Thursday, June 20, 2013

Ocean's little fish are a big deal

Tiny fish play a major role in the ocean's food web. Commonly known as forage fish, small schooling fish like herring and anchovies are a crucial food source for larger, more familiar species like tuna, whales, and seabirds.
The Pew Environment Group produced this animation to show how reasonable limits on catching for forage fish can help maintain a vibrant and productive Pacific coast ecosystem for generations to come.

 From CSMonitor (Paul Shively works to conserve West coast forage fish as manager of the Pacific Fish Conservation Program at The Pew Charitable Trusts. He is a lifelong angler.)

Small 'forage fish' are a crucial source for larger animals in the ocean ecosystem.
Without little fish, there can be no big fish. Pacific coast fishing leaders should thus adopt safeguards to prohibit fishing of saury until it can be shown that this would not adversely impact the ecosystem.

When people think of a healthy ocean, the first thing that comes to mind is usually a large iconic animal, perhaps a humpback whale leaping majestically out of the water or a pelican swooping low across the ocean surface.
In my case, I’m hooked by the thrill of a big salmon as it pulls the line off my reel.

All of these animals dine on vast schools of tightly packed prey fish, commonly referred to as forage fish.
Scientists and fishermen are becoming increasingly aware of their singular importance as the fuel that drives productive coastal ecosystems.

 An infographic from The Pew Charitable Trusts shows an oceanic ecosystem chain.
Op-ed contributor Paul Shively writes: 'To its credit, the [Pacific Fishery Management Council] unanimously adopted a fishery ecosystem plan' whose 'top priority is to make sure that no new fishing begins on forage species without first evaluating the effect on the larger ecosystem.'

At the same time, global demand is growing to catch forage fish for secondary purposes such as chicken feed, fertilizer, and bait for industrial longline fishing overseas.

But catching too many of these forage fish can severely disrupt the ocean life that they sustain. A lack of forage fish can have serious repercussions – especially for the fishing industry.
Without little fish, there can be no big fish.

That’s why many fishing and conservation organizations – including The Pew Charitable Trusts – are rightly advocating for new measures to safeguard forage fish.
The Pacific Fishery Management Council, which is responsible for managing marine fish on the West Coast, will have the opportunity to adopt some of these safeguards as it meets in Garden Grove, Calif., this week.

At the meeting, these West coast fishery leaders should decide to prohibit new commercial fishing on saury – a key forage fish – until it can be shown that it won’t harm bigger fish, whales, and seabirds that depend on saury as a food source.
Doing so will enable the council to ask important questions before US forage fishing begins rather than waiting until industrial-scale fishing boats are catching these important fish.

Internationally, these forage fish – including sardines, anchovies, and saury – already account for more than a third of the total catch of wild marine fish, with 90 percent of it processed into fish meal or oil.

To its credit, the council unanimously adopted a fishery ecosystem plan that begins to consider how everything is connected in the ocean.
The plan’s top priority is to make sure that no new fishing begins on forage species without first evaluating the effect on the larger ecosystem and on other predator fish such as salmon, tuna, and lingcod.

Forage fish eat tiny plants and animals drifting on the ocean’s surface and, in turn, become a crucial food source for whales, seabirds, and bigger fish.
Diminishing forage fish populations can have serious consequences for the larger ecosystem.
Just this year, wildlife rehabilitation centers in California have treated more than 1,500 emaciated and dehydrated sea lion pups at a time when prey fish were scarce.

Pacific saury is exactly the type of currently un-fished forage species that the council’s new ecosystem plan intends to protect.
This dart-shaped fish makes up as much as 78 percent of the diet of the sooty shearwater, a type of seabird that is now arriving by the millions along the California shore from breeding grounds near Chile and New Zealand.

We know that saury is already extensively fished elsewhere around the world, and its relatively high abundance makes it a potential target for fishermen here on the West Coast.
As it stands, fishing could begin on saury at any time with no restrictions – and no consideration of how it would affect predators.
That would be a mistake.
It is one the Pacific Fishery Management Council can – and should – avoid by approving restrictions on forage fishing at its meeting this week.

In April, the Pacific fishery council’s chairman cited the strong public testimony of the seafood industry, birding community, scientists, and fishermen in adopting a meaningful ecosystem plan.
Protecting saury would help to maintain a productive ocean along the Pacific coast while demonstrating that regional fishery managers are serious about moving ecosystem-based management from theory into practice.

Some may wonder why we should act now.
After all, no one on the West Coast is currently fishing for forage fish like Pacific saury, sandlance, or various kinds of smelts.
To answer this concern, it’s worth looking north to Alaska.
North Pacific fishery managers proactively protected dozens of unfished forage species more than a decade ago with the strong support of commercial fishermen.
As one industry organization noted at the time, fishing for predators and their prey is akin to burning a candle at both ends.

