, it's unclear whether the feeding or climbing movements evolved first.

The climbing galaxias, Galaxias brevipinnis (photo Robert McCormack)

There are many other fish that have a diadromous life-history, eels and salmon being the classic examples. There are fewer fish that climb waterfalls. However, in southern Australia and New Zealand there is a fish close to my heart that has a very similar life-history to the Nopili goby, but it climbs waterfalls in a different way. The climbing galaxias, Galaxias brevipinnis, climbs using its broad pectoral and pelvic fins and wiggling upwards.

Cullen J. A., Maie T., Schoenfuss H. L., & Blob R. W. (2013). Evolutionary Novelty versus Exaptation: Oral Kinematics in Feeding versus Climbing in the Waterfall-Climbing Hawaiian Goby Sicyopterus stimpsoni PLOS One, 8 (1) DOI: 10.1371/journal.pone.0053274

Shifting baselines in coral cover

A great problem for conserving marine ecosystems is that we rarely have a good data on what things were like before human impacts started. In my last post, I wrote about a study that showed that coral cover had declined on the Great Barrier Reef by 50.7% since 1985. At the start of the study coral cover was at 28%, but pristine coral reefs can have over 70% coral cover. This suggests that impacts on the Great Barrier Reef predate the time monitoring started by many years.

A coral outcrop on the Great Barrier Reef (photo Wikipedia)

John Pandolfi at the University of Queensland has been trying to establish the past state of the Great Barrier Reef in numerous ways. One way is to take sediment cores from coral reef and compare the historical diversity and abundance of corals on the reef to the modern community composition. A new study lead by Pandolfi has reconstructed the past coral communities on reefs around Pelorus Island in the Palm Island group. They took cores containing coral remains dating back as far as the mid-third century.

They found that there was a pronounced transition in the coral species on the islands reefs between 1920 and 1955. The transition strongly correlated with a 5 to 10 fold increase in the amount of sediment found in the cores beginning in 1870, but showing several large peaks between the 1920s and 1970s. White settlement and land clearing of the area began in about 1870, the same time that high sediment loads were found in the cores. Prior to that, there was remarkable stability in the coral communities and the amount of sediment reaching the reef.

The new study highlights that reefs in 1985 that were thought to be relatively pristine probably had not been for 50 or 60 years. Therefore attempts to conserve reefs as they were in 1985 is inadequate because these reefs are likely to be already severely impacted by human activities. If we a serious about returning coral reefs to a pristine state, we should be restoring them to what they were like prior to white settlement, not what they were like now after a century of mistreatment.

Roff, G., Clark, T., Reymond, C., Zhao, J., Feng, Y., McCook, L., Done, T., & Pandolfi, J. (2012). Palaeoecological evidence of a historical collapse of corals at Pelorus Island, inshore Great Barrier Reef, following European settlement Proceedings of the Royal Society B: Biological Sciences, 280 (1750), 20122100-20122100 DOI: 10.1098/rspb.2012.2100

Conservation priorities on the Great Barrier Reef

A recently published paper on the decline of coral cover on the Great Barrier Reef serves to illustrate an important point; even without climate change we are doing a great deal of damage to some ecosystems. The study by De'ath et al. and published in the Proceedings of the National Academy of Science, finds that coral cover has declined by 50.7% since 1985. They partitioned the losses into 48% tropical cyclones, 42% predation by crown of thorns starfish and 10% to coral bleaching.

The crown of thorns starfish, Acanthaster planci (image Wikipedia)

The declines were not uniform across the reef. Most of the declines were in the southern part of the reef and near to shore, where more people live. Partly this may be due to more frequent storms in the southern part of the reef, but storm frequency has declined in the last 100 years or so. Mostly it's probably because outbreaks of crown of thorns starfish are linked to human activities, such as agriculture and fishing. And these same human activities leave coral less resilient to other impacts and make it more difficult for them to recover from disturbances.

Pollution, sedimentation and overfishing can all change the dynamics of coral reef communities by impairing the ability of corals to recover from other disturbances. Human activities can also increase the mortality of adult coral and reduce the number larvae that survive to become coral. Shifts from coral-dominated communities to seaweed-dominated communities due to these impacts are well documented.

