Thursday, November 21, 2019

Scientists develop new method to estimate seal breeding frequency

New research, led by the Sea Mammal Research Unit (SMRU) at the University of St Andrews, develops method to better record breeding histories of seals, allowing for improved fecundity calculations.

Fecundity is a defining feature of the population dynamics of long-lived animals. Adult female seals typically give birth to single pups in most years so recording how often seals breed is a vital stage in estimating population size. However, some seals appear to “skip” breeding in some years and determining how often individuals breed is then complicated by observability; is a ‘missing’ year a failure to breed or a failure to record a breeding event?
Researchers have used the pattern of sequential changes in a seal mother’s body mass over several years to reconstruct incomplete breeding histories.

The new approach, developed in collaboration with the University of Edinburgh, and published in the Journal of Animal Ecology (Thursday 21 November) allows missing years to be assigned as breeding or non-breeding, producing complete breeding records for each seal and fecundity of all seal mothers to be estimated.
The new method relies on understanding the mass changes that mothers experience in the course of rearing a pup. Rearing offspring is costly, and a seal mother must be in good condition to breed successfully. Grey seals in the UK are true capital breeders, that is, a mother fasts during the brief but demanding period of pup-rearing, so that all the costs of rearing a pup, including nursing the offspring with high fat milk and sustaining the mother’s own requirements are met from body reserves accumulated before breeding. If food is scarce before breeding takes place or the mother experiences other difficulties, breeding in that year may be sacrificed as a trade-off against her future survival and breeding. 

Multidecadal studies of known seals at the breeding colonies of North Rona in the Outer Hebrides and Isle of May in the Firth of Forth have followed mothers’ mass changes over successive breeding seasons. A mother can lose 40% of her initial mass in each breeding season while she nurses a pup, and typically this is recouped by the start of the following season. Crucially, a mother who misses a breeding year usually returns the following year with a larger mass gain than a mother who bred. This change in mass between years allows inferences to be made about breeding in a “missing” year. 

“The new modelling approaches used here allowed us to consider different types of information simultaneously. We use mark-recapture data, body mass measurements and environmental variation to come up with new fecundity estimates” explains Dr Sophie Smout, lead modeller on the study from the School of Biology at the University of St Andrews.  “We found that mothers were probably breeding in around one third of “missing” years, so this increased our fecundity estimates for both colonies.” However, over the study, numbers of grey seal pups born at North Rona have declined, while at the Isle of May, pup numbers have increased and stabilised.

“If a mother expends too much in breeding, she is likely to suffer reproductive consequences”, said Dr Paddy Pomeroy, from the Sea Mammal Research Unit. “Mothers in poor condition after breeding at North Rona didn’t regain mass as successfully as mothers at the Isle of May, and low body mass makes them likely to skip breeding. Grey seals at North Rona appear to be coping less well with the conditions they experience and the contrast between pup production at Outer Hebrides and North Sea colonies suggests this is part of a larger pattern.  Long-term studies like this one are critically important, allowing us to understand how long-lived animals such as seals respond to environmental challenges.”  

Sunday, September 14, 2014

Environmental risks connected with fracking

Fracking or to be more precise hydraulic fracturing is just another example in constant fight between economy and ecology, and yet again it looks like ecology will come up short sleeves because of serious money involved in fracking business.

The fracking technology has developed significantly in the last couple of years and now thanks to this rapid development this business has potential value of trillions of dollars since it makes previously unreachable oil and natural gas reachable.

Why is fracking problem for our environment? Basically, process that involves blasting huge amounts of water, sand and chemicals deep into underground rock formations is certain to be connected with several major environmental risks.

One of the most talked about environmental risks connected with fracking is the large consumption of water, which is thing to worry, especially considering the latest droughts in United States. Fracking has larger water requirements compared to conventional gas drilling, though smaller than those of coal and nuclear power plants. There is also the fear of contaminating drinking water supplies with pollutants (failures in the steel and cement casings of wells nearer to the surface and the disposal of wastewater can lead to contaminated drinking water).

Most fracking wastewater in the United States is injected deep underground. This can lead to several major environmental risks and not just the contamination of drinking water, for instance it can cause earthquakes and unwanted seismic activity.

Why not use solar and wind energy instead of this natural gas found in shale rocks? The natural gas found in these rocks is abundant and cheap which makes it hard for renewable energy to compete against.

Fracturing wells can lead to significant release in volatile organic compounds and air pollutants which is not only harmful for our environment but also for our health.

