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[MARINE_BIOLOGY_INTERNATIONAL] BOTULISM, AVIAN - USA (06): (MARYLAND) AQUATIC BIRDS
Thursday, August 30, 2012 | By Science
BOTULISM, AVIAN - USA (06): (MARYLAND) AQUATIC BIRDS
****************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases <http://www.isid.org>
Date: Sat 25 Aug 2012
Source: CapitalGazette.com [edited]
<http://www.capitalgazette.com/news/environment/avian-botulism-hits-poplar-island-birds/article_13c31006-0f40-5f9e-8a9c-36830eed4839.html>
Poplar Island attracts hundreds of species of birds, from shorebirds to waterfowl to birds of prey. But some of them are in trouble. Avian botulism is sickening and killing some of the shorebirds and waterfowl at Poplar, according to the US Fish and Wildlife Services one of the government agencies involved in restoring the Chesapeake Bay island as a wildlife sanctuary.
This summer's [2012] heat waves and lack of rain have allowed avian botulism to thrive on the island, where dredged material is being used to reclaim the island as a wildlife habitat, said Chris Guy, a biologist with the Fish and Wildlife Service's Chesapeake Bay office in Annapolis.
Avian botulism is not harmful to humans but can cause lethargy and dehydration in birds. If left untreated, it can be fatal to birds.
The concern started 2 Aug [2012] when a black-neck stilt, a large black-and-white shorebird, was spotted with signs of avian botulism.
In recent weeks, biologists from the US Fish and Wildlife Service and the Maryland Environmental Service have collected nearly 300 sick or dying birds, mostly sandpipers and mallards.
A total of 78 birds have been sent to Tri-State Bird Rescue and Research in Delaware for treatment. The goal is to eventually allow the birds to be released.
Biologists think they caught the outbreak in time to prevent a large-scale loss of birds. "By recognizing warning signs and taking decisive action, we were able to keep the number of birds harmed by this event very low," said Pete McGowan, a biologist with the US Fish and Wildlife Service.
More than 130 species of birds have been spotted nesting, feeding, or resting at Poplar Island. It has a particularly robust population of cormorants, as well as many egrets, terns, and ducks.
[Byline: Pamela Wood]
--
Communicated by:
ProMED-mail from HealthMap alerts
<promed@promedmail.org>
[Avian botulism is a paralytic disease caused by ingestion of a toxin produced by the bacteria _Clostridium botulinum_. These bacteria are widespread in soil and require warm temperatures, a protein source, and an anaerobic (no oxygen) environment in order to become active and produce toxin. Decomposing vegetation and invertebrates combined with warm temperatures can provide ideal conditions for the botulism bacteria to activate and produce toxin. There are several types of toxin produced by strains of these bacteria; birds are most commonly affected by type C and to a lesser extent type E. Outbreaks of botulism in wild aquatic birds are a natural phenomenon in North America.
A map of the affected area can be accessed at <http://healthmap.org/r/3cWH>. - Mod.PMB]
[see also:
Botulism, avian - USA (05): (WY) pheasants 20120824.1262052 Botulism, avian - USA (04): (CA) waterfowl, susp. 20120802.1225667 Botulism, avian - USA (03): (OH) waterfowl, susp 20120706.1192230 Botulism, avian - USA (02): (HI) 20120624.1178706 Botulism, avian - USA: (CA) 20120430.1117985 Botulism, avian - New Zealand: (CB) susp 20120213.1040575
2011
----
Botulism, avian - USA: (CO) 20110914.2797 2010
----
Botulism, avian - USA (05): (FL) susp. 20100817.2848 Undiagnosed die-off, avian - USA (08): (CA) botulism susp.
20110923.2878]
............................................sb/pmb/mj/dk/ll
*##########################################################*
************************************************************
ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the
information, and of any statements or opinions based
thereon, are not guaranteed. The reader assumes all risks in
using information posted or archived by ProMED-mail. ISID
and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material.