Overfishing, particularly of herbivorous fish, has been strongly linked to shifts in community composition. In direct competition corals lose out to seaweed, which overgrows coral and in some cases uses toxins to kill the coral. Herbivorous fish though, eat the seaweed tipping the balance in favour of the corals. So important are herbivorous fish to corals that some have formed mutualistic relationships with fish, which they signal for help when seaweeds encroach on their space. 

Overfishing has also been suggested to reduce predation on larvae of the crown of thorns starfish, allowing it to reach plague proportions when fish would normally control their numbers. A second hypothesis is that nutrient inputs from farms and cities provides the crown of thorns larvae with large amounts of food, increasing their survival. Neither hypothesis is well supported, but there is growing evidence that both mechanisms are playing a role in crown of thorns outbreaks. 

For corals, like seagrasses, access to light is critical for their survival. Coral derive as much as 90% of their energy from symbiotic algae growing in their tissues. Nutrient inputs and sedimentation reduce the light available to their algal symbionts, which reduces the energy available to them. This can decrease the resilience of corals to other stressors, such as natural disturbance events. The main sources of sedimentation on the Great Barrier Reef are from human activities, such as agricultural run-off and dredging.  

De'ath et al. conclude that there is an urgent need to control crown of thorns outbreaks, especially through improvements to water quality. In the absence of disturbances, the data showed that reefs were able to increase in cover by nearly 3% per year. This is likely to be higher when the full impact of human activities are taken into account. Moreover, their data only go back to 1985, but human impacts on the reef date back to about 100 years before that. The true decline of coral cover on the Great Barrier Reef is, therefore, likely to be far greater than that measured in their study.

De'ath et al. also highlight the impending effects of climate change and ocean acidification. Many people are focused on human emissions of carbon dioxide as the sole problem we need to fix to save the reef. But, it's clear that even without the threats of climate change and ocean acidification the Great Barrier Reef is in great deal of trouble. In order to conserve the reef we need to address the source of these issues now.

De'ath, G., Fabricius, K., Sweatman, H., & Puotinen, M. (2012). The 27-year decline of coral cover on the Great Barrier Reef and its causes Proceedings of the National Academy of Sciences, 109 (44), 17995-17999 DOI: 10.1073/pnas.1208909109

Rapid speciation in starfish

Australian waters are extremely rich in starfish species. Indeed, a little over 15% of all known species of starfish occur in Australia. For at least two of these starfish, speciation occurred extraordinarily fast. At most, they became separated about 22 thousand years ago, but the best estimate for the timing of the split is about 6 thousand years ago.

We know that evolution can be very rapid (e.g. sticklebacks) and that sometimes this leads to speciation (e.g. cichlids). But, in these cases selection is probably acting on a small number of alleles that are already present in the population. What makes the starfish study so breathtaking is that there has been profound changes to life history in the two species, which likely involved selection on many morphological and physiological traits.

Puritz et al. looked at Cryptasterina pentagona and its sister species C. hystria. Like most starfish, C. pentagona has separate sexes and reproduces by 'broadcasting' sperm and eggs into the water column where fertilisation occurs. In stark contrast, C. hystria produces both sperm and eggs simultaneously, and it exclusively self-fertilises within its own body cavity. The embryos of C. pentagona develop in the plankton, while C. hystria broods its offspring within the gonad until they are ready to emerge as small starfish.

It takes an expert to distinguish Cryptasterina hystria (top) and C. pentagona (bottom) in the wild. In fact I've seen the bottom picture shown as C. hystria and C. pentagona, but I think I got it right (photo Jon Puritz).

Puritz et al. speculate that water temperature may have provided the selective pressure that favoured the evolution of the C. hystria life history. Viviparity, like that seen in C. hystria, has been documented in a number of other starfish species. And it is consistently associated with species that occur in colder water. The two Cryptasterina species are separated by about 375 kilometers, with C. pentagona in the warmer north and C. hystria to the cooler south.

The authors also argue that small population size may have selected for self-fertilisation. If there are so few individuals in the population that your gametes are unlikely to meet another individual's, it's better to fertilise your own than to not reproduce at all. It's expected that genetic variation in a population that self-fertilises should be very low. But, genetic variation in C. hystria is so low it suggests the whole species derived from very few individuals, perhaps just a single one.


The transition from broadcast spawning with planktonic larval development to self-fertilisation with larvae brooded within the gonad has occurred in another Cryptasterina species, C. pacifica. In the closely related genus Parvulastra, a similar transition has occurred too, but probably over 500 thousand years. This suggests that the genetic variation required for the dramatic shift in life history is widely present in the group of starfish to which the genera Cryptasterina and Parvulastra belong. But, the speed at which evolution has occurred is truly astonishing.

