New Great Barrier Reef coral species discovered


This video is called Great Barrier Reef [National Geographic Documentary HD 2017].

From the Schmidt Ocean Institute:

New corals discovered in deep-sea study of Great Barrier Reef Marine Park

September 9, 2020

For the first time, scientists have viewed the deepest regions of the Great Barrier Reef Marine Park, discovered five undescribed species consisting of black corals and sponges, and recorded Australia’s first observation of an extremely rare fish. They also took critical habitat samples that will lead to a greater understanding of the spatial relationships between seabed features and the animals found in the Coral Sea.

The complex and scientifically challenging research was completed aboard Schmidt Ocean Institute’s research vessel Falkor, on its fourth expedition of the year, as part of the Institute’s Australia campaign. Using a remotely operated underwater robot to view high-resolution video of the bottom of the ocean floor, some 1,820 meters deep, the science team examined deep-sea bathymetry, wildlife, and ecosystems. The collaborative mission brought together scientists from Geoscience Australia, James Cook University, University of Sydney, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Queensland Museum Network, and Queensland University of Technology, to answer a range of questions about the geological evolution and biology of the deep-sea canyons and reefs.

“This included the most comprehensive midwater robotic dive survey series to ever have been conducted in the South Pacific,” said Dr. Brendan Brooke, the expedition’s lead scientist from Geoscience Australia. “Research vessel Falkor has integrated a range of technologies that have allowed us to work across the full range of ocean depths in the Coral Sea and to provide data for multiple disciplines including geology, biology, and oceanography.”

During the expedition, researchers took the deepest samples ever collected of soft coral and scleractinian coral in the Coral Sea. They also collected the first sample of ancient bedrock beneath the Great Barrier Reef, estimated to be between 40 and 50 million years old. Scientists made the first recorded observation in Australia of the extremely rare fish Rhinopias agroliba, a colorful and well-camouflaged ambush predator in the scorpionfish family. The cruise also included the most comprehensive survey of midwater jellyfish in the South Pacific.

In addition to the underwater dives, high-resolution mapping of the seafloor was conducted and covered 38,395 square kilometers, an area three times greater than Sydney. The maps include all the major coral atolls on the Queensland Plateau within the Coral Sea Marine Park and an 80-kilometer section of canyons off the northern Great Barrier Reef Marine Park.

“These maps, samples, and images are fascinating and provide a new understanding of the geological diversity and biological wealth of a region that is already world-renowned for its natural beauty,” said Dr. Jyotika Virmani, executive director of Schmidt Ocean Institute. “The data will help marine park managers to protect these ecosystems that are so vital for our global biodiversity and human health. ”

Live streaming of the 18 underwater robotic dives via Schmidt Ocean’s channel on YouTube and 112 hours of high definition underwater video during the month-long expedition, which ended August 30, allowed the science team to share their knowledge and excitement of the voyage’s discoveries with the world. Through the livestreams, the scientists could interact directly with the public via chat and commentary.

“Schmidt Ocean Institute and the technology that it has brought to Australia is a huge enabler in better understanding our marine resources from a lens of diverse disciplines,” said Dr. Scott Nichol, one of the lead expedition scientists from Geoscience Australia. “This work brings new understanding and will keep the scientists busy for years.”

How corals spawn, new research


This November 2019 video about the Great Barrier Reef in Australia is called Witness a Massive Coral Spawning.

From Rutgers University in the USA:

Surprising coral spawning features revealed

Stony coral sperm and eggs share similar genetic functions, new study shows

August 18, 2020

When stony corals have their renowned mass spawning events, in sync with the moon’s cycle, colonies simultaneously release an underwater “cloud” of sperm and eggs for fertilization. But how do the sperm and eggs survive several hours as plankton, given threats from predators, microbes and stresses such as warming waters?

A Rutgers-led team has discovered some surprising features in coral sperm and eggs (collectively called gametes), according to a study in the journal PeerJ.

While coral eggs are large and sperm cells are tiny and far more numerous, the scientists showed for the first time that eggs and sperm appear to be surprisingly similar when it comes to the gene functions they express during the planktonic stage. Proteins encoded by genes, in a process called gene expression, play many critical roles and perform most of the work in cells.