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[MARINE_BIOLOGY_INTERNATIONAL] New DNA-Method Tracks Fish and Whales in Seawater
| By Science
Copenhagen, DENMARK — Danish researchers at University of Copenhagen lead the way for future monitoring of marine biodiversity and resources by using DNA traces in seawater samples to keep track of fish and whales in the oceans. A half litre of seawater can contain evidence of local fish and whale faunas and combat traditional fishing methods. Their results are now published in the international scientific journal PLOS ONE.
"The new DNA-method means that we can keep better track of life beneath the surface of the oceans around the world, and better monitor and protect ocean biodiversity and resources," says PhD student Philip Francis Thomsen from the Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen.
Marine ecosystems worldwide are under threat with many fish species and populations suffering from human over-exploitation, which greatly impacts global biodiversity, economy and human health. Today, marine fish are largely surveyed using selective and invasive methods mostly limited to commercial species, and restricted to areas with favourable conditions.
However, researchers at Centre for GeoGenetics now lead the way for future monitoring of marine biodiversity. They have shown that seawater contains DNA from animals such as fish and whales. The species leave behind a trace of DNA that reveals their presence in the ocean based on water samples of just half a litre.
The development of the novel DNA monitoring approach was accomplished by PhD student Philip Francis Thomsen and Master's student Jos Kielgast from the Centre for GeoGenetics headed by Professor Eske Willerslev. In December last year, they showed that small freshwater samples contain DNA from several different threatened animals, and after having published these results they began to focus on seawater. Here it also proved possible to obtain DNA directly from the water, which originated from local species living in the area.
"We analysed seawater samples specifically for fish DNA and we were very surprised when the results started to show up on the screen. We ended up with DNA from 15 different fish species in water samples of just a half litre. We found DNA from both small and large fish, as well as both common species and rare guests. Cod, herring, eel, plaice, pilchard and many more have all left a DNA trace in the seawater," says Philip Francis Thomsen.
In the other study the researchers showed that it is also possible to obtain DNA from harbour porpoise in small water samples taken in the sea, so the approach is not only limited to fish, but can also track large marine mammals.
The study also compares the new DNA method with existing methods traditionally used for monitoring fish such as trawl and pots. Here, the DNA method proved as good as or mostly better than existing methods. Moreover, the DNA method has a big advantage that it can be performed virtually anywhere without impacting the local habitat -- it just requires a sample of water. Associate Professor and fish expert Peter Rask Møller from the National History Museum of Denmark, who also participated in the study, is optimistic.
"The new DNA method has very interesting perspectives for monitoring marine fish. We always keep our eyes open for new methods to describe marine fish biodiversity in an efficient and standardised way. Here, I look very much forward to follow the DNA method in the future, and I think it could be very useful to employ in oceans around the world," says Peter Rask Møller.
The researchers also see great perspectives in the method for estimating fish stocks in the future.
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[MARINE_BIOLOGY_INTERNATIONAL] AVIAN PARAMYXOVIRUS - CANADA (SK): CORMORANT
Wednesday, August 29, 2012 | By Science
AVIAN PARAMYXOVIRUS - CANADA (SK): CORMORANT
**********************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases <http://www.isid.org>
Date: 17 Aug 2012
Source: <http://www.healthywildlife.ca/>
Epidemic disease in double-crested cormorants in Saskatchewan
----------------------------------------------------------
An outbreak of a virus infection of the brain and spinal cord (encephalitis and myelitis) occurred in August 2012 at a large colony of double-crested cormorants (DCCO) on Dore Lake in the southern boreal forest of Saskatchewan. The cause of the outbreak was avian
paramyxovirus-1 (APMV-1), a virus that occurs in DCCO across their range in North America and regularly results in mortality of nearly full grown young-of-the year DCCO close to the end of the nesting season. Acutely-infected cormorants show a range of signs associated with damage to the central nervous system.
Many birds die during outbreaks, but some recover with various forms of paralysis. At affected colonies, it is common to see birds attempting to take off and fly with only one wing due to paralysis of the other wing, and birds "walking" on their wings or unable to dive due to leg paralysis. Total mortality appears to reach about 50 per cent of hatch year birds in some outbreaks. The surviving birds with paralysis also will die when winter arrives. Only young cormorants appear to suffer disease from APMV-1. Affected birds generally are 5-8 weeks of age; by 16 weeks of age, they no longer show signs of disease when they become infected.