I've been fishing almost as long as I can remember.
Yet the thrill of being out on the water with friends, and the rush when a salmon or tuna bends my fishing rod, will never grow old.

OPINION: A better way to prevent overfishing

It’s time for regional managers on the Pacific coast and elsewhere in the country to acknowledge what those of us on the water already know: Little fish are a big deal.
It’s time to protect them.

Links :
  • The Guardian : Small and wild: how to feed fish to the world
 

Wednesday, June 19, 2013

NZ Linz nautical chart tutorial


Tutorial which provides a high level overview of the types of nautical Charts published by Land Information New Zealand (LINZ).
Includes a demonstration of how to access Chart images on the LINZ website.

Links :
  • Nautical charts video with Jennifer Ryan, Manager Chart Production for the New Zealand Hydrographic Authority (NZHA) 
 

NZ Linz update in the Marine GeoGarage


12 charts have been updated in the Marine GeoGarage
(Linz May update published June 5 2013

  • NZ5124 Plans in the Bay of Islands
  • NZ5221 Cradock Channel and Mokohinau
  • NZ5222 Great Barrier Island (Aotea Island)
  • NZ5223 Great Barrier Island (Northwestern Part)
  • NZ5314 Mercury Islands
  • NZ5412 Port of Tauranga
  • NZ6153 Queen Charlotte Sound
  • NZ6154 Tory Channel Entrance and Picton Harbour
  • NZ8275 Approaches to Nuku'alofa Harbour
  • NZ8277 Nuku'alofa Harbour
  • NZ14908 Cape Adare to Cape Daniell
  • NZ14909 Cape Hooker to Coulman Island
Today NZ Linz charts (178 charts / 340 including sub-charts) are displayed in the Marine GeoGarage.

Note :  LINZ produces official nautical charts to aid safe navigation in New Zealand waters and certain areas of Antarctica and the South-West Pacific.


Using charts safely involves keeping them up-to-date using Notices to Mariners
Reporting a Hazard to Navigation - H Note :
Mariners are requested to advise the New Zealand Hydrographic Authority at LINZ of the discovery of new or suspected dangers to navigation, or shortcomings in charts or publications.

Brazil DHN update in the Marine GeoGarage

32 charts have been updated since the last update  :

  • 231      DA ILHA DO MACHADINHO AO CABO MAGUARI (PROXIMIDADES DA BARRA SUL DO AMAZONAS)
  • 300      DA ILHA DO MACHADINHO AO CABO GURUPI
  • 410      PROXIMIDADES DA BAÍA DE SÃO MARCOS
  • 411      BAÍA DE SÃO MARCOS
  • 413      TERMINAL DA PONTA DA MADEIRA E PORTO DE ITAQUI
  • 1102      PORTO DE SALVADOR
  • 1110      BAÍA DE TODOS OS SANTOS
  • 1501      BAÍA DE GUANABARA
  • 1531      ILHA DO BOQUEIRÃO E ADJACÊNCIA
  • 1632      BAÍA DA ILHA GRANDE - PARTE CENTRO NORTE
  • 1633      BAÍA DA ILHA GRANDE - PARTE OESTE
  • 1801      PORTO DE ITAJAÍ
  • 1908      PORTO DE IMBITUBA
  • 21050      DO RIO ITARIRI AO ARQUIPÉLAGO DOS ABROLHOS
  • 21800      DA PONTA DE ITAPAGÉ A FORTALEZA
  • 23500      DE PINHAL AO RIO GRANDE
  • 201      BARRA NORTE DO RIO AMAZONAS
  • 202      DA ILHA DO BAILIQUE À PONTA DO CAPINAL
  • 204      DAS ILHAS PEDREIRA À ILHA DE SANTANA
  • 220      DA BARRA NORTE AO PORTO DE SANTANA
  • 4105A      DE PARINTINS À COSTA DO GIBA
  • 4105B      DA COSTA DO GIBA À ITACOATIARA
  • 303      DO CABO MAGUARI À MOSQUEIRO
  • 315      DA BOCA DA VIGIA À MOSQUEIRO
  • 316      DE MOSQUEIRO A BELÉM
  • 320      PORTO DE BELÉM
Today 424 charts (465 including sub-charts) from DHN are displayed in the Marine GeoGarage
Don't forget to visit the NtM Notices to Mariners (Avisos aos Navegantes)

No, you can't outrun a tsunami


This video shows the panic of some people trying to outrun the tsunami that hit Japan in 2011.
You can see in the video the horrific force of the tsunami as it hits and how fast the tsunami was.
People trying to climb a hill to get away from the waves, while others are trying to help.
The video also shows the courage of other people that ran back down the hill to try and save some people, only to be swept away themselves.
Despite their efforts, the speed of the rising water engulfs the person they are trying to save -- and one of the rescuers appears to disappear.
The man in the red jacket can be seen through the trees.

