Extinction of threatened marine megafauna would lead to huge loss in functional diversity

Date: April 17, 2020

Source: Swansea University

In a paper published in Science Advances, an international team of researchers have examined traits of marine megafauna species to better understand the potential ecological consequences of their extinction under different future scenarios.

Defined as the largest animals in the oceans, with a body mass that exceeds 45kg, examples include sharks, whales, seals and sea turtles.

These species serve key roles in ecosystems, including the consumption of large amounts of biomass, transporting nutrients across habitats, connecting ocean ecosystems, and physically modifying habitats.

Traits, such as how large they are, what they eat, and how far they move, determine species' ecological functions. As a result, measuring the diversity of traits allows scientists to quantify the contributions of marine megafauna to ecosystems and assess the potential consequences of their extinction.

The team of researchers -- led by Swansea University's Dr Catalina Pimiento -- first compiled a species-level trait dataset for all known marina megafauna to understand the extent of ecological functions they perform in marine systems.

Then, after simulating future extinction scenarios and quantifying the potential impact of species loss on functional diversity, they introduced a new index (FUSE) to inform conservation priorities.

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How the humble dung beetle engineers better ecosystems in Australia

MARCH 11, 2020

by Paul Weston and Theo Evans, The Conversation

Dung beetles play an important role helping clear up all the dung left by other animals in an environment.

In Australia there are approximately 475 native species of dung beetle.

But there's a problem. Most of them are adapted to deal with marsupial dung. When British colonisers brought livestock down under, they introduced an entirely new type of dung that the native dung beetles were ill-equipped to handle.

Not touching that dung

Cattle dung is wet and bulky. It is very unlike marsupial dung—which is typically small, dry pellets—and so the native dung beetles largely left it alone. As a result, large deposits of cattle dung accumulated in the Australian agricultural landscape.

Besides fouling the land, the dung was an excellent breeding site for bush flies and other nuisance insects, as well as internal parasites that plague the digestive tracts of livestock.

So CSIRO embarked on an ambitious plan to introduce into Australia many dung beetles that were adapted to livestock dung. Starting in 1966, it imported and released 43 species of dung beetles over 25 years.

The beetles came from places such as South Africa, France, Spain and Turkey. The chosen beetles had similar climate requirements and were adapted to wild and domestic livestock, so they could live in Australia and process livestock dung.

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Expert explains key role of frogs in healthy ecosystems

MARCH 29, 2019

by Penny Jones, University of New South Wales

Dr. Jodi Rowley explains why frogs are so vital for healthy ecosystems, how she is working to conserve them and the positive impact she has already made to the study of amphibians in Southeast Asia.

Dr. Jodi Rowley has dedicated much of her career to illuminating what she calls 'the black hole' in the world's knowledge of amphibian life in South-East Asia. Her original impetus started following the release of the 'Global Amphibian Assessment' in 2004 which was published by the IUCN Red List of Threatened Species.

"The report was the first comprehensive examination of how amphibians are doing on a world level and highlighted the fact that they are in a lot of trouble. Today we estimate that an incredible 42 percent of all known species of amphibians are threatened with extinction," she says.

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Nightlights for stream dwellers? No, thanks

Date:  December 19, 2018

Source:  Ohio State University

Artificial light at night isn't just a health problem for those of us sitting in bed scrolling through Instagram instead of hitting the sack -- it hurts entire outdoor ecosystems.

When the critters that live in and around streams and wetlands are settling into their nighttime routines, streetlights and other sources of illumination filter down through the trees and into their habitat, monkeying with the normal state of affairs, according to new research from The Ohio State University.

"This is among the first studies to show that light at night has detrimental effects not just on individual organisms in the environment, but also on communities and ecosystems," said Mažeika Sullivan, lead author of the study, which appears today (Dec. 19, 2018) in the journal Ecological Applications.

"Nighttime light is having profound impacts that extend to the entire ecosystem," said Sullivan, director of Ohio State's Schiermeier Olentangy River Wetland Research Park and associate professor of environment and natural resources.

Though many people might not consider it, artificial light is a pollutant, changing the natural course of life for people, animals and plants, he said, adding that urbanization is rapidly increasing both in the United States and around the globe.

"We are experiencing this pollution that we don't think about, but it's all around us and it's chronic and it's happening everywhere -- from newly lit villages in rural Africa to streams alongside the highway in Columbus, Ohio," he said. "It's also unprecedented in Earth's history."

