When sharks are fished-out from coral reefs, fish body shapes change

Sounds kinda weird.. but studying nearly identical coral reef systems off Australia, my collaborators and I discovered something unusual on the reefs subjected to nearly exclusive fishing of sharks—fish with significantly smaller eyes and tails. This provides evidence of body shape changes in fish due to human-driven shark declines from overfishing.

For these reef fish, eye size is critical for detecting sharks, especially under low-light conditions, and tail size is important for escaping sharks with burst speed. Graphic: Hiram Henriquez and Alberto Cairo, University of Miami

In the study, our research team analyzed seven different fish species from two neighboring coral reef systems off the coast of northwestern Australia. The coral reef systems, known as the Rowley Shoals and the Scott Reefs, are each comprised of multiple atoll-like reefs, are nearly identical biologically and physically in all but one way— the coral reefs in Rowley Shoals are protected from fishing, while the coral reefs in the Scott Reefs have been subjected to nearly exclusive commercial shark fishing for centuries. Targeted shark fishing has intensified in the region in recent decades to fuel the demand of shark fin soup. As a result, shark populations have been decimated at the Scott Reefs, but remain healthy at the Rowley Shoals.

Our team collected 611 fish of seven different species across multiple sites from different coral reefs within the Rowley Shoals and the Scott Reefs. We then took photographs of each fish and digitally analyzed photographs, measuring body length, body width, eye area and tail area of each fish.

We found that at Scott Reefs, where shark populations have declined, the eyes of fishes that are normally prey for sharks were on average up to 46 percent smaller compared to the same sized fish of the same species on reefs at the Rowley Shoals where shark populations are healthy. The same pattern was true for fish tail sizes, with the overall size of fish tails being on average up to 40 percent smaller at the Scott Reefs compared to the Rowley Shoals. Interestingly, these patterns were consistent across seven fish species that vary in behavior, diet and trophic-guild.

Eye size is critical for detecting predators, especially under low-light conditions when many sharks usually hunt, and tail shape enables burst speed and rapid escape from sharks. So we believe that the removals of sharks by humans have potentially caused a reduction in the size of fish body parts that are otherwise normally important for detecting and avoiding sharks. It’s possible that the removal of sharks have lead to an evolutionary change in the fish.

The differences in fish body shapes measured between the two coral reef systems could also have consequences for energy flow throughout the ecosystem, ultimately impacting the food web. These results are particularly important since sharks are among the most threatened marine animals and the consequences of their global removals due to fishing is not well understood and has been a topic of significant speculation, debate and concern. However, these finding shed new light on  our understanding of the potential cascading effects the loss of sharks on marine ecosystems.

Source material Rosenstiel School of Marine & Atmospheric Science, University of Miami

Research paper: Hammerschlag N, Barley SC, Irschick DJ, Meeuwig JJ, Nelson ER, Meekan MG (2018) Predator declines and morphological changes in prey: evidence from coral reefs depleted of sharks. Marine Ecology Progress Series 586:127-139.

Originally posted 2018-08-16 00:49:39.

New weather stations support climate and water research in Bhutan

Researchers have set up four weather stations in a preserve in the mountains of north Bhutan for the first time, allowing them to monitor conditions at various altitudes over the long-term. Data collected by these stations will help determine the best ways to help wildlife in the region adapt to climate change.

The Ugyen Wangchuk Institute for Conservation and Environmental Research (UWICER) set up these hydro-meterological (hydromet) stations at elevations between 9,100 feet and 13,400 feet along a slope in the institute’s research preserve to monitor weather data, and help gauge long-term climate trends. These weather stations, set up with support from WWF’s Conservation and Adaptation in Asia’s High Mountains (AHM) project and funded by USAID, are part of an integrated, climate-smart approach to conservation and adaptation in the region.

The hydro-meteorological data collected—such as daily precipitation, temperature, and the volume of water moving down a river or stream during a given period—will fill a gap in climate information at the edge of snow leopard range in Bhutan, and complement ongoing studies at the institute. The institute currently assesses animal and plant life; sets and monitors camera traps; safely captures and tags birds; and studies tree growth and the amount of energy stored in forests.

Data from these weather stations will be at the core of new studies on the impact of climate change on the water cycle and stream ecosystems. Researchers have already mapped 350 water sources around the research preserve with AHM support, and this new data will provide the needed climate angle.