Parvulastra exigua, note its similarity to the Cryptasterina species (photo Museum Victoria).

Puritz JB, Keever CC, Addison JA, Byrne M, Hart MW, Grosberg RK, & Toonen RJ (2012). Extraordinarily rapid life-history divergence between Cryptasterina sea star species. Proceedings. Biological sciences / The Royal Society, 279 (1744), 3914-3922 PMID: 22810427

Australia's new marine parks revisited

Last month I wrote about the release of a draft plan for a set of marine parks in Australian Federal waters. I expressed concern that the large area and their distance from shore would make enforcement of the fully protected areas difficult. It seems I'm not alone in this concern. Three marine scientists in Western Australia have written an article in The Conversation expressing similar concerns and others about the design of the marine parks, including the under-representation of some habitats within the parks.

Marine parks and the Great Barrier Reef World Heritage Area

One of the biggest stories in marine conservation in Australia this year is the announcement that 2.3 million square kilometers of Australian waters will receive some form of protection in marine reserves. About a third, or 800 thousand square kilometers will be fully protected as Marine National Parks. This new announcement takes the total area protected by the Federal Government to 3.1 million square kilometers. Which is all cause for some optimism.

A map of the newly declared marine reserve network in Australia. Green denotes the areas which are fully protected as Marine National Parks. Yellow denotes 'special protection areas' which exclude commercial fishing, but allow recreational fishing. Dark blue denotes 'special purpose zones', which allow only some forms of commercial fishing. Light blue denotes 'multiple use zones', which only prevent the most destructive commercial fishing practices. The grey areas in the south-east are the bits of the reserve network that were established in 2007. If you would like a PDF of the map, and other information go here.

The largest contiguous protected area is the Coral Sea Marine Reserve, which adds to the already established Great Barrier Reef Marine Park. There was a storm of criticism when the Coral Sea Marine Reserve draft plan was released because many experts believed that it did not go far enough to protect the reef. In a rare win for the environment, the Australian Government extended the boundaries in the final plan.

A map of the Coral Sea Marine Reserve. Colours denote the same levels of protection as above. If you would like a PDF of the map, and other information go here.

There is, however, still significant disquiet about the future of the Great Barrier Reef, which is estimated to have lost half of its coral cover in the last 50 years. A UNESCO mission to Australian in March strongly criticised the management of the reef and indicated that its listing as a World Heritage Area was at risk of being downgraded. Several of the threats that UNESCO identified will not be addressed by the new marine reserves. 

The UNESCO mission identified climate change, catchment runoff, coastal development, ports and shipping, and fishing as the most pressing threats to the Great Barrier Reef World Heritage Area. Three of these (catchment runoff, coastal development and climate change), are due to activities outside the marine reserve and World Heritage Area. Moreover, the other activities will be allowed in at least some areas of the new marine reserve. 

The cynic in me can't help also noticing two things. Firstly, that the bulk of the areas that receive full protection as marine national parks are generally those which are furthest offshore, where impacts are already low. And, secondly, that there will need to be enforcement of the new restrictions, but there is mention of additional funds to achieve this. Apparently, enforcing compliance will be achieved using existing infrastructure; infrastructure that is already used for other important activities.

Despite my slight cynicism, I think the new marine reserve network is excellent news for the conservation of the marine environment in Australia. But, the network doesn't address all of the threats to Australia's seas. And there are at least three state governments (Victoria, Queensland and Western Australia) that have ignored environmental threats and sought to erode existing protections. It would be incredibly embarrassing for Australia on the world stage and disastrous for Queensland's marine tourism industry if UNESCO were to downgrade the Great Barrier Reef World Heritage Area listing.

Further reading

For the UNESCO mission report go here.

For the Great Barrier Reef Outlook Report, which sparked the UNESCO mission, go here.

For an interesting expert commentary on the UNESCO report go here.

UPDATE:
Just after posting this article I found another article that is more hopeful that the protections granted by the new marine reserves will be adequately enforced. I think they can be too, but enforcement needs funding and I haven't seen those details yet.