The new study explored the role of light on streams and wetlands in and around Columbus. Moonlight under a clear sky can give an illuminance of 0.1 to 0.3 lux, Sullivan said. The streams in the study were headwater streams draining into the Scioto and Olentangy rivers, with light ranging from 0.01 to 4.0 lux. Wetlands of the Olentangy River Wetland Research Park had lighting from 0 to 20 lux.

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Study finds indications for recovery after ecosystem pollution

December 5, 2018, University of Konstanz

Environmental damage caused by human activity can reduce the number of plant and animal species dramatically. At the same time, very little is known about how biodiversity recovers after ecosystem pollution is curtailed and has been cleaned up. As was common in the mid-1900s, Lake Constance, one of the largest freshwater lakes in Europe, suffered from eutrophication, or nutrient contamination caused by agricultural and waste water run-off. A study by the universities in Konstanz and Glasgow has now revealed that one European whitefish species expanded its genetic variation through hybridization with other whitefish species during the period of eutrophication. The study, led by the Konstanz-based biologist Dr. Jasminca Behrmann Godel along with her colleague Dr. Kathryn R. Elmer from the University of Glasgow, was published in the journal Nature Ecology and Evolution. This genetic mixture contributed to an expansion in biodiversity once the ecosystem recovered.

The diminished water quality in Lake Constance due to eutrophication destroyed the natural habitats and led to the extinction of two of the five whitefish species that had only existed in this lake as well as to the hybridization of the three remaining species. This had an impact on commercial fisheries in the lake. In the 1980s, concerted efforts to reduce eutrophication quickly re-established Lake Constance's original state.

Biologists examined the functional phenotypical and genomic variation of the European whitefish (gangfisch: Coregonus lavaretus macrophthalamus) in order to demonstrate that its biodiversity expanded within a short period of time after the ecosystem had recovered from nutrient contamination. In less than ten generations, the European whitefish developed a wide variation in the number of gill rakers—which are used to filter plankton from the water—thus rendering it able to occupy a broader ecological niche than before eutrophication. This is one of the fastest evolutionary rates ever recorded in the animal kingdom.

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Wind Farm Predator Effects Ecosystem - via Herp Digest

The team observed an explosion in the raptors' favorite meal - fan-throated lizards - in areas dominated by the turbines.

by James Marshall, 11/8/18, Lancashire Independent News

"We found that people began to settle closer because of birds of prey became less of their population in the area of wind farms fell by 75%".

After testing, the lizards near the turbines were found to have lower levels of a stress hormone - something that must have emerged in the two decades since wind farms were built in the Western Ghats.

In particular, the team observed an explosion in the raptors' favorite meal - fan-throated lizards - in areas dominated by the turbines.

Researchers of Indian Institute of Science, Bengaluru, found that wind turbines can act as top predators in ecosystems by driving down numbers as well as activity of birds of prey and triggering knock-on effects across food chains - it results in an increase in the density of vertebrates like lizards on the ground.

Fan-Throated Lizard 

The study was done in the Chalkewadi plateau in Satara district in the northern Western Ghats which is the site of one of the largest and longest-running wind farms in the region.

Ornithologists already named wind turbines "predators of our time". Researchers found nearly four times more predatory birds in areas without wind turbines than around wind farms. Here are a large number of wind power plants, which provoke the extinction of these birds, and lizards. They suggested similar effects would also probably be found around British wind farms.

In order to record changes in the physiology of lizards, researchers measured hormonal stress reactivity. Blood samples were collected from lizards picked up from both sites - areas with wind farm and area without wind farms.

By now, it's common knowledge that wind turbines reduce the number of local birds and bats, disrupting their migratory paths.

Furthermore, they saw significant changes in lizard behavior and appearance, living as though they were in an essentially predator-free environment. However, the assumption that wind turbines only affect flying species fails to take into account how fewer birds, who are often predators, can change an ecosystem's dynamic.

Even small changes within an ecosystem can have detrimental effects

Interactions between small organisms are 'keystone' interactions that scale up to shape whole ecosystems

Date:  February 1, 2018

Source:  Binghamton University

Summary:

A mutualistic relationship between species in an ecosystem allows for the ecosystem to thrive, but the lack of this relationship could lead to the collapse of the entire system. New research reveals that interactions between relatively small organisms are crucial to mutualistic relationships in an ecosystem dominated by much larger organisms, including trees and elephants.