The scientists also identified two genes that may be involved in how coral sperm and eggs recognize each other in dynamic ocean waters, allowing fertilization.

“Much more attention needs to be paid to coral gametes because both egg and sperm are vulnerable to climate change and other insults,” said senior author Debashish Bhattacharya, a distinguished professor in the Department of Biochemistry and Microbiology in the School of Environmental and Biological Sciences at Rutgers University-New Brunswick. “It goes without saying that without robust sperm and egg, the coral reproductive cycle will be significantly weakened. Therefore, we need to understand in more detail how natural selection has acted on coral gametes to ensure their survival, leading to successful fertilization.”

Coral reefs protect coastlines from erosion and storms; serve as habitat, nursery and spawning grounds for fish; and provide food for about 500 million people as well as their livelihoods, according to the National Oceanic and Atmospheric Administration. But corals are threatened by global climate change that warms the ocean and leads to coral bleaching, disease, sea-level rise and ocean acidification. Other threats include unsustainable fishing, land-based pollution, tropical storms, damage from vessels, marine debris and invasive species.

By analyzing the genes of the Hawaiian stony coral Montipora capitata, the scientists revealed a blueprint for how coral eggs and sperm function. The next steps include further analyses of coral genomes to identify the substances they produce to ensure their survival and fertilization. The scientists are also interested in investigating coral species that don’t release sperm and eggs into the water before fertilization and comparing the results to the stony coral study.

“Our results pave the way for future genetic investigations, particularly in the context of climate change influences on the marine environment,” Bhattacharya said.

Studying coral with microscopes, new method


This July 2016 video says about itself:

A new microscope mimics the human eye to study the intimate lives of coral

A new microscope gives unprecedented access to the lives of coral, from feeding to kissing, on the ocean floor.

Video Editor: Leigh Anne Tiffany

Video provided by: Jaffe Lab for Underwater Imaging, Scripps Institution for Oceanography at UC San Diego

Music: Blue Dot Sessions via Creative Commons

From the Marine Biological Laboratory in the USA:

Microscope allows gentle, continuous imaging of light-sensitive corals

June 30, 2020

Summary: Many corals are sensitive to bright light, so capturing their dynamics with traditional microscopes is a challenge. To work around their photosensitivity, researchers developed a custom light-sheet microscope (the L-SPI) that allows gentle, non-invasive observation of corals and their polyps in detail over eight continuous hours, at high resolution.

Corals are “part animal, part plant, and part rock — and difficult to figure out, despite being studied for centuries,” says Philippe Laissue of University of Essex, a Whitman Scientist at the Marine Biological Laboratory. Many corals are sensitive to bright light, so capturing their dynamics with traditional microscopes is a challenge.

To work around their photosensitivity, Laissue developed a custom light-sheet microscope (the L-SPI) that allows gentle, non-invasive observation of corals and their polyps in detail over eight continuous hours, at high resolution. He and his colleagues, including MBL Associate Scientist and coral biologist Loretta Roberson, published their findings this week in Scientific Reports.

Coral reefs, made up of millions of tiny units called polyps, are extremely important ecosystems, both for marine life and for humans. They harbor thousands of marine species, providing food and economic support for hundreds of millions of people. They also protect coasts from waves and floods, and hold great potential for pharmaceutical and biotechnological discovery.

But more than half of the world’s coral reefs are in severe decline. Climate change and other human influences are gravely threatening their survival. As ocean temperatures rise, coral bleaching is afflicting reefs worldwide. In coral bleaching, corals expel their symbiotic algae and become more susceptible to death.

“The L-SPI opens a window on the interactions and relationship between the coral host, the symbiotic algae living in their tissues, and the calcium carbonate skeleton they build in real time,” Roberson says. “We can now track the fate of the algae during [coral] bleaching as well as during initiation of the symbiosis.”

Roberson is also using Laissue’s imaging technology to measure damage to corals from “bioeroders” — biological agents like algae and sponges that break down a coral’s skeleton, a problem exacerbated by ocean acidification and increasing water temperatures.

