Compact semi submarine

From Mashable

Hop into this Ego Compact Semi Submarine, and without any extensive training you can be on your way to exploring the deep blue sea in no time.

Why is this called a semi-submarine?
The entire boat is not submerged, but it’s more like a pontoon boat with a transparent waterproof compartment hanging from its middle.

That means James Cameron is not going to be using one of these subs for that deep-water shoot for his Avatar sequel, but it’s still suitable for giving you an eye-popping view of the undersea world.
Think of it as more akin to snorkeling than scuba diving.

The little boat cruises along at a leisurely sightseeing pace that’s unspecified by its maker, which will only say that its batteries will last eight hours at cruising speed or four hours at top speed.

It’s built by South Korean company Raonhaje, which plans to sell fleets of these Ego Semi-Submarines to resorts, and single units to individuals and yacht owners.
The company offers to build custom moorings for the craft, as well as hoists for yachts.

We’re thinking super-safe leisure subs like these would be a huge hit at a resort, especially seaside marinas near coral reefs, with their colorful and bustling underwater wildlife.
Just think, even people who can’t swim can enjoy the spectacular view.

Pollution Triggers genetic resistance mechanism in a coastal fish

Mature tagged Atlantic tomcod collected from the Hudson River
(Mark Mattson, Normandeau Associates, Inc.)

From WHOI

For 30 years, two General Electric facilities released about 1.3 million pounds of polychlorinated biphenyls (PCBs) into New York’s Hudson River, devastating and contaminating fish populations (see EPA).
Some 50 years later, one type of fish—the Atlantic tomcod—has not only survived but appears to be thriving in the hostile Hudson environment.
Researchers from Woods Hole Oceanographic Institution (WHOI) have joined colleagues from New York University (NYU) and NOAA to investigate this phenomenon and report that the tomcod living in the Hudson River have undergone a rapid evolutionary change in developing a genetic resistance to PCBs.

Although this kind of reaction has been seen when insects develop resistance to certain insecticides, and bacteria to antibiotics, “This is really the first demonstration of a mechanism of resistance in any vertebrate population,” said Isaac Wirgin of NYU’s Department of Environmental Medicine and leader of the study. Moreover, he said, the team has found that “a single genetic receptor has made this quick evolutionary change possible.”

The findings, reported online in the Feb. 17 issue of Science, provide a first look at “natural selection going on over a relatively short time, changing the characteristics of a population,” said WHOI Senior Scientist Mark E. Hahn, who, together with WHOI biologist Diana Franks, collaborated with Wirgin on the study.
“It’s an example of how human activities can drive evolution by introducing stress factors into the environment.”

Looking at the ability of the fish to respond to the contaminants, the researchers found the primary changes occurred in a receptor gene called AHR2, which is important in mediating toxicity in early life stages and can control sensitivity to PCBs.
In his work over the last 16 years in the Acushnet River Estuary near New Bedford, Mass., biologist Hahn has found the same gene involved in controlling other fishes’ responses to PCBs.

The AHR2 proteins in the Hudson Rover tomcod, he said, appear to be missing two of the 1,104 amino acids normally found in this protein.
This causes the receptor to bind more weakly with PCBs than normal, suggesting a reason why the contaminant does not affect the tomcod in this location as much as it does tomcod in other locations
The Hudson River tomcod “are not as sensitive to PCBs,” Hahn said. “The mechanism by which PCBs cause toxicity is dampened in this population.”

While this may be good news for the tomcod, it may bode not so well for their predators, and even humans.
“The tomcod survive but they still accumulate PCBs in their bodies and pass it on to whatever eats them,” Hahn said.

Wirgin noted that tomcod spawn in the winter, and in the summer become “a major component of the diets of striped bass and other fish.”
This can lead to “an abnormal transfer of contaminants up the food chain,” perhaps all the way to humans who may consume them.

In addition, the tomcod’s genetic changes “could make them more sensitive to other things,” and affect their ability to break down certain other harmful chemicals, such as PAHs (polycyclic aromatic hydrocarbons), Hahn said.
“So it’s conceivable that the Hudson River tomcod could be more susceptible to PAHs because it cannot degrade them properly,” he said.

Also, he added, these receptors are involved in normal development, and a genetic change could lead to a change in a fish’s health.
“There could be evolutionary costs,” Hahn said.
“We don’t know yet what they are but it’s something that needs to be considered.”

