Nissos Rodos ship of Hellenic Seaways in the port of Chios

The Hellenic Seaways Ro-Ro Nissos Rodos moors stern to in the port of Chios, a Greek island located in the Aegean Sea.

 Chios harbor in the GeoGarage platform (NGA chart)

Human : storm

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Finding hidden shoals on the North Slope

NASA Earth Observatory images by Jesse Allen, using Landsat data from the U.S. Geological Survey.
Caption by Laura Rocchio, NASA Landsat Communication and Public Engagement Team.

From NASA

On a recent nautical chart of the Beaufort Sea, in a place where the long, narrow Tapkaluk Islands separate the sea from the shallow Elson Lagoon, a massive underwater shoal appears just west of the entrance to the lagoon.
On the chart it looks like a massive blue thumb jutting into the sea from Alaska’s North Slope.
The National Oceanic and Atmospheric Administration (NOAA) identified this potential 6-mile-long, 2-mile-wide navigation hazard using Landsat satellite data.

Looking at natural-color Landsat imagery of this area, no shoal jumps out to the naked eye.
The image above was acquired by the Operational Land Imager on Landsat 8 on September 6, 2014, and it captures the swirling sediments typical of the North Slope and Elson Lagoon.
Those suspended sediments block most of the light that would normally be reflected by the seafloor.

 NOAA 16081 chart in the GeoGarage platform overlayed on Google imagery

Seafloor reflectance is what typically enables researchers to estimate water depth, a technique known as satellite-derived-bathymetry (SDB).
In regions like the North Slope—where the waters are turbid and access to hydrographic survey vessels is limited—scientists are developing ways to derive the bathymetry from multiple satellite images taken on different dates.
They employ traditional SDB techniques, examining the seafloor reflectance on different dates; they also analyze those images for differences in the swirl of suspended sediment in the water column. From these two approaches, they can detect signs of underwater shoals, gas plumes, or other seafloor formations.

The approach is experimental, and it is only used for reconnaissance now.
Until a survey vessel is dispatched to the North Slope, the exact depths around this potential shoal cannot be known.
But the potential for a large, shallow shoal provoked NOAA to add it to the chart and alert mariners to the potential danger.

It was around 1950 that a hydrographic survey ship last took depth measurements in these waters.
At the time, surveyors built their maps from a single-beam echo sounder and visual navigation.
The data points were laboriously merged with shoreline and hazard information to create a chart.
Given the low ship traffic in the region for many years afterward, updating the chart was a low priority compared to other high-traffic areas.

But things change.
Fishing and water-commuting traffic have increased in the area, as has marine tourism.
But that’s not all: Bottom depths have changed as currents, erosion, and sediments have sculpted the seafloor.
The Marine Chart Division of NOAA’s Office of Coast Survey is responsible for updating more than 1,000 nautical charts that keep mariners safe in U.S. waters.
Charged with providing accurate charts, NOAA cartographers need to know when existing charts are out-of-date.
They monitor navigation hazard reports submitted by mariners.
They watch ship traffic patterns via vessel positioning information (the Automatic Identification System).
And more-and-more they are turning to satellite imagery, especially Landsat data.
“NOAA is now been using Landsat imagery for chart adequacy assessment and mission planning,” said Shachak Pe’eri, a professor from the Joint Hydrographic Center at the University of New Hampshire. Pe’eri and Lieutenant Anthony Klemm, a NOAA Corps Officer in the Marine Chart Division, have developed new NOAA policies for prioritizing ship-based hydrographic surveys based in part on assessments from satellite-derived-bathymetry.
“These charts are considered intermediary, but they can be made publicly available and used until a proper hydrographic survey can be performed,” Pe’eri explains.
Such was the case with nautical chart 16081; NOAA is now warning mariners of the massive shoal suggested by the Landsat data.
“We’re making charts safer up there,” Klemm says, “and that’s so exciting.”

Links :

• Klemm, A., et al. (2015) “Nautical Chart Adequacy Evaluation using Publicly-Available Data.” Conference Proceedings, US Hydrographic Conference.
• GeoGarage blog : Avoiding rock bottom: How Landsat aids nautical charting / GeoGarage: Keeping false pass true

Chinese Navy ships came within 12 Nautical Miles of U.S. Coast

From WSJ by Jeremy Page

Chinese navy ships off Alaska in recent days weren’t just operating in the area for the first time: They also came within 12 nautical miles of the coast, making a rare foray into U.S. territorial waters, according to the Pentagon.

Chinese navy ships off the coast of Alaska came within 12 nautical miles of the U.S. coast, making a rare foray into U.S. territorial waters. WSJ's Gordon Lubold reports.

Photo: Zuma Press

Pentagon officials said late Thursday that the five Chinese navy ships had passed through U.S. territorial waters as they transited the Aleutian Islands, but said they had complied with international law and didn’t do anything threatening.

“This was a legal transit of U.S. territorial seas conducted in accordance with the Law of the Sea Convention,” said Pentagon spokesman Cmdr. Bill Urban.
U.S. officials said there was no known official communication to the U.S. from the ships.
The passage was seen as significant as Beijing has long objected to U.S. Navy vessels transiting its territorial waters or operating in international waters just outside.

 The US confirmed 5 Chinese vessels recently passed with about 12 NM of the Aleutian islands after a joint military exercise with Russia.

The exact location was unclear.

NOAA nautical chart in the GeoGarage platform

China’s Defense Ministry confirmed that its navy ships had sailed to the Bering Sea for training after joint exercises with Russia in late August, but said the activity was routine and not aimed at any particular country.

U.S. officials said earlier that they were tracking the five ships in the area, where they hadn’t seen the Chinese navy operating before, but they didn’t say how close the ships had come to U.S. territory.

The foray, just as President Barack Obama was visiting Alaska, threw a fresh spotlight on China’s expanding naval power and ambitions on the eve of a lavish military parade in Beijing.
It also came just three weeks before China’s President, Xi Jinping, begins a state visit to the U.S. already clouded by tensions over alleged cyberattacks on the U.S. and China’s island-building in the South China Sea.

The flotilla apparently traveled east from somewhere near Russia and entered the Bering Sea, navigating north of the Aleutian Islands before transiting south, where they undertook the “innocent passage” through U.S. waters between two islands, a defense official said.

That principle allows military ships to transit foreign territorial waters if they don’t conduct threatening activity.
The Chinese didn’t give prior notification to the U.S. before doing so, but under international law, they don’t need to.
The Chinese don’t always acknowledge those laws, however, according to U.S. defense reports.
For example, Beijing claims that U.S. warships should request permission before making their own “innocent passage” in Chinese territorial waters.

During fiscal years 2012 and 2013, the Pentagon challenged this notion, deploying U.S. naval ships through Chinese territorial waters without notifying Beijing first.
According to those reports, the U.S. did not make the same challenge during fiscal 2014.
There is no data available for the current fiscal year.

U.S. officials believe China is building a “blue-water” navy capable of operating far from its shores, while also developing missiles and other capabilities designed to prevent the U.S. Navy from intervening in a conflict in Asia.
Many of those capabilities, including a new antiship ballistic missile, were put on display for the first time on Thursday during the parade to mark the surrender of Japanese forces at the end of World War II.

Some U.S. military experts saw the Chinese transit through the Aleutians as a positive step, in that they had adhered to the “innocent passage” principle.
“As a matter of fairness and equity, these operations are a big step forward for U.S. interests in that Beijing now has no basis to object to similar passage through China’s territorial sea by the U.S., for instance in vicinity of China’s islands in the South China Sea,” said Peter Dutton, director of the China Maritime Studies Institute at the U.S. Naval War College.
China took another step in that direction last year during the U.S.-led Rim of the Pacific, or RIMPAC, joint naval drills in Hawaii.

U.S. officials said then that an uninvited Chinese spy ship had observed the drills from international waters.
China’s Defense Ministry said that its operations complied with international law.
Still, Mr. Dutton and other experts said it was doubtful that China would suddenly stop objecting to U.S. naval ships passing through its waters or conducting surveillance nearby.

 Potentila new runway presents new headaches

source : AMTI CSIS

Pentagon officials said in May they were drawing up plans to send U.S. Navy ships or aircraft within 12 nautical miles of artificial islands that China has been building in the disputed South China Sea.
Later that month, China expressed “strong dissatisfaction” and accused the U.S. of irresponsible and dangerous action after a U.S. Navy surveillance jet flew close to the islands, but not within 12 nautical miles.
China has also repeatedly demanded that the U.S. cease surveillance operations within its exclusive economic zone, or EEZ, which under international law extends 200 nautical miles from the coast.

 Exclusive Ecnomic Zones (EEZ) in the East China Sea

source : Global Security

For that reason, Beijing would likely say its ships off Alaska weren't conducting surveillance, although they probably were, said Taylor Fravel, an expert on China’s military at the Massachusetts Institute of Technology.
“China faces contradictory impulses to limit the activities of foreign navies within its own EEZ and to operate within the EEZs of others,” he said.
“Over time, especially as China’s military becomes even more capable, it could downplay objections to the activities of foreign navies in its EEZ as it seeks to operate more frequently out of the region.”
China’s Defense Ministry didn’t respond to questions about which ships were in the flotilla near Alaska or how close they came to U.S. territory.

The joint exercises with Russia ran from Aug. 20-28 off the Russian Pacific coast—about 2,000 miles west of the Bering Sea—according to the official Xinhua News Agency. Seven Chinese ships took part, including two destroyers, two frigates, two landing ships and one supply ship, Xinhua said.
U.S. officials said the five ships near the Aleutians included three Chinese combat ships, a supply vessel and an amphibious landing ship.

Links :

• GeoGarage blog : Troubled waters: why China's navy makes Asia nervous / China's navy breaks out to the high seas / Troubled waters: the South China Sea dispute / US: China failed to clarify 9-dash line with law / Battle of the South China Sea charts / New map boosts China's maritime claims / China's lawful position on the South China Sea /
• The Diplomat : The Nine Ironies of the South China Sea Mess

Tuna and mackerel populations suffer catastrophic 74% decline, research shows

ocean.panda.org/#report

From The Guardian by Fiona Harvey 

WWF says we risk losing species critical to human food security unless action is taken to halt overfishing and other threats to marine life

 Yellowtail and albacore tuna are becoming increasingly rare, as well as bluefin.

Photograph: Brian Skerry/WWF

Tuna and mackerel populations have suffered a “catastrophic” decline of nearly three quarters in the last 40% years, according to new research.
WWF and the Zoological Society of London found that numbers of the scombridae family of fish, which also includes bonito, fell by 74% between 1970 and 2012, outstripping a decline of 49% for 1,234 ocean species over the same period.

 Father and son fishermen in dugout canoe bringing in net at sunset, 

Ohoidertutu Village, Kei Islands, Moluccas, Indonesia.

©Juergen Freund / WWF

The conservation charity warned that we face losing species critical to human food security, unless drastic action is taken to halt overfishing and other threats to marine life.
Louise Heaps, chief advisor on marine policy at WWF UK, said: “This is catastrophic. We are destroying vital food sources, and the ecology of our oceans.”
Attention in recent years has focused on species such as bluefin tuna, now on the verge of extinction, but other close relatives commonly found on restaurant menus or in tins, such as yellowtail tuna and albacore, are now also becoming increasingly scarce. Only skipjack, also often tinned, is showing “a surprising degree of resilience”, according to Heaps, one of the authors of the Living Blue Planet report, published on Wednesday.

 Sea cucumbers, a luxury food in Asia, have fallen 98%.

Photograph: Cat Holloway/WWF

Other species suffering major declines include sea cucumbers, a luxury food in Asia, which have fallen 98% in number in the Galapagos and 94% in in the Egyptian Red Sea.
Populations of endangered leatherback turtles, which can be seen in UK waters, have plummeted.
Overfishing is not the only culprit behind a halving of marine species since 1970.
Pollution, including plastic detritus which can build up in the digestive systems of fish; the loss of key habitats such as coastal mangrove swamps; and climate change are also taking a heavy toll, with the oceans becoming more acidic as a result of the carbon dioxide we are pouring into the atmosphere.

Half of marine life wiped out in just 40 years, says WWF

 “I am terrified about acidification,” Heaps told the Guardian.
“That situation is looking very bleak. We were taught in the 1980s that the solution to pollution is dilution, but that suggests the oceans have an infinite capacity to absorb our pollution. That is not true, and we have reached the capacity now.”
She predicts that all of the world’s coral reefs could be effectively lost by 2050, if current trends are allowed to continue unchecked, and said that evidence of the effects of acidification – which damages tiny marine animals that rely on calcium to make their shells and other organs - could be found from the Antarctic to the US west coast.

 Tubbataha reef in the Philippines appears bleached due to an infestation of crown-of-thorn starfish. Photograph: Juergen Freund/WWF 

Although overfishing is a global problem, the Pacific is of particular concern, as the Chinese, Japanese and Korean fleets are among the world’s biggest, greater in size and fishing capacity than Europe’s.
Chinese fishermen are also increasingly fishing in other waters, expanding their reach. Shark-finning, the practice of removing only the fins from sharks and throwing the bodies back, to make the Asian delicacy shark-fin soup, has taken a severe toll on stocks, with a quarter of shark species predicted to become extinct in a decade if nothing is done.
However, Heaps said there were solutions.
“It’s not all doom-and-gloom. There are choices we can make. But it is urgent.”
Overfishing can be managed with better governance – Heaps points to the recovery in North Sea cod stocks as an example of how management can work.
She also urged governments to adopt the sustainable development goals, proposed by the United Nations and including provisions for protecting marine life, at the UN general assembly later this month.

 A silvertip shark swimming in Beqa lagoon, near Suva, the capital of Fiji.

Photograph: Brent Stirton/WWF

Heaps urged people only to eat fish certified as sustainable by the Marine Stewardship Council (MSC), which examines fisheries against a range of criteria to ensure that they are being properly managed.
An increasing number of fisheries have been accredited by the MSC, and at present about half of global white fish stocks are certified, including many in the North Sea.
She called for more partnerships between private sector fishing fleets and governments, in order to conserve stocks.
“We need to keep [fishermen] on board, because they must see that good governance is in their interests,” she said.

Links :

• Le Marin (in French) : Oceans, la voix des invisibles