Tuna 1 - TAG 1

We left the wharf knowing that the wind would pick up later that afternoon...we just weren't sure when. The boys from mainland Nova Scotia (Steve McInnis and Bernie Chisolm) met us off Mabou early in the morning. It was flat calm, and after jigging up some mackerel we drifted close to shore hopping to get bit. There was no wind and the tide was running against the drift, so after doing a 360 around our baits we decided to head off shore. Local scientist, Aaron Spares, spotted some fish jumping from the top of the cab, so we set up.

Craigor Cameron battles a bluefin

With the camera rolling, three or four fish splashed 500 yards off the stern and looked like they were headed towards our Huey bait (named after a local fisherman that flat lines a mackerel with a balloon). The boat waited with anticipation, but the fish didn't look like they were going to bite...then...WHAM...the line went tight, the rubber band shattered, and the reel zinged as the Bay Queen IV scrambled into position. We fought the fish for a good 45 minutes and we could tell it was a big fish by the way it behaved and marked on the sounder. We would reel it up to 50 feet and it would dive back to 120. This cat and mouse game ended when the mono chaffed and the line broke. Tuna 1...TAG team 0.

This bluefin is being tagged with an acoustic tag

Dejected but optimistic, the team regrouped and got the lines back in the water. The clouds over Cape Breton gathered and the wind began to puff. Capt. Dennis put his favorite pink balloon on the down bait for good luck...and just as we were thinking it might be time to head home...Zing...we were tight again. This time the tuna couldn't out smart us, and after a short fight the 250 lb bluefin was on board and back in the ocean with a new acoustic tag that will last for 1300 days.

By the time we were done tagging, the sea had turned into a frothy mess and we were all happy to head to shore.

-Robbie Schallert

Let's Go Fly a Kite!

The Celtic Colors are in full swing here in Cape Breton, along with a cool autumn breeze. The Bay Queen IV headed north up the coast line to the Mabou Coal Mines to meet up with the PEI tag boats. After a quick stop for mackerel, we started to set-up our gear a quarter mile from shore...but before we could get our last bait in the water, the Neptuna crackled over the radio that he had a fish on. After a short, 20 minute fight, Ross Keus and TAG Team 2 were on the board with an acoustically tagged 400 lber.

The SE wind picked up in the morning allowing the boats to fly their kites. The kite allows the boats to fish on the downwind side of the boat, and it keeps the mackerel right on the surface so the tuna can't see the line. I have been staring at the "kite bait" for five years now...and at high noon I was rewarded. The crew was forward in the cab eating lunch and I was about to join them...when SMASH...out of the water...20 feet from the boat...an 850 pound bluefin ripped through the surface under the kite. I have pictured this moment in my head a thousand times, especially how I would react when this actually happened...of course, I froze with excitement. Capt. Dennis tried to yell but he was muffled by the hamburger in his mouth...Craig knocked his bag of mini licorice in the air that rained down like confetti...and after what seemed like minutes I finally reached the rod to crank in the slack. The line went tight...and with a triumphant roar...I had finally seen and hooked a Giant off the kite! Sheldon Gillis took over from there and the TAG team readied the equipment. Everyone's adrenaline was soaring...if you haven't seen a kite strike...get up to Port Hood...it is spectacular!!! After a 31 minute battle, the 800 lb bluefin came aboard and was fitted with a satellite tag along his right dorsal.

We tagged one more fish and saw and two leatherback turtles swimming off the stern. All in all it was a great Cape Breton tuna fishing day!

-Robbie Schallert

Highs and Lows

Well, as the ol’sayin’ goes, when it rains, it pours...especially in Nova Scotia.  The past 10 days have set records for Nova Scotia and the Tag-A-Giant team fishin’ for Giant Atlantic Bluefin off Port Hood on the Island of Cape Breton.  Intense high and low pressure systems have brought unseasonal weather.  Water temperatures have remained warm, and this past Canada Thanksgiving Weekend set record air temperatures.  Twenty-three ^oC is very nice for October.  It also blew a gale last Wednesday, gusts up to 118 km/h.

Gannet aboard

The TAG Team tied the record number of tuna tagged in one day in Canada, 9 fish on Monday, October 3^rd.  The bite didn’t begin until noon.  But when it started, it didn’t stop.  Tuna after tuna came to the tagging vessel, Bay Queen IV.  According to the fishers, the hooked-up tuna ranged from ‘scrawny little rats’ to ones ‘hard to see swim away’.  A true Nova Scotian, scientist, Aaron Spares, put on the kilt to tag the first fish, and kept it on until setting foot back on the dock at Murphy’s Pond.  The four vessel fleet kept Dr. Steve Wilson, Capt’n Dennis Cameron, Canada’s top wireman Sheldon Gillis and mate Craig Cameron busy as can be.

