Eastern Seaboard Climate Change Initiative

30 04 2009
© A. Perkins
© A. Perkins

I’ve just spent the last few days in Sydney attending a workshop on the Eastern Seaboard Climate Change Initiative which is trying to come to grips with assessing the rising impact of climate change in the marine environment (both from biodiversity and coastal geomorphology perspectives).

Often these sorts of get-togethers end up doing little more than identifying what we don’t know, but in this case, the ESCCI (love that acronym) participants identified some very good and necessary ways forward in terms of marine research. Being a biologist, and given this is a conservation blog, I’ll focus here on the biological aspects I found interesting.

The first part of the workshop was devoted to kelp. Kelp? Why is this important?

As it turns out, kelp forests (e.g., species such as Ecklonia, Macrocystis, Durvillaea and Phyllospora) are possibly THE most important habitat-forming group of species in temperate Australia (corals and calcareous macroalgae being more important in the tropics). Without kelp, there are a whole host of species (invertebrates and fish) that cannot persist. The Australian marine environment is worth something in the vicinity of $26.8 billion to our economy each year, so it’s pretty important we maintain our major habitats. Unfortunately, kelp is starting to disappear around the country, with southern contractions of Durvillaea, Ecklonia and Hormosira on the east coast linked to the increasing southward penetration of the East Australia Current (i.e., the big current that brings warm tropical water south from Queensland to NSW, Victoria and now, Tasmania). Pollution around the country at major urban centres is also causing the loss or degradation of Phyllospora and Ecklonia (e.g., see recent paper by Connell et al. in Marine Ecology Progress Series). There is even some evidence that disease causing bleaching in some species is exacerbated by rising temperatures.

Some of the key kelp research recommendations coming out of the workshop were:

  1. Estimating the value of kelp to Australians (direct harvesting; fishing; diving)
  2. Physical drivers of change: understanding how variation in the East Australian Current (temperature, nutrients) affects kelp distribution; understanding how urban and agricultural run-off (nutrients, pollutants, sedimentation) affects distribution and health; understanding how major storm events (e.g., East Coast Lows and El Niño-Southern Oscillation) affects long-term persistence
  3. Monitoring: what is the distribution and physical limits of kelp species?; how do we detect declines in ‘health’?; what is the associated biodiversity in kelp forests?
  4. Experimental: manipulations of temperature/nutrients/pathogens in the lab and in situ to determine sensitivities; sensitivity of different life stages; latitudinal transplants to determine localised adaption
  5. Adaptation (management): reseeding; managing run-off; managing fisheries to maintain a good balance of grazers and predators; inform marine protected area zoning; understanding trophic cascades

The second part of the discussion centred on ocean acidification and increasing CO2 content in the marine environment. As you might know, increasing atmospheric CO2 is taken up partially by ocean water, which lowers the availability of carbonate and increases the concentration of hydrogen ions (thus lowering pH or ‘acidifying’). It’s a pretty worrying trend – we’ve seen a drop in pH already, with conservative predictions of another 0.3 pH drop by the end of this century (equating to a doubling of hydrogen ions in the water). What does all this mean for marine biodiversity? Well, many species will simply not be able to maintain carbonate shells (e.g., coccolithophore phytoplankton, corals, echinoderms, etc.), many will suffer reproductive failure through physiological stress and embryological malfunction, and still many more will be physiologically stressed via hypercapnia (overdose of CO2, the waste product of animal respiration).

Many good studies have come out in the last few years demonstrating the sensitivity of certain species to reductions in pH (some simultaneous with increases in temperature), but some big gaps remain in our understanding of what higher CO2 content in the marine environment will mean for biota. Some of the key research questions in this area identified were therefore:

  1. What is the adaptation (evolutionary) potential of sensitive species? Will many (any) be able to evolve higher resistance quickly enough?
  2. In situ experiments outside the lab that mimic pH and pCO2 variation in space and time are needed to expose species to more realistic conditions.
  3. What are the population consequences (e.g., change in extinction risk) of higher individual susceptibility?
  4. Which species are most at risk, and what does this mean for ecosystem function (e.g., trophic cascades)?

As you can imagine, the conversation was complex, varied and stimulating. I thank the people at the Sydney Institute of Marine Science for hosting the fascinating discussion and I sincerely hope that even a fraction of the research identified gets realised. We need to know how our marine systems will respond – the possibilities are indeed frightening. Ignorance will leave us ill-prepared.

CJA Bradshaw

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Plight of frogs

27 04 2009

I’m off to a conference shortly, so this will be brief.

