Friday, November 19, 2010

Klondike shipwreck brought to life with 3D scans



From CBC

A
Gold Rush-era shipwreck at the bottom of a Yukon lake is coming to life with the help of cutting-edge digital 3D scan images.

The images were produced in June by researchers working on the wreck of the A.J. Goddard, a 19th-century sternwheeler that vanished in Lake Laberge in 1901.

Researchers from the Institute of Nautical Archaeology captured images of the sternwheeler with underwater sonar scanners supplied by the U.S. firms BlueView Technologies and Oceangate.

Millions of captured images were then assembled into a 3D model, similar to a recent map of the wreck of the Titanic off the east coast of Newfoundland.

Last year, an archeological team that included the Texas-based institute and the Yukon Transportation Museum announced that it had discovered the shipwreck, mostly intact, at the bottom of Lake Laberge.

Shipped north in pieces

"To get that vessel to the North, it's an amazing story," Lindsey Thomas, a post-graduate student from Texas who is studying the A.J. Goddard, told CBC News.

Thomas said the sternwheeler was built in Seattle, then shipped in pieces over the Chilkoot Pass in the spring of 1898 to Bennett Lake, where it was reassembled.

Thomas said the new digital scans show how exactly the sternwheeler parts were put together at Bennett Lake.

"The people who built the vessel on the shores of Lake Bennett, where they [could] cut corners, they did," she said.

"It's kind of like the way that we build furniture from Ikea: follow the directions for the most part but where you need to, it's not done exactly the same way they might have done it in the factory."

The A.J. Goddard became the first sternwheeler in Dawson City, transporting miners and supplies along the Yukon River until Oct. 22, 1901, when it disappeared in Lake Laberge during a storm. Three of the A.J. Goddard's crew members drowned in the storm, while two survived.

Phonograph, records found

Divers retrieved artifacts from the shipwreck this past summer, including a phonograph player and some perfectly intact records.

"It's just a really unusual item to think of with a vessel that we know was really an industrial kind of workhorse," said Val Monahan, the Yukon government's heritage conservator.

"You don't think of something like music on board."

Monahan and Doug Davidge, president of the Yukon Transportation Museum, both said they hope some of the records can be restored to a playable condition.

"It does paint a quite a unique picture of how people would have enjoyed their time on the river," Davidge said.

"Hopefully there'll be something there that they can actually pull off the vinyl — in terms of a music track or sound or what have you — that might have been on that record, and hopefully in time we'll find out what type of music they were listening to."

Links :
  • Wired : 3-D scanner takes on the Goddard shipwreck
  • CBC : Gold Rush shipwreck named historic site

Thursday, November 18, 2010

Bahamas, a new chart layer in the Marine GeoGarage


The Marine GeoGarage is glad to announce a first license agreement with some private nautical map publisher Wavey Line Publishing to display nautical charts for :
  • Bahamas,
  • Turks & Caicos Islands,
  • Hispaniola
  • and Caribbean.
Today 260 charts are available in a new chart layer accessible publicly.
(some iPhone/iPad application will be available soon).
Note : for ordering any of these maps seen in the viewer, please go to the American Nautical Services website.

An aerial view of Exuma, part of the chain of 365 islands that form the Bahamas
Photograph: Onne van der Wal/Bluegreen/Rex Features

Explorers and Surveyors (extract from Wavey Line Publishing website)
The Dark Ages!
Wavey Line charts have origins way back in the days before GPS completely revolutionized navigation and marine surveying.
After his first Atlantic crossing in the late 1970's, Bob Gascoine started cruising the Antilles and Bahamas Chain.
Bob found great inadequacy in the government chart publications as did many cruisers of that period, and he started to compile his own sketch charts and pilotage notes.
These were first published in 1983 as a Yachtsman's Guide for the Turks & Caicos Islands.
Escape from City Life
Bob's background includes experience in the London printing and graphic arts industry.
This knowledge was bolstered when Jane Minty teamed up with him in the early 1990's and contributed artistic and computer graphic skills.
Soon after, they began exploring and surveying using a sophisticated GPS receiver as their main tool.
Milt the Mentor
Milt Baker, founder of the well-known
Blue Water Books & Charts store, encouraged Bob and Jane to publish their data and TC001, their first chart, was printed in December 1993.
It had the distinction of being the first navigation sea chart designed primarily for use with GPS and featured new innovations such as '
one mile grid' (note : removed in the Marine GeoGarage as the map is georeferenced) and 'waypoint list'.
This first edition sold out in six months, so Bob and Jane quit their day job - which had been sailing and scuba diving charters - and took up hydrography as a full time occupation.