APMV-1 infection has occurred on this same breeding colony many times since it was first noted in 1995. Although large numbers of American white pelicans nest here among the cormorants, and several species of gull, ravens, crows, and bald eagles regularly visit the colony and feed on the dead cormorants, significant mortality and clinical disease due to APMV-1 has only been seen in the cormorants.
Some strains of APMV-1 can cause severe disease in chickens and these strains are then referred to as "Newcastle disease" viruses. It has not yet been determined whether or not the 2012 virus in Saskatchewan DCCO falls into this category.
--
communicated by:
Christine Wilson
Canadian Cooperative Wildlife Health Centre
[Saskatchewan Province, Canada may be found on the interactive healthmap at <http://healthmap.org/r/2bqZ>.
A photograph of a cormorant may be viewed at <http://www.allaboutbirds.org/guide/double-crested_cormorant/id>.
There are 9 serotypes of avian paramyxovirus (APMV), including APMV-1, or Newcastle disease virus. Some sources report as many as 11 serotypes. These viruses, which are called either APMV-1 or Newcastle disease viruses (NDV), are members of the genus _Avulavirus_ in the family Paramyxoviridae. APMV-1 strains maintained in pigeon populations have some antigenic differences from other NDV isolates, and are sometimes called pigeon paramyxovirus type 1 (PPMV-1).
Newcastle disease primarily affects birds. Some avian species become ill, while others carry these viruses asymptomatically. Infections also occur in humans, but have not been reported in other species of mammals.
Virtually all birds are considered susceptible to infection with Newcastle diseases virus (NDV; Fam. Paramyxoviridae). NDV has been categorized into 5 pathotypes based on clinical signs in infected chickens, designated: a) viscerotropic velogenic, b) neurotropic velogenic, c) mesogenic, d) lentogenic or respiratory and e) subclinical enteric.
The clinical signs vary with the pathogenicity of the isolate and the species of bird. In chickens, lentogenic strains usually cause subclinical infections or mild respiratory disease with coughing, gasping, sneezing and rales. Mesogenic strains can cause acute respiratory disease and neurologic signs in some chickens, but the mortality rate is usually low. Lentogenic or mesogenic strains can produce more severe symptoms if the flock is co-infected with other pathogens.
Unfortunately, vaccination is not practical in wild birds. But the carcasses of any dead birds will have to be removed from the area or we will be hearing about a send die off due to avian botulism.
Portions of this comment were extracted from < <http://www.cfsph.iastate.edu/Factsheets/pdfs/newcastle_disease.pdf>
and from <http://www.jwildlifedis.org/content/46/2/481.abstract>. - Mod.TG]
[see also:
Newcastle disease, wild birds - USA: (MN) susp. 20120809.1237146
2011
---
Paramyxovirus, pigeons - Australia (02): (VI) 20110921.2862 Paramyxovirus, pigeons - Australia: (VI) 20110908.2735] .................................................mhj/tg/sh/ll
*##########################################################*
************************************************************
ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the
information, and of any statements or opinions based
thereon, are not guaranteed. The reader assumes all risks in
using information posted or archived by ProMED-mail. ISID
and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material.
__._,_.___
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[MARINE_BIOLOGY_INTERNATIONAL] New Approach Needed to Restore New England River Herring
| By Science
Amherst, MA — Despite evidence from their recent study that populations of two river herring species are dangerously low, ecologists at the University of Massachusetts Amherst and Stony Brook University say removing dams and adding fishways can still revive alewife and blueback herring numbers in New England and help to restore a long-neglected natural link between marine and freshwater ecosystems.
Ecologists Adrian Jordaan at UMass Amherst, Michael Frisk at Stony Brook and lead author Carolyn Hall, an independent researcher, also say if numbers of these anadromous fish, which live in the ocean but spawn in fresh water, rebound it would be good news for their predators including striped bass, tuna, Atlantic salmon and cod -- all human dining favorites that are experiencing declines.
Current management of predator fish species in isolation isn't effective, the authors say. They call for a realignment of restoration goals to aid economically important fisheries and recognize the critical interdependence of ocean and freshwater ecosystems. Their work appears in a recent issue of the journal BioScience.