Pete’s Pair-Of-Dice had a very hockey-like hat-trick, 3 fish in the tagging arena.   The other 3 vessels, Capt’n Steve’s Carrie Anne, Bernie’s Nicole Brandy and the tagging boat, Bay Queen IV topped their hats to two each, which totaled the previous record set here last year.  The low came the next day, Tuesday, October 4^th, a shut-out for the tuna.  The fishers never got one on the board.

On alert - Sheldon, Craig and Aaron (kilted)

The winds blew until today, Wednesday, October 12^th.  Low temperatures last night had frozen a few puddles by 5 am this morning, but high sun warmed it up enough for a T-shirt and loafers day on the deck.  Tuna streaked the surface, marked the depth sounder, and graced 1 or 2 commercial fishers, but none took the bait for the TAG team consisting of PEI’s ‘North Lake Breeze’, ‘Neptuna’ and the ‘Bay Queen IV’.  Tanned and tuned out, the team trudged up the gangway slightly dejected, but still smiling at the thought of the next day’s potential to break the record.

Depth sounder marking giants

-Aaron Spares

Ophelia? Nine Fish Tagged!

The impending arrival of Hurricane Ophelia in the Canadian maritimes had prevented team member Robbie Schallert from getting back from his brothers wedding in Texas, so longtime reserve liphooker Aaron Spares was called into action on Monday morning. The day started quietly and few fish were marked on the 4 boat fleets’ echo sounders. As noon approached, Captain Dennis Cameron and I discussed the possibility of sending the boats back to port due to a lack of bluefin and marginal weather. A commercial fisherman a few miles inshore of the fleet then radioed Pete Sutherland aboard Pete’s Pair A’Dice to request help. He had lost his steering while fighting a hooked fish. Peter pulled his gear and moved to lend assistance. That turned out to be a turning point for our tagging efforts today. After helping his colleague, Pete noticed a large area of bird activity and busting bluefin. He summoned the fleet and hooked up within seconds of dropping his line in the water. An epic afternoon ensued. We tagged nine fish ranging from 203 to 276 cm in length, a mixture of pre-spawners and true giants. The tagging boat was fighting fish after fish until well after the sun set. Aaron performed flawlessly on the liphook, despite frigid winds nipping at nether regions beneath his kilt. Pete hooked three while the Carrie Anne, Nicole Brandy and Bay Queen each hooked two. Nine fish tagged matches the record number of fish tagged by our team in Canadian waters last year with a fleet twice as large.

-Steve Wilson

Fall in Nova Scotia

There was a brisk autumn bite to the air as the team headed to the boats. We decided to stop and get some mackerel for a change…and caught a good number of tinkers. Dennis’s brother started pulling his net, so the fleet moved over to see if any of our tuna friends were waiting for the herring again. At first we thought maybe our luck around Carl had run out, but soon enough he had a good size school underneath. We tossed a herring into the boil and we were hooked up. It was a fairly quick fight, and at first we thought the fish was small…we were mistaken…fish was 266 cm and fat as can be. Once on deck, the tag team sprang into action putting in a pop-up satellite tag and sending the fish on his way. Pete Sutherland snagged one off the net too, but it pulled the hook…and so the Carl herring net trick was over for the day.

We drifted for awhile but came up empty, and then tied off to our own herring net. A bald eagle paid us a visit…he circled for a bit and he swooped down with talons out to pluck a herring right out of the water. After about an hour, we were visited by a lone bluefin…he looked at our mackerel for a good 45 minutes…streaking up and down as we moved the bait through the water column. Finally, Dennis “Magic Hands” Cameron switched the mackerel to a herring and within seconds we were tight for the second time in the day. It took a little over an hour to get the 700 lber to the boat, but once on deck the well oiled TAG team fitted our new friend with the second pop-up tag of the day!!

-Robbie Schallert

Back in the Hood

TAG-A-Giant Canada returned to Port Hood, Cape Breton, Nova Scotia for another year of tagging Atlantic bluefin. We were welcomed by unseasonably warm weather and a flat calm day. In order to knock off the rust, we decided to start the season off with three boats...two PEI boats (North Lake Breeze and Neptuna) came across the straight to join the TAG boat (Bay Queen IV). It was a fairly quiet day...marked a lot of fish...hooked three and tagged a beautiful 247 cm bluefin tuna. It is great to be back on the water...especially with the weather and the number of fish around.

