sail-world.com
 
 
News Home Cruising Australia Cruising USA Cruising Canada Boats for Sale Sail-World Racing Photo Gallery FishingBoating
Video Gallery Newsletters
Sail-World.com : Where the whales are
Where the whales are

'Whales fast food joint - the Great South Channel'    .

There are patches in the ocean where right whales congregate to feed. Nobody knows how these patches form. But understanding why they do would certainly help design policies to conserve marine animals - and perhaps help cruising sailors to avoid contact. Nicholas Woods, in this Oceans Watch Essay, here describes an expedition into an Atlantic Ocean patch, located in the 'Great South Channel':

When people are hungry, they go to a place where they know they can find their favorite food. Right whales do much the same thing.

Where the whales are -  .. .  

In the Great South Channel, a deep-water passage between Nantucket and Georges Bank in the western Atlantic Ocean, thick swarms of tiny marine organisms known as copepods appear every spring. Basking sharks, cod, haddock, and endangered North Atlantic right whales all feast upon these dense patches. In a way, the Great South Channel is like the right whales’ favorite restaurant, and they keep coming back every year.

Nobody knows how these patches form. But understanding why they do would certainly help policymakers design marine protected areas and fisheries regulations to help conserve marine animals. This is why we are at sea aboard the research vessel Tioga at the crack of dawn. Our team from the Autonomous Systems Laboratory at Woods Hole Oceanographic Institution (WHOI) is helping to untangle the combination of physical and biological processes that form these dense copepod patches.

Above the steady drone of the engines, a loud 'beep' penetrates the air on the bridge. The tone indicates that we are close to an underwater glider that has been surveying the area for the past two weeks. It’s 8 a.m. on a Saturday morning in mid-May, and everyone is in position to recover the glider.

Whales underwater glider being launched -  .. .  

Back ashore in the lab, Dave Fratantoni, a WHOI physical oceanographer and my Ph.D. advisor, checks the glider’s most recent position and relays the information to the rest of us in the field. Captain Ken Houlter, at the helm, guides the ship toward the waypoint. Ian Hanley, the first mate, rigs the deck for recovery. I huddle over a computer with Ben Hodges, our lab’s research assistant, reading the data stream that accompanies the tone, trying to discern the range and bearing to the vehicle. We relay the information to Houlter, who alters course accordingly. Then we begin to scan the horizon for the glider’s little yellow tail, a flag smaller than a sheet of paper marking not only the location of the vehicle but also a new piece to the puzzle of plankton patchiness.

At the mercy of currents:
Scientists have known for many years that right whales and other predators feed on copepods in the Great South Channel, but what makes this place so special remains a mystery. In fact, biologists don’t know how whales even find these dense patches. Past research has suggested that the physical environment—the currents, tides, and possibly the bathymetry of the ocean floor—might play roles in creating these important feeding areas. However, no one has yet identified the specific mechanisms—physical, biological, or a combination—by which dense copepod patches form.

The waters of the Great South Channel are extremely dynamic. A fairly steady coastal current flows south along the east coast of Cape Cod’s forearm and into the Great South Channel. When it reaches the channel, some of this coastal current flows south around Nantucket Shoals, while another part turns toward the east and joins the northeastward flow along the northern flank of Georges Bank.

Whales feeding patch in the Atlantic -  .. .  

To the south, part of another current, flowing southwestward along the southern flank of Georges Bank, turns north into the Great South Channel.

On top of all this, strong currents driven by winds and tides are also flowing. At any given moment, these may be twice as fast as the steady currents. The copepods are at the whim of these complex flow patterns. To determine where the copepods will go, we must understand the flows that move them around.

A multipronged approach:
The complex nature of the currents in the Great South Channel demands that we employ a variety of different techniques and tools to study the ocean circulation. Each is better suited for studying some aspects of the physical oceanography than others; combining methods allows us to understand more of the picture than any one method alone.

Research ships serve as platforms from which we deploy our vehicles, but they also take useful measurements of the water near the surface, including temperature and salinity. Meteorological moorings provide data on wind speed and direction at locations around the Great South Channel. These data tell us how winds move the surface waters. In addition, satellite-tracked surface drifters deployed in the region throughout the past thirty years give us an idea of how the surface water flows.

Another useful tool is the autonomous underwater glider. These underwater robots 'fly' through the ocean by shifting their buoyancy, alternating between sinking and rising in the water. The wings on their sides provide lift, which allows them to glide for many days at a time.