Jordaan says, "Our research does point to a really big deficit in these fish populations, but if we can agree on a restoration path, using fishways and some dam removal as is already happening now, we can alleviate many of the pressures on these fish. We're not going to fix it overnight, but if we continue forward with intelligent planning, if we can get river herring into the old ponds they used to spawn in, I think we could see a great deal of improvement."
Results of his study with Hall show that damming significantly altered the ecology of coastal waterways much earlier than previously suspected, by removing a huge reservoir of forage fish that the ecologists call a "key vector of marine-terrestrial nutrient exchange."
For this analysis, Hall, Jordaan and Frisk used a combination of harvest data and a fishery-independent habitat model using historical dam records to reconstruct for the first time a picture of fish populations in nine Maine rivers between 1600 and 1900. They figure cumulative lost fisheries production of 11 billion fish occurred from 1750 to 1900 due to dams, that is, fish lost to harvest. They also estimate the number of young fish missing from the system (not available to ocean predators) from a 95 percent loss of spawning habitat at 100 million in 1700, increasing to 1.4 billion fish per year by 1850.
Jordaan acknowledges, "Those are shocking new numbers for biologists to hear, but we were also surprised that the losses came so early. Our numbers show the rate of damming and its impact was dramatic. We didn't expect to see it happening at this magnitude by 1850."
Among other techniques, the researchers identified the location of catches to show how the range shrank throughout Maine. As dams went into major rivers, the catch moved into smaller and smaller watersheds. Jordaan says, "If these nine rivers had been left completely unobstructed, they would have produced the numbers of fish caught in the entire United States in the 1950s. Our study puts it all in real terms. Within the overall perspective of the eastern United States, the loss is overwhelming."
Of course, damming the major rivers of New England fueled the industrial revolution in the United States, making it a world power, "but it came at a cost, and we're paying it now," he adds.
When fish populations are at low abundance as they are now, fish are less able to meet environmental challenges such as climate change and pollution. The current low production capacity of these fish is "coming back to haunt us," he adds. "We harvest too many alewife and blueback herring. That's where we are now, and New England is viewed as having the healthiest populations of these fish. But we have only a small fraction of habitat left, and we see climate change beginning to have an effect."
The authors say another aspect of the study that should not be lost on fishery managers, ecologists and waterway planners is that forage fish link phytoplankton in the ocean to our dinner tables, and their role in the ecosystem has been gravely undervalued.
"We feel these species represent a lost connection between marine and freshwater systems that is more important than the numbers," explains Jordaan. "The modern science of ecology grew up after all these changes had already occurred. So we've failed to appreciate how interconnected the marine and freshwater systems were in pre-colonial times. We can't appreciate its significance for a whole range of factors."
Their conclusions serve as a cautionary tale, the authors point out, for planners in China, Laos and Cambodia, where engineers are on the verge of constructing 200 new dams, 11 of them main stem, on the Mekong River. It is the second most biodiverse freshwater system and host to the world's most productive inland fisheries in the world.
"Losing the connections and ecosystem services provided by anadromous species will have lasting, ecosystem-wide impacts that may not be compensated through fish passage technology," they say.
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[MARINE_BIOLOGY_INTERNATIONAL] Less Is More for Reef-Building Corals: Surprisingly More Flexible Corals Are Mor
Tuesday, August 28, 2012 | By Science
Honolulu, HI — Researchers at the University of Hawaii -- Manoa (UHM) School of Ocean and Earth Science and Technology (SOEST) made a discovery that challenges a major theory in the field of coral reef ecology. The general assumption has been that the more flexible corals are, regarding which species of single celled algae (Symbiodinium) they host in coral tissues, the greater ability corals will have to survive environmental stress.
In their paper published August 29, 2012, however, scientists at the Hawaii Institute of Marine Biology (HIMB) at SOEST and colleagues documented that the more flexible corals are, the more sensitive to environment disturbances they are.
"This is exactly the opposite of what we expected," said Hollie Putnam, PhD candidate at UHM and lead author of the study. This finding was surprising, as it is thought corals exploit the ability to host a variety of Symbiodinium to adapt to climate change. "Our findings suggest more is not always better," she continued.
