Marine biology discoveries off Western Australia


This video from Australia says about itself:

Deep-sea secrets of the cryptic Perth Canyon unveiled

15 March 2015

Scientists have completed a successful two-week mission unlocking the secrets of Perth Canyon, a deep ocean gorge the size of the USA’s Grand Canyon.

From LiveScience:

Huge Underwater Canyon Is Home to Amazing Deep-Sea Creatures

by Laura Geggel, Staff Writer | March 23, 2015 03:51pm ET

A two-week-long seafaring mission off the coast of western Australia has helped illuminate a deep and dark underwater abyss the size of the Grand Canyon.

During the trip to Perth Canyon, researchers encountered countless deep-sea organisms, including Venus flytrap anemones and golden coral. They even found a lost piece of equipment — an autonomous ocean glider that had gone missing two years earlier.

The scientists, from the University of Western Australia‘s Oceans Institute, began their mission on March 1 on the Falkor, a research vessel owned by an American nonprofit organization. Once aboard, they sailed about 19 miles (30 kilometers) from Fremantle, a city on the western Australian coast. They then used a remotely operated vehicle (ROV) to explore the underwater canyon, which extends from the continental shelf for more than 2.5 miles (4 km) to the ocean floor. [Marine Marvels: Spectacular Photos of Sea Creatures]

“We have discovered near-pristine, sheer-drop cliffs of over 600 meters [1,968 feet] and mapped structures that are rarely found in other parts of the ocean,” Malcolm McCulloch, the project’s leader and a professor of earth and the environment at the University of Western Australia, said in a statement. “It is truly a huge canyon.”

The canyon likely formed more than 100 million years ago, the researchers said. Back then, it appears that an ancient river cut the canyon during rifting that separated western Australia from India. Nowadays, the submerged canyon is a hotspot for marine life, attracting blue whales and other sea life in search of a tasty meal.

Researchers knew little about the canyon’s structure and the creatures that inhabited it until this expedition. Using the Falkor’s cutting-edge mapping systems and ROV, they explored Perth Canyon at depths of more than 1.2 miles (2 km). By the end of the mission, the research team had traveled more than 1,118 miles (1,800 km) to map the canyon’s 154 square miles (400 square km).

The canyon’s deepest point is 2.6 miles (4,276 m) below the ocean’s surface, McCulloch said.

“It is at a depth where light can’t penetrate, making a dark water column where there are no signs of light from above or below,” he said.

Still, the researchers found a surprisingly rich community of deep-sea creatures that cling to the canyon’s walls. For instance, about 1 mile (1.6 km) below the surface, they found brisingid seastars and mushroom soft corals. Other researchers have documented these animals living in Perth Canyon before, and now these creatures have been found in other deep-sea areas around the world.

The team also used the ROV to collect samples of the deep-sea corals. In the coming months, the scientists plan to determine the coral‘s age, how fast they grow, and whether global warming or ocean acidification has changed their habitat.

The work may also help other researchers, especially those who study deep-sea ecosystems and the factors that threaten survival in these places, they said.

During the project, the researchers also stumbled across an old piece of equipment — an autonomous ocean glider that went missing while it was exploring the canyon more than two years ago. When the team spotted the bright-yellow glider at a depth of about 0.4 miles (700 meters) underwater, everyone celebrated, said Chari Pattiaratchi, a professor of coastal oceanography at the University of Western Australia.

Next up, researchers will use the Falkor to test underwater robotic vehicles at Scott Reef, off the coast of northwestern Australia.

Rare breeding birds in the Netherlands


This video is called White-winged [Black] Terns (Chlidonias leucopterus) in Belarus 2013.

According to the recently published Dutch breeding birds survey for 2013, several species, rare for the Netherlands, nested then.

They included one shag nest, which unfortunately failed.

Also: two red kite nests. A Caspian gull male had a cross-species nest with a female herring gull. There were 11 white-winged black tern nests.

Dutch reed warblers depend on African rainfall


This video is about a young cuckoo, fed by its foster parent, an Eurasian reed warbler.

Translated from the Dutch SOVON ornithologists:

When it rains in the Sahel more Eurasian reed warblers survive

Friday, March 20th, 2015

About various migratory birds including the purple heron and the sedge warbler it was already known: if there is enough rainfall in the autumn in their wintering grounds in West Africa, it increases the likelihood that they will survive the winter.

An analysis of reed warblers captured in the Netherlands shows the same effect. How many reed warblers return to the Netherlands therefore depends in part on the amount of precipitation that falls in West Africa. This is reflected in the Breeding Birds Report 2013 published today by SOVON.

Arctic marine mammals, new study


This video is called How marine mammals survive underwater life – BBC wildlife.

From Wildlife Extra:

First global review on the status, future of Arctic marine mammals published

For Arctic marine mammals, the future is especially uncertain. Loss of sea ice and warming temperatures are shifting already fragile Northern ecosystems.

The precarious state of those mammals is underscored in a multinational study led by a University of Washington scientist, published this week in Conservation Biology, assessing the status of all circumpolar species and subpopulations of Arctic marine mammals, including seals, whales and polar bears. The authors outline the current state of knowledge and their recommendations for the conservation of these animals over the 21st century.

“These species are not only icons of climate change, but they are indicators of ecosystem health, and key resources for humans,” said lead author Kristin Laidre, a polar scientist with the UW Applied Physics Laboratory.

The overall numbers and trends due to climate change are unknown for most of the 78 populations of marine mammals included in the report: beluga, narwhal and bowhead whales; ringed, bearded, spotted, ribbon, harp and hooded seals; walruses; and polar bears.

The paper reviews population sizes and trends over time, if known, for each group, ranging from millions of ringed seals to fewer than a hundred beluga whales in Northern Canada’s Ungava Bay.

“Accurate scientific data – currently lacking for many species – will be key to making informed and efficient decisions about the conservation challenges and tradeoffs in the 21st century,” Laidre said.

The publicly available report also divides the Arctic Ocean into 12 regions, and calculates the changes in the dates of spring sea ice retreat and fall freeze-up from NASA satellite images taken between 1979 and 2013.

Reductions in the sea ice cover, it finds, are “profound.” The summer ice period was longer in most regions by five to 10 weeks. The summer period increased by more than 20 weeks, or about five months, in the Barents Sea off Russia.

The species most at risk from the changes are polar bears and ice-associated seals.

“These animals require sea ice,” Laidre said. “They need ice to find food, find mates and reproduce, to rear their young. It’s their platform of life. It is very clear those species are going to feel the effects the hardest.”

Whales may actually benefit from less ice cover, at least initially, as the open water could expand their feeding habitats and increase food supplies.

Approximately 78 percent of the Arctic marine mammal populations included in the study are legally harvested for subsistence across the Arctic.

“There’s no other system in the world where top predators support human communities the ways these species do,” Laidre said.

The study recommends:

Maintaining and improving co-management with local and governmental entities for resources that are important to the culture and well-being of local and indigenous peoples.

Recognizing variable population responses to climate change and incorporating those into management. In the long term, loss of sea ice is expected to be harmful to many Arctic marine mammals, however many populations currently exhibit variable responses.

Improving long-term monitoring while recognizing monitoring for all species will be impossible. Alternatives include collecting valuable data from subsistence harvests, using remote methods to track changes in habitat, and selecting specific subpopulations as indicators.

Studying and mitigating the impacts of increasing human activities including shipping, seismic exploration, fisheries and other resource exploration in Arctic waters.

Recognizing the limits of protected species legislation. A balanced approach with regard to regulating secondary factors, such as subsistence harvest and industrial activity, will be needed, since protected species legislation cannot regulate the driver of habitat loss.

While the report aims to bring attention to the status and future of Arctic mammals, the authors hope to provoke a broader public response.

“We may introduce conservation measures or protected species legislation, but none of those things can really address the primary driver of Arctic climate change and habitat loss for these species,” Laidre said. “The only thing that can do that is the regulation of greenhouse gases.”

The report was funded by the Greenland Institute of Natural Resources and NASA. Co-authors are Harry Stern at the UW; Kit Kovacs, Christian Lydersen and Dag Vongraven at the Norwegian Polar Institute; Lloyd Lowry at the University of Alaska; Sue Moore at the U.S. National Marine Fisheries Service; Eric Regehr at the U.S. Fish and Wildlife Service in Anchorage; Steven Ferguson at Fisheries and Oceans Canada; &Ostroke;ystein Wiig at the University of Oslo; Peter Boyeng and Robyn Angliss at the Alaska Fisheries Science Center; Erik Born and Fernando Ugarte at the Greenland Institute of National Resources; and Lori Quakenbush at the Alaska Department of Fish and Game.

The study builds on a 2013 report by the Conservation of Arctic Flora and Fauna, a multinational group that advises the Arctic Council on biodiversity and conservation issues. Laidre was one of the lead authors for the chapter on marine mammals.

Barn owls’ male and female colours, new research


This video from Britain is called An Introduction to the Barn Owl.

From the Biological Journal of the Linnean Society in England:

Signalling value of maternal and paternal melanism in the barn owl: implication for the resolution of the lek paradox

17 MARCH 2015

Abstract

Secondary sexual characters often signal qualities such as physiological processes associated with resistance to various sources of stress. When the expression of an ornament is not sex-limited, we can identify the costs and benefits of displaying a trait that is typical of its own sex or of the other sex.

Indeed, the magnitude and sign of the covariation between physiology and the extent to which an ornament is expressed could differ between males and females if, for instance, the regulation of physiological processes is sensitive to sex hormones.

Using data collected over 14 years in the nocturnal barn owl Tyto alba, we investigated how nestling body mass covaries with a heritable melanin-based sex-trait, females displaying on average larger black feather spots than males. Independently of nestling sex, year and time of the day large-spotted nestlings were heavier than small-spotted nestlings.

In contrast, the magnitude and sign of the covariation between nestling body mass and the size of parental spots varied along the day in a way that depended on the year and parental gender. In poor years, offspring of smaller-spotted mothers were heavier throughout the resting period; in the morning, offspring sired by larger-spotted fathers were heavier than offspring of smaller-spotted fathers, while in the evening the opposite pattern was found.

Thus, maternal and paternal coloration is differentially associated with behaviour or physiology, processes that are sensitive to time of the day and environmental factors. Interestingly, the covariation between offspring body mass and paternal coloration is more sensitive to these environmental factors than the covariation with maternal coloration. This indicates that the benefit of pairing with differently spotted males may depend on environmental conditions, which could help maintain genetic variation in the face of intense directional (sexual) selection.