They can fly under any weather conditions, including rough seas that would send an oceanographic vessel back to port. They collect temperature, salinity, and optical data that we can use to look for phytoplankton, which is fodder for copepods. They also can be equipped with acoustic instruments that can measure ocean velocity and look for copepods or listen for whales. The vehicle we are attempting to recover is one of these.

We know from our biologist colleagues that copepods enter the Great South Channel mainly via the coastal current that flows along the Cape Cod seashore and down into the channel. The glider we’re chasing has traveled back and forth across this coastal current four times in ten days. The coastal current is fresher than surrounding waters, which makes it easy to identify using the salinity sensor on the glider.

We are interested to see that each of the glider crossings displayed a different salinity pattern: During the first transect, the fresher water was confined to a small area on the western edge of the Great South Channel. During the next three crossings, however, the fresher water spread farther across the channel, and during the last crossing, the coastal current water was saltier. Changes in the coastal current may lead to changes in the supply of copepods it delivers to the Great South Channel, so we are trying to figure out what controls the coastal current.

Storms mix it all up:
One potential factor we are investigating is surface wind. Wind at the sea surface may partly determine how wide, fast, and deep the coastal current flows. As the wind blows over the surface, it pushes the current around, bringing it closer to the beach or farther offshore; or accelerating it into the Great South Channel or slowing it down; or making it deeper or shallower.

But the wind can also have other effects on the coastal current. If the wind blows hard enough, the current—and all the copepods within it—may get mixed up with surrounding seawater. The winds during strong nor’easter storms drastically affect the coastal current.

In 2005, a strong storm on Mother’s Day weekend did exactly that. Before the storm, a well-defined coastal current flowed near the surface, and lots of right whales were sighted in and around the Great South Channel. After the storm, however, the current had mixed vigorously with the water surrounding it, and right whales were not seen in the area.

We have data from both gliders and a research ship in Great South Channel before and after the storm. We also use a numerical model that incorporates all known physics about fluid flow to simulate the ocean’s circulation during the storm. Together, these help us piece together how the storm affected the shape of the current.

Ocean fronts:
If ocean currents can sweep copepods into the Great South Channel, other ocean motion may actually cause the organisms to cluster. Copepods typically cannot swim fast enough to overcome swift horizontal currents in the ocean, but vertical water motion is much slower, and copepods are able to swim up and down in the water. Past theoretical studies have suggested a mechanism by which the copepods’ swimming ability can combine with a certain pattern of currents to result in an aggregation of the animals.

Suppose there is a region in which the surface currents all horizontally converge on a spot. Unable to fight the horizontal motion, copepods would drift with the flow toward the spot. Since the water can’t pile up in that place, it would be forced to sink. The copepods in the area of these converging currents would all seek to stay near the surface (to feed on phytoplankton, for example). They would swim upward to buck this downward motion, and they would remain in this spot.

As more and more copepods drift to this location and stay there, the density of copepods would increase. This type of mechanism, if it were to occur in the real ocean, would create a hotspot for whales, birds, fish, and anything else that feeds upon copepods.

Just as the atmosphere contains boundaries between warm and cold air known as fronts, which determine weather, the ocean also has fronts between warm and cold or salty and fresh water. If the surface water converges at ocean fronts in the Great South Channel, we might expect to find copepods clustered there.

Complex processes such as these are not likely to be well-characterized by a single observational technique. Using our suite of methods, instruments, and vehicles, we are taking steps to answer important questions about how this critical ecosystem works. Since copepods are food for so many different animals, the factors affecting how and where they aggregate influence the overall health of the marine ecosystems they sustain. So our work will provide fundamental information that resource managers need to make decisions on regulating fisheries and designating marine protected areas.

This research was funded by the Coastal Ocean Institute at WHOI, the NOAA National Marine Fisheries Service Northeast Fisheries Science Center, and the Office of Naval Research Marine Mammals and Biology Program. It was an Ocean Watch Essay for Sailors for the Sea, written by Nick Woods


by Nicholas Woods

  

Click on the FB Like link to post this story to your FB wall

http://www.sail-world.com/index.cfm?nid=95738

6:10 AM Fri 6 Apr 2012GMT


Click here for printer friendly version
Click here to send us feedback or comments about this story.