-Robbie Schallert

One for the Record Books

As scientists, anglers and passionate fans of Pacific bluefin tuna we live for day like we have had here on Shogun in the past 24 h. Our mission- to collect tunas for studies back at our home laboratory- the Tuna Research and Conservation Center (TRCC). We arrived in the area where fishing reports had been excellent and proceeded from dawn to dusk to have a wide open bluefin bite. And this time, for the first time in years, we were more than prepared. The Stanford University team had programmed over 100 tags prior to coming out on the trip and anticipation was high.

This year we had some older TAG team members from our lab, including Tag-A-Giant and TRCC technicians Robbie Schallert and Alex Norton, Stanford technician for our Gulf oil spill team Ben Machado. Also on board were Stanford graduate students Dane Klinger and Dan Madigan, and undergraduates who had interned with the TRCC this summer including undergraduates Natalie, Ethan, Sarah, Andrew and James.

Captain and Professor Norm put us in a great spot to drift and before sun up Dan Madigan hooked up. This year to prepare with our younger team, we had held a “tagging class," and went over the cradling of fish on the swim step. Sure enough chaos occurred during the first fast bite when the team barely had their feet wet. We put the fish that first appeared as yellowfin into the side wells and quickly filled to capacity.

We then heard the first call from the crew of,  "Bluefin!"  The tagging team (Barb, Robbie, Dr. Joe Bonaventura) went into the action- tagging 7 yellowfin. The bite slowed down and we moved on. Within an hour, Norm glanced and viewed a sonar hit that was extremely interesting- the fish were down on the thermocline- in the “feed layer” or deep scattering layer the area I call the "peanut butter of the ocean," filled with small crustaceans and squid. From the moment we stopped on the sonar school until 6 PM we had steady bluefin action that led to what I think may be the highest single electronic tagging stop for bluefin tuna-96 archival tagged bluefin (all with one tagging station!). In addition, we filled up the slammer with bluefin. Scientific samples were taken by Dan and Ben from a handful of bluefin to discern isotopic signatures (think "You are what you eat!") and to also determine from where the fish had come (signatures from the open sea are lower in numerical value than in the productive California Current).

I was a bit surprised to see Captain Bruce, Randy and Tommy admiring an albacore as if they had not seen one in a while. This was the first albacore of the season – remarkable given it happened the third week in August. I thought the albacore were quite skinny - suggesting they had come from offshore. History was made here today aboard the Shogun-by the end of the day, we had collected all the bluefin required for the TRCC this year, tagged 103 tunas and released another 50 more. All in all, we could have tagged 200 bluefin today! Too bad we did not have more conventional and electronic tags! The fish were very young, potentially new arriving fish on the west coast. From prior tagging we know that this year class will be retentive to the California current and provide super fishing on a 30lb 3rd year fish next season so let’s hope their survival will lead to more knowledge and great fishing!

-Dr. Barbara Block

"She'll be right, Mate" - Shark Tagging with NOAA/NMFS

This summer marked another great shark tagging cruise for NOAA/NMFS’ Large Pelagics Group, with over 200 blue, short fin mako, and common thresher sharks tagged. The Ventura II set out near the Channel Islands for a ten-day trip under blue skies with a great crew, in hopes of catching  as many juvenile sharks as possible. As a bio undergrad with hopes of doing research, it was an awesome experience to be able to handle and tag some of these shark and all three of the interns- Mackenzie Merkel, Nathan Mertz and I- saw firsthand the importance of planning and execution for research. I feel extremely fortunate to be have been under the wing of John Hyde and Natalie Spear from NOAA/NMFS, and Paul Rogers from Flinders University in Australia- all three very motivated scientists and good people. This high tagging tally forms the basis for a large pool of information and samples that can be obtained from these annual juvenile surveys- DNA samples, muscle biopsies, length, condition and sex of sharks, as well as stomach contents and a few organs from dead specimens. Also collected this trip were parasitic copepods for  Paul Roger’s continuing study of mako sharks. These copepods found on the skin and fins of both mako and blue sharks are being studied as possible biological markers to indicate interactions of different shark subpopulations or species.