SKA split across 3 countries

A decision has finally been made on which of the competing Australia/ New Zealand and South Africa bids will host the Square Kilometer Array. And it seems to be a clever compromise. The square kilometer array (SKA) will now be the 2 square kilometer array. The part of the planned array that will study the fundamental nature of gravity and make detailed images of individual objects will be built in South Africa. Another part of the array, which will be optimised to study the composition and history of the universe through wide sky surveys, will be built in Western Australia.

To meet the goals of the array it will need to cover the range of radio wave from 70 MHz to over 10,000 MHz and it was never going to be possible for a single type of antenna to cover all of it. The low frequency component, consisting of receivers that do not move and cover the whole sky at once, will be built in Australia to take advantage of the 'radio quietness' of the Murchison site in WA. The MeerKAT array of steerable telescopes in South Africa's Karoo desert, will be extended to cover the high frequency range.

Another piece of the array is the technology that will allow the telescopes a wide field of view that has been compared to a fish-eye lens on a camera. This 'phased array feed' technology is currently being developed in Australia and New Zealand, but is most likely going to be installed on the South African telescopes.

Yay! And a correction

A few weeks ago I reported that South Africa had won backing to host the Square Kilometer Array. I got it wrong. The Advisory Committee had recommended that the project go to South Africa, but there was no decision that it would. The final decision is to be made mid-May and apparently the backing of South Africa by the Advisory Committee has not ruled the joint Australia and New Zealand bid out of the race. 

Older fourlegs

China seems to have had the lion's share of the cool fossils unearthed in the last 10 years or so. A new   paper¹ on a coelacanth fossil from south China is another example of their phenomenal treasure trove of fossils. It pushes back the origin of anatomically modern coelacanths by 17 million years to 409 million years ago. The previous oldest coelacanth was known from a jaw found in Australia. 

Coelacanths are interesting for many reasons, not least because they are more closely related to us than they are to other fish. The group was though to have gone extinct around the same time as the dinosaurs, 65 million years ago. But, in 1938 an extant representative was found in South Africa (although it had been known by the local fishermen for a while before that). A book about the discovery dubbed the fish 'old fourlegs'. There was more excitement in 1997, when a second extant species of coelacanth was found off Indonesia.

A preserved specimen of the extant coelacanth, Latimeria chalumnae, or old fourlegs.

The modern coelacanths look almost the same as their ancestors did a few hundred million years ago. So, much like the sharks, they represent 'living fossils'. To put their ancient history in a little perspective, about the same time as the anatomically modern coelacanth body plan emerged, our ancestors were probably taking their first steps on land². 


References:
1 Zhu, M., Yu, X., Lu, J., Qiao, T., Zhao, W., and Jia, L. (2012) Earliest known coelacanth skull extends the range of anatomically modern coelacanths to the Early Devonian. Nature Communications 3, doi: 10.1038/ncomms1764


2 Niedz´wiedzki, G., Szrek, P., Narkiewicz, K., Narkiewicz, M., and Ahlberg, P. E. (2010) Tetrapod trackways from the early Middle Devonian period of Poland. Nature 463, 43 - 48.

Bisexual dolphins or media fail?

Total. Media. Fail... Again...

While there is some evidence that dolphins display homosexual and bisexual behaviours, this, this, this, this and many other places are examples of the media completely failing to communicate the results of a scientific study¹. The results of the paper in question do not provide any evidence, at all, that would suggest that male dolphins are bisexual. The media has jumped on the word bisexual, which is used just once in the introduction (i.e. before the results of the study are described), and failed to understand it in the context that it was used; perhaps willfully in order to create a more sensational story.

The sentence in the paper reads:

The social system of Indo-Pacific bottlenose dolphins (Tursiops sp.) in Shark Bay, Western Australia, features a fission–fusion grouping pattern with stronger associations between adult males than adult females and bisexual philopatry.

The word 'philopatry' provides the context in which the word 'bisexual' should be interpreted. Here it does not refer to the sexual behaviour of the dolphins, but the fact that both sexes are philopatric. That is, both sexes have the tendency to stay in the area that they were born.


Although I can't be sure, I think the churnalism all started with a story on Discovery News. The story does do a pretty good job of discussing the results of the study, but includes the sentence:

Male bottlenose dolphins also were found to engage in extensive bisexuality, combined with periods of exclusive homosexuality.

This gets the situation completely wrong. An earlier paper² showed that male dolphins in Shark Bay form alliances with one or two other males. These first order male alliances cooperate to  aggressively herd females to gain mating access*. The first order alliances also prevent other males from mating with the females that they're herding. 


The first order male alliances can also cooperate with other first order groupd to produce a second order alliance, which in turn may join to form a third order alliance. The higher level alliances cooperate to 'steal' females from smaller groups. But, lower level alliances can also recruit other first order groups to defend the female they are herding. If a female is successfully stolen, only one of the joined first level alliances will herd her afterwards.


The higher level alliances are much less stable than first order alliances. For example, groups A and B may cooperate to steal a female from group C one day, then groups B and C may cooperate to steal a female from group A on another day. However, some high level alliances may persist for well over a decade. The reasons for such fluid, reversible alliances at higher levels are unclear, but it may have to do with the context of the encounters.


Despite the findings being less 'juicy' than the popular science articles make it seem, the paper is really interesting. The purpose of the paper was to test hypotheses about the structure of dolphin societies. Evidence from previous studies, such as the one described above, is strongly suggestive that males form their strong alliances in otherwise open social networks. This type of social structure has never been previously documented in mammals.


In mammals, male alliances form to acquire or defend valuable resources from other males, such as territories or female groups. Although it did not seem like this was occurring in the Shark Bay dolphins, two hypotheses had not been properly tested. The 'community defence model', which argues that there are dominant alliances that range over the entire population, and the 'mating season defence model', which argues that males defend territories or females only during the breeding season.


The study found little evidence to support either of the two hypotheses. No male alliances ranged over the entire site as the 'community defence model' predicted. Alliances also overlapped during the mating season and females were not consistently associated with particular alliances as the 'mating season defence model' predicted. So, now we have strong evidence that dolphin societies are unlike any other mammal societies.


The authors of the study point out that a society organised in such a way would put unusual pressures on social cognition. Not only must they remember previous encounters with other dolphins, but they must cope with uncertainty that the relationships are still the same. Individuals that were friends in earlier encounters may have formed new alliances since you last interacted with them and become foes. 


It's little wonder that social complexity correlates quite well with brain size, but it's hard to tell which came first. Larger brains may allow more complex social interactions to occur, but more complex social interactions may place selection pressure on large brain size. The authors argue that the complexity of dolphin society is probably a driver of brain size evolution in dolphins, and I tend to agree.


The authors also make the interesting argument that increased locomotion efficiency and low movements speeds have played a role in producing the social complexity and, therefore, brain size evolution. They argue that more efficient travel allows individuals to exploit larger areas and this would increase the chance that competitive encounters occur. A greater number of competitive encounters would, in turn, favour the formation of alliances with other individuals. I'm not so sure about this argument. Brains are energetically expensive to maintain, and probably favour more efficient use of resources elsewhere. Evolution always involves trade-offs.


So, it was a very interesting article with exciting results and the media did not communicate it at all well because they couldn't get past the word bisexual. They didn't even check to see whether it was used to mean what they thought it meant. Again I am disappointed with the media's coverage of science. 

*It's been called 'gang rape' by some articles, but this is not at all what it actually is. Although, by human standards, it's definitely not romantic. The herding males threaten, bite, hit and crash into the females they are herding.

Further reading:

1 Randic, S., Connor, R. C., Sherwin, W. B., and Krutzen, M. (2012) A novel mammalian social structure in Indo-Pacific bottlenose dolphins (Tursiops sp.): complex male alliances in an open social network. Proceedings of the Royal Society B. doi: 10.1098/rspb.2012.0264

2 Connor, R. C., Smolker, R. A., and Richards, A. F. (1992) Two levels of alliance formation among male bottlenose dolphins (Tursiops sp.). Proceedings of the National Academy of Sciences 89: 987 - 990

Tweets in the deep

When the intrepid adventurers in the Lord of the Rings reached Moria they heard drums in the deep. Now James Cameron has reached the oceans deepest point, the Challenger Deep in the Marianna Trench off Guam. I'm not sure if he heard drums, I suspect he didn't, but he's sent a tweet:

Just arrived at the ocean's deepest pt. Hitting bottom never felt so good. Can't wait to share what I'm seeing w/ you.

I'll bet he can't wait because he's going to charge you money to "share" what he's seeing with you. He has plans to release two documentaries with the footage he collects.


It's the first time since 1960 that anyone has been to the Challenger Deep. At 10, 898 meters below the surface, it's an impressive feat. Nice work James. And nice work Australian engineering team who built the submersible he piloted. Now how about lending me the keys?...