"The relationship of coral species to their algal symbionts is fundamental to their biology," says David Garrison, program director in the National Science Foundation (NSF)'s Division of Ocean Sciences, which funded the research. "This study gives us a new understanding of how corals are likely to respond to the stresses of environmental change."
Reef corals are the sum of an animal (host), and single celled algae that live inside the corals' tissues (also called 'endosymbionts'). This is a mutually beneficial arrangement -- the coral provide protection and keep the algae in shallow, sunlit seas; and the algae produce large amounts of energy through photosynthesis, which coral use to survive and build their skeletons. The stability of this symbiosis is critical to the survival of corals and if they lose their endosymbionts they bleach and often die. Corals can host different types of endosymbionts, which affects their response to stress.
Putnam and other scientists from Dr. Ruth Gates' laboratory at HIMB took tiny tissue samples from 34 species of coral in Moorea, French Polynesia. By analyzing the DNA from the endosymbionts in these samples, they were able identify the types of Symbiodinium. This revealed that some corals host a single Symbiodinium type that is the same in all individuals of that coral species, and that others host many types that vary among individuals within a coral species.
"The corals we sampled spanned a range of environmental sensitivities from resistant to susceptible, and we were able to link, for the first time, patterns in environmental performance of corals to the number and variety of symbionts they host," reported Putnam. These patterns show that corals hosting diverse Symbiodinium communities, those that are flexible with respect to endosymbionts (termed 'generalists'), are environmentally sensitive. In contrast, environmentally resistant corals were those that associate with one or few specific types of Symbiodinium (termed 'specifists').
"Coral reefs are economically and ecologically important, providing a home for a high diversity of organisms necessary for food supplies, recreation, and tourism in many countries. The better we understand how corals respond to stress, the more capable we will be to forecast and manage future reefs communities," said senior author Professor Ruth Gates. Coral reefs can undergo mass mortality due to high temperatures, and ocean acidification is threatening the capacity for skeletal growth. These global stressors are superimposed on the local threats of pollution, coastal development and overfishing, together threatening the persistence of corals as a functional ecosystem in the future.
In the future, the Gates Lab will examine what causes the differences in success between corals that are flexible and inflexible in their Symbiodinium associations and compare the symbiotic flexibility in corals and reefs across much larger areas -- in locations such as Hawaii, Moorea, Taiwan and American Samoa. This further understanding will allow better predictions of the future of reefs under further ocean warming and acidification.
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[MARINE_BIOLOGY_INTERNATIONAL] Underwater robots to 'repair' Scotland's coral reefs
| By Science
Edinburgh, SCOTLAND - Underwater robots tasked with saving coral reefs are being developed at Heriot-Watt University in Scotland.
Dubbed "coralbots", they are being designed to work in groups, in a similar manner to bees and ants.
The team is still "training" the software that will control the bots to "recognise" corals and distinguish them from other sea objects.
Corals are easily damaged by pollution and destructive fishing practices, and it takes decades for them to re-grow.
They are colonies of tiny living organisms, most commonly found in warm shallow waters in the tropics.
But the depths of the Atlantic Ocean off the west coast of Scotland are home to cold-water reefs.
When they get damaged, scuba divers re-cement broken fragments, helping them re-grow - but it is tricky for divers to reach depths over 200m.
Coralbots, the researchers hope, will be a lot more efficient, able to repair the reefs in days or weeks.
The team, which consists of a marine biologist, an artificial intelligence scientist, a roboticist, and a machine vision scientist, said it was trying to raise £2m to hold a first demonstration.
It is much harder for divers to reach deep water corals to repair them The scientists said that if they got all the cash they needed, the bots could be embark on their first mission within a year.
Initially, the robots would be adaptations of those already developed at the university's Ocean Systems Lab.
They would be about a metre long, with built-in video, image-processing and simple manipulation tools, such as scoops and arms, and would operate in "swarms".
Swarming in nature is collective action of a large number of agents that are individually stupid but collectively can complete complex tasks.
Besides insects, birds and fish also swarm, as well as the smallest and simplest micro-organisms, such as bacteria.