For a student who doesn’t quiet have her sea-legs yet, what would seem mundane for seasoned scientists was more than new for me, from baiting 200 hooks with sleepy eyes to the actual tagging of sharks. I had also never participated in long lining before and with all the negative perceptions surrounding this industry, it was surprisingly less invasive in terms of by-catch than I had expected. With two sets a day for ten days, the total tally of 202 animals included 1 opah, 1 pelagic ray and 1 Mola mola, the latter two of which were thankfully unhooked at the rail and swam away. This personal realization about long lining, which although based on a very small sample-size using only a fraction of the industrial hooks, could be testament to the gap between an assumption and the actual experience. I would like to avoid sounding cliché, but it’s amazing how much more you learn from hands-on experience than from just reading about it. No book has or can describe the smell of blue shark under the fingernails at the end of the day, or the pure muscle that makes up the body of even the smallest sharks we tagged. I really loved the actual handling of the sharks, which on our busiest set, was up to 43 blues in a row! It was the mako’s however, that were my favorite, their black eyes and the way they thrash violently from side to side was plenty more aggressive than the characteristic wriggling of the blue sharks.

One set in particular stood out not only because of the low count of two sharks, but for the healthy dose of adrenaline it gave us. The first, a small mako, appeared to be dead as we pulled it on deck and the water running over its gills thankfully paid off. With time and attention, what seemed to be a lifeless little mako turned into a lively one. The next shark was memorable for its 202 cm length paired with how feisty it was. Once on the cradle, it demonstrated its teenage angst by biting through one of the four supporting ropes of the cradle. The rope broke completely off the hydraulic pulley and all of us just looked at each other with wide eyes, surprised.  We sprang into a chaotic impromptu rearrangement of shark, personnel, and ropes, and the cradle was  fixed onboard to bring up the shark. The shark had tired out enough for everyone to hold it down, but as the first big fish of the trip, it definitely made its debut one to remember. I was quickly reminded of the awesome power and agility of these sharks that had been somewhat diluted by handling so many docile juveniles up to that point- a much needed paradigm shift to say the least.  

All but one of the sharks was given a conventional tag- a metal arrow-shaped anchor about a centimeter long attached to a six-inch flexible plastic flag label. These metal anchors are placed in the muscle next to the dorsal fin, from which a small fin clip was taken. The largest mako was given a GTOPP-funded SPOT tag (Smart Position and Temperature Tag), which unlike the conventional plastic tags, can transmit to the satellites which calculate a position. Because of its large size, this mako was given the tag in the assumption that it would  move through different territories more so than juveniles might. The team affixed the plastic tag onto the dorsal fin to keep the oval, battery-operated device from falling off, yet to not be invasive in the shark’s daily behaviors. Hopefully in the near future, the shark we brought onboard on that very day can indicate to the team its movement patterns and where it spends most of its time.

The shark deterrents we picked up in Avalon, Catalina, were tested in our lone night set, with an  outcome differing from our expectations. We clipped a deterrent- a plastic cylinder wrapped in foam, containing a battery-induced electrical field- on almost every other lead going out on the mainline. Unfortunately, the ratio of sharks on deterrent hooks to total number of deterrents used was about 16:21. This high ratio could indicate that improvements are needed for these to effectively repel shark, however, the sample sizing was also very small. Regardless, the possibility of using shark deterrents on future surveys and in commercial fishies could help reduce shark bycatch.

The waters of the Southern California Bight have not only been my personal playground since childhood, but also for sailors, divers, and commercial fishermen, due in part to the biological diversity of pelagic predators. The Ventura II was flanked by a pod of dolphins almost every day, not to mention the pod of white scarred Risso’s dolphins, giving us false hope of nearby swordfish. About three whale spouts were seen returning into coastal waters, almost greeting us before diving down deep. Every night and day, we saw salps forming large stringy colonies that feed on phytoplankton blooms. These salps were joined by a transluscent pink pyrosoma we found during the night set, a column-shaped and hard tunicate that are closely related to salps. It was refreshing to see this kind of life throughout the cruise, especially with the amount of juvenile sharks tagged, because all members of this pelagic environment play a role in the health of the environment. On two occasions, we saw evidence of the predatory instinct of the sharks in the area. We pulled up a mako hooked in the mouth but missing its body from the gills down; the bite marks were testament to an attack from a larger shark. Another live shark was pulled on deck with a large bite mark on its back, while the opah also had a cookie cutter shark bite. All these were seen above water, however we were itching to see some underwater action. Paul and I rigged up a classy little contraption we called the “Ghetto-Pro”, a makeshift version of the professional “Go-Pro” cameras, by duct taping and zip-tying my digital underwater camera to a gaff. Running video over the rail, we were able to see some footage of hooked sharks- a small mako and a large blue- along with a pretty cool sequence of a mola mola being unhooked and swimming away in their odd manner.