This issue requires new comprehensive studies that would compare the economic benefits with environmental risks. If the risks are too great then even the cheap natural gas shouldn't come up as the winner but as always it is very difficult to emerge victorious against the most powerful industry in the world.

Sunday, March 9, 2014

Shark conservation campaign in Maldives

Sharks, the great predators of the sea, are under great threat of extinction. Each year, more than 70 million sharks are being killed on global scale, and if this situation doesn't change the marine food web could soon be irreparably damaged because sharks are on top of the marine food web.

The shark conservation will need to be improve significantly in years to come, and world definitely needs more protected areas where sharks can roam freely without interference from humans.

The Soneva Group recently announced that its Maldives resort, Soneva Fushi, will serve as regional headquarters for the largest worldwide shark conversation campaign, FINished with Fins. FINished with Fins can boast the support of over 100 of Hong Kong’s taste makers and opinion leaders, 150 celebrities from Singapore, Malaysia, Taiwan and China, and has now added Sonu and Eva Shivdasani, founders of The Soneva Group, to its list of campaigners.

Jonn Lu, Regional Director, Asia Pacific for Shark Savers, who was instrumental in founding the FINished with Fins movement, flew to the Maldives to sign the resort up to the cause. Sonu and Eva have pledged their support to help lobby against illegal shark fishing in their local area as well as on a global stage to help recruit other corporations to support shark conservation, notably other resorts in the Maldives and travel industry leaders.

Back in 2000, their waters were teeming with sharks, however as the years have gone by the shark population has depleted significantly. This led to the Maldivian government commendably introducing a ban on shark fishing in all its waters in 2010. The ban was a great step forward for shark conservation however it only prevented fishermen from hunting sharks up to 12 nautical miles (22 kilometres) off the atoll coasts. This has led to poachers shark fishing and trading outside of the perimeter. Soneva Fushi would like to see the perimeter extended further to make it a lot more difficult for shark fishing and trading to take place and try and put a stop to it once and for all.

The resort is aware of sharks’ role in the ocean’s food chains, and that their depletion is due to the unsustainable demand for shark fin soup in A.

Friday, December 6, 2013

The main hazards of geoengineering

Geoengineering refers to deliberate large-scale manipulation of the planetary environment to counteract human-caused climate change, most notably global warming. Some scientists look at geoengineering as one of the few remaining solutions to tackle climate change but there are many things that could go wrong with this approach. Let me mention the most important ones:

1) The most obvious is of course the climate catastrophe. Computer models and simulations, despite taking into account countless factors that contribute to our climate are still incomplete because science is yet to fully grasp everything that goes behind the climate meaning that our still limited understanding of the world's climate system could result in major climate catastrophe, even worse than the one we tried to fix.

2) Various political issues would also occur because if changes in the climate affect various parts of the world, the question of who should control the global thermostat also raises issues, and one must ask whether one or few nations really have the right to decide what is best for the rest of the world.

As some middle solution, there were scientific proposals called a "soft-geoengineering" approach, in which changes we make are still widespread, but are reversible and predictable, though whether we actually can predict all factors and guarantee 100% reversibility and predictability, still remains a question.

Geoengineering should really be the last weapon against climate change, and even then it should be taken only in small doses because sometimes even the best possible intentions can go horribly wrong. The world should rather focus on reducing the carbon emissions by shift to clean energy sources. That's much safer solution to our planet and life on Earth in general.

Friday, October 4, 2013

Diesel pollution can cause serious damage to honeybee population

Honeybees play extremely important role in global economy, due to pollination which significantly increases the yield of many crops, thus resulting in more food. Sadly, bees are said to be rapidly declining in many parts of the world due to pollution with pesticides and several other reasons. The latest study from the University of Southampton showed that diesel fuel is also among the factors that have negative impact on honeybees.

The UK scientists from the Southampton University have found the connection between the air pollutants found in diesel exhaust and the bees inability to recognize flower odors.

Honeybees use floral odors in order to locate, identify and recognize the flowers from which they forage but chemicals found in diesel exhaust such as NOx gases alter the odor's profile of flowers thus making honeybees unable to recognize flowers.

Emissions limits for nitrogen dioxide are regularly exceeded in large parts of the world, especially in urban areas which could lead to even bigger decline in honeybee population thus further reducing global pollination activity and leading to reduced food production.

It has been said that honeybees use a variety of chemicals found in a floral blend to discriminate between different blends and they certainly do not need various nitrogen oxides to disrupt their recognition process, especially now when world is rightly worried about the ongoing decline in bee population.

Global food security without preserving honeybees is almost unimaginable and we must discover all the factors that have contributed to decline in honeybee population and reduce them as much as possible.