Socially Acceptable to Nature
In addition to work on private publications, Bob and Jane have been engaged by the
Turks & Caicos Islands National Parks Service and Harbour Authority to conduct various marine projects.
They have also checked and advised the UK Hydrographic Office on new British Admiralty publications for the region.
Being conservation activists, Bob and Jane include advice on environmental issues and local etiquette in their publications in the hope that visiting cruisers will respect local ways and go easy on the environment - this should help reduce the need for restrictive legislation in the future.
Out Islands 'R' Us
Bob and Jane are now finishing surveys for two new Bahamas charts and will be updating and re-surveying areas of the Turks & Caicos Islands so that all chart publications have up-to-date information and '
WAAS' accuracy.
But don't expect to see them giving presentations or 'Volleyball Beach' talks, for they prefer to keep a low profile and moor away from the crowd.
Still, if you notice their catamaran 'Mage Magic' (yes, the one with the barking "potcake") and decide to stop by and visit, you'll be warmly received.

USA NOAA update in the Marine GeoGarage

18453 : TACOMA HARBOR

38 charts
have been updated in the Marine GeoGarage (NOAA update 10/10/2010)

  • 1115A : LEASE BLOCK FOR CAPE ST. GEORGE TO MISSISSIPPI PASSES
  • 11313 : MATAGORDA LIGHT TO ARANSAS PASS
  • 11360 : CAPE ST. GEORGE TO MISSISSIPPI PASSES
  • 11429 : FOWEY ROCKS; HILLSBORO INLET TO BIMINI ISLANDS
  • 11505 : SAVANNAH RIVER APPROACH
  • 11520 : CAPE HATTERAS TO CHARLESTON
  • 12375 : CONNECTICUT RIVER LONG ISLAND SOUND TO DEEP RIVER
  • 13246 : CAPE COD BAY MA
  • 13281 : GLOUCESTER HARBOR AND ANNISQUAM RIVER
  • 18428 : OAK AND CRESCENT HARBORS
  • 18440 : PUGET SOUND
  • 19013 : HAWAIIAN ISLANDS NORTHERN PART
  • 11373 : MISSISSIPPI SND and APPROACHES DAUPHIN ISL TO CAT ISL
  • 11539 : NEW RIVER INLET TO CAPE FEAR NORTH CAROLINA
  • 12354 : LONG ISLAND SOUND-EASTERN PART CONN-NY
  • 13009 : GULF OF MAINE AND GEORGES BANK
  • 13229 : SOUTH COAST OF CAPE COD TO BUZZARDS BAY MA
  • 14826 : MOSS POINT TO VERMILION OHIO
  • 11536 : APPROACHES TO CAPE FEAR RIVER
  • 13230 : BUZZARDS BAY
  • 13309 : PENOBSCOT RIVER ME
  • 18656 : SUISUN BAY
  • 18744 : SANTA MONICA BAY
  • 25649 : ST THOMAS HARBOR
  • 11358 : BARATARIA BAY AND APPROACHES
  • 11425 : CHARLOTTE HARBOR TO TAMPA BAY
  • 11478 : PORT CANAVERAL
  • 11485 : TOLOMATO RIVER TO PALM SHORES FLORIDA FF-GG
  • 12277 : CHESAPEAKE and DELAWARE CANAL SALEM RIVER EXTENSION
  • 12347 : HUDSON RIVER-WAPPINGER CREEK TO HUDSON-RIGHT PANEL
  • 13253 : HARBORS OF PLYMOUTH KINGSTON AND DUXBURY MA
  • 13288 : MONHEGAN ISLAND TO CAPE ELIZABETH
  • 13290 : CASCO BAY
  • 13292 : PORTLAND HARBOR AND VICINITY ME
  • 16645 : GORE PT. TO ANCHOR PT.
  • 16713 : NAKED ISLAND TO COLUMBIA BAY
  • 18430 : ROSARIO STRAIT NORTH PART
  • 18453 : TACOMA HARBOR
Today 1019 NOAA raster charts (2932 including sub-charts) are included in the Marine GeoGarage viewer.

