BajaNomad

Squid Studies: Changing Seas and Shrinking Squid

BajaNews - 7-26-2011 at 01:38 PM

http://www.scientificamerican.com/blog/post.cfm?id=squid-stu...

By William Gilly
Jun 20, 2011

SEA OF CORTEZ— During the night we moved west, sampling acoustic data the whole time, to an area east of Isla Tortuga. Today we followed a routine that was established yesterday and will continue for the rest of the cruise. We glide along at five knots sampling acoustic data in a box-like pattern, and every so often stop the ship to deploy an instrument that continuously measures properties of the seawater under the ship as a winch lowers the device to the desired depth. These properties include electrical conductivity (from which salinity is derived), temperature and depth, and the device is therefore known as a CTD. Our CTD is also equipped with an oxygen sensor, because this environmental feature is relevant to much of our work here.

Humboldt squid, like most animals that we are familiar with, require oxygen for the biochemical reactions that generate energy and support life. But Humboldt squid have the peculiar ability to be able to tolerate low levels of oxygen that would be lethal to many organisms, particularly large, athletic ones. Not only can the squid tolerate low oxygen, they actually spend much of their time in a midwater region of low-oxygen known as the oxygen minimum zone (OMZ). The OMZ can be defined as the depth range where oxygen is less than one-tenth its concentration at the sea surface (where oxygen in water is basically in equilibrium with oxygen in air). In this part of the Gulf, the upper boundary of the OMZ is typically 200-300 meters, and the lower boundary is about 1,200 meters. From a terrestrial point of view, 10 percent oxygen saturation would occur at an altitude far higher than the top of Mt. Everest, where saturation is about 40 percent. The OMZ is indeed a hostile environment.

How the OMZ comes to exist in some of the most productive oceanic ecosystems on the plane is explained in a bit more detail in a previous post. To make a long story short, excess organic matter that sinks from the productive surface layer is metabolized by microbes on the way down through the water column, and microorganisms thus shape this vast midwater, or mesopelagic, world. At OMZ depths it is also cold, and there is little or no sunlight, so most animals living in this strange world are small, move slowly and use oxygen very efficiently. Many of them also produce their own light, including myctophid lanternfishes (a favorite food of Humboldt squid) and the silvery hatchet fish.

We sample these midwater organisms by using several types of trawl-nets. This additional part of our daily routine shows us the most abundant prey items for Humboldt squid in the local environment, and we can then compare this menu to what the squid are actually eating based on analysis of stomach contents of captured squid. Trawls at this site produced many myctophids, deep-water shrimp and other species of small squid—a diverse buffet for a growing jumbo squid.

Many of the organisms that inhabit the OMZ do not penetrate far into its core, where oxygen can reach nearly zero, and instead remain near the upper. These organisms can be extremely abundant, and in the daytime they form a dense layer that can be detected using the acoustic-sonar gear employed by Kelly Benoit-Bird's team. We use sonar to target our trawls to the same depth as this acoustic deep-scattering-layer (DSL). This allows us to selectively sample the creatures there, and we can evaluate the oxygen and temperature at the same depth using the CTD. In this case pictured, the sonar on the drifting vessel recorded the CTD as it passed through two distinct scattering layers at 300 and 400 meters depth.

As sunset approached, the sonar revealed another classic property of the DSL—or depending on your point of view, of the behavior of organisms that comprise the layer. A daily migration towards the surface occurs at night, and this allows these small mesopelagic animals to feed on plankton in surface waters under the relative security of darkness. The return migration to the upper OMZ at dawn leads to a dark, cold, hypoxic refuge from active visually oriented predators. But Humboldt squid can tolerate the conditions in the upper OMZ quite well, and the DSL sashimi-bar remains available to them all day long. And at night the squid can feed in near-surface waters. This non-stop feeding capability is likely to be part of the explanation as to how they can grow so large so rapidly.

Nightfall again saw us perched along the rail, fishing rods poking into the blackness and pulling up squid for our daily sampling. Tonight we quickly captured our desired sample of 30 squid, and then the bite turned off. These animals were a bit smaller than those from the last two nights, and there were more immature animals.

As we cleaned up the deck, we began noticing the slow rocking of the ship, despite the lack of wind and waves. Five or six hundred miles to the south, Hurricane Adrian was raging in the Pacific, and this category 4 storm was sending a significant ocean swell halfway up the Gulf of California. We turned in hoping that this storm would turn west and track into the open Pacific.

The next day we continued our box-transect in the same area as yesterday until early afternoon and then started toward Isla San Marcos and Santa Rosalia . In a normal year there would be 200 small, open boats (pangas) with outboard motors engaged in the local fishery for big squid—but this is not a normal year, and fishermen have not been able to find any large squid here for the last year. They are anxious to learn when the squid will return. Rumors have reached us that thirty or so boats recently started fishing out of Santa Rosalia, but now it is Saturday night, and fishermen here traditionally take this night off.

Soon Chad Waluk from Oregon State once more revealed the wonders beneath the surface with sonar. Shortly before sunset he thought that he saw a dense aggregation of squid as the ship passed over the ridge of seamounts that runs north from Isla San Marcos. Schools of some kind of fish appeared to be beneath the squid—the dense, red ball-like structure is characteristic of fish with swim bladders that produce a strong acoustic signal. Squid lack swim bladders but nevertheless produce a good signal that often look like vertical tick-marks on a display like that in the photograph. Squid signals also have a characteristic signature based on comparing different frequencies of sound, and the sonar we use has four frequencies. This feature permits using this approach to judge whether a given target represents squid.

With the sonar image in mind, we started jigging for squid and collected our sample of 30 individuals within 15 minutes or so. In addition, we were able to collect an equal number for Oscar, our cook, because he requested some fresh squid tubes (mantle not cut open) for another dish he was planning. We were more than happy to oblige, and these small squid were a perfect size.