© D. Bickford
© D. Bickford

In an effort to raise awareness about the plight of amphibians (see previous posts on ConservationBytes.com regarding drivers of amphibian extinction risk and over-harvesting frogs for human consumption), the mob at SaveTheFrogs.com have initiated ‘Save The Frogs Day’ for tomorrow (28 April 2009).

I encourage people to get involved – there are some particularly good ideas for teachers and students found at the dedicated ‘Save The Frogs Day’ website.

CJA Bradshaw





More than just baby sharks

23 04 2009

Sharks worldwide are in trouble (well, so are many taxa, for that matter), with ignorance, fear, and direct and indirect exploitation (both legal and illegal) accounting for most of the observed population declines.

Despite this worrisome state (sharks have extremely important ‘regulatory’ roles in marine ecosystems), many people have been slowly taking notice of the problem, largely due to the efforts of shark biologists. An almost religious-like pillar of shark conservation that has emerged in the last decade or so is that if we save nursery habitats, all shark conservation concerns will be addressed.

Why? Many shark species appear to have fairly discrete coastal areas where they either give birth or lay eggs, and in which the young sharks develop presumably in relative safety from predators (including their parents). Meanwhile, breeding parents will often skip off as soon as possible and spend a good proportion of their non-breeding lives well away from coasts. Sexual segregation appears to be another common feature of many sharks species (the boys and girls don’t really play together that well).

The upshot is that if you conserve these more vulnerable ‘nursery’ areas in coastal regions, then you’ve protected the next generation of sharks and all will be fine. The underlying reason for this assumption is that it’s next-to-impossible to conserve entire ocean basins where the larger adults may be frolicking, but you can focus your efforts on restricted coastal zones that may be undergoing a lot of human-generated modification (e.g., pollutant run-off, development, etc.).

However, a new paper published recently in Conservation Letters entitled Reassessing the value of nursery areas to shark conservation and management disputes this assumption. Michael Kinney and Colin Simpfendorfer explain that even if coastal nurseries can be properly identified and adequately conserved, there is mounting evidence that failing to safeguard the adult stages could ultimately sustain declines or arrest recovery efforts. The authors support continuing efforts to identify and conserve nurseries, but they say this isn’t enough by itself to solve any real problems. If we want sharks around (and believe me, even though the odd swimmer may get a nip or two, it’s better than the alternative of no sharks), then we’re going to have to restrict fishing effort on the high seas as well.

I think this one qualifies for the ‘Potential‘ list.

CJA Bradshaw

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No end in sight for tropical deforestation

20 04 2009

Just a quick one while I wade through the swamp of overdue deadlines.

Despite years of conservation biologists telling the world about the woeful state of the world’s forests, the loss of essential ecosystem services and the biodiversity extinction crisis, it seems the message doesn’t really get out. I’m in a state of semi-shock about the following Reuters release on the potential deal to deforest 10 million hectares for agricultural expansion in the Republic of Congo. There isn’t a single mention of the deforestation aspects or what it will mean for the Congolese. Sure, turn your country (the last remaining large tracts of rainforest in Africa) into a paddock, and see how long your ‘food security’ lasts under climate change. From poor to destitute in a matter of decades.

South African farmers have been offered 10 million hectares of farm land to grow maize, soya beans as well as poultry and dairy farming in the Republic of Congo, South Africa’s main farmers union said on Wednesday.

The deal, which covers an area more than twice the size of Switzerland, could be one of the biggest such land agreements on the continent agreed by Congo’s government in an effort to improve food security, Theo de Jager, deputy president of Agriculture South Africa (AgriSA), told Reuters.

South Africa has one of the most developed agriculture sectors on the continent, and is Africa’s top maize producer and No.3 wheat grower.

“They’ve given us 10 million hectares, and that’s quite big when you consider that in South Africa we have about 6 million hectares of land that is arable,” De Jager told Reuters on the sidelines of an agriculture conference in Durban.

De Jager said the agreement — to be finalised in South Africa next month — would operate as a 99-year lease at no cost, with additional tax benefits.

“The offer which we got and we’ve agreed on paper, is a 99-year lease, of which the value would be zero and it’s not allowed to escalate over the 99 years. So it is free use for 99 years,” he said.

The Republic of the Congo’s population of around 4 million people is concentrated in the southwest, leaving the vast areas of tropical jungle in the north virtually uninhabited.

De Jager said some 1,300 South African farmers were keen to farm in the Congo Republic.

“We have two groups of farmers who are interested, one of farmers who want to leave South Africa and relocate entirely to farm over there and another of farmers who want to diversify their farming operations to the Congo,” he said.

“We’ve got guys wanting to get into poultry and dairy farming, as well as maize and soya bean production.”