Note : NOAA updates their nautical charts with corrections published in:
  1. U.S. Coast Guard Local Notices to Mariners (LNMs),
  2. National Geospatial-Intelligence Agency Notices to Mariners (NMs), and
  3. Canadian Coast Guard Notices to Mariners (CNMs)
While information provided by this Web site is intended to provide updated nautical charts, it must not be used as a substitute for the United States Coast Guard, National Geospatial-Intelligence Agency, or Canadian Coast Guard Notice to Mariner publications

Please visit the
NOAA's chart update service for more info.

Canada CHS update in the Marine GeoGarage

4460 : CHARLOTTETOWN HARBOUR

96 charts have been updated for Canada (CHS update published September 29, 2010) :

  • 1234 :CAP DE LA TETE AU CHIEN TO CAP AUX OIES
  • 1235 : POINTE AU BOISVERT TO CAP DE LA TETE AU CHIEN
  • 1236 : POINTE DES MONTS TO ESCOUMINS
  • 1311 : SOREL-TRACY TO VARENNES
  • 1317 : SAULT-AU-COCHON TO QUEBEC
  • 1350A : SOREL - TRACY TO RUISSEAU LAHAISE
  • 1350B : RUISSEAU LAHAISE TO SAINT-ANTOINE-SUR-RICHELIEU
  • 1350C : SAINT-ANTOINE-SUR-RICHELIEU TO ILE AUX CERFS
  • 1350D : ILE AUX CERFS TO OTTERBURN PARK
  • 1351A : BASSIN DE CHAMBLY TO ILE SAINTE-THERESE
  • 1351B : ILE SAINTE-THERESE TO POINTE LA MEULE
  • 1351C : POINTE LA MEULE TO POINTE NAYLOR
  • 1351D : POINTE NAYLOR TO LAKE CHAMPLAIN
  • 1435 : CARDINAL TO WHALEBACK SHOAL
  • 1514A : CARILLON TO L'ORIGNAL
  • 1514B : L'ORIGNAL TO PAPINEAUVILLE
  • 1551 : CHATS FALLS TO CHENAUX
  • 2123 : PELEE PASSAGE TO LA DETROIT RIVER
  • 2242 : GIANTS TOMB ISLAND TO FRANKLIN ISLAND
  • 3001 : VANCOUVER ISLAND ILE DE VANCOUVER JUAN DE FUCA STRAIT TO QUEEN CHARLOTTE SOUND
  • 3419 : ESQUIMALT HARBOUR
  • 3441 : HARO STRAIT BOUNDARY PASS AND SATELLITE CHANNEL
  • 3475 : PLANS - STUART CHANNEL
  • 3477 : BEDWELL HARBOUR TO GEORGESON PASSAGE
  • 3539 : DISCOVERY PASSAGE
  • 3543 : CORDERO CHANNEL
  • 3547 : QUEEN CHARLOTTE STRAIT EASTERN PORTION PARTIE EST
  • 3602 : APPROACHES TO JUAN DE FUCA STRAIT
  • 3606 : JUAN DE FUCA STRAIT
  • 3960 : APPROACHES TO PORTLAND INLET
  • 4002 : GOLFE DU SAINT-LAURENT GULF OF ST. LAWRENCE
  • 4003 : CAPE BRETON TO CAPE COD
  • 4013 : HALIFAX TO SYDNEY
  • 4015 : SYDNEY TO SAINT-PIERRE
  • 4022 : CABOT STRAIT AND APPROACHES DETROIT DE CABOT ET LES APPROCHES
  • 4026 HARVE-SAINT-PIERRE AND CAP DES ROSIERS TO POINTE DES MONTS
  • 4375 : GUYON ISLAND TO FLINT ISLAND
  • 4377 : MAIN-DIEU PASSAGE
  • 4381 : MAHONE BAY
  • 4432 : ARCHIPEL DE MINGAN
  • 4529 : FOGO HARBOUR SEAL COVE AND APPORACHES LES APPROCHES
  • 4617 : RED ISLAND TO PINCHGUT POINT
  • 4820 : CAPE FREELS TO EXPLOITS ISLANDS
  • 4839 : HEAD OFFOND DE PLACENTIA BAY
  • 4862 : CARMANVILLE TO BACALHAO ISLAND AND FOGO