"Our key idea is that coral reef restoration could be achieved via swarm intelligence, which allows us to exploit co-operative behaviours we see from natural swarms of bees, termites and ants that build complex structures such as hives and nests," said marine biologist Lea-Anne Henry who is lead scientist on the project at Heriot-Watt.
She said the robots would be intelligent enough to navigate and avoid obstacles.
"We are developing new intelligent object recognition routines, exploiting the data from hundreds of coral reef images, to enable each swarm member to recognise coral fragments and distinguish them from other materials and objects in the environment in real-time," she said.
One AI expert not involved in the project called it "very worthwhile".
"I think they have a very good chance of being successful," Prof Noel Sharkey of the University of Sheffield told the BBC.
The Mingulay reef complex in Scottish waters was discovered in 2003 "And it's an ideal task for swarm robotics. Look at termites - a termite follows a simple rule, pushing a little ball of dirt until it meets another ball of dirt. And you end up with these huge mounds that termites build and live in.
"It's the same here - these robots will have micro-rules, and even though each robot is dumb, collectively they will move and do something - and in the end, a reef will be repaired."
A quarter of all marine life on the planet inhabits corals, according to the World Wildlife Fund.
In coastal areas, they also provide an important barrier against natural disasters such as storms, hurricanes, and typhoons.
There are fears that coral reefs may begin to disappear within 50 years.
Besides destructive fishing practices, other contributing factors are careless tourism and carbon dioxide emissions that make seawater more acidic, leading to the death of key coral species.
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[MARINE_BIOLOGY_INTERNATIONAL] Male Snails Babysit for Other Dads: Family Secrets of Marine Whelk
| By Science
Davis, CA — Pity the male of the marine whelk, Solenosteira macrospira. He does all the work of raising the young, from egg-laying to hatching -- even though few of the baby snails are his own.
The surprising new finding by researchers at the University of California, Davis, puts S. macrospira in a small club of reproductive outliers characterized by male-only child care. Throw in extensive promiscuity and sibling cannibalism, and the species has one of the most extreme life histories in the animal kingdom.
The family secrets of the snail, which lives in tidal mudflats off Baja California, are reported online in a study in the journal Ecology Letters.
In the study, UC Davis researchers report that, on average, only one in four of the hundreds of eggs that a male S. macrospira carries around on his back belong to him. Some carry the offspring of as many as 25 other males.
Such extreme cases provide the raw material on which natural selection can work and shed light on more "mainstream" species, said study author Rick Grosberg, a professor of evolution and ecology at UC Davis.
"It opens our eyes to viewing other kinds of behavior not as weird or harmful but as normal," he said.
The snails were first described in an amateur shell-collectors newsletter, The Festivus, in 1973. Grosberg started studying the animals in 1994, when he brought some back from a collecting trip and realized that only male snails had egg capsules on their shells.
When the snails mate, the female glues capsules containing hundreds of eggs each to the male's shell.
The male's shell likely acts as a substitute rock, since the snails' habitat offers few surfaces on which to glue eggs, said co-author Stephanie Kamel, a postdoctoral researcher in Grosberg's lab.
Moving in and out with the tide on dad's (or stepdad's) back also protects the egg capsules from the extremes of heat and drying they might face if left on a stationary rock.
A male's shell may become covered in dozens of capsules, each containing up to 250 eggs. As the eggs hatch, a process that takes about a month, some of the baby snails devour the rest of their littermates. Typically only a handful of hatchlings survives the fratricide to emerge from a capsule and crawl away.
Kamel carried out DNA analysis of brood capsules to determine the eggs' parentage. On average, she found that the male snails had sired just 24 percent of the offspring on their backs. Many had sired far less.
"The promiscuity in the female snails is extraordinary," Kamel said, noting that some females mate with as many as a dozen different males.
Why do they do it? Typically in the animal kingdom, females invest more resources in an egg than a male does in a sperm, so mothers have a stronger interest in providing parental care. Males may mate with multiple partners to increase their chances of siring offspring, but typically make less investment in caring for those young. When dads do get involved, it's nearly always because they are assured that all or most of the offspring are their own. Male sea horses, for example, carry developing young in a pouch -- but all are their own genetic offspring.