During the fishing period, we witnessed squid attacks directed against each other many times. If a squid was being pulled up from beneath the ship, half a dozen others would follow along, attacking the one on the jig. All attacks were directed against the individual on the jig, a most unnatural situation, and it is unclear to what extent cannibalism contributes to natural diet. In the opinion of Unai Markaida, our collaborator from Colegio Frontera Sur, Campeche, it might account for 10 percent or more. But in seeing how effective the attacks were on their hooked cohorts, it is hard to believe that this behavior is not part of the natural foraging repertoire of these awesome predators. Years ago, when we were raising California market squid in the lab, one of the first behaviors displayed by the tiny hatchlings (about the size of a rice grain) was to steal food from another squid that had successfully captured a copepod prey. The miniature squid sensed the capture event and rushed over to investigate. The resulting struggles over the contested copepod were generally quite violent, with much twisting and rolling. Taking advantage of a developing situation, often at another's expense, is perhaps characteristic of squids in general. You just can't trust them at all.

At this stop on the Santa Rosalia fishing grounds, nearly all of the squid were small, only 25-30 centimeters mantle length, and immature. This was a big difference from 2010, when squid of this size were fully mature and spawning. We collected statoliths of small immature squid, but determination of age and comparison with the 2010 data will have to wait until we return home.

Hatchet_fish.jpg - 26kB

dtbushpilot - 7-26-2011 at 03:58 PM

Interesting, thanks.

I didn't see anything about the little fish, perhaps I missed it. It is the same as the 2 that I found here on the beach.....dt

BajaNomad - 7-26-2011 at 04:30 PM

Quote:
Originally posted by dtbushpilot
I didn't see anything about the little fish, perhaps I missed it. It is the same as the 2 that I found here on the beach.
Quote:
Originally posted by BajaNews
At OMZ depths it is also cold, and there is little or no sunlight, so most animals living in this strange world are small, move slowly and use oxygen very efficiently. Many of them also produce their own light, including myctophid lanternfishes (a favorite food of Humboldt squid) and the silvery hatchet fish.

Squid Studies: Correction, Connections and Calamar

BajaNews - 7-26-2011 at 06:31 PM

http://www.scientificamerican.com/blog/post.cfm?id=squid-stu...

By William Gilly
Jun 27, 2011

SEA OF CORTEZ—I'd like to start by correcting some ambiguous wording that may lead to a misunderstanding in the previous post. Our ship is not owned or operated by the University-National Oceanographic Laboratory System (UNOLS)—nor the National Science Foundation. New Horizon is owned/operated by Scripps Institution of Oceanography, part of University of California, San Diego. UNOLS does not operate or own any research vessels per se and is an advisory body, of which Scripps is partner.

Today brought us close to lonely, desolate Isla Tortuga, a caldera floating alone 20 miles off the coast of the Baja peninsula. From here the Tres Virgenes volcanoes loom, even though it is hazy and they are 60 miles away. Once again we are carrying out an acoustic survey in this area, because it tends to attract sperm whales, and that suggests it is also attractive to their main prey, Humboldt squid. But we will have to wait till dark to sample squid—they tend to be at a depth of several hundred meters during the daytime, hanging out in the deep scattering layers with the myctophids and krill and other small creatures that are their favorite prey. Here on the surface, none of that is visible, only the shell of the great turtle—or "tortuga"—floating on the sea where it holds up the world. Perhaps the tortuga can peer into the depths and reveal secrets even the piercing acoustic eye of the sonar can't see.

What exactly is the turtle that supports the world? John Steinbeck used the image, and wrote to a college friend, "Modern sanity and religion are a curious delusion. Yesterday I went out in a fishing boat—out in the ocean. By looking over the side into the blue water, I could quite easily see the shell of the turtle who supports the world." Of course Steinbeck also used the turtle imagery in Grapes of Wrath, a book that is peppered with non-teleological ideas that seem to be developed more fully and explicitly in Sea of Cortez a few years later. Perhaps Sea of Cortez is an unintended Rosetta stone for Grapes—the same images and issues must have been swirling in Steinbeck's mind when he wrote both of these great books.

Our limited Web capability onboard has revealed that a turtle supporting the world is a common mythological symbol in several cultures around the world, but I did not find any real source myths in my quick search. In general it seems that the turtle carries the earth or firmament on top of its shell. I was somewhat surprised by this, because I had always seen the turtle from another frame of reference—one from outer space in which the turtle is beneath the globe balanced on its feet. In this view, the lowly turtle becomes Atlas holding up the world, and what it does matters to everything on the planet. But you must step back and view the bigger picture to see this. Perhaps Steinbeck's plodding reptile in Grapes held the dustbowl up in this same way, connecting people and land with an ancient force that was being destroyed in California.

As I watch Tortuga slip into the haze, my thoughts move to one of those holistic nuggets in Sea of Cortez that pops up in the first chapter: "We take a tiny colony of soft corals from a rock in a little water world. And that isn't terribly important to the tide pool. Fifty miles away the Japanese shrimp boats are dredging with overlapping scoops, bringing up tons of shrimps, rapidly destroying the species so that it may never come back, and with the species destroying the ecological balance of the whole region. That isn't very important in the world. And thousands of miles away the great bombs are falling and the stars are not moved thereby. None of it is important or all of it is. "

Being here on the empty Gulf with the turtle makes you remember this.

Today we were treated once more to squid for lunch—stuffed calamares prepared by Oscar, the recipe follows below. Oscar's recipes are often more like procedures (or perhaps philosophies), so please experiment. After dusk we again sampled many small squid, mostly immature. So far, the size of squid and maturity states are reminiscent of last year's cruise. This is intriguing, because even though El Niño ended over a year ago, and two generations of squid have come and gone in this region, the squid are still small. It seems that recovery from El Niño is a multi-generational process with an uncertain ending—at least to us.