Corals discovered off Greenland


This 29 June 2020 video says about itself:

Captioned video showing and describing a new soft coral garden habitat discovered deep off the coast of Greenland.

From University College London in England:

Soft coral garden discovered in Greenland’s deep sea

June 29, 2020

A deep-sea soft coral garden habitat has been discovered in Greenlandic waters by scientists from UCL, ZSL and Greenland Institute of Natural Resources, using an innovative and low-cost deep-sea video camera built and deployed by the team.

The soft coral garden, presented in a new Frontiers in Marine Science paper, is the first habitat of this kind to have been identified and assessed in west Greenland waters.

The study has direct implications for the management of economically important deep-sea trawl fisheries, which are immediately adjacent to the habitat. The researchers hope that a 486 km2 area will be recognised as a ‘Vulnerable Marine Ecosystem’ under UN guidelines, to ensure that it is protected.

PhD researcher Stephen Long (UCL Geography and ZSL (Zoological Society London)), first author on the study, said: “The deep sea is often over-looked in terms of exploration. In fact, we have better maps of the surface of Mars, than we do of the deep sea.

“The development of a low-cost tool that can withstand deep-sea environments opens up new possibilities for our understanding and management of marine ecosystems. We’ll be working with the Greenland government and fishing industry to ensure this fragile, complex and beautiful habitat is protected.”

The soft coral garden discovered by the team exists in near-total darkness, 500m below the surface at a pressure 50 times greater than at sea-level. This delicate and diverse habitat features abundant cauliflower corals as well as feather stars, sponges, anemones, brittle stars, hydrozoans, bryozoans and other organisms.

Dr Chris Yesson (ZSL), last author on the study, said “Coral gardens are characterised by collections of one or more species (typically of non-reef forming coral), that sit on a wide range of hard and soft bottom habitats, from rock to sand, and support a diversity of fauna. There is considerable diversity among coral garden communities, which have previously been observed in areas such as northwest and southeast Iceland.”

The discovery is particularly significant given that the deep sea is the most poorly known habitat on earth, despite being the biggest and covering 65% of the planet. Until very recently, very little was known about Greenland’s deep-sea habitats, their nature, distribution and how they are impacted by human activities.

Surveying the deep sea has typically proved difficult and expensive. One major factor is that ocean pressure increases by one atmosphere (which is the average atmospheric pressure at sea level) every 10 metres of descent. Deep-sea surveys, therefore, have often only been possible using expensive remote operating vehicles and manned submersibles, like those seen in Blue Planet, which can withstand deep-sea pressure.

The UK-Greenland research team overcame this challenge by developing a low-cost towed video sled, which uses a GoPro video camera, lights and lasers in special pressure housings, mounted on a steel frame.

The lasers, which were used to add a sense of scale to the imagery, were made by combining high-powered laser pointers with DIY housings made at UCL’s Institute of Making, with help from UCL Mechanical Engineering.

The team placed the video sledge — which is about the size of a Mini Cooper — on the seafloor for roughly 15 minutes at a time and across 18 different stations. Stills were taken from the video footage, with 1,239 images extracted for further analysis.

A total of 44,035 annotations of the selected fauna were made. The most abundant were anemones (15,531) and cauliflower corals (11,633), with cauliflower corals observed at a maximum density of 9.36 corals per square metre.

Long said: “A towed video sled is not unique. However, our research is certainly the first example of a low-cost DIY video sled led being used to explore deep-sea habitats in Greenland’s 2.2million km² of sea. So far, the team has managed to reach an impressive depth of 1,500m. It has worked remarkably well and led to interest from researchers in other parts of the world.”

Dr Yesson added: “Given that the ocean is the biggest habitat on earth and the one about which we know the least, we think it is critically important to develop cheap, accessible research tools. These tools can then be used to explore, describe and crucially inform management of these deep-sea resources.”

Dr Martin Blicher (Greenland Institute of Natural Resources) said: “Greenland’s seafloor is virtually unexplored, although we know is it inhabited by more than 2000 different species together contributing to complex and diverse habitats, and to the functioning of the marine ecosystem. Despite knowing so little about these seafloor habitats, the Greenlandic economy depends on a small number of fisheries which trawl the seabed. We hope that studies like this will increase our understanding of ecological relationships, and contribute to sustainable fisheries management.”