One explanation could be that caring for the kids just doesn't cost the male snails much. But by tethering individual snails to a post sunk in the sand, Grosberg was able to follow them over time and show that the capsules do impose a significant burden, reflected in weight loss.
It may be that carrying the egg capsules simply represents the best of limited options for the males, Grosberg said, since it's impossible for them to mate without the female attaching an egg capsule to their backs.
Or carrying egg capsules may be a way for a male to show a female that he's good parent material.
"If he wants to get any action, he has to pay the price," Grosberg said.
Grosberg is fascinated by the conflicts that occur between parents, between siblings, and between parents and offspring as they each try to get resources and maximize their success in breeding. You can see these conflicts and rivalries all the way from simple animals to humans, he notes.
"Everything that intrigues me about family life happens in these snails," he said.
At the same time, no animal has gone as far as humans in evolving increasing cooperation between relatives, tribes and larger and larger (and less closely related) groups over time.
"We're good at seeing other forms of reward," Grosberg said.
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[MARINE_BIOLOGY_INTERNATIONAL] DIE-OFF, FISH - USA (05): (OHIO), REQUEST FOR INFORMATION
| By Science
DIE-OFF, FISH - USA (05): (OHIO), REQUEST FOR INFORMATION
*********************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases <http://www.isid.org>
Date: Wed 22 Aug 2012
Source: WKYC.com [edited]
<http://www.wkyc.com/news/article/257306/6/Akron-Thousands-of-fish-dead-in-Cuyahoga-River?utm_>
The Ohio Division of Wildlife is reporting a fish kill in the Cuyahoga River. About 2000 dead fish, mostly minnows, suckers, and carp, were found by investigators this past weekend [18-19 Aug 2012]. The fish were in a fairly advanced state of decomposition, according to a source.
The area affected is an approximately 3-mile stretch of water starting just north of the Akron Sewage Treatment Plant to Bolanz Road, the home of Szalay's Farm and Market.
The cause of the kill is under investigation by the Ohio EPA. Water tests now show no toxins present at this time and ample dissolved oxygen for fish and other aquatic life.
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Communicated by:
ProMED-mail from HealthMap alerts
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[There is not much information to speculate about a possible cause.
More data on the episode would be useful. A HealthMap of the affected area can be accessed at: <http://healthmap.org/r/3bnk>. - Mod.PMB]
[see also:
Die-off, fish - USA (02): (GA) comment 20120601.1153265 Die-off, fish - USA: (GA) pollution susp. 20120531.1152141
2011
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Undiagnosed die-off, fish - USA (02): (GA) columnaris 20110528.1641 2010
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Undiagnosed fish die-off - USA (04): (WV, OH, PA) columnaris
20100610.1946
2009
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Columnaris disease, fish - USA 20091111.3908
1999
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Columnaris, white bass - USA (Kansas) 19990713.1178] .................................................sb/pmb/msp/dk/ll
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[MARINE_BIOLOGY_INTERNATIONAL] Baby beluga whale born at Chicago's Shedd Aquarium
| By Science
Baby beluga whale born at Chicago's Shedd Aquarium
Aug 28, 2012 9:45 AM EDT
CHICAGO (AP) - There's a new baby beluga at Chicago's Shedd Aquarium.
Aquarium officials announced the baby beluga whale was born early Monday at 4 1/2-feet long and 150 pounds. Officials say both mother and calf appear to be doing well and are under 24-hour observation by animal health staff.
The calf is the third baby for its mother, Mauyak (my-AK'). Animal care experts at the aquarium say the baby has taken its first breath and tried to nurse with its mother.
The baby beluga arrives less than three months after the Shedd Aquarium had the birth of its first Pacific white-sided dolphin calf on Memorial Day. The baby whale is the sixth successful birth since 1999 for the Shedd as part of the beluga whale breeding cooperative.