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Badger cull could see boom in foxes, stoats and weasels

Conservationists fear negative impact on ecosystem and call on the government to release cull data

Jamie Doward

Saturday 8 July 2017 22.01 BST Last modified on Saturday 8 July 2017 23.40 BST

It is one of the more neglected dimensions of the badger cull, but one that could reignite the controversy surrounding the attempt to control the spread of bovine tuberculosis.

Conservationists have long claimed that eliminating badgers from certain areas is likely to trigger an increase in other predators, such as foxes, leading to serious consequences for species and habitats. But the government has refused to publish data showing what impact the cull is having on local ecosystems for fear that the results will be used by animal rights activists to identify the farmers and landowners carrying out the extermination.

Now, following a three-year battle, the Information Commissioner’s Office has told Natural England – the government’s adviser on the natural environment – to provide the analysis within weeks or risk ending up in the high court. The ruling will also have significant consequences for the other information that the body is withholding on the grounds of public safety, conservationists predict.

A recent report for the Welsh assembly suggested that removing badgers would see numbers of other predators – such as foxes, stoats and weasels – increase, something that could have a negative impact on ground-nesting birds, notably the chough, a member of the crow family. Research sponsored by the Department for Environment, Food and Rural Affairs and published in 2007 suggested that “badger culling … is likely to result in markedly higher fox densities. This raises issues relating to the costs of predation on livestock and game, the ecological impact of foxes in conservation terms as predators of ground-nesting birds and hares, and risks to public health as potential vectors of rabies”.

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Restoration strengthens the resilience, function of pollination networks

Date: January 31, 2017

Source: Technische Universität Darmstadt

Removing exotic plant species has a much greater impact on ecosystems than previously thought. Pollination processes become more efficient, and the pollination network soon becomes more resilient. These are the findings of a major field study carried out on the Seychelles, details of which biology researchers of the TU Darmstadt are now publishing online, before an article appears in the scientific journal, Nature.

Ecosystem restoration often focuses on plant species, explains PD Dr Christopher Kaiser-Bunbury, member of the Ecological Networks Study Group of the TU Darmstadt Biology Department. Kaiser-Bunbury is the lead author of the article "Ecosystem restoration strengthens pollination network resilience and function" which is published in the international journal Nature. An established method was used to remove all non-native plants that were becoming too dominant and invasive. "Up until this point, however, we did not know whether interfering with the vegetation in this way would have any effect on pollinators and, in turn, on important processes within the ecosystem." This very question was the focus of biologists in a research project carried out on eight inselbergs on the Seychelles' largest island, Mahé.

In a defined area on four inselbergs, all exotic flora -- such as cinnamon, eucalyptus and Prune de France -- was removed, leaving behind the original, native vegetation. For comparison, the vegetation of four other inselbergs was left untouched.

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Massive sea lion, fur seal hunting in the Patagonian coasts is altering Southern Atlantic Ocean ecosystems

Date: January 18, 2017

Source: Universidad de Barcelona

Sea lion hunting by the Europeans at the Atlantic coasts of South America -it started in the 19th Century and continued up to the second half of the 20th century in Argentina and Uruguay- changed its nutrition guidelines of these pinnipeds as well as the structure of the coastal trophic network, according to the studies by the team codirected by Lluís Cardona, from the Department of Evolutionary Biology, Ecology and Environmental Sciences and the Biodiversity Research Institute of the University of Barcelona (IRBio), and Enrique Crespo, from the Patagonian National Center and the National University of Patagonia (Argentina).

The results of this study are shown in two articles, published in the scientific journals Oecologia and Paleobiology, its co-authors being Fabiana Saporiti and Lisette Zenteno (UB-IRBio), and Damian G. Vales (Patagonian National Center), among others.

This research is one of the results of the project Efectes de l'explotació humana sobre depredadors apicals i l'estructura de la xarxa tròfica del Mar Argentí durant els darrers 6000 anys (Effects of human exploitation on apex predators and structure of the trophic network in the Argentinian sea over the last 6000 years), financially supported by BBVA Foundation and led by Professor Àlex Aguilar (UB-IRBio), head of the Research Group on Large Marine Vertebrates of the University of Barcelona.

A megafauna exploited by humans in all oceans

Hunting and fishing usually create a reduction in the abundance of bigger species. Therefore, megafauna is considered to be one of the most threatened compounds of biodiversity. Marine mammals are an essential element of megafauna in all oceans and they have been extremely exploited by humans. However, knowing about the effects of this exploitation on the functioning of food networks in marine ecosystems -a high complex structural framework- is still a hard challenge for the scientists due to the difficulty to perform manipulative experiments.

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