  • 4911 : ENTREE ENTRANCE TO MIRAMICHI RIVER
  • 4912 : MIRAMICHI
  • 4913 : CARAQUET HARBOUR BAIE DE SHIPPEGAN AND MISCOU HARBOUR
  • 4921 : HAVRE DE BEAUBASSIN
  • 4950 : ILES DE LA MADELEINE
  • 5024 : NUNAKSALUK ISLAND TO CAPE KIGLAPAIT
  • 5048 : CAPE HARRIGAN TO AUX KITLIT ISLANDS
  • 5049 : DAVIS INLET TOUX SENIARTLIT ISLANDS
  • 7565 : CLYDE INLET TO CAPE JAMESON
  • 1220 : BAIE DES SEPT ILES
  • 1233 : CAP AUX OIES TO SAULT-AU-COCHON
  • 1234 : CAP DE LA TETE AU CHIEN TO CAP AUX OIES
  • 1313 : BATISCAN TO LAC SAINT-PIERRE
  • 1429 : CANAL DE LA RIVE SUD
  • 1430 : LAC SAINT-LOUIS
  • 1550 : BRITANNIA BAY TO CHATS FALLS
  • 2042 : WELLAND CANAL ST.CATHERINES TO PORT COLBORNE
  • 2205 : KILLARNEY TO LITTLE CURRENT
  • 3461 : JUAN DE FUCA STRAIT EASTERN PORTION
  • 3462 : JUAN DE FUCA STRAIT TO STRAIT OF GEORGIA
  • 3493 : VANCOUVER HARBOUR WESTERN PORTION
  • 3515 : KNIGHT INLET
  • 3545 : JOHNSTONE STRAIT PORT NEVILLE TO ROBSON BIGHT
  • 3912 : PLANS VICINITY OF DE BANKS ISLAND
  • 3945 : APPROACHES TO DOUGLAS CHANNEL
  • 3947 : GRENVILLE CHANNEL TO CHATHAM SOUND
  • 3984 : PRINCIPE CHANNEL - SOUTHERN PORTION
  • 3985 : PRINCIPE CHANNEL - CENTRAL PORTION AND PETREL CHANNEL
  • 3986 : BROWNING ENTRANCE
  • 3987 : KITKATLA CHANNEL AND PORCHER INLET
  • 4002 : GULF OF ST. LAWRENCE
  • 4021 : POINTE AMOUR TO CAPE WHITTLE AND CAPE GEORGE
  • 4307 : CANSO HARBOUR TO STRAIT OF CANSO
  • 4308 : ST. PETERS BAY TO STRAIT OF CANSO
  • 4335 : STRAIT OF CANSO AND APPROACHES
  • 4342 : GRAND MANAN (HARBOURS HAVRES)
  • 4381 : MAHONE BAY
  • 4406 : TRYON SHOALS TO CAPE EGMONT
  • 4416 : HAVRE DE GASPE
  • 4420 : MURRAY HARBOUR
  • 4432 : ARCHIPEL DE MINGAN
  • 4460 : CHARLOTTETOWN HARBOUR
  • 4466 : HILLSBOROUGH BAY
  • 4498 : PUGWASH HARBOUR AND APPROACHES
  • 4529 : FOGO HARBOUR SEAL COVE AND APPORACHES
  • 4530 : HAMILTON SOUND EASTERN
  • 4653 : BAY OF ISLANDS
  • 4661 : BEAR HEAD TO COW HEAD
  • 4820 : CAPE FREELS TO EXPLOITS ISLANDS
  • 4830 : GREAT BAY DE L'EAU AND APPROACHES
  • 4832 : FORTUNE BAY - SOUTHERN PORTION
  • 4841 : CAPE ST. MARY'S TO ARGENTIA
  • 4862 : CARMANVILLE TO BACALHAO ISLAND AND FOGO
  • 4909 : BUCTOUCHE HARBOUR
  • 4913 : CARAQUET HARBOUR BAIE DE SHIPPEGAN AND MISCOU HARBOUR
  • 5032 : APPROACHES TO APPROCHES WHITE BEAR ARM
  • 5138 : SANDWICH BAY
  • 7777 : CORONATION GULF WESTERN PORTION
Note : don't forget to visit 'Notices to Mariners' published monthly and available from the Canadian Coast Guard both online or through a free hardcopy subscription service.
This essential publication provides the latest information on changes to the aids to navigation system, as well as updates from CHS regarding CHS charts and publications.