TAX HOLIDAYS

“It is a tax holiday for the first five years and you’re also exempted from import tax on all your agricultural inputs and equipment,” he said.

“So you can import directly from the source and take all your profits out for the duration of this lease,” he said.

He said there was a government-to-government bilateral agreement on the promotion and protection of investments.

“There are also rules for disengagement, for example if they find oil or minerals on your farm they can move you off, but compensate you for the loss of income and they must give you land to the same value or more in a different area,” he said.

De Jager said food in Congo was expensive because the country lacks an established agriculture sector and most of its foodstuff is imported.

“On their side, (the Congo government) is promising the Congolese that they will be self-sufficient in food production in five years, and the way they want to do it is by importing, according to them, high technology farmers,” De Jager said.

South African farmers had also been invited to farm in Mozambique, Angola, Nigeria, Libya, Kenya, Democratic Republic of Congo, Malawi and Zambia, he said.





Cartoon guide to biodiversity loss IV

15 04 2009

And the most degraded and self-flagellating humour on Earth continues (see also previous instalments here, here and here) …

cartoonenvironment_cartoon_7030

hourglass-earth

5765_shark_cartoon

CJA Bradshaw

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Band-aid approach to fix ecological and economic ruin

10 04 2009

An excellent article by Andrew Simms (policy director of the New Economics Foundation) posted by the BBC:

It is like having a Commission on Household Renovation agonise over which expensive designer wallpaper to use for papering over plaster cracks whilst ignoring the fact that the walls themselves are collapsing on subsiding foundations.

While most governments’ eyes are on the banking crisis, a much bigger issue – the environmental crisis – is passing them by, says Andrew Simms. In the Green Room this week, he argues that failure to organise a bailout for ecological debt will have dire consequences for humanity.

“Nature Doesn’t Do Bailouts!” said the banner strung across Bishopsgate in the City of London.

Civilisation’s biggest problem was outlined in five words over the entrance to the small, parallel reality of the peaceful climate camp. Their tents bloomed on the morning of 1 April faster than daisies in spring, and faster than the police could stop them.

Across the city, where the world’s most powerful people met simultaneously at the G20 summit, the same problem was almost completely ignored, meriting only a single, afterthought mention in a long communiqué.

World leaders dropped everything to tackle the financial debt crisis that spilled from collapsing banks.

Gripped by a panic so complete, there was no policy dogma too deeply engrained to be dug out and instantly discarded. We went from triumphant, finance-driven free market capitalism, to bank nationalisation and moving the decimal point on industry bailouts quicker than you can say sub-prime mortgage.

But the ecological debt crisis, which threatens much more than pension funds and car manufacturers, is left to languish.

It is like having a Commission on Household Renovation agonise over which expensive designer wallpaper to use for papering over plaster cracks whilst ignoring the fact that the walls themselves are collapsing on subsiding foundations.

Read the rest of this entry »





Fishing for conservation

3 04 2009

Here’s a guest post from one of my newest PhD students, Jarod Lyon of the Arthur Rylah Institute in Victoria. He’s introducing some of his ongoing work and how he incorporates anglers into conservation research.

As most conservationists know, snags (fallen trees and branches in rivers) are the riverine equivalent of marine reefs, providing critical habitat for many plants and animals, from microscopic bacteria, fungi and algae through to large native fish. They are the places where the greatest numbers and diversity of organisms occur in lowland sections of rivers. Their presence has an important influence on the overall health of these rivers.

Murray River, Australia
Figure 1

Ins southern Australia, Murray cod, trout cod and golden perch are three iconic fish species that occur in the Murray River (Figure 1). Recent investigations into the ecology of these species have demonstrated a strong dependence on the presence of snags – a relationship well-known to recreational anglers who target both Murray cod and golden perch. Unfortunately, the abundance of these species has declined over the past 100 years and they are now considered threatened. Excessive removal of snags has been identified as a primary cause for this decline. For example, in the Lake Hume to Lake Mulwala reach of the Murray River, over 25000 snags were removed in the 1970s and 1980s to improve the passage of water between Lake Hume and the large irrigation channels at Yarrawonga.

Figure 2
Figure 2

The largest resnagging project ever undertaken in Australia is now in full swing. It aims to reverse the legacy of clearing snags that has occurred along the Murray reaches since European settlement. The resnagging is occurring in the Hume-Mulwala reach of the Murray using trees that were cleared for the Hume Highway extension between Albury and Tarcutta, and will create substantially more physical habitat for native fish in this reach of the river. By creating this habitat, the size of the native fish population in this reach is expected to increase thereby improving the conservation status of the native species present, and improving the quality of the recreational fishery for native species (particularly Murray cod and golden perch). It is the largest project of its kind ever undertaken in Australia, and is a great step towards recovering fish populations. The project is funded under the Murray Darling Basin Commission‘s Living Murray Program, and is being undertaken by a variety of state and national organisations, in particular NSW Department of Primary Industries and Victorian Department of Sustainability and Environment (DSE).

