They’re tiny tortoises.
More on the successful hatching at ZooBorns.com and at Marwell Wildlife. You can learn more about the Egyptian tortoise (Testudo kleinmanni) at the IUCN Red List of Threatened Species.
Image via the Wildlife Conservation Society’s Afghanistan Program
The Persian leopard (Panthera pardus ciscaucasica) was “long thought to have disappeared from” Afghanistan. However, a camera trap captured an image of one cat, which suggests that a breeding population may still occur in parts of the war-torn country. More via National Geographic:
The newly released photographs, taken in the fall, include this September shot of an adult leopard investigating the camera, “appearing to threaten it with canines exposed,” according to the Wildlife Conservation Society, which helped set up the camera traps. The images are “indisputable proof” that the big cat is hanging on in the region, the group said.
Via io9
Northern white rhino image via Wikipedia
Due to poaching, the northern white rhino (Ceratotherium simum cottoni) is on the brink of extinction. Today, it’s thought that there are fewer than five northern white rhinos remaining worldwide. However, scientists are trying to use stem cells to save this remarkable animal. More via New Scientist:
For the first time researchers have turned frozen skin cells from two highly endangered species – the northern white rhino and the baboon-like drill – into stem cells that can become any cell in the body, including sperm and eggs. These could be used to impregnate animals through techniques similar to in vitro fertilisation (IVF).
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Loring’s work is made possible by a menagerie on ice called The Frozen Zoo, a collection of skin cells from more than 8600 animals representing around 800 species at the San Diego Zoo Institute for Conservation Research, California.
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Using viruses, the researchers introduced four genes that are highly expressed in human embryonic stem cells into the skin cells. This reverted the animals’ skin cells to their embryonic state. A few weeks later the researchers had colonies of induced pluripotent stem cells (iPSCs) for both drills and rhinos.
The researchers now hope to turn the drill iPSCs into sperm cells and the rhino iPSCs into egg cells, which could help preserve the species through techniques similar to IVF. They wouldn’t need a living drill or northern white rhino to carry the pregnancy – another primate could be a surrogate mother for a drill embryo, for instance.
Continue reading this article at New Scientist
Image via Joachim S. Müller on Flickr.
Scientists are “re-wilding islands and even continents” in order to remedy sickened or damaged ecosystems. In one example of re-wilding ecosystems, scientists introduced a species of giant tortoise, from Aldabra Atoll in the Seychelles, to take on the ecological role that was played by a similar species of giant tortoise that went extinct on Ile aux Aigrettes, which is an island associated with Mauritius. More via Scientific America:
In 1965 the largely denuded 25 hectares of [Ile aux Aigrettes] were declared a nature reserve. But even in the absence of logging, the slow-growing ebony forests failed to thrive. Why? Because they had lost the animals that ate their fruit and dispersed their seeds. So in 2000 scientists relocated four giant tortoises from the nearby Aldabra atoll in the Seychelles, and by 2009 a total of 19 such introduced tortoises roamed the island, eating the large fruits and leaving behind more than 500 dense patches of seedlings. The team reported its results in April in the journal Current Biology.
For this tiny island, at least, rewilding appears to have worked. And that holds out hope for other restoration ecology projects in the midst of the sixth mass extinction in the earth’s history. In Europe conservationists have received €3.1 million to begin bringing bison, bovines and horses back to “abandoned” agricultural lands in places such as western Spain or the Carpathian Mountains. Ecologists have proposed repopulating parts of the U.S. with elephants, which would replace extinct mastodons. The Dutch, for their part, have already built what amounts to a Pleistocene park at Oostvaardersplassen, adding Konik horses and Heck cattle to replace extinct wild horses and cattle.
Of course, humans have a mixed track record when it comes to interfering in natural ecological systems—the introduction of the cane toad to Australia to manage other pests has resulted in a frog march of havoc across the continent. “There are no guarantees when trying to manipulate nature,” notes ecologist Mark A. Davis of Macalester College in Minnesota. Others argue that humans should fix what they have broken. “There is no place on this planet that humans have not interfered with, and it is time for us to become actively involved in engineering solutions,” says marine biologist Ove Hoegh-Guldberg of the University of Queensland in Australia. “There are no other options except extinction at this point.”
Continue reading this article at Scientific America.
Images: The first image shows, via the United Nations’ Fisheries and Aquaculture Department, a tuna longline. A yellowfin tuna is caught on a weak hook in the second image. Larger species are excluded, because the hooks “straighten when a large fish, such as bluefin tuna, is hooked, releasing it but holding on to smaller fish.” The image is via Mike Carde. Via NOAA, some weak hooks, at various stages of bending, are shown in the third image. The fourth image, via izik on Flickr, illustrates some longline hooks from an Alaskan fishery.
In a fishery, which can mean many things, fishers target certain species for personal consumption or for market. However, sometimes, fishers catch other species in addition to the species that they’re targeting. These non-target species are known as bycatch, and even though bycatch might be illegal to keep, to consume, to target, or to market, bycatch may still be incidentally caught in some fisheries.
Therefore, if the fisher doesn’t have a permit to keep certain species or if the species is illegal to keep, it’s simply wastefully discarded overboard. Bycatch isn’t wasted, however, if a fisheries observer is onboard to scientifically sample the species or if the fishers keep the specimen to turnover to scientists for research. As a result, bycatch can yield valuable data about a species and its interaction with commercial fishing gear.