Needless to say, the cruise was a blast, I’m still grinning about the experience. With the information gathered not only on this cruise, but from years past and years to come, the abundance and distribution of juveniles sharks in the Southern California Bight might be better understood for scientists and the general public alike.

-Liana Heberer

Nature Paper Receives Extensive Media Coverage

On June 22 the paper "Tracking Apex Marine Predator Movements in a Dynamic Ocean" was published on-line in the journal Nature.  It appeared in the printed edition July 7.  The result of a decade of biologging research on 23 species in the North Pacific Ocean, this paper described for the first time the marine hotspot of the California Current, which extends along the West Coast of North America from the US-Canada border to the tip of Mexico's Baja Peninsula.

As we had hoped, the paper generated broad media coverage in newspapers around the globe.  Click on the links below to read some of the coverage:

Washington Post: West Coast boasts underwater Serengeti, study finds

New York Times: Oceans Imperiled But Still Teeming

San Francisco Chronicle: The Pacific Ocean's 'Corridors of Life'

San Jose Mercury News: California Coast is Hot Spot for Marine Life

MSNBC: Where do Ocean's Predators Roam? The Amazing Answers

Santa Cruz Sentinel: Study: Marine Life Population Rich But Fragile

Sign On San Diego: Marine Predators Flock to California Coast

Oregon Live: In Pacific's Fertile California Current, Marine Predators Bountiful, Study Shows

Big Country Comes to Town

(This is a cross-posting from our Tag A Giant blog, courtesy of TAG Scientist Robbie Schallert)

The TAG team was back on the water Friday in search of more bluefin. After a long run past The Point in some sporty seas, Captain Dale put us on the fish immediately...in fact we had a tuna hit the flat line as it was being let out! Anglers Daragh Brown and Erin Wright, having been trained by living legend Peter Wright, brought the fish in with ease. Once to the back of the boat, Alan "Big Country" Scibal took charge of the leader and wired the fish to the transom door. Dr. Dre surgically implanted the tags, and with a couple of quick stiches, the fish were ready to head out the door to show the school their new hardwear. By the end of the day, we had 4 fish tagged, all in the 220-260 pound size range. It was a long ride home as we battled a head sea the whole way but no one seemed to mind after a great day on the water. You can see some of the action below...

Luck of the Irish

Our Tag-A-Giant team is currently off the coast of North Carolina tagging bluefin tuna.  I'm going to be cross-posting their blog entries here, or you can follow them directly at the Tag-A-Giant blog.  This first one is courtesy of TAG Scientist Robbie Schallert.  Go TAG Team!

TAG-A-Giant 2011 got underway with four bluefin tagged on a gorgeous North Carolina day. The Sensation, captained by Dale Britt and Mate Alan Scibal, hooked a double header to kick off St. Patty's Day with Irish scientist Daragh Browne in the chair. Duke grad student Caitlin Hammer fought the next two fish under guest captain Peter B. Wright's tutelage. The ocean was filled with life on the other side of the Gulf Stream with schools of hammerhead sharks, mantas and tuna exciting the crew. There were literally hundreds of tuna surfing down swell...a site to behold! It is great to get the season started...hopefully the weather will hold through the weekend!

White Shark Team Take Census of Northern California Population

The white shark research team has published two papers in the past few days, documenting the ability to recognize individual sharks year after year by the distinctive shapes and markings on their dorsal fins; and then using this information to estimate the total size of the white shark population in this region.

The first study, which was published March 1 in the journal Marine Biology (Anderson et. al., 2011) shows that it is possible to positively identify the same shark year after year - even over time periods as long as 15-22 years!

Figures a and b show the fin of a single shark in 2007 and 2008;

Figure c shows a different shark in 2008 - illustrating how

distinctive the fin edge shape can be.

  The second study, published today in the journal Biology Letters (Chapple et. al., 2011), uses fin photographs like those above to calculate the total size of the white shark population that returns to northern California each year - and the estimate was just 219 individuals.

Because this marks the first census of this population, we have no way of knowing whether this number is typical, or if it is unusually low (or even unusually high).  What it provides, however, is a baseline that can be used in the years ahead to monitor changes in the adult white shark population - which will be a key step in managing and, if needed, protecting these animals in the wild.