Tonight was also spent in experiments. We carried out our first successful test of squid escape-response under the conditions of low oxygen and temperature that the squid would experience in the oxygen minimum zone (OMZ). Results confirmed what we saw last year: When oxygen falls below 5 percent saturation or so, rapid escapes are significantly impaired. This decrease in performance ability fits in with observations based on pop-up satellite tagging—fast vertical movements appear to be greatly suppressed in the OMZ when measured by free-swimming squid. Breathing and low-velocity vertical movements do not appear to be impacted by OMZ conditions in the wild or in the lab. This would suggest that the squid can carry out maintenance activities in the OMZ, perhaps including foraging on slow-moving myctophids. But a price for this capability would be an inability to escape from a foraging sperm whale or other predator that dives down to OMZ depths to hunt. I felt much like an OMZ-squid when I crawled into my bunk at 3 AM.

Three hours later at dawn, we are again sailing past Isla Tortuga and then Santa Rosalia on our way north. Glass-flat seas and mild air accompanied us past Cabo Virgenes all the way to Bahia San Carlos, a site explored by Steinbeck and Ricketts on their 1940 expedition. After dusk a warm, brisk wind started to blow down the long slopes leading up to the Tres Virgenes. It stopped as suddenly around midnight. This is a common phenomenon here, and one that undoubtedly is behind a recommendation to avoid the area in all yachting guides that I am aware of. But why worry about sudden squalls at night? Here on the New Horizon the wind does little except stir up some whitecaps in the moonlight as we sample squid. We catch our 30 in 15 minutes, and the squid are getting larger—more than 40 centimeters mantle length (compared to 25-30 cm in the Tortuga area) with many mature males and few mature females. But this picture is again not so different than in 2010; there are no large squid in this aftermath of El Niño.

The stretch of coast north of Santa Rosalia is extremely remote and about as untouched as one can find in the Gulf. I first managed to get here in 2004 on our retracing of the Steinbeck/Ricketts trip and have been back several times since. There are no roads leading to the sea for seventy miles or so, with San Carlos lying right in the middle of this stretch. I've heard of a rough jeep-trail that snakes past the volcanoes into this region, and one day I would like to make that exploration. But the view from the sea reveals some spectacular real, and a whole county could be developed on these gently terraced, volcanic slopes leading to the sea. I've been told in Santa Rosalia that a large tract of land near San Carlos is for sale. There is so much one could do with a good road… Luckily this area is part of the Vizcaino Biosphere Reserve, so perhaps it will not be so easy to develop. Time will tell.

All night we cruise back and forth in a box-pattern making another acoustic transect.

--

Recipe: Stuffed Calamares – Oscar P. Buan

Stuffing of a cleaned squid tube is a classic and versatile preparation. Ground beef was used for the example shown, but ground pork also works well. Other choices would be worth trying. As with a creative meat loaf, the stuffing can be as simple or complex as desired.

Mix ground meat of choice with salt, pepper and diced onion and stuff inside squid tubes
Pepper outside of tube, spray with cooking oil.
Bake at 350° F until done on the inside and golden brown on the outside.

gnukid - 7-26-2011 at 08:11 PM

It's unclear what the significance of the title is--what is shrinking and what is changing? What evidence exists?

[Edited on 7-27-2011 by gnukid]

BajaNews - 7-26-2011 at 08:46 PM

http://www.scientificamerican.com/blog/post.cfm?id=it-is-not...

By William Gilly
Jun 29, 2011

SEA OF CORTEZ—Once again dawn finds us escaping from our overnight acoustic-transect box, and we head north from San Carlos, running about five miles from the coast. From here you can see all the way from Cabo Virgenes, just north of Santa Rosalia, to San Fransquito—70 miles of roadless coast that is essentially pristine. This coast is rough and rocky to about 10 miles south of San Carlos, where the plunging cliffs and headlands rather suddenly change to rolling, terraced foothills that slope upward to the massive Reforma dome and the distant Tres Virgenes. Several more rocky headlands lie to the north before San Francisquito, but the massive cliffs are gone.

Despite the remoteness of this region, if you are close enough to the shore you will see a good number of small arroyos and pocket beaches with signs of temporary fish camps … places out of time with no names. Such camps have always been part of the Gulf landscape. During the first circumnavigation of the Gulf in 1539, Franscisco de Ulloa describes in his log the scene at such a beach:

"They had a little enclosure of woven grass without any cover on top, where they lodged, some ten or twelve paces from the sea. We found inside no sort of bread nor anything resembling it, nor any other food except fish, of which they had some which they had killed with well-twisted cords which they had and with some thick hooks made of tortoise shell bent in the fire, and with others, smaller made of thorns. They kept their drinking water in certain skin pouches which we thought must be the stomachs of seals. They had a little raft which they must have used in fishing. It was made of canes tied in three bundles, each part separately, and then tied all together, with the middle section being larger than the laterals. They rowed it with a slender oar, little more than half a fathom long, and two small badly made paddles, one at each end. We judged these people to be nomads, possessed of little intelligence."

Clearly the Spanish explorers did not see far enough into a future that would lead to expansive development of beach-front hotels, condos and homes from which many sport fishermen would set to sea in small, but expensive boats. But until this recent explosion and the availability of outboard motors to the local communities, the deeply ingrained tradition of subsistence from the rich waters of the Gulf persisted.

Steinbeck and Ricketts noted in Sea of Cortez:

"Above Santa Rosalia very few trading boats travel. One would be really cut off up here. And yet here and there on the beaches we found evidence of large parties of fishermen. On one beach there were fifteen or twenty large sea-turtle shells and the charcoal of a bonfire where the meat had been cooked or smoked. In this same place we found also a small iron harpoon which had been lost, probably the most valued possession of the man who had lost it."

These fishermen were indeed nomadic, departing from a place like Santa Rosalia in a small, open boat with only oars and a small sail, some bottles of water, and crude fishing gear. They traveled the waves, often for months at a time, existing on whatever nature provided—caguama (turtle), lobster, fish, bird eggs collected from islands. Ray Cannon called them "vagabundos del mar" in his classic 1966 Sunset Book, The Sea of Cortez:

"Vagabundos del mar, or sea gypsies, are men who prefer to roam the Cortez alone. You may get close to one sometime, and if you do, you'll find them friendly and helpful, but he will not seek your company. The vagabundos stop their roaming only when they die and are buried on the southernmost tip of Isla Ceralvo."

Despite the unlikely scene of a mass vagabundo burial site on Isla Ceralvo, these men of the sea are not a myth. I have spoken at length with two of them, both from Santa Rosalia, and their independent accounts tell the same story. These men know the Gulf like no others, and there is a regal quality to their wisdom.

I met one of these treasures, Guillermo Castro Miranda, also known as Memo Playa, in Loreto last month at the Conservation Science Symposium. Memo was born in Santa Rosalia in 1938, spent his life fishing and has collected his experiences into Memorias de un Cachanía, published in 2005 by the Gobierno del Estado de Baja California Sur/Instituto Sudcaliforniano de Cultura. In 2009 he won first prize in the First National Literary Competition, "The Old Man and the Sea," with an essay, "Un día de pesca," that has been translated by Susana Mahieux of La Paz.

"A Fishing Day" begins:

"I go with the wind and sometimes against the wind. I plough the Sea of Cortez, but the waves erase my tracks and the silence of its immensity swallows my jubilant cries when I catch a good fish. Although my tracks cannot be seen, my presence is always there, in the depth of its blue horizon. I do not feel alone, because the sea gulls and pelicans accompany me. In an environment without smoke, dust or bad smells I only perceive the odor of fish, of sea weed and the salt in the sea.

I am not afraid to fish at night because when I look at the stars, I am certain that amongst some of them, the eyes of God are watching me with indulgence.

My life has passed according to the tides... "

And the essay ends with a eulogy for the rich Sea of Cortez he knew so intimately:

"We squandered it in only fifty years, with noxious fishing methods and no control. With wire traps, kilometer long lines with hundreds of hooks, with crawl nets, gill nets, boundless use of gunpowder, and lately with compressors and harpoons, we are emptying what remains.

With sadness I realize that like this abundance, my strength and youth have also gone. I am left with nothing.

Death I do not fear you. What I fear is the time it will take for you to come."

Perhaps Ray Cannon was right—Ceralvo is a symbol rather than a place on a map. None of us will never now the truths that the vagabundos lived. Their recollections are our only link to a vanished past.

Susanna and I are currently trying to help Memo with translations of additional pieces and to find a publisher for a bilingual collection of his work.

BajaNews - 7-26-2011 at 09:29 PM

http://www.scientificamerican.com/blog/post.cfm?id=squid-stu...

By William Gilly
Jul 1, 2011

SEA OF CORTEZ—After the early morning reverie, undoubtedly fueled by coffee on deck and sleep deprivation (maybe three hours a night), I return to the realities of the cruise. I check the status of the squid in our animal holding system that is tirelessly maintained by Ian Wilson, a volunteer from Colorado State University. All five small squid are alive and well—they were caught last night. This is Ian's first ocean-going research cruise and part of a summer internship. We also have Elizabeth Hogan, from the Community College System of New Hampshire, who is here as a volunteer with the MATE program (Marine Advanced Technology Education) to work with Chad Waluk and Kelly Benoit-Bird's team. I hadn't known about this program before, even though it is based in my backyard in Monterey, Calif. I'm eager to learn more. It's good that students just starting out on their hopeful quest of a career in marine science can participate in cruises like this. They quickly learn that a research cruise is not a vacation. If you don't love it, you won't be coming back.

We plow north past San Francisquito into the Salsipuedes canal that separates Isla San Lorenzo from Baja peninsula. This narrow channel is over 1,000 meters deep and supports fierce tidal currents as the upper half of the Gulf tries to drain into the lower half twice a day—and tries to fill twice a day from the southern half. It is little wonder that the racing, confused tidal surges in this area churn up deep water and bring it to the surface. This tidal upwelling of cold, nutrient-rich water makes this area, all of the Midriff Islands area really, extremely productive. Sea creatures know this, and in this region you will find many large creatures like blue whales and whale sharks as well as vast numbers of sea birds. Today a frenzy of diving pelicans greets us, but we are here searching for squid—big ones. This is the only region that held large squid during our cruise last year, and we are eager to see what this region holds now.

But high productivity in a marine environment can bring surprises other than wildlife. As we move into Bahia San Rafael the water darkens to a blood-red color, and the air temperature plummets—so much that it feels colder than inside the air-conditioned ship. We are in the midst of a vast algal bloom, a red-tide that will end up stretching at least all the way to Bahia Las Animas, twenty miles to the north, and persist for the two days that we will be here. This is the result of tidal upwelling of cold, nutrient-rich water in a hot, sunny area, and it is amazing to feel it grab you in this way. Our CTD casts in this region show that the sea surface temperature is about 10 degrees Celsius colder than it has been everywhere else so far.