To ensure that the resnagging is having a beneficial effect on the numbers of native fish in the reach, a comprehensive monitoring and evaluation program is being implemented by scientists from the DSE’s Arthur Rylah Institute. This program is determining whether an increase in the size of the native fish populations is the result of:

  • Increased recruitment in the reach
  • Increased survival of adults in the reach
  • Increased immigration of adults and juveniles form Lake Mulwala and the Ovens River
  • Decreased emigration form the reach

To measure these changes, the fish populations between Hume Dam and Lake Mulwala are being surveyed once a year to determine the population size and level of recruitment. For the purpose of comparison, surveying between Yarrawonga and Tocumwal, in the lower Ovens River, and in Lake Mulwala, is also being undertaken.

Figure 2
Figure 3

Some of the fish caught (Figure 2) will be tagged with an external tag, internal tag or radio transmitter (Figures 3 & 4). All tags have a unique number that identifies the individual. The recapture of these individuals, both by researchers and by anglers, allows survival and movement patterns to be measured.

The external tags are plastic polymer tags and are easily visible, protruding from the dorsal fin area. These tags are used to allow information from anglers to be directly used in the monitoring. A phone number is printed on each tag and when anglers call this number to report that they have caught a tagged fish, this provides valuable information on the not only fish survival and growth, but also the performance of the recreational fishery. These tags have a lifespan of 2-5 years. Anglers who call in tag information are also eligible for a reward (usually a stubby holder or lure) and get sent a certificate which gives details of the history of the fish which they have captured and reported.

The internal tags are implanted into the area to the front of the pectoral fin, are not visible, and unlike the external tags, are permanent. The tags are passive integrated transponder (PIT) tags (Figure 4), similar to those used in the pet and livestock industry. The tags are important as they allow a long-term record of fish survival, growth and movement to be measured. Fishways across the Murray Darling Basin are increasingly being installed with readers that can detect these tags. This can give researchers valuable information on long-range movements. For example, one fish (a 20-kg Murray cod) that was tagged in the Murray river near Corowa, was picked up on a PIT tag reader at the bottom of the Torrumbarry Weir fishway – a fair feat when you consider that this fish has had to get through both Mulwala and Torrumbarry Weirs, as well as travel a distance of over 200 river km downstream!

Figure 3
Figure 4

Radio transmitters are surgically inserted into the body cavity of the fish (Figure 3). These tags emit a radio signal that can be tracked continuously (Figure 5), and allow a rapid assessment of the movements (i.e., emigration and immigration rates) of a population to be determined. The tags are also detected by an array of 18 logging stations located along the river between Lake Hume and Barmah (Figure 1). Approximately 1000 radio tags will be implanted over the life of the project – making it possibly the largest radio-tagging program in the country.

If you catch a tagged fish, please record the type of fish, its number, its length (and its weight if possible) and the location of its capture and report this information on the phone number printed on the tag. These angler records improve the quality of the data collected and reporting of angler captures is encouraged through the rewards program.

As well as the general tag return program, a more targeted “Research Angler Program” is being undertaken. The angler program commenced operations in July 2007. The project was developed to assist with the scientific monitoring and communication requirements of the native fish habitat restoration project.

This section of the monitoring recognises that local anglers can contribute information about the state of native fish in the River Murray by recording their fishing effort and the amount of fish captured. Such information, in addition to greatly increasing the community awareness of the monitoring program, also adds another ‘string to the monitoring bow’ in that it will form a long-term dataset of fish captures, which can eventually be linked to the resnagging effort. The information gathered will be entered into a database and analysed to help assess changes in fish population size in relation to the habitat rehabilitation project.

Figure 5

Figure 5

Instream woody habitat is a vital component to the lifecycle of Murray Cod and the endangered trout cod. The resnagging of the River Murray – Hume Dam to Yarrawonga, will conserve and enhance native fish communities. Continual monitoring and interactions with the local angling fraternity is a crucial part of the success of this project.

The anglers have logbooks and have been trained in removing the otoliths, which are the earbones, from fish that they are taking for the table. We can then use the otoliths to determine the age and growth of the fish in response to the resnagging work.

Since December 2007 the fishers with the resnagging Angler Monitoring Program have captured over 65 Murray Cod, with over 95% of these fish released. Anglers have caught and released other native species such as golden perch and the endangered trout cod.

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