“Hudson River tomcod have experienced rapid evolutionary change in the 50 to 100 years since release of these contaminants,” the researchers say in their paper.
Added Wirgin: “Any evolutionary change at this pace is not a good thing.”

Ironically the recently begun EPA-mandated cleanup of Hudson River PCBs could be trouble for the tomcod.
If there are evolutionary costs to having the variant AHR2 gene, the absence of the toxic substance that triggered its adaptation might leave it at a disadvantage.

“If they clean up the river,” Wirgin said, “these fish may need to adapt again to the cleaner environment.”

The WHOI portion of the study was funded by an NIH Superfund Research Program Center grant through the Superfund Research Center at Boston University.
The NYU work was funded by an NIH Superfund Research Program individual grant and an NIH Environmental Health Sciences Center grant.
"This research could not have been attempted without the unique multidisciplinary focus of our funding vehicle, Superfund Basic Research," Wirgin said.

Links :

• Wired : Mutant fish safely store toxins in fat
• Livescience : Fish evolved to survive GE toxins in Hudson River
• NYTimesBlog : Speedy evolution, indeed
  

Mud volcano emerges from the Arabian Sea

download large image (1 MB, JPEG) acquired January 11, 2011

download large image (962 KB, JPEG) acquired February 11, 2010

From NASA

On November 26, 2010, Pakistani fishermen returned from a day at sea to report that a new island had emerged.
The tiny dot of land was a mud volcano, and it was still visible on January 11, 2011, when the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite acquired the top image.
The mud volcano was absent in a previous overpass on February 11, 2010, shown in the lower image.

There’s no need to change any maps, however; mud volcanoes have risen off the coast of Pakistan in the past and disappeared again within a few months, washed away by the waves and currents in the Arabian Sea.
It is quite likely that this new volcano will meet the same fate. Indeed, a stream of pale brown sediment was snaking away from the volcano to the west on January 11, suggesting that erosion was already underway.

Pakistan’s mud volcanoes form as a result of plate tectonic activity.
The Arabian plate—the section of Earth’s crust that carries the Arabian Sea—is sinking beneath the Eurasian land mass at about four centimeters per year.
Some of the thick sediment and rock on top of the Arabian plate has sloughed onto the edge of the Eurasian plate, forming Pakistan’s coastal plain, the Makran Desert, and the underwater slope leading away from the shore.
It is from this sloughed-off land that the mud volcanoes form.

Beneath the sediment, along the accretionary front, the sinking Arabian plate heats up under extreme pressure and rock melts into magma.
Volcanic gases and magma heat the groundwater, turning it in a hot acid that dissolves rock into a slurry of mud and clay.
The mud and gas seep through faults, eventually erupting at the surface as a mud volcano.

Pakistan has a number of mud volcanoes in the Makran Desert and offshore.
According to the U.S. Geological Survey, mud volcanoes are usually less than 1-2 meters (3-7 feet) tall.
But Pakistan’s Chandragup Complex includes a mud volcano that is 100 meters (330 feet) high.

The same tectonic activity and fault systems that produce these volcanoes occasionally produce large earthquakes, such as the magnitude 7.2 quake that shook southwest Pakistan on January 18, 2011.

Links :

• download Google Earth file (KML) acquired February 11, 2019 - January 11, 2011
  

Eat more anchovies, herring and sardines to save the ocean's fish stocks

Short Sardine Run insert shot in South Africa by underwater cameraman Charles Maxwell

From The Guardian

We should consume less of the fish at the top of the food chain and more of their prey to rebalance the marine ecosystem, says fisheries scientist

Cut back on tuna and salmon and load your plate instead with herring and sardines if you want to help save the world's fish.
So says the scientist who led the most comprehensive analysis ever carried out of fish stocks in the world's oceans and how they have changed over the past century.

The study by Villy Christensen of the University of British Columbia's Fisheries Centre confirmed some previous indications that populations of predator fish at the top of the food chain, such as cod, tuna and groupers, have suffered huge declines, shrinking by around two-thirds in the past 100 years.
More than half that decline occurred in the past 40 years.

Christensen found that the total stock of "forage fish", such as sardines, anchovy and capelin, has more than doubled over the past century.
These are fish that are normally eaten by the top predators.
"You remove the predator, you get more prey fish," said Christensen.
"That has not been demonstrated before because people don't measure the number, they don't go out and count them."

His call for consumers to shift their attention down the marine food chain from predators like tuna and cod to more unusual fish echoes that by celebrity chef Jamie Oliver, who suggests we should eat more coley, mackerel, dab, pouting, herring and sardines.

"I know you like your fish suppers, but our appetite for the same fish, day in, day out, is sucking the seas dry," Oliver has said.
"I wouldn't bother waiting for the politicians to sort this one out, guys, you can really help from the comfort of your own kitchen ... Lay off the cod, haddock and tuna, diversify and cook up a wider range of fish."

Christensen presented his findings on Friday at the annual meeting of the American Association for the Advancement of Science (AAAS) in Washington, DC.

Predatory fish stocks have declined by around two-thirds in the past 100 years

"Overfishing has absolutely had a 'when cats are away, the mice will play' effect on our oceans," said Christensen.
"By removing the large, predatory species from the ocean, small forage fish have been left to thrive."

Christensen urged consumers to eat more of the burgeoning population of forager fish such as sardines and anchovies, while reducing their intake of top predators, in order to re-balance the world's fish species.

Today, the vast majority of forage fish that are being caught are used inefficiently in fish farms to feed salmon, for example.
"Currently, forage fish are turned into fishmeal and fish oil and used as feeds for the aquaculture industry, which is in turn becoming increasingly reliant on this feed source," said Christensen.

The rise in wild forage fish populations has knock-on effects on marine ecosystems.
These fish eat more of the zooplankton in the oceans, which means that the next stage down the food chain – the plant plankton normally consumed by the zooplankton – blooms.
"You get into a situation where you get a green soup, you get anaerobic conditions [low oxygen levels]. There are clear examples in the Black Sea," said Christensen.

In their analysis, Christensen's team collated data from more than 200 models of marine ecosystems around the world, using a technique called Ecopath, to estimate the mass of various fish in the world's oceans and how it has changed from 1880 to 2007.

Predators in general are an important component in food chains, said Christensen, preventing the spread of disease, for example.
"In England some years ago, there was a crisis where they had killed a lot of the predators such as eagles. You had rabbits that got problems with diseases, there was massive die-off, the sick ones were not being eaten by the predators. We see less stable ecosystems if we do not have predators there."

Marlins fishing sardines in Mexique (B. Reinhard Dirscher)

The precipitous drop in top predator fish was also linked, in a separate study presented at the AAAS, to the rise in global fishing capacity.
This has increased by 54% from 1950 to 2010 with no sign of a decrease in recent years.

"We need to cut back fishing efforts," said Christensen.
"Society needs to decide what we want with the ocean – do we want to turn it into a farm? Or do we want to have something that is more of a natural ecosystem?"

Links :

• YouTube : News from the 2011 AAAS Annual Meeting : Interview with Professor Villy Christensen
  
• TheGuardian : We need to eat less fish – not more sustainable fish
• Time : Why the World's Fisheries are going bankrupt
  

Netherlands NLHO, a new chart layer in the Marine GeoGarage

Netherlands charts from NLHO

Marine GeoGarage is glad to announce a new chart layer with Netherlands maps coming from the Netherlands Hydrographic Office (NLHO).

The 1800-series charts are issued mainly for smaller SOLAS shipping (Safety Of Life At Sea) and recreational purposes.
The series consist of 8 atlases with an average of 9 charts (loose-leaf).
The charts cover the Netherlands and Belgian coasts, the Wadden Sea, the IJsselmeer and the Zeeland delta area (but not Caribbean Sea, Netherlands Antilles, Aruba and Surinam).

As far as practicable the 1800-series charts are consistent with the corresponding paper nautical charts, however chart scale, bathymetry and symbolisation may differ.
Maritime limits are not charted in the 1800 series.

79 charts (228 including sub-charts -see list-) are reproduced with the permission of the Netherlands Hydrographic Office.

Don't forget to visit the Notices to Mariners published by NLHO for corrections on Netherlands nautical charts (Lists).

Note : the 'UK & misc.' layer also proposes 26 maps for Netherlands because UKHO also manages third-parties copyrights for some other international Hydrographic Services (including NLHO)

UKHO RNC for Netherlands