Later tonight I email a colleague at NOAA back home in Pacific Grove, and he sends the official NASA image of our world in Salsipuedes a few days earlier. Satellite remote-sensing is an amazing tool that can reveal events like this anywhere in the world, and his chlorophyll map reveals peak values of 30 milligrams per cubic meter, but that appears to be as high as the NOAA scale goes. Our ship has a sensor that estimates chlorophyll in the surface water continuously, and it seldom drops below 50 all day long. Eventually it will reach 75 and stick there until the technician on board cleans it out and resets the electronics.

Soon another layer is added onto the surrealistic surface on which we float. Looking to the northeast reveals a few small islands off the northern end of San Lorenzo. But as we watch them, they grow, shrink, bridge together and merge as if they were part of a living Dali seascape—a mirage. A photograph cannot do this phenomenon justice; it is like trying to photograph a spirit. But we capture some images of change in late afternoon over 15 minutes, and in the morning, under new light, the distortion is even more disturbing.

Of course we are not the first to marvel at such a vision. Steinbeck and Ricketts describe it perfectly in Sea of Cortez (1940):

"As we moved up the Gulf, the mirage we had heard about began to distort the land. While it is worse on the Sonora coast, it is sufficiently interesting on the Peninsula to produce a heady, crazy feeling in the observer. As you pass a headland it suddenly splits off and becomes an island and then the water seems to stretch inward and pinch it to a mushroom –shaped cliff, and finally to liberate it from the earth entirely so that it hangs in the air over the water. Even a short distance offshore one cannot tell what the land really looks like. Islands too far off, according to the map, are visible; while others which should be near by cannot be seen at all until suddenly they come bursting out of the mirage. The whole surrounding land is unsubstantiated and changing.."

It is little wonder that this place of cold, red water with strong, swirling currents and disappearing islands (and often fog as well) is called Salsipuedes, which can be translated as "Leave if you can." But we must stay for now, even if one cannot tell whether the sea is red from reflection of the surrounding hills or from the microscopic algae at the base of the food chain.

Nightfall brings squid sampling, and we again collect our quota of 30 squid in about 15 minutes. This time they are all medium-sized and mostly immature. But in San Rafael we find our first large squid—a seeming monster with a 72 cm mantle length. And once again, we see that the smile is proportional to the size of the squid. But there are no small ones (<30 cm) for the experiments we are trying to carry out, so we select the smallest we can catch and put them in the temperature-controlled squid condo (each squid has its own tube with flowing seawater) for use tomorrow morning. Brad Seibel puts one in his respirometer apparatus for an overnight run. Then we clean up the squid remains and feed them to a flock of Heerman's gulls that has been patiently waiting for hours. The scene is a bit too Hitchc-ck for comfort.

In the morning, of course, we have a hundred trained gulls perched on the rails expecting breakfast, and they laugh heartily when we protest. Although this development could have been predicted, what I discover on checking the condition of our captive squid is totally unexpected. All three of our squid died overnight in their tubes, despite great effort to select ones that appeared to be in perfect condition. Normally squid live in this set-up for at least two days. Temperature and oxygen in the system are normal, but the squid are dead. Brad's squid also died during his experiment, again not a normal event.

Is this morality a coincidence, or is there a connection to the red-tide? Our squid system was filled with water collected from the bloom area, and it is totally recirculated. This means that the captive squid could not descend to depths below the bloom, which appears to be limited to the top 10 meters or so based on our CTD casts. Harmful algal blooms have become a hot topic, and a number of neurotoxins are known to be generated by certain species of dinoflagellates and diatoms, including saxitoxin (paratlytic shellfish poisoning), brevitoxins (neurotoxic shellfish poisoning) and domoic acid (amnesic shellfish poisoning). Undoubtedly there others waiting to be discovered, perhaps some that affect squid more than humans—in which case, it will be a long time before we know anything about them. If people get sick, the National Institute of Health pays attention, and research dollars flow. But if squid are selectively affected...well, that's a different priority.

Right now the potential effects of this algal bloom on squid are our reality, and we are left mystified. Our experiments later tonight are carried out on freshly caught squid, and we get results that are odd. Instead of reacting to a stimulus with a strong, smooth escape jet (like every squid we have tested thus far), a squid tonight responds with a jet that lasts for an abnormally long time, and our high-speed video observations show that the mantle appears to fibrillate and not relax properly. Conceivably this could reflect intoxication with some toxin associated with the red-tide, but resolving this puzzle will have to await another research effort with new funding at some future time. We file the odd results away in our "maybe one day…" folder.

A brilliant sunset, perhaps the finest of the trip thus far, is again a prelude to squid sampling after dark. Tonight, outside Bahia Las Animas, squid of all sizes are caught, from 33 cm to 60 cm mantle length. This is the only place where we have found mature squid at both extremes of this size range. Last year we also found large, mature squid here (and only here), but small squid in this region were all immature. Aging studies suggested that the large squid were 1 year old, whereas the small squid were about 6 months old—sort of the normal pattern one would expect, with small squid growing big before they mature. But now we find two size-classes of mature squid in the same place at the same time.

This is really interesting, and reinforces the idea that recovery form the 2009-2010 El Nino is still going on and that it indeed involves two paths. It seems that some squid migrated into this productive Salsipuedes region that is buffered from El Nino by tidal upwelling, where they have continued their normal life cycle of about one year and grow to a true, jumbo size. The large squid here this year would thus be the direct offspring of last year's large squid. But most squid reacted to El Niño with precocious spawning and a six-month life cycle. That means the small, mature squid here would be the second generation to mature after the El Niño officially ended in May of 2010. But if you are a squid, there is a good chance that you are still in the recovery process from that transformative event over a year ago.

Recovery from El Niño thus appears to be a multi-generational process, and how long it will take for big squid to recolonize the former commercial fishing grounds off Santa Rosalia and Guaymas remains a huge unknown. All we know for sure is that they are not there yet. To us, it is an intellectual puzzle, but to the many families that depend on fishing, it is a much more serious matter. I wonder how they cope.

Although this place is likely to hold other secrets, we make a decision to escape the red-tides and mirages by heading back south to Isla San Pedro Martir immediately after the jigging session. And so we leave the Salsipuedes while we can.

Squid Studies: Saving the Sea of Cortez? We all need to help

BajaNews - 7-26-2011 at 09:40 PM

http://www.scientificamerican.com/blog/post.cfm?id=squid-stu...

By William Gilly
Jul 19, 2011

SEA OF CORTEZ—Back in the Guaymas Basin east of Isla Tortuga by sunset, we get a good jigging session in after sunset and restock our squid-condo with fresh animals. Fortunately, the squid are again small, and they fit nicely into our tubes in our temperature-controlled, squid condo. Each squid gets its own tube with flowing, chilled seawater to keep it from interacting negatively with vertical tank surfaces and other squid. They eagerly eat one another in captivity, and this really complicates husbandry effort. In the morning all the squid are alive and well—it would appear that the red tide problems of Salsipuedes are over—and that there really was some toxic agent in the water in that region.

Experiments continue day and all night. We are trying to determine how the combined condition of low oxygen and low, like that the squid experiences in the depths of the Oxygen Minimum Zone (OMZ), impact swimming performance. Our tagging results suggest that squid can forage all day long in the OMZ, but this leads to more questions. Do squid move more slowly in the OMZ? Their decrease in metabolic rate under OMZ conditions (Brad is studying this) would seem to require slowing down. But by how much? The organisms that the squid forage on during the daytime in the OMZ are probably also slowed down, so sacrificing speed may not be such a penalty in prey capture.

But what happens when the predator becomes the prey? A main predator of squid in the OMZ is the sperm whale, a deep-living leviathan that carries its own oxygen supply and temperature regulator. Impairment of a squid's strong swimming, sensory capabilities, reaction times or coordination of complex motor outputs could all act to compromise performance during an escape response. An escape response may be a fairly rare event in the life of a squid, but you don't get a second chance—failure means death. Impairment of escape response under OMZ conditions may therefore be an ecologically critical problem for a squid.

Our previous tagging studies suggested that this was the case—sperm whales seemed to prefer to hunt squid at daytime depths of the OMZ even at night, when most squid were much shallower. To test this idea further, we would like to challenge the squid in the laboratory under temperature and oxygen conditions that mimic those in the OMZ.

To do this, we assay the escape response. Our experimental setup is conceptually simple, but in reality it's a Rube Goldberg nightmare. This creation gradually emerged during the time onboard, and photos will help maintain our memory of how it actually worked and lead the way to its recreation at home in the lab.

Basically, we have a squid in a tank and subject it to controlled temperature and oxygen regimes while monitoring escape responses that are stimulated through a sensitive structure that monitors head-position, the "neck organ." It seems that this organ is also strongly connected to the neural circuitry that controls escape responses, at least in Dosidicus.

Escape jetting in squid is far from simple, but it has really been studied in only one species, the much smaller California market squid, Doryteuthis (previously Loligo) opalescens. We did much work on that species years ago in the lab, and now we are trying to see how Dosidicus compares. It's always useful to have some sort of established framework to describe results in a new system. With data from this cruise in hand, we will return to the lab in Pacific Grove and re-test market squid in the identical way. We already know there are major differences between these two species. For example, a strobe flash invariably triggers an escape response in loligo but causes no reaction in Dosidicus. We never noticed the functional connection between the neck organ and escape responses with loligo, but we never really looked. But right now, we are trying to make sure we get enough replicates of our experiments here. Repetition may be boring, but it is critical to building a convincing case.

Unfortunately there is just not enough time right now to do experiments and analyze the data, and this is a huge problem: You don't really know what you've done until you get home. But then it's too late to repeat critical manipulations, to double-check something. Indeed, once we are off the ship, this predicament will be captured by Joni Mitchell 's lyrics "Don't it always seem to go ... That you don't know what you got till it's gone." But there is a way around this dilemma—bring the squid home with you.

Last year I reported on developing a collaboration with a new technical college here, the Instituto Tecnologico Superior de Mulegè, or ITESME. The overall goal is to create a program of research and education focused on the basic ecology of the Guaymas Basin and adjacent Baja peninsula, a huge area that has includes Mexico's largest wildlife refuge, the Vizcaíno Biosphere Reserve of more than 55,000 square miles. Santa Rosalia is the perfect portal to this vast treasure, and this region has largely escaped commercial (tourist) development. Much rugged, remote wilderness remains, and we need to learn more about all aspects of it if we are to use its resources in intelligent and sustainable ways.

As we again parallel the coast off Santa Rosalia on our last days of acoustic transects, the need for a shore-based lab to do experiments on squid and other marine organisms remains. Developing such a lab is a primary goal of the ITESME collaboration, and we are making progress toward realizing such a creation. During the past year we have had several meetings with Mexican scientists, government agencies and non-governmental organizations that have been extremely helpful and encouraging.

Our project is now a Program (with the requisite acronym of course)—Approvechamiento Sustenable e Investigacion de Centro del Mar de Cortez (ASIMAR), or its English version, Sustainable Use and Research of the Central Mar de Cortez (SURMAR). Its mission will be to develop a holistic understanding of the region, including its human inhabitants and their interactions with the environment, from scientific, social and commercial viewpoints. The physical laboratory component, where we and others will be able to work, will be the Centro de Investigacion Vizcaíno del ITESME (CIV), or Vizcaíno Research Center (VRC). This facility will be located on the nine-acre ITESME campus south of Santa Rosalia.