AHM has also established two climate-smart demonstration villages in partnership with UWICER, that provide remote communities with biogas, greenhouses, water source management, and solar fencing to help them adapt to the climate changes they are already experiencing. The project has also supported the development of the institute’s expertise in water and climate science.

By building weather stations to collect climate data, establishing demonstration sites that allow the testing of adaptation interventions, and organizing events at which researchers can come together and share both their research and practice, WWF is helping UWICER lay a foundation for better climate research and interventions for years to come.

Learn more about Asia High Mountains.

Originally posted 2018-01-18 13:00:00.

Want to help save the world’s forests? Look for the FSC label when you shop

It’s one of the easiest things you can do to help save the world’s forests. Look for the label that says FSC® when you buy paper towels, tissues, furniture or any other products that come from forests.

What does FSC mean?

FSC stands for the Forest Stewardship Council®, a certification system co-founded by WWF 26 years ago. What it really means is that the product you buy comes from a forest that is responsibly managed. Trees in these forests are grown and harvested according to a robust set of guidelines that, ultimately, benefit the environment and economy.

Some of these guidelines include limiting the number of trees cut down, restricting highly hazardous pesticides and protecting the rights of indigenous people, as well as wildlife habitats.

Why it matters

Forests are essential to our survival. They filter the air we breathe and water we drink. And do so much more. Nearly half the world’s wildlife call forests home. Three 300 million people live in forests and more than a billion depend on them for their livelihoods.

Today, trees are being lost at a rate of 27 football fields per minute. Every action we take to protect the world’s forests makes a difference.

This Earth Day, help the world’s forests: Look for the label and buy FSC.

Originally posted 2018-04-22 12:00:00.

Want to help the world’s forests? Look for the FSC label when you shop

It’s one of the easiest things you can do to help save the world’s forests. Look for the label that says FSC when you buy paper towels, tissues, furniture or any other products that come from forests.

What does FSC mean?

FSC stands for the Forest Stewardship Council, a certification system co-founded by WWF 26 years ago. What it really means is that the product you buy comes from a forest that is responsibly managed. Trees in these forests are grown and harvested according to a robust set of guidelines that, ultimately, benefit the environment and economy.

Some of these guidelines include limiting the number of trees cut down, restricting highly hazardous pesticides and protecting the rights of indigenous people as well as wildlife habitats.

Why it matters

Forests are essential to our survival. They filter the air we breathe and water we drink. And do so much more. Nearly half the world’s wildlife call forests home and 300 million people live in forests and more than a billion depend on them for their livelihoods.

Today, trees are being lost at a rate of 27 football fields per minute. Every action we take to protect the world’s forests makes a difference.

This Earth Day, help the world’s forests: Look for the label and buy FSC

Originally posted 2018-04-22 12:00:00.

Meet the small wild cats of Bhutan

Bhutan: a hotspot of wild cat diversity

Did you know that Bhutan is a hotspot of wild cat diversity? It is home to 11 species of wild cats which is about 30% of all wild cat species found in the world. Considering that Bhutan only covers .03% of the earth’s surface, that number seems even more amazing. Jigme Singye Wangchuck National Park in central Bhutan alone is home to eight wild cat species which is perhaps the world’s highest number of wild cat species sharing a single space.

Bhutan has three big cats: tiger, snow leopard, common leopard; one medium-sized cat: clouded leopard and seven smaller wild cats: Pallas’s cat, leopard cat, marbled cat, Asiatic golden cat, jungle cat, lynx* and the fishing cat*.

Small wild cats of Bhutan

As a wildlife biologist, I study many of our cat species through camera trapping. Recently I have also started a tiger project in Bhutan using non-invasive genetics. While the big cats are always impressive, I also have a special interest in the lesser known small cats.

So let’s focus on the small wild cats of Bhutan. Mostly of the size of an ordinary house cat, they are charismatic, unique and just as awe-inspiring as their bigger cousins. They can be found across diverse habitats: in the plains, valleys, near rivers and wetlands, dense forests to alpine mountains and snow and also show different behavioral habits such as climbing trees and fishing. However, they can be challenging to see: they are shy, elusive and in Bhutan, the remoteness and abundant forest provide them the ideal cover to hide.