Shipwreck Coral Reefs, video


This 24 June 2020 video says about itself:

Exploring Shipwreck Coral Reefs

Next on Blue World, Jonathan learns how to dive without a scuba tank by holding his breath a long time! But first, he investigates shipwrecks that are turning into coral reefs. All of this today on Jonathan Bird’s Blue World!

Restoring Mexican coral reefs, video


This 17 June 2020 video says about itself:

Oceanographer and National Geographic Explorer Paola Rodriguez works to restore coral reefs in her native Mexico. Once thought impossible, Paola and her team are proving that reefs can recover from even serious damage if given a chance.

How deep sea corals grow, new research


This December 2016 video from the USA says about itself:

In the deep waters off Florida’s Atlantic coast grow magnificent structures, capable of reaching 300 feet in height. These are the corals of the deep sea. Porcelain-white and centuries-old, few humans have seen these delicate reefs. The Ivory Tree Coral, Oculina varicosa, and Lophelia pertusa flourish in harsh, sunless environments, yet these branch-like formations provide food and shelter for a variety of deepwater organisms. Rich in biodiversity, this mysterious underwater kingdom is threatened by destructive fishing practices such as bottom trawling. However, a recently proposed 23,000 square mile marine protected area could save these fragile reefs from ruin.

Changing Seas follows scientists 50 miles offshore on a unique expedition to further pinpoint the locations of these thousand-year-old coral mounds. Using cutting-edge technology, experts from three of the country’s premier ocean research institutions have joined forces to investigate portions of Florida’s seafloor. The science team lives aboard a research vessel for seven days. Their mission: To scan the ocean bottom and create detailed maps using specially built Autonomous Underwater Vehicles or AUVs. Their results could help save Florida’s corals of the deep. But what will they find?

From the University of Hawaii at Manoa:

Surprising growth rates discovered in world’s deepest photosynthetic corals

June 15, 2020

New research published in the journal Coral Reefs revealed unexpectedly high growth rates for deepwater photosynthetic corals. The study, led by Samuel Kahng, affiliate graduate faculty in the University of Hawai’i at M?noa School of Ocean and Earth Science and Technology (SOEST), alters the assumption that deep corals living on the brink of darkness grow extremely slowly.

Leptoseris is a group of zooxanthellate coral species which dominate the coral community near the deepest reaches of the sun’s light throughout the Indo-Pacific. Symbiotic microalgae (called zooxanthellae) live within the transparent tissues some coral — giving corals their primary color and providing the machinery for photosynthesis, and in turn, energy.

Deeper in the ocean, less light is available. At the lower end of their depth range, the sunlight available to the Leptoseris species examined in the recent study is less than 0.2% of surface light levels. Less light dictates a general trend of slower growth among species that rely on light for photosynthesis.

Previous studies suggested that photosynthetic corals at the bottom of the ocean’s sunlit layer grow extremely slowly — about 0.04 inch per year for one species of Leptoseris. Until recently, there were very few data on growth rates of corals at depths greater than about 225 feet given the logistical challenges of performing traditional time series growth measurements at these depths.

Kahng, who is also an associate professor at Hawai’i Pacific University, collaborated with SOEST’s Hawai’i Undersea Research Laboratory (HURL), the Waikiki Aquarium, National Taiwan University and Hokkaido University to collected colonies of Leptoseris at depths between 225 and 360 feet in the Au’au Channel, Hawai’i using HURL’s Pisces IV/V submersibles. The research team used uranium-thorium radiometric dating to accurately determine the age of the coral skeletons at multiple points along its radial growth axis — much like one might determine the age of tree rings within a tree trunk.

“Considering the low light environment, the previous assumption was that large corals at these extreme depths should be very old due to extremely slow growth rates,” said Kahng. “Surprisingly, the corals were found to be relatively young with growth rates comparable to that of many non-branching shallow-water corals. Growth rates were measured to be between nearly 1 inch per year at 225 feet depth and 0.3 inches per year at 360 feet depth.”