We have lots of ideas about education and outreach as well as research. An important component of this program will involve training through involvement of students, both from ITESME and Stanford. We will directly involve ITESME students in our research projects, and these students can carry out thesis projects (a requirement for graduation) using the facility. An established Stanford teaching program will also visit the VRC/ CIV and interact with ITESME students in the classroom and field.

Finally, we are working towards incorporating the project into the Baja California conservation efforts of The Ocean Foundation. We are excited about this affiliation and have been working for the last several months to bring it to fruition—we are almost there. And now all we need is a logo—any suggestions?

Squid Studies: Dealing with Collapse--Lessons from a Squid?

BajaNews - 7-26-2011 at 09:49 PM

http://www.scientificamerican.com/blog/post.cfm?id=squid-stu...

By William Gilly
Jul 25, 2011

SEA OF CORTEZ—Every day the winds blew, and an undersea factory silently hummed along, welling up millions of tons of cold, nutrient-rich seawater from the depths to replace the water at the surface that had been pushed out to sea by the wind and the invisible hand of the rotating earth. In the Baja California port of Santa Rosalia on the Gulf of California, this system continued from mid-spring to late fall, and the ensuing richness supported the vast numbers of Humboldt squid that drove the ecology of this region, both in the sea and on shore. On a typical summer night several hundred lights glittered on the dark waters off shore—one car dome lightbulb on each small panga carrying two or three fishermen and, when they were finished, a ton of squid. From the grade leading down the mountain into town it appeared that the city was literally on the Gulf rather than next to it.

In the winter, the winds reversed from northward to southward, a seasonal clock as regular as the length of the day. When this happened, the squid sensed something was changing as the surface water grew colder. And then the squid moved away, not all at once but gradually over the course of a few months until only a few stragglers were left behind. They would stay in the area all winter, but most of the other squid would make the 80-mile migration across the Gulf to the mainland coast where the city of Guaymas is located. Winter winds now drove the productivity conveyor that fed the squid on this coast, and that would continue until mid-spring. Here, too, the squid were fished with intensity, so people cared. When the north wind battered back the south wind in the spring, the nomadic squid would return to Santa Rosalia and summertime bounty.

This cycle has replayed yearly since 2001. Hurricanes have come and gone, but the squid shrugged them off, perhaps altering their behavior or distribution for a week or two, delaying a migration a bit, but the cycle continued. There was a simple, natural order to the system that benefitted both squid and fishermen. Everyone understood the rules and invested accordingly.

In 2010 this wind-driven bubble burst. A mild El Niño event in the second half of 2009 grew quite strong as the year ended, pushing warm surface water in the Gulf down to a depth much greater than normal. This warm surface-water is typically low in nutrients, so when wind-driven upwelling occurs, it does not bring the rich soup of nutrients to the surface. Phytoplankton, the base of marine food webs, needs these nutrients, and the loss of primary productivity by phytoplankton impacts nearly everything else in the sea from tiny fishes to blue whales and seabirds. So when El Niño comes knocking, it is a signal of potentially hard times ahead, perhaps for a year or more. If you are a fast-growing annual species, like a Humboldt squid, this presents a problem.

Humans have learned to ignore El Niño at great peril. NOAA constantly monitors the state of El Niño and informs the public on a monthly basis, because a lot of investment, jobs and lives are impacted by the changes in weather patterns associated with this powerful environmental perturbation. Although squid don't have the internet, they do appear to have a set of remarkable strategies for dealing with the uncertainties associated with a developing El Niño and impending collapse. In many ways it seems analogous to the bursting of an economic bubble and the inevitable slow recovery. Maybe they can teach us something.

The primary reaction of squid is simple—abandon the highly productive areas that are fueled by wind-driven upwelling, because these areas may not be able to support their numbers for an unknown time. Where do the squid go? Again, a simple answer—to an area that is buffered from the effects of El Niño. Our work over the last two years has shown us that there are at least two such buffered areas in the Gulf of California, and the squid take advantage of both.

In the more straightforward strategy, the squid move a hundred miles or more to the north into the "Midriff Islands" archipelago. Here, halfway up the Gulf, tidal currents funnel through deep channels and lead to upwelling driven not by wind but by tidal energy. The area is extremely productive and is well known for immense seabird rookeries on some of the islands such as Isla Rasa, where nearly all of the planet's Heermann's gulls and elegant terns come to breed.

Isla Rasa lies just to the east of the Salsipuedes canal, the only location where we have found big Humboldt squid since May 2010. But relocating here requires some readjustment. There is no midwater oxygen minimum zone (OMZ) here, normally the favored daytime feeding ground in the Guaymas Basin, and there is a correspondingly lower number of myctophid lantern fish, the favored prey. Instead, squid here consume krill and an assortment of small fishes. In this krill-dominated ecosystem the squid are well fed, but their diet is not very diverse. What might be the associated price? At this point we don't know. Perhaps there is an inherent danger to living in a place that lacks diversity, but evidently this gamble is better than facing the potential collapse associated with El Niño. So the big squid are here, having liquidated their diverse portfolios at the first sign of trouble and shifting everything to a money market account.

A second strategy is remarkable. Instead of seeking an area with maintained productivity, the squid seemingly take the opposite approach and move offshore to inhabit the blue-water pelagic environment of the open sea. Although this world is much less productive than the favored shelf closer to shore, it is not so dependent on wind-driven upwelling, and is therefore less impacted by El Niño. In this case, the OMZ and its myctophids are still there, but the density of prey may be low lower. Bounty is traded for security, but in addition to changing habitats, the squid accelerate their maturation and reproduce at a very small size when they are only six months old (rather than a year or more) —one pound versus twenty or thirty. In effect, any penalty for living in the less productive, but more dependable, pelagic environment is minimized by passing the problem on to a new generation. A small squid will produce fewer offspring, but with 5 million eggs in a small squid versus 25 million in a large one, the numbers are immense either way. This more aggressive strategy seems to almost be a metamorphosis, a radical change in morphology (size anyway) and life history. Perhaps in economic terms, it would be analogous to moving assets from a blue-chip portfolio to high-risk new ventures during a depression with the hope that a few will take off as markets evolve during the inevitably unpredictable recovery.