The small wild cats are one of the lesser knowns, and lesser studied group of animals in Bhutan. Very little information is available about their ecology and threats and unfortunately, the same is true for many small cat species around the world. The lack of knowledge, conservation funding, and attention belie their essential role in the ecosystem. Recent camera trapping exercises on tigers and snow leopards in the country by the Department of Forest and Park Services have provided some useful insights into their distribution. Here are five small wild cat species that have been successfully camera trapped in Bhutan:

1. Pallas’s cat Otocolobus manul

Pallas’s cat. © Nancy Vandermy, courtesy of Small Wild Cat Conservation Foundation

Pallas’s cat or Manul is a rare small wild cat. They are fluffy and cute and are a high-altitude species living in the alpine grasslands and shrub steppes. They are known to occur in low numbers naturally and are habitat specialists making them highly vulnerable to threats such as habitat degradation, conversion, and climate change. They were first recorded in Bhutan in 2012 in Wangchuck Centennial National Park. In the same year, they were reported in the western part of Jigme Dorji National Park. These two locations are the only known distribution records of the species in the country. They are listed as Near-threatened on the IUCN red list of threatened species.

2. Asiatic golden cat Catopuma temminckii

A common morph of the Asiatic golden cat in Phrumsengla National Park in central Bhutan. © Phrumsengla National Park

Also known as the Temminck’s cat, the Asiatic golden cat is a “feline of many costumes.” The species occur in four different coat colors known as morphs: golden, grey, melanistic and spotted. Interestingly all morphs are reported in Bhutan. At one instance in Bumthang in central Bhutan, individuals of all the four different morphs were recorded at the same locality, and few were observed to interact with each other socially. The golden cat is a habitat generalist, widely distributed and occurs from low elevations to more than 4000 meters. Previously thought to be rare, they now are frequently caught on camera traps in Bhutan. They are also listed as Near Threatened on the IUCN red list of threatened species.

3. Marbled cat Pardofelis marmorata

Marbled cat camera trapped in Bumthang in Central Bhutan. Notice the tail hanging horizontally to the ground. © UWICER

Primarily a species of the moist tropical forests, they have been recorded up to 3177 meters in Wangchuck Centennial National Park. The cat is reputed as one of the “fiercest of all cats.” They look like a smaller version of the clouded leopard and share a similar coat pattern. They have a long bushy tail which they use to balance their body while climbing trees or jumping from one branch to another. They are arboreal and secretive in nature and are rarely spotted by our camera traps. They are listed as Vulnerable on the IUCN red list of threatened species.

4. Leopard cat Prionailurus bengalensis

Leopard cat camera trapped in southern Bhutan. The cat is a strong nocturnal animal and pictures during the peak hours of the day are rare. © UWICER/RMNP

The leopard cats are the most widely distributed and the most common smaller cat species in Bhutan. They are also habitat generalists and can be found across numerous habitat types including in and around human settlements. Recently there have been cases of stranded leopard cat kittens being picked up by people. Leopard cat moms are often known to leave their kittens behind when they hunt, and people who come across the kittens mistakenly believe they are abandoned and in need of rescue. Historically, the leopard cat was thought to be rare and was listed as a protected species under the Forest and Nature Conservation Act of Bhutan 1995. However, today they are listed as Least Concern on the ICUN red list

5. Jungle cat Felis chaus

The jungle cat looks like an ordinary grey house cat. © Neville Buck, courtesy of small wild cat conservation foundation

Although known to be a common species, they are hard to camera trap. So far, they have been reported in only two national parks in Bhutan: Jigme Singye Wangchuck National Park and the Royal Manas National Park. However, anecdotal accounts suggest that they are widespread and can be found near villages. They may easily be mistaken for a house cat to an inexperienced eye. They can be differentiated by a yellowish red tinge on their grey coat, and their ears have a small tuft of black hair at the tip. They are listed as Least Concern on the IUCN red list.

Next

Species-specific studies are needed to generate baseline information on the small wild cats of Bhutan. Many feel that fishing cat and lynx must occur in the country and dedicated surveys in their ideal habitats would be an important step to confirm their range.

Overall, the small wild cats need attention from the global conservation community. Funding is a significant constraint on people who are passionate about small cat conservation. From 2007-2013, small cats have received less than 1% of the total conservation funding on all wild cats. In total, there are seven big cats but there are 33 small cat species, and so, they are a big part of the ecosystem and should be a priority. Just like the lions, tigers and snow leopards, they are also globally threatened by habitat loss and poaching. If we don’t start taking action now, many of them could be on the verge of extinction or even gone by the time we know and act.

Note:
*the presence of lynx and fishing cats are based on anecdotal sources; however, they are expected to occur in Bhutan as they are found just across the border in India: fishing cat in Assam and lynx in Sikkim.  

Originally posted 2018-08-14 13:02:53.

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