Nonetheless, bycatch is a serious problem in some fisheries — particularly in some commercial fisheries, where the ecological footprint can be significant. Bycatch might include other species of fish, undersized or juvenile target species, marine mammals, sea turtles, sea birds, or invertebrates. Fisheries with little or no bycatch and minimal impact to the environment are often called clean fisheries. For example, “environmental seafood guides produced by Audubon and the Monterey Bay Aquarium have cited the Albacore troll fishery as an example of a clean fishery with little bycatch or impact on the environment.”
Due to being incidentally caught, some species, in particular, are at risk. For example, populations of endangered species, valuable species, or species that are easily caught as bycatch in certain fisheries suffer from illegal fishing or from fisheries that are inefficient or dirty. However, fisheries research can result in improvements that mitigate or even eliminate bycatch of certain species (thus making the fishery cleaner), so cooperative research is important in ensuring continued seafood production and in making fisheries more sustainable.
Big, fat female fish, which have a higher fecundity, and therefore are important to sustaining certain fish stocks or populations, are vulnerable as bycatch in some fisheries. The loss of important breeding individuals is devastating to certain fish stocks or to certain populations of fish species. One such fishery, which is problematic for incidentally removing important breeding individuals, is the surface-longline fishery. However, conservationists, fishery managers, and scientists are working to improve the fishery by tweaking fishing gear or utilizing bycatch reduction devices. Starting May 5, 2011, for example, “NOAA’s Fisheries Service will require commercial fishermen who fish for yellowfin tuna, swordfish and other species with longlines in the Gulf of Mexico to use a new type of hook, called a weak hook, designed to reduce the incidental catch of Atlantic bluefin tuna.” More via NOAA:
Directed fishing for bluefin tuna in the Gulf has been prohibited since the early 1980s, however bluefin are caught incidentally by longline fishermen who target other species. The Gulf of Mexico is the only known spawning area for the western stock of Atlantic bluefin tuna, a historically overfished species. Many bluefin die from the stress endured in this incidental capture in warm water even if fishermen release them.
“NOAA worked with longline fishermen from the Gulf to test the weak hook carefully over the last three years,” said Eric Schwaab, assistant NOAA administrator for NOAA’s Fisheries Service. “Our cooperative scientific research with fishermen is showing that this new technology can protect bluefin tuna in the Gulf while still allowing fishermen to target yellowfin tuna and swordfish.”
The weak hook is a circular hook constructed of thin gauge wire, and is designed to straighten when a large fish, such as bluefin tuna, is hooked, releasing it but holding on to smaller fish. The average size of bluefin tuna landed in the Gulf of Mexico longline fishery is 485 pounds, while the average for yellowfin tuna is about 86 pounds.
Yellowfin tuna and swordfish are valuable commercial fisheries in the Gulf of Mexico, supporting fishing jobs on approximately 50 vessels as well as jobs on shore. The two species bring longline fishermen annual dockside earnings of $7 million. Research showed that the weak hook could result in some reductions in target catch while some longline fishermen have reported weak hooks did not hurt their businesses.
“During our tests, we used regular hooks for half our hooks and half were the new weak hooks,” said Capt. Mike Carden, a longline fisherman from Panama City, Fla. who took part in the cooperative research. “We were so happy with the weak hooks we quit using the heavy hooks. The weak hook releases fish we don’t want to catch. Because it’s smaller and lighter, we catch more yellowfin tuna on the weak hook. There’s several of us who have gone to the weak hook.”
And from Dot Earth:
Federal fisheries officials, after field studies and public debate, have issued a new rule requiring commercial fishing boats deploying long lines of fish hooks in the Gulf of Mexico to use “weak hooks” that hold smaller, abundant species like yellowfin tuna but, in theory, will allow depleted Atlantic bluefin tuna and other rare large species to escape. Here’s background in a news release from the National Oceanic and Atmospheric Administration.
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The agency release included a supporting comment from a captain of one of the 50 or so commercial longline vessels in the fishery:
“During our tests, we used regular hooks for half our hooks and half were the new weak hooks,” said Capt. Mike Carden, a longline fisherman from Panama City, Fla., who took part in the cooperative research. “We were so happy with the weak hooks we quit using the heavy hooks. The weak hook releases fish we don’t want to catch. Because it’s smaller and lighter, we catch more yellowfin tuna on the weak hook. There’s several of us who have gone to the weak hook.”
The Pew Environmental Trusts, which has been tracking the issue closely, gave a very mixed review to the move. Here’s a statement e-mailed to me by Dave Bard, a spokesman, followed by a video the group has produced on bluefin and the gulf:
Pew is pleased that the National Marine Fisheries Service (NMFS) has recognized the major bycatch problem with bluefin tuna in the Gulf of Mexico, the fish’s only known spawning area in the western Atlantic Ocean. The agency has issued a short-term solution requiring the use of “weak” hooks starting May 5, 2011. Pew is also pleased that NMFS has left the door open to consider long-term solutions including time and area closures. But, a year-round prohibition on surface longlines is the only way to provide effective long-term protection for bluefin tuna and other rare and beautiful species in the Gulf. This prohibition would still allow fishermen in the Gulf to catch swordfish and yellowfin tuna; they would just be required to use more selective alternatives to wasteful surface longlines.
Here’s the video report:
You can continue reading more about this story at Dot Earth.
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