Click for further information on
Environment and the ocean

Related News Stories:

19 Mar 2012  GreenBlue wants a report card
18 Mar 2012  Sailing ketch Irene - goodbye billionaires, hello cargo!
14 Mar 2012  Climate Change misconceptions and realities - an Ocean Watch Essay
06 Mar 2012  Gulf of Aden crossing and a pirate rendezvous - PlanetSolar
02 Mar 2012  New theory: Neanderthals were great sailors
11 Feb 2012  America pauses on E15 - study bill passes
03 Feb 2012  Whales, whales and more whales in Southern California
17 Jan 2012  Solar ship PlanetSolar takes security forces for Gulf of Aden crossing
15 Jan 2012  Adventure sailing and marine protection - OceansWatch's winning combo
14 Jan 2012  Whale Wars - Australian protesters transferred from Japanese whaler
MORE STORIES ...






Sail-World Cruising News - local and the World

The spirit of the ARC is the spirit of camaraderie and adventure, which makes every one of the 1,250 ARC sailors a winner, not just those on stage to receive awards. After a 20-hour delay to the scheduled start, caused by strong winds in Gran Canaria, ARC 2014 got off to a flying start for this trade wind classic. ... [more]  

The Atlantic hurricane season will officially end on November 30, and will be remembered as a relatively quiet season as was predicted. Still, the season afforded NOAA scientists with opportunities to produce new forecast products, showcase successful modeling advancements, and conduct research to benefit future forecasts. Improved model, new surge forecast products and research projects debuted. ... [more]  

The second edition of this alternative route to the traditional ARC route saw 50 yachts and over 200 crew enjoy the same great activity programme before and after their ARC crossing, but also an interesting and enjoyable stopover on São Vicente, one of the less visited of the Cape Verde islands. Crews were full of praise for ARC+ route, now an integral part of the Atlantic Rally for Cruisers. ... [more]  

Waves within waves by Leslie G. Baehr
Scientists have a name for this phenomenon—internal waves. By definition, internal waves occur in the deep, well beyond people’s purview. Scientists have generated miniature internal waves in small tanks in the lab, but out in the wild, they’re as elusive as a white horse in a snowstorm. ... [more]  

The Cruising Yacht Club of Australia has received overwhelming support for its Parade of Sail, to be held prior to the Rolex Sydney Hobart Yacht Race on December 26, and staged in honour of the 70th Hobart and the Club’s 70th anniversary. ... [more]  

Over the past 30 years, the Arctic has warmed more than any other region on Earth. As sea ice continues to thin and melt, understanding the rapid changes going on in this sensitive part of the world and its ecosystems becomes even more crucial. The new vehicle, called Nereid Under Ice (NUI), is remotely operated by pilots aboard a surface ship via a lightweight, micro-thin, fiber-optic tether. ... [more]  

Tabor Boy - A century of service by Capt. James E. Geil
The history of Tabor Boy, the 92-foot flagship of coeducational Tabor Academy, in Marion, Massachusetts, is that of a working vessel. Although she was designed and built in 1914 to support the commercial shipping trade, Tabor Boy’s real calling turned out to be teaching young people about life and the sea. ... [more]  

The Gunboat 55 has been crowned Cruising World’s 2015 Domestic Boat of the Year. The publication’s annual competition is judged by a panel of independent judges. This year’s judges, Tim Murphy, Ed Sherman and Mark Schrader, were unanimous in their praise and selection. ... [more]  

In 2013, over 955,000 boats changed hands on the pre-owned boat market. That meant for a nearly a million boat buyers, hiring an accredited marine surveyor to inspect their potential dreamboat was often the first step after finding it. ... [more]  

In a world first study researchers have found a coral-eating fish that disguises its smell to hide from predators. 'For many animals vision is less important than their sense of smell,' says study lead author Dr Rohan Brooker from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University. ... [more]  

Writing in the Journal of Animal Ecology the authors set out to answer important and fundamental questions on how life in the ocean will respond to projected changes in the coming decades. Despite evidence of increasing acidification of the world's oceans, questions remain over whether marine species will be able to adapt to these changing conditions. ... [more]  

By studying the colour of seabird guano in the infrared part of the spectrum the researchers from British Antarctic Survey (BAS), University of Cambridge and University of Edinburgh were able to identify and isolate the poo's unique spectral signature from bare rocks and snow. ... [more]  