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[MARINE_BIOLOGY_INTERNATIONAL] New Maps May Reduce Tourism Impacts On Hawaiian Dolphins
Monday, August 27, 2012 | By Science
Durham, NC — Over-eager tourists intent on seeing spinner dolphins up close may inadvertently be disturbing the charismatic animals' daytime rest periods and driving them out of safe habitats in bays along Hawai'i's coast. But a study led by researchers at Duke and Stony Brook universities gives scientists and resource managers a promising new tool to curb the frequency of the repeated human disturbances and help reduce their negative impacts.
"Using the maps produced through this study we can identify the bays where the effects of human activities on spinner dolphins should be monitored most closely, and where immediate conservation actions are required," said David W. Johnston, research scientist at Duke's Nicholas School of the Environment.
The mapping models developed by the researchers indicated that only a small number of bays – 21 out of 99 – in a study area along the western coastlines of the main Hawaiian islands were suitable habitats for resting dolphins. Knowing this, Johnston said, "conservation efforts can be focused on specific areas of importance."
"We may be able to minimize detrimental effects on dolphins by putting restrictions or preventative measures into place in a relatively small number of bays, rather than limiting access to dolphins along the entire coast," said the study's lead author, Lesley H. Thorne, a lecturer in marine science at Stony Brook University, who received her PhD from Duke in 2010. "That benefits tourists and tourism operators as well as the dolphins."
To create the new mapping models, the researchers used the geographic coordinates and key environmental factors – such as water depth, the size and proportions of the bays, and proximity to deep-water foraging grounds – for hundreds of spinner dolphin sightings made throughout the study area between 2000 and 2010.
Spinners are small dolphins famed for their graceful aerial movements and balletic spins. Found in tropical and subtropical oceans around the world, coastal populations of the animals divide their time between daytime rest periods in shallow, protected bays and nighttime foraging in more exposed waters.
Distinguishing between sightings of resting and active dolphins was key to defining critical habitats, Thorne said, because while socially active spinner dolphins are more tolerant of humans' presence, resting dolphins will leave the safety of a bay and retreat to less suitable open waters if they are repeatedly interrupted.
"Sleep is essential for most animals," added Johnston. "When deprived of their necessary `zzzz's,' they gradually show a decreased ability to process information and remain attentive to environmental stimuli. In technical lingo, we call this a `vigilance decrement'."
Spinner dolphins are no exception to the rule, he said. Over time, dolphins that are harassed by people daily during rest periods will never fully recover their vigilance decrement, and their ability to forage successfully and detect the presence of nearby predators will be degraded. Their ability to produce sounds used for communication and navigation may also be impaired.
Scientists and conservationists have long worried that spinners' popularity with tourists – and overlap of their resting habitats with popular ocean recreation destinations – may be placing them at risk. Reports of interactions have increased sharply in recent years, but few published studies have examined the detrimental impacts these interruptions may have on the animals, especially at the population level.
"It would be next to impossible to survey spinner populations and human activities in every bay that might be a resting habitat. We're talking about hundreds of bays in the Hawaiian islands alone," said Thorne.
"Using predictive models, such as the maximum entropy spatial modeling approaches we've produced, is a much more cost-effective method," she said. "This type of modeling has only recently been applied to the study of marine mammals, but our work suggests it may be especially useful for studies (where data is) derived from opportunistic sightings and surveys using different types of research platforms."
The study was published August 27 in the online, peer-reviewed journal PLoS ONE.
Thorne and Johnston plan to test their models by conducting similar studies of spinner dolphin distributions and habitat use in the Northwestern Hawaiian Islands and elsewhere in the Pacific islands region. Results from those studies, they said, could confirm the new models' usefulness.
Johnston and Thorne's co-authors on the PLoS ONE study include Dean L. Urban, professor of landscape ecology at Duke's Nicholas School, and Lars Bejder, associate professor at Murdoch University, Australia, and adjunct assistant professor at Duke.
The data on spinner dolphin sightings used to develop the models in the study were provided by a team of eight additional co-authors from Murdoch University, the Pacific Islands Photo-Identification Network, the Cascadia Research Collective, the Hawai'i Marine Mammal Consortium, the Hawai'i Association for Marine Education and Research, the Dolphin Institute, the University of Hawai'i (UH) at Hilo, UH at Mânoa, and Marine Mammal Research Consultants.
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