As one might expect, we've had a lot of media interest in the story.  You can check out the latest news coverage at the GTOPP website.

GTOPP data to be integrated into Ocean Observing System

Back in the early days of TOPP, one of our goals was to see if it might be possible to one day use the data we get from tagged animals to help us understand the ocean itself. This concept, which we dubbed "Animals as Ocean Sensors," came a giant step closer to reality last week, with the birth of a new partnership between GTOPP and the national Integrated Ocean Observing System (IOOS).

The concept behind the partnership is simple: electronic tags often carry a variety of environmental sensors to detect light, temperature, pressure and sometimes even salinity or other ocean chemistry. When we attach these tags to an animal - especially one like an elephant seal that dives continuously throughout its journeys - it provides an exceptionally rich dataset, profiling regions of the ocean that would be expensive and logistically difficult to access by human oceanographers.

In a series of meetings held March 2-3, 2011 at the NOAA Fisheries Service lab in Santa Cruz, California, biologging scientists worked directly with the IOOS team to discuss how best to begin the process of integrating animal tagging data into the Ocean Observing System. On Friday, March 4, we were joined here at the Hopkins Marine Station by the IOOS Director Zdenka Willis, to share the results of the meeting with the media and the public. You can see highlights of these discussions at the links below:

Monterey County Herald:  Agencies Join Forces to Track Marine Animals in Monterey Bay

TOPP Researchers Describe Habitat Preferences of Leatherback Sea Turtles: A Key First Step in Open Ocean Conservation

 

Today in the scientific journal Marine Ecology Progress Series, Stanford University marine biologist, and Center of Oceans Solutions’ Marine Spatial Planning Director Dr. George Shillinger and his colleagues published their findings from a three-year study of leatherback sea turtles tagged with satellite transmitters at Playa Grande, Costa Rica.  By following the movements and diving behavior of these turtles, in the context of the oceanographic conditions around them, the researchers were able to identify the habitat most suitable for them.  With this information, it is possible to predict where leatherbacks will go in the open ocean based on oceanographic conditions – and thus to help reduce mortality through interactions with fisheries or other human activities on the high seas.

 

Leatherback sea turtles are the largest and widest-ranging turtle species, and they spend most of their long lives in the open ocean.  Unfortunately, their numbers have declined precipitously in the wild – especially in the Pacific.  This decline is attributed to a variety of human activities, including habitat loss, poaching of both turtles and their eggs, and fisheries bycatch.  Although there have been significant conservation efforts aimed at protecting the turtles on their nesting beaches, little information has been available to help protect them at sea where they spend the majority of their time.

 

Working on the beaches of northwest Costa Rica, Shillinger and his colleagues attached electronic tags to female leatherback sea turtles that had come ashore to lay eggs.  A total of 46 turtles were tagged from 2004 to 2007.  After leaving the beaches, the turtles were followed for an average of 217 days as they traveled offshore into the southeastern Pacific Ocean. During these journeys, the tags recorded information about location, depth and temperature – giving the researchers a detailed profile of their behavior in the wild.  By studying the frequency and depth of their dives, the researchers were able to identify specific behavior types – some of which appeared to be characteristic of traveling, and others of foraging for food.

 

Using a sophisticated computer model, the turtle behavior data was combined with satellite-based measurements of oceanographic conditions including sea surface temperature, chlorophyll a (indicative of the presence of microscopic plant life called “phytoplankton,” which forms the base of the ocean food web), and Ekman upwelling – which is associated with the presence of nutrient-rich water rising to the surface.  By analyzing all these factors together, the researchers demonstrated that the turtles’ foraging behavior was associated with regions of cooler surface temperatures, higher chlorophyll aconcentrations, and strong upwelling – all of which can be observed from earth-orbiting satellites.

 

“The ability to predict where leatherback sea turtles go is a critical first step in being able to protect these animals in the open ocean,” says Shillinger.  “Our improved understanding regarding the forces that shape their movements,  will help to inform our efforts to reduce fisheries-turtles interactions,  and to advance  ecosystem-based marine spatial planning efforts in the Pacific.”

 

One of the fundamental goals of the TOPP program was to explore whether ecosystem-level tagging studies, carried out on multiple species over an extended time period, could help inform ecosystem-based resource management.  This study demonstrates the viability of such an approach.

 

You can read an excellent article about this study on the Stanford News website here, or read the paper itself here.