Sail-World is now live testing the changed website format. If you are using this format for the first time, please scroll to the bottom of the site and check that your region is set for your region and not some other. It can be correctly set up using the drop down boxes. Then go to the top, click refresh, and you should be away. ... [more]  

Oceanographer Bob Pickart will never forget his first cruise aboard Woods Hole Oceanographic Institution’s (WHOI) research vessel Knorr. It was February 1997, and the ship was headed to the fierce Labrador Sea in the dead of winter. Sailing into the teeth of wintry conditions was the whole point of the 47-day research cruise. ... [more]  

Fifty-five years ago, the group of twelve nations who’d been involved in the International Geophysical Year of 1957 signed the Treaty. The Treaty has ensured that Antarctica remains a natural reserve, devoted to peace and science. ... [more]  

Scientists urge protection of world's deltas by Woods Hole Oceanographic Institution
Extensive areas of the world’s deltas — which accommodate major cities such as Shanghai, Dhaka and Bangkok — will be drowned in the next century by rising sea levels, according to a Comment piece in this week’s Nature. ... [more]  

The BBC has reported that nine Somali pirates should get thousands of Euros because they were not immediately brought before a French judge, the court ruled. One is to get 9,000 Euros (£7,000) and the others sums of up to 7,000 Euros. The judges faulted France for keeping them in custody for an extra 48 hours. ... [more]  

Yacht lost on Majuro by John Martin
Monday morning I awoke early and watched the sky grow light listening to the quiet morning sounds here in our anchorage off the island of Eneko. At 7:30 the cruiser’s net anchor started off with the usual good morning, and she asked if there was any emergency traffic. ... [more]  

When we taught the intense 12-week Professional Mariner Program at the Chapman School of Seamanship, top priority the first week was to get each student into a mindset where they inspected a boat from stem to stern before casting off and after they tied up. Note the dual inspections. Bookends if you will. Before sailing; after sailing. Every time. ... [more]  

Leopard by Finland crossed the finish line in Rodney Bay Saint Lucia this morning at 01:09:51 UTC (02/12 21:09:51 Local time) smashing the ARC Course Record by 2 days 6 hours 45 minutes and 19 seconds. Sailing across the Atlantic from Las Palmas de Gran Canaria to Rodney Bay, Saint Lucia in a total of 8 days 14 hours, 39 minutes and 51 seconds. ... [more]  

Fort Lauderdale greets Oceans of Hope yacht by Sailing Sclerosis Foundation
Oceans of Hope sailed into Fort Lauderdale this morning at 11:00 a.m. local time to an enthusiastic dockside audience awaiting their arrival. Cheers ensued, horns blared and the crew looked happy to arrive in the tropical landscape of Florida. It has been a long and arduous journey for some, including Christina Lamb Sidell, who joined the Oceans of Hope crew several weeks ago in New Jersey. ... [more]  

As I look back over nearly 40 years of sailing around Mediterranean waters I can't help but reflect on time passing by. 'Isn't it a bit like painting the Forth Bridge?' a friend asked of my pottering around looking at harbours and anchorages. ... [more]  

Try as you might, it just won’t work. Ropes are for pulling, and pulling alone. Similarly, most things on a boat and in a rig have a specific job to do and hence reason for the way they’re designed. Form follows function, after all. So with this adage firmly in mind, let’s see what Sydney Rigging Specialists have been up to and why they stick to this theory, like rust marks on a trusty kite. ... [more]  

2014 has truly been an Odyssey year, as our boats have criss-crossed the Atlantic on epic journeys, starting in January when the Atlantic Odyssey II yachts sailed from La Palma to Grenada, and followed by the summer adventure of the Blue Planet Odyssey yachts up in the High Arctic attempting the transit of the North West Passage. ... [more]  

Sailing within the ARC+ fleet, Alubat Cignale 18 Eleonora 2 crossed the ARC+ finish line at 07:38:46 local time after a fast 2100NM passage from Mindelo in the Cape Verde Islands. The international crew on board were in great spirits having enjoyed their 12 days at sea and are now looking forward to experiencing the delights of the Caribbean. ... [more]  

Every year, thousands of people suffer from CFP, a poisoning syndrome caused by eating toxic reef fish. CFP symptoms are both gastrointestinal and neurological, bringing on bouts of nausea, vomiting, diarrhea, headaches, muscle aches, and in some cases, the reversal of hot and cold sensations. Some neurological symptoms can persist for days to months to years after exposure. ... [more]  