Scientists question widely used indicator of ocean health

If humans were fishing down the marine food web then catches of top predators, at trophic levels 3.5 and above, would be decreasing.
But catches at those levels have generally increased according to newly compiled information. Named next to each trophic level is the species most often caught, for example bigeye tuna is the most often caught fish at level 4.5.
The wider the line, the more fish are being caught at that trophic level.
(Credit: Trevor Branch/U of Washington)

From NewsWise

Scientists question widely adopted indicator of fisheries health and evidence for ‘fishing down marine food webs’

The most widely adopted measure for assessing the state of the world’s oceans and fisheries led to inaccurate conclusions in nearly half the ecosystems where it was applied according to new analysis by an international team led by a University of Washington fisheries scientist.

“Applied to individual ecosystems it’s like flipping a coin, half the time you get the right answer and half the time you get the wrong answer,” said
Trevor Branch, a UW assistant professor of aquatic and fishery sciences.

In 1998, the journal Science published a groundbreaking paper that was the first to use trends in the trophic levels of fish that were caught to measure the health of world fisheries.
The trophic level of an organism shows where it fits in food webs, with microscopic algae at a trophic level of one and large predators such as sharks, halibut and tuna at a trophic level of around four.

The 1998 paper relied on four decades of catch data and averaged the trophic levels of what was caught.
The authors determined those averages were declining over time and warned we were “fishing down the food web” by overharvesting fish at the highest trophic levels and then sequentially going after fish farther down the food web.


The gray line represents the average trophic level of what was caught worldwide starting in 1950 according to a 1998 Science paper about fishing down the marine food web.
Newly revised and updated information, the black line, shows that the average trophic level of what is being caught has, instead, been generally going up since the mid 1980s.

(Credit: Trevor Branch/U of Washington)

Twelve years later, newly compiled data has emerged that considers such things as the numbers and types of fish that actually live in these ecosystems, as well as catch data.
An analysis in the Nov. 18 issue of
Nature reveals weaknesses in assessing ecosystem health from changes in the trophic levels of what is being caught.

“This is important because that measure is the most widely adopted indicator by which to determine the overall health of marine ecosystems,” said Branch, lead author of the new analysis in Nature.
Those involved with the
U.N.’s Convention on Biological Diversity, for instance, chose to use the average trophic level of fish being caught as the main measure of global marine diversity.

An example of the problem with the measure is in the Gulf of Thailand, where the average trophic level of what is being caught is rising, which should indicate improving ecosystem health according to proponents of that measure.
Instead, it turns out fish at all levels have declined tenfold since the 1950s because of overharvesting.

“The measure only declines if fisheries aimed for top predators first, but for the Gulf of Thailand the measure fails because fisheries first targeted mussels and shrimps near the bottom of the food web, before shifting to predators higher up in the food web,” Branch said.

Including the Gulf of Thailand, Branch found that changes in the average trophic levels of what was being caught and what was found when fish populations were surveyed differed in 13 of the 29 trawl surveys from 14 ecosystems.
Trawl surveys, generally done from research vessels, count the kinds and abundance of fish and are repeated over time to reveal trends.