From LiveSciences

Maybe the fastest man in the world could run a 6-minute mile for 6 miles (10 kilometers) while a terrifying wall of water chased him through a coastal city.
But most people couldn't.

Yet a myth persists that a person could outrun a tsunami.
That's just not possible, tsunami safety experts told LiveScience, even for Usain Bolt, one of the world's quickest sprinters.
Getting to high ground or high elevation is the only way to survive the monster waves.

"I try to explain to people that it doesn't really matter how fast [the wave] is coming in, the point is that you really shouldn't be there in the first place," said Rocky Lopes of the National Oceanic and Atmospheric Administration's Tsunami Mitigation, Education and Outreach program.

But because they didn't know the warning signals, ignored them or just couldn't get to safety in time, more than 200,000 people died in tsunamis in the past decade.
And it's not just tsunamis: Underestimating the power of the ocean kills thousands every year in hurricane storm surges.

 Tsunamis gain height as they approach the shore.
CREDIT: NOAA

Stay off the beach

A tsunami is a series of waves caused by a sudden underwater earth movement.
The kick-off is akin to dropping a big rock in a children's pool filled with water.
In an ocean basin, tsunami waves slosh back and forth, reflecting off coastlines, just like the (much smaller) waves in a child's pool, Lopes said.

Because many people mistakenly think a tsunami is a single wave, some return to the beach after the first wave hits, Lopes said.
On March 11, 2011, a man in Klamath River, Calif., died after he was swept away by a second wave while taking pictures of the Japan tsunami, Lopes said.

Tsunamis race across the deep ocean at jet speed, some 500 mph (800 km/h).
Near shore, the killer waves slow to between 10 to 20 mph (16 to 32 km/h) and gain height.
If the offshore slope is gentle and gradual, the tsunami will likely come in looking like a rapidly approaching tide.
If the transition from deep ocean to shoreline is steep and cliff-like, then the wave will resemble a movie-like specter, arriving as an onrushing wall of water.
[Waves of Destruction: History's Biggest Tsunamis

Water receding on the beaches of Santa Cruz, Calif., on March 11, 2001,
just after the earthquake and tsunami struck Japan
Credit: @darrenmason

Look and listen for warning signs

Either way, standing at the beach, at sea level, means losing perspective.
"It's a matter of optical illusion and how fast your eye interprets the speed of moving water," Lopes said.
"People just can't estimate the speed of the wave, and [so they] get themselves in trouble."

Linger too long and you may run out of time to find somewhere safe.
"If they're on the beach, there's no way in heck they're going to outrun it," said Nathan Wood, a tsunami modeler with the U.S. Geological Survey in Portland, Ore.
"Technically, if you're 10 blocks in, and the waves are full of debris [and slowing from friction], there's a chance, but for most people that's not realistic," he said.

So if the beach starts shaking or the ocean looks or sounds strange, head for the highest elevation around immediately.
"Sometimes the only warning you may get are these environmental clues," Lopes said.
"These are the indicators that you are in serious danger."

High ground is best in situations like these; steel-reinforced concrete buildings or parking structures work in a pinch, but even climbing trees will help if nothing else is available.
Some people who sought refuge in trees survived the 1960 Chile tsunami, though others were torn from their branches.

 Storm surge floods a section of Coast Guard Station New York, located on Staten Island, as Hurricane Sandy approaches New York Harbor, Monday, Oct. 29, 2012.
CREDIT: U.S. Coast Guard photo by Petty Officer 2nd Class Erik Swanson.

Why people put themselves at risk

Another fatal mistake people make when fleeing from tsunamis is underestimating how far the water can travel inland, Lopes said.
In this graphic video of the 2011 Japan tsunami, shot from a hillside, residents fleeing the tsunami are nearly caught by the powerful wave even after it had already destroyed half the town.

Tsunamis can travel as far as 10 miles (16 km) inland, depending on the shape and slope of the shoreline.

Hurricanes also drive the sea miles inward, putting people at risk.
But even hurricane veterans may ignore orders to evacuate.
As with tsunamis, a lack of understanding lays at the heart of this willingness to risk everything, according to studies by NOAA.
"We've consulted with social scientists and communications experts, and the number one reason why people stay is that they don't understand storm surge," said Jaime Rhome, storm surge team leader at the National Hurricane Center in Miami.
Hurricane evacuation orders are due to dangers from storm surges, not wind, Rhome explained. "People are enamored with the wind, but it's storm surge that has the greatest potential to take life," he said.
"The majority of deaths occurring in hurricanes are from drowning, not wind."

Storm surge is the force of hurricane winds driving the ocean landward, which raises sea level.
The water penetrates miles inland.
Waves kicked up by the hurricane travel on top of the storm surge, pounding everything in their path. People who go out in the surge — residents who wait too long to evacuate, for example — may find themselves knocked off their feet and swept away.

"People have a hard time imagining seawater can come that far inland," Rhome said.
"They can't envision the ocean can rise that high or be that violent."