Little Pines Multimedia has released a new series of instructional apps for Android available at their website Apps4Sailing.com, Google Play and Amazon. ... [more]  

Scientists from the UK, USA and Australia say the new technology provides accurate ice thickness measurements from areas that were previously too difficult to access. The results, published this week in the journal Nature Geoscience (Monday 24 November 2014), step up the pace of research in the polar regions aimed at understanding the dramatic sea ice changes in the context of climate change. ... [more]  

The Antigua and Barbuda Marine Association (ABMA) is very pleased to announce that Falmouth Harbour Marina, Catamaran Marina and Antigua Yacht Club Marina are now providing only ultra-low sulphur fuel to yachts. This is as a result of joint efforts of the marinas and the ABMA in raising the issue of the fuel previously supplied having a sulphur content higher than legal requirements in Europe ... [more]  

The new application from PredictWind for Mac and PC is revolutionary for accessing weather data when offshore. Accessing GRIB files, Weather Routing, GMDSS forecasts and Satellite Imagery is now a simple task with the unique and user friendly interface. ... [more]  

The government will expedite permitting for yachts wanting to enter the country’s ports, from taking weeks to taking one day only, with an online one-stop service protocol under the management of the Foreign Ministry, said Coordinating Maritime Affairs Minister Indroyono Soesilo. ... [more]  

As an investment in a FLIR camera is not inexpensive or even one that can be taken quickly due to having to carefully think through the installation process, we thought long and hard about the perceived benefits of the system. At the end of the day we decided to go ahead with the FLIR camera and also decided, that we would pair the FLIR thermal camera with the new Furuno TZ9. ... [more]  

The 29th Atlantic Rally for Cruisers (ARC) set sail today bound for Saint Lucia following a delayed start due to strong winds locally in the harbour of Las Palmas de Gran Canaria yesterday. For only the third time in the rally's history, the decision was made to delay the start, initially planned for 12:30 on Sunday 23 November by 20 hours. ... [more]  

Sometimes the waiting is just as good as the journey
Tips on boating with dogs
Four Tips - How to safely truck your boat over the road
Atlantic Odyssey – Emergency Medi-Vac from Cocojet III
ARC 2014 - ARC start delayed
Antarctic ‘ghost mountains’ preserved by ice sheet
Clear the Decks!
Sail-World Team holds first Continental Conference at METS
British Cycling grows by over 500%, can sailing do the same?
Extinction risk not the answer for reef futures
ARC+ fleet sets sail for Saint Lucia
Sail safer with these 'landfall light' secrets
Sailing the Mediterranean – An infographic
New transducer line from Garmin boasts scanning sonar
Building on borrowed time + Video
Marion to Bermuda Race announces the M2M2B Yacht Rally
34 Atlantic Odyssey yachts cross start line off Arrecife
World ARC fleet explores Zululand
Visit Doyle Sails New Zealand at METS 2014
ARC 2014 Opening Ceremony: Flags and bands, one week to the start
Sailing veteran celebrates his 20th Atlantic Rally for Cruisers   
All set for ARC+ arrivals in São Vicente   
Caribbean 1500 - Lest We Forget: Crews who won't make it to Tortola   
Crews visit ARC Forest at Las Palmas de Gran Canaria   
Security Council renews action to fight piracy off Somali Coast   
World Odyssey Race cancelled   
Caribbean 1500 - One fleet, two very different stories   
Eccletic ARC fleet assemble in Las Palmas   
Antigua 2 Falmouth - Notice of Race released for 2015 edition   
Oceans of Hope yacht arrives in New York City in unique global voyage   
Spirit of Tradition   
Tropical storm-like conditions in Malta and Sicily as Medicane hits   
ARC+ Cape Verde fleet slows, more wind expected tomorrow   
Top 20 cruising realities no-one talks about!   
Busy schedule begins for ARC crews in Las Palmas   
Slow progress in the Caribbean 1500 fleet   
Crystal Blues finds good medicine in Penang   
ARC+ Cape Verde sets sail from Las Palmas de Gran Canaria   
Destination: Balmy Brentwood Bay and peaceful Tod Inlet   
Safety and enjoyment order of the day in Marina Lanzarote   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png http://www.sail-world.com/event_images/image/FaceBook-icon.png  http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph, contact the photographer directly.
XLXL NEW CRU NH
LocalAds   DE  ES  FR  IT