The research team found that these low light, deep water specialists employ an interesting strategy to dominate their preferred habitat. Their thin skeletons and plate-like shape allow for an efficient use of calcium carbonate to maximize surface area for light absorption while using minimal resources to form their skeleton. These thin corals only grow radially outward, not upward, and do not thicken over time like encrusting or massive corals.

“Additionally, the optical geometry of their thin, flat, white skeletons form fine parallel ridges that grow outward from a central origin,” said Kahng. “In some cases, these ridges form convex spaces between them which effectively trap light in reflective chambers and cause light to pass repeatedly through the coral tissue until it is absorbed by the photosynthetic machinery.”

The strategic efficiency of Leptoseris enabling its robust growth rates in such low light has important implications for its ability to compete for space and over-shade slower-growing organisms.

“It also illustrates the flexibility of reef-building corals and suggests that these communities may be able to develop and recover from mortality events much faster than previously thought,” said Kahng.

Coral reef fish evolution, new research


This 2018 video says about itself:

The Coral Reef: 10 Hours of Relaxing Oceanscapes | BBC Earth

Sit back, relax and enjoy the colourful world of coral reefs as we take you on a journey through some of the most vibrant parts of our blue planet with this 10-hour loop.

From the ARC Centre of Excellence for Coral Reef Studies in Australia:

Big vegetarians of the reef drive fish evolution

June 2, 2020

Summary: New research finds fish diets, not geography, dictate how fast species evolve.

A new study reveals the diets of reef fish dictate how fast different species evolve. The breakthrough adds another piece to the fascinating evolutionary puzzle of coral reefs and the fishes that live on them.

“Up until now we knew that many factors could have influenced the pace of reef fish evolution, but these factors were never examined altogether,” said Alexandre Siqueira, the study’s lead author from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU).

“By building an evolutionary ‘tree of life’ for nearly all fishes associated with reefs, we were able to examine the variation in rates of species formation and ask what drives it,” said co-author Dr Peter Cowman, also from Coral CoE at JCU.

The ‘tree of life’ contains more than 6,000 fish species that live on coral reefs across the globe. Ecological and geographical data — such as diet and geographical range — were also gathered for the majority of these species.

The authors were surprised to find that what really matters in reef fish evolution isn’t geography, but what fish eat and how big they get.

“We found that the fastest way to have more species, or biodiversity, on a reef is to be big and vegetarian,” said co-author Professor David Bellwood, also from Coral CoE at JCU.

“Herbivores, such as surgeonfishes and parrotfishes, are key to the ecological diversity of coral reefs today.”

The study suggests these fishes also made way for today’s coral reefs to evolve and flourish.

“By feeding on the algae that compete with corals, herbivorous fishes may have also helped corals to expand through time,” Mr Siqueira said.

“In turn, this expansion in the corals allowed the diversification of other reef fish groups that depend on them.”

And these herbivorous fishes — big and small — still maintain coral reefs to this day.

The study offers a new way of looking at reefs with a functional, rather than taxonomic, approach. Very little is known about the functional evolution of reefs: what they do and how they work. Scientists previously only looked at how many reefs there were and what species were present.

“In this study it was important to understand the origins of the functional role a fish species plays on a reef — not just the species itself,” Dr Cowman said.

Today’s coral reefs differ from their early counterparts. It was only during the Miocene, less than 23 million years ago, that herbivorous fish species developed features that allowed them to explore different areas of the reef.

“Because of this, today’s reefs are highly dynamic and have a fast turnover. These herbivores are the key element that established modern coral reefs,” Prof Bellwood said.

“Understanding how reefs are constructed throughout their evolution means we can reach a better understanding of the fundamental processes that maintain them in a healthy state today,” Mr Siqueira said.

Saving a coral reef in the Philippines


This 29 May 2020 video says about itself:

Grandpa’s Reef – 360 | National Geographic

Travel with us to the Philippines, where a young girl takes up her grandfather’s lifelong pursuit of protecting an endangered coral reef. Inspired by true stories, this virtual reality experience will take you diving on some of the world’s most beautiful reefs. For a better viewing experience, watch in a VR headset using the YouTube app.