Branch and his co-authors are the first to combine so many trawl surveys for analysis – no one had combined more than a handful before.
The trawl survey data came from efforts started three years ago by fisheries scientists and ecologists gathered at the
National Center for Ecological Analysis and Synthesis in Santa Barbara, Calif.
They brought together worldwide catch data, stock assessments, scientific trawl surveys, small-scale fishery data and modeling results.
What emerged is the most comprehensive set of data yet for fisheries researchers and managers.
It paints a different picture from previous catch data and has revealed another major new finding: on a global scale humans don’t appear to be fishing down the food web, Branch said.

The new catch data reveal that, following declines during the 1970s in the average trophic levels of fish being caught, catches of fish at all trophic levels have generally gone up since the mid-80s.
Included are high-trophic predators such as bigeye tuna, skipjack tuna and blue whiting.

“Globally we’re catching more of just about everything,” Branch said.
“Therefore relying on changes in the average trophic level of fish being caught won’t tell us when fishing is sustainable or if it is leading to collapse.”
That’s because when harvests of everything increase about equally, the average trophic level of what is caught remains steady.
The same is true if everything is overfished to collapse.
Both scenarios were modeled as part of the Nature analysis.

“The 1998 paper was tremendously influential in gathering together global data on catches and trophic levels and it warned about fishing impacts on ecosystems,” Branch says.
“Our new data from trawl surveys and fisheries assessments now tell us that catches weren’t enough. In the future we will need to focus our limited resources on tracking trends in species that are especially vulnerable to fishing and developing indicators that reflect fish abundance, biodiversity and marine ecosystem health. Only through such efforts can we reliably assess human impacts on marine ecosystems.”

“In this paper we conducted the first large-scale test of whether changes in the average trophic levels of what is caught are a good indicator of ecosystem status,” says
Beth Fulton, a co-author and ecosystem modeler with the Commonwealth Scientific and Industrial Research Organisation, Australia.
“Catch data might be easiest to get, but that doesn’t help if what it tells us is wrong. Instead we really need to look directly at what the ecosystems are doing.”

Other co-authors are
Reg Watson and Grace Pablico, University of British Columbia; Simon Jennings, Centre for Environment, Fisheries and Aquaculture Science and University of East Anglia, England; Carey McGilliard, University of Washington; Daniel Ricard, Dalhousie University in Halifax, Nova Scotia; and Sean Tracey, University of Tasmania, Australia.

The work was supported by the
National Science Foundation, Gordon and Betty Moore Foundation and the UW School of Aquatic and Fishery Sciences.
It used data from the
National Center for Ecological Analysis and Synthesis working group, used the stock assessment database funded by the Canadian Natural Sciences and Engineering Research Council and the Canadian Foundation for Innovation and used data from the Sea Around Us project funded by Pew Charitable Trust.

Sources willing to comment, who are not co-authors:
  • Henry Gholz, program director National Science Foundation's Division of Environmental Biology : "Monitoring all the fish in the sea would be an enormous, and impossible, task. But this study makes clear that the most common indicator, average catch trophic level, is a woefully inadequate measure of the status of marine fisheries."
  • Phillip Taylor, section head, National Science Foundation's Division of Ocean Sciences : "The research shows the importance of synthesis to furthering an understanding of fisheries impacts and management strategies. For complex ecosystem interactions, answers can only come from repeated scrutiny of data, and comparisons of different scientific methods and systems. This synthesis points to a path forward to evaluate fisheries influences on ocean ecosystems."
  • Stephanie Hampton, deputy director National Center for Ecological Analysis & Synthesis, University of California, Santa Barbara : "Refining scientific concepts is a process of iterative testing. This group accelerated the call-and-response dialog that normally occurs among scientists, by doing what we do here at NCEAS - assembling experts with different perspectives under the same roof, with all the data they can find, and using some really sharp analytical tools to challenge important concepts."
Links :
  • USAToday : Widely-used measure of ocean health flawed
  • NSF : Inaccurate conclusions may have been reached in many ecosystems
  • NewScientist : row erupts over number of big fish in the sea
  • TheVancouverSun : new study questions work of celebrated B.C. scientist
The analysis being published in Nature was based on:
Fishing down marine food webs
Other research led by UW in recent years concerning marine food web: