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Jan

9

2008
 
 

A quarter of a billion footprints



Caribbean coral reefs suffer from the mere presence of humans, study shows If only it was just one...A large-scale study of potential threats to coral reef health has found one that dominates all others: us. Writing in the Proceedings of the Royal Society this week, Camilo Mora and Robert Ginsberg show that human-caused impacts – coastal development, agricultural run-off, fishing pressure and the sheer density of humans living around the Caribbean coastline – exert the strongest influence on coral reef health. Worse, some of these factors work in concert with others. For example, temperature- or disease-triggered coral die-offs allow macroalgal blooms that exceed the ability of the reef’s herbivores to control them. Agricultural fertilizers and sewage-based nutrients finding their way to the sea then fuel the explosive growth, resulting in a feedback loop that is tough to break. The Dalhousie and Miami University duo suggest that now it’s clear that what goes on above the water surface can have a major effect on what goes on below it, perhaps it’s time to consider tougher land-based controls around Marine Protected Areas. A whole-system approach? We need an unprecedented outbreak of common sense first... Source: Mora C & Ginsburg R (2008) A clear human footprint on the Caribbean coral reefs. Proceedings of the Royal Society of London B DOI: 10.1098/rspb.2007.1472 Image © Norbert Rehm

Filed Under Climate change, Community-based conservation, Economics and conservation, Endangered species, Habitat, Marine, Monitoring, Restoration, Socio-political issues | Leave a Comment

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Nov

28

2007
 
 

Forty two degrees C



Extreme climate events take flying-foxes to the brink If you can't take the heat you shouldn't hang aroundJanuary 13 and 14, 2002 must have been bleak days for Justin Welbergen and colleagues, as they collected the corpses of thousands of Australian fruit bats whose deaths they had documented the day before. The bats, mainly grey-headed Pteropus poliocephalus and black flying-foxes P. alecto had succumbed to an extreme heat wave, with the temperature at Dallis Park, New South Wales, topping 42.9°C – that’s 107.6°F. Writing in Proc. Royal Soc. B this week, Cambridge University’s Welbergen presents an analysis of the tragic die-off – one of at least nineteen to have taken place since 1994. In mixed colonies, P. alecto fared worse than P. poliocephalus: juveniles and adult females were far less tolerant of the searing heat than males. Extreme climatic events are expected to become more common, so monitoring roosts when the mercury is set to soar above the critical mark sounds like a good idea. That way, falling off the perch might not mean the end. Source: Welbergen JA, Klose SM, Markus N & Eby P (2007) Climate change and the effects of temperature extremes on Australian flying-foxes. Proceedings of the Royal Society of London B DOI: 10.1098/rspb.2007.1385 Image © Jan Rihak

Filed Under Climate change, Endangered species, Monitoring | Leave a Comment

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Nov

14

2007
 
 

One in five fish is missing



Global species inventories are incomplete in the worst places, fish study finds I'm just a number, meIf “difficultizing” ever becomes a word (and a certain current world leader might just make it so) it will surely apply to taxonomic databases. A study published today in the Proceedings of the Royal Society of London complains that the blackest holes in our knowledge of marine fish are where we least need them. Camilo Mora and colleagues at Dalhousie University analyzed the largest publicly available dataset of marine fish -- the 2.1 million datum-strong Ocean Biogeographical Information System -- and found it wanting. At a global scale, the scientists estimate that only 79% of species have been formally described, with the biggest gaps occurring in known biodiversity hotspots. Given that fish are one of the most intensively studied marine taxonomic groups, things don’t bode well for the remaining oceanic biota. And if we don’t know what we’ve got, how can we save it? Source: Mora C, Tittensor DP & Myers RA (2007) The completeness of taxonomic inventories for describing the global diversity and distribution of marine fishes. Proc. Roy. Soc. Lond. B DOI: 10.1098/rspb.2007.1315 Image © Tammy Peluso

Filed Under Economics and conservation, Marine, Monitoring, Socio-political issues, Tools and technology | 1 Comment

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Sep

12

2007
 
 

The sailing snail’s trail



Did prehistoric snail farms provide modern refugia for embattled molluscs? these ones are all dead...Genetic data have helped clear up a problem that’s been puzzling scientists for over a century: how the endangered Tahitian tree snail Partula hyalina is absent from neighbouring islands, yet [relatively] thriving populations occur on islands more than a thousand kilometres away. Writing in the Proceedings of the Royal Society, University of Michigan biologist Diarmaid Ó Foighil and colleagues show that founder populations radiated from Tahiti to islands in the Cook and Austral archipelagos, probably within the last thirty thousand years. The timing of the snails’ spread coincides with a period of human exploration, settlement and trade among the remote Oceania athols. The species’ unusual white shell -- valued in traditional jewelry making -- could explain why P. hyalina reached its far-flung shores, whereas its altogether-less-striking sister species P. clara never made it off the island. And with Tahiti’s tree-snail population being decimated by the carnivorous alien Euglandina rosea, those distant outposts could make all the difference. Source: Lee T, Burch JB, Coote T, Fontaine B, Gargominy O, Pearce-Kelly P & Ó Foighil D (2007) Prehistoric inter-archipelago trading of Polynesian tree snails leaves a conservation legacy. Proceedings of the Royal Society of London B DOI: 10.1098/rspb.2007.1009 Related story in Conservation magazine: Extinction at a Snail’s Pace Image © Vladislav Mitic

Filed Under Endangered species, Invasive species, Marine, Monitoring, Restoration, Socio-political issues | Leave a Comment

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May

30

2007
 
 

Love cheetahs



Female felids play the field, DNA study reveals Who's the daddy?If following a large carnivore around until it “answers the call of nature” is your thing, read on. Working in the Serengeti National Park, Tanzania, biologists from the Zoological Society of London, led by Dada Gottelli, did just that to collect 171 dung samples from cheetahs Acinonyx jubatus that were traceable to their owners. DNA analysis of said stools, published this week in the Proceedings of the Royal Society of London, revealed a hitherto unknown facet of cheetah reproductive biology: females often mate with more than one male. Forty-three percent of litters containing more than one cub were sired by more than one male. That’s good news for cheetah conservation prospects because it suggests that a much higher number of males contribute to the gene pool, so helping to keep levels of genetic diversity from being eroded. The findings should inform management plans for the survival of this most flighty, promiscuous of cats. Source: Gottelli D, Wang J, Bashir S & Durant SM (2007) Genetic analysis reveals promiscuity among female cheetahs. Proceedings of the Royal Society of London B DOI: 10.1098/rspb.2007.0502 Related story in Conservation magazine: More than Meets the Eye: Behavior and Conservation Image © Susann Evans

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Mar

14

2007
 
 

The trouble I’ve been



Feral pigs -- among the worst alien predatorsAlien predators pose a bigger threat to prey than natives Alien predators have long been considered more damaging than their native counterparts, but no one really knew for sure. Now, a review paper published this week in Proceedings of the Royal Society shows just how great their impact is. Pälvi Salo, at the University of Turku, and colleagues looked at the combined findings of 80 field experiments from around the world, most of which had been carried out in the last ten years. Introduced predators are indeed significantly more harmful to native prey, and their effects are most devastating in island ecosystems. Australia skewed the data quite heavily though: Salo and colleagues say this might be because the effect of invasive species Down Under has been studied in more detail. It could also be due to differences in the way marsupial and placental predators behave -- as usual, more experimental work is needed to find out. Source: Salo P, Korpimäki E, Banks PB, Nordström M & Dickman CR (2007) Alien predators are more dangerous than native predators to prey populations. Proceedings of the Royal Society of London, B DOI: 10.1098/rspb.2006.0444 Image © Alvaro Pantoja

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Jan

30

2007
 
 

Chips down for battered cod



cod...pieces!Genetic response to selective fishing hampers stock recovery from collapse Evolution is a two-edged sword -- just ask any Atlantic cod. Having withstood the ravages of decades of overfishing, collapsed populations have been slow to recover, and a study published this week shows why. Cod numbers in the Gulf of St Lawrence dwindled in the 1960s and 1970s but recovered well during the 1980s, only to crash again in the 1990s, since when they have remained at low densities. So why no second cod comeback? Gulf Fisheries Centre, New Brunswick, marine biologist Douglas Swain and colleagues think the increase in mesh size around the late 1970s was crucial, bringing about a fast evolutionary shift in the cod. The change was intended to allow fish stocks to build, but instead seems to have selected for slow growth and thus delayed maturity and reproduction. Swain’s findings show how rapid genetic changes can be: fishermen should ignore the warning at their peril! Source: Swain, DP, Sinclair, AF & Hanson, JM (2007) Evolutionary response to size-selective mortality in an exploited fish population. Proceedings of the Royal Society of London, Series B. DOI: 10.1098/rspb.2006.0275

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Jan

30

2007
 
 

Who’s afraid now?



Grey_wolfSurvey suggests Scots would welcome wolves back to the fold Plans to reintroduce grey wolves to Scotland haven’t rattled the natives, according to a study published this week. The idea of putting wolves – hunted to extinction in the 18th Century – back into the Highlands has been mooted for many years but failed to become a reality. The study, led by Erlend Nilsen at the University of Olso, Norway, combined a survey of public opinion with computer models to predict the impact of wolf packs on Scotland’s red deer population. The virtual wolves dutifully went on the rampage, producing a suitably satisfying degree of digital carnage. The desolate real-world hills of Northern Britain are all but overrun by red deer, and the annual cull is a costly exercise. However, the wolf’s fate in Scotland is intertwined with sheep, which are somewhat easier to catch than nervy deer. But leaving aside the ethical and animal rights issues, sheep predation need not raise too much concern: most farms operate at a loss and survive on agricultural subsidies. The big bad wolf might just turn out to be the Scottish sheep farmer’s best friend. Source: Nilsen, EB, Milner-Gulland, EJ, Schofield, L, Mysterud, A, Stenseth, N-C & Coulson, T (2007) Wolf reintroduction to Scotland: public attitudes and consequences for red deer management. Proceedings of the Royal Society of London, Series B. DOI: 10.1098/rspb.2006.0369

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