The International Union for Conservation of Nature (IUCN) Red List announced Thursday that 31 species are now considered “extinct”, including “17 freshwater fish species that are native to Lake Danao and its outlets in the Philippines”.
The IUCN’s posted report on December 10 said the extinctions were due to predatory species that were introduced, “compounded by overharvesting and destructive fishing methods” in the lake.
It said all of the world’s freshwater dolphin species are also now threatened with extinction.
Dr. Bruno Oberle, IUCN director general, said that from the report, the European bison (Bison bonasus), the largest land mammal in Europe, and 25 other species have recovered from “vulnerable” to “near threatened” as also reported in the IUCN Red List, which demonstrates the power of conservation.
“Yet the growing list of extinct species is a stark reminder that conservation efforts must urgently expand. To tackle global threats such as unsustainable fisheries, land clearing for agriculture, and invasive species, conservation needs to happen around the world and be incorporated into all sectors of the economy,” Oberle was quoted in saying.
“The conservation successes in today’s Red List update provide living proof that the world can set, and meet ambitious biodiversity targets. They further highlight the need for real, measurable commitments as we formulate and implement the post-2020 global biodiversity framework,” said too by Dr. Jane Smart, global director of IUCN’s Biodiversity Conservation Group.
There are now 128,918 species on the IUCN Red List, of which 35,765 are threatened with extinction.
Conservation drives European bison recovery
The IUCN Red List said the recovery of the European bison from vulnerable to near threatened was the result of long-term conservation efforts of its wild population, which has grown from 1,800 in 2003 to 6,200 in 2019.
The species survived only in captivity in the early 20th century and was reintroduced to the wild in the 1950s. The largest subpopulations are now found in Poland, Belarus, and Russia. There are currently 47 free-ranging European bison herds.
However, herds are largely isolated from one another and confined to non-optimal forest habitats, and only eight of them are large enough to be genetically viable in the long term. The species remains dependent on ongoing conservation measures such as translocations of bison to more optimal open habitats and reduction of human-bison conflicts.
“Historically, European bison were reintroduced mostly to forest habitats, where they don’t find enough food in winter. However, when they move out of the forest into agricultural areas, they often find themselves in conflict with people. To reduce the conflict risk and the bison’s dependence on supplementary feeding, it will be important to create protected areas that include open meadows for them to graze”, said Dr. Rafał Kowalczyk, co-author of the new assessment and member of the IUCN SSC Bison Specialist Group.
All of the world’s freshwater dolphins now threatened
With the tucuxi (Sotalia fluviatilis) moving from data deficient to endangered, the IUCN Red List reported that all of the world’s freshwater dolphin species are now listed as threatened.
This small grey dolphin species found in the Amazon river system has been severely depleted by incidental mortality in fishing gear, damming of rivers, and pollution. Eliminating the use of gillnets – curtains of fishing net that hang in the water – and reducing the number of dams in tucuxi habitat are priorities to enable numbers to recover.
Enforcing the ban on the deliberate killing of tucuxis is also essential.
Aside from the 17 freshwater fishes in Lake Danao, the IUCN said the lost shark (Carcharhinus obsoletus), which was only formally described last year, has entered the Red List as critically endangered (possibly extinct).
The species was last recorded in 1934. Its habitat in the South China Sea has been extensively fished for more than a century and remains one of the most overexploited marine regions in the world. As it is unlikely that the species could have persisted under this heavy pressure, the lost shark may already be extinct, said the IUCN Red List report.
Three Central American frog species have been newly declared extinct. Additionally, 22 frog species across Central and South America were listed as critically endangered (possibly extinct).
The main driver of these drastic declines is chytridiomycosis disease. Conservation efforts to protect critical habitats are helping populations of several other amphibian species to recover. Among them is the Oaxaca Treefrog (Sarcohyla celata), which moved from critically endangered to near threatened, thanks to actions by local communities in Mexico.
“As a conservationist, the most emotionally impactful news to present is the confirmation of extinction. The causes range from overexploiting to disease, with some threats easier to mitigate than others,” said Dr. Thomas E Lacher, Jr., Texas A&M University.
“The impact of chytrid fungus on amphibian populations has been particularly vexing, challenging conservationists worldwide. There have been successes and recoveries, as noted in the update, and we need to redouble our efforts to address this and other emerging disease threats to biodiversity,” said Dr. Thomas E Lacher, Jr., Texas A&M University.
Plants: proteas and oaks under pressure
The protea family has been comprehensively assessed with this update, revealing that 45% (637 of 1,464 species) of these striking flowering plants that grow mainly across the Southern Hemisphere are vulnerable, endangered, or critically endangered. Many of the species have highly restricted ranges, making them more vulnerable to the spread of invasive alien species, changes to natural fire cycles caused by humans and linked with climate change, and loss of habitat to agriculture.
The protea family includes three Macadamia species – the same species that produce the farmed macadamia nut crop – which has entered the IUCN Red List as threatened with extinction in the wild. The macadamia nut (Macadamia integrifolia) is listed as Vulnerable, while M. ternifolia and M. tetraphylla are listed as Endangered.
Oak trees have been comprehensively assessed, revealing that almost one third (31%, 113 of 430 species) are threatened with extinction. Nine Asian oaks enter the IUCN Red List already Critically Endangered (Possibly Extinct or Possibly Extinct in the Wild).
The highest numbers of threatened species are in China and Mexico, followed by Viet Nam, the United States, and Malaysia. Land clearance for agriculture and logging are the most common threats in China, Mexico, and Southeast Asia. Invasive alien species and diseases and climate change are the key threats to oaks in the United States.
Meanwhile, Clayton Meredith, species survival officer for Plants, ABQ BioPark, said in addition to documenting both recoveries and extinctions, the Red List update includes several species that are heavily traded medicinal plants, including Nagchatri (Trillium govanianum), and Oshá (Ligusticum porteri).
“As we continue to grapple with a global pandemic, these assessments are a testament both to the importance of monitoring trends in a changing environment, and to the critical role of zoos, aquariums, and botanic gardens who contributed to hundreds of species assessments even while under deep financial strain,” said Meredith.