We have learned something about how the squid responded quickly and decisively as species to El Niño, but recovery is another matter. It seems to be painfully slow. Productivity and oceanographic conditions are back to normal, but the squid are still in the two response modes outlined above—after two or three generations. But our work leads to some ideas. Small, mature squid were significantly bigger this year than last—about 40 cm average mantle length versus 30 cm. Each generation may be getting larger, but the squid are still far below the 'normal' size at maturity of 70 cm or so. Fishermen in Santa Rosalia began fishing a few weeks ago for the first time in a year, but the squid are small. It takes a lot of time to catch a ton of 2-pound squid, so the fishermen remain troubled. But if the squid are returning en masse to the traditional fishing grounds, it is probably an important step in the recovery process. Squid recolonizing this productive area may have more to eat, remain here longer, grow larger and reproduce at an older age. Whether size at maturity jumps in one generation to the full 70 cm or by accretion remains to be seen. A similar recovery process may occur independently in other regions previously known to support large numbers of squid, and possibly new areas as well. Judging by our recent experience on the open Guaymas Basin, there are a lot of squid ready for near-shore bounty.

And what about the big squid that have retained their one-year life cycle in the Salsipuedes region? Will they remain in large numbers in this region and establish a new population center as the traditional fishing areas in the Guaymas Basin rebuild? To our knowledge, there have never been so many squid in this region during the years before El Niño, but the area had not been very well studied in this regard. In July 2006 we explored this region a bit and found big squid, and squid that we tagged in the northern Guaymas Basin near San Pedro Martir moved into the area near Isla Tiburon. We don't really know more than that. To our knowledge, commercial squid fishing in this region was virtually non-existent here before 2010 when it boomed.

In the end, it seems that both asset-reallocation strategies of the squid may succeed. Although the fishermen worry about the lack of squid, recovery seems to be on the way. It is quite possible that the squid population in the Gulf may actually benefit from this El Niño through a more permanent expansion into the Salsipuedes region. And the vast numbers of small squid that we encountered in the Guaymas Basin may fuel a population explosion there. Analysis of our acoustic data will shed a lot of light on these questions and others posed above.

An adaptive strategy to cope with a system-wide perturbation as powerful as El Niño that involves multiple generations and may actually benefit the species seems incredible. I have often said that if you were to design the perfectly adaptable organism, you could easily end up with something like a Humboldt squid—flexible diet, environmental tolerance to temperature and oxygen changes, ability to migrate rapidly, and so forth. But the ability to capitalize on an environmental anomaly that can greatly decrease productivity with bottom-up effects that ripple throughout the food web is something else. Making good from bad is something that we need to learn more about, and perhaps economics theorists can learn from the strategies of the Humboldt squid. I am not the first to suggest such a trajectory—check the fascinating article "Ecology for Bankers" by Robert May, Simon Levin and George Sugihara in Nature, Vol. 451, p. 893 (2008).

Things are what you make of them, and everything is connected. I am reminded of the non-teleological thinking espoused by Ed Ricketts and John Steinbeck in Sea of Cortez (1941) — "That Zeitgeist operates everywhere, and there is no escape from it. Again, this is not to be considered good or bad."


http://www-marine.stanford.edu/gilly.htm

Stanford professor and students find answers to squid mystery

BajaNews - 11-20-2011 at 12:03 AM

http://www.fis.com/fis/worldnews/worldnews.asp?l=e&count...

By Natalia Real
November 18, 2011

Stanford University marine biologist William Gilly and other researchers have been studying Humboldt squid in Mexico's Sea of Cortez to determine why the animals have been spawning at a much younger age and smaller size than usual. They believe El Niño is the cause.

Gilly is in the second year of studying how exactly an El Niño weather pattern during the winter of 2009-10 has affected squid.

In May 2010, Gilly and a biology class of Stanford undergraduates discovered that the typically abundant squid were largely gone.

"There were far fewer of them than normal, they were spread out over a huge area and they were very small. But they were also sexually mature and spawning – at a ridiculously small size," Gilly said.

"It was obvious that the squid were pretty screwed up," he remarked.

While normally Humboldt squid (Dosidicus gigas) spawn when they are 12-18 months old, Gilly found spawning squids of less than 6 months and weighing 1 lb each, compared with the usual 20-30 lb at maturity.

Gilly and students eventually found large squid about 100 mi farther north than normal, near the Midriff Islands, where Gilly surmises they had ventured in search of food.

Squids' usual coastal habitat off Baja California provides them with copious phytoplankton and thereby food consisting of marine animals of all types, thanks to upwelling which stirs cold nutrient-rich waters up from the deep.

But El Niño brings warm nutrient-poor tropical water by forcing cooler water down 150 ft or more below the surface, which is then too weak to haul the cool, nutritious water back up. As a result, the phytoplankton population and all the creatures it nourishes disappear.

This may be why the squid swam farther in search of better food stocks.

"Squid can move to an area of tidal upwelling, which remains productive during an El Niño condition, and continue on their merry, giant-squid lifestyle and live to spawn when they are a year and a half old," Gilly said.

Squid may also move into an open-ocean environment where food is less plentiful but the supply is steady.

"It is comparatively meager fare and it will not get to be a big giant squid, so instead it reproduces when it is 6 in-long," he said.

Although oceanographic conditions returned to normal this year, Gilly again found big squid only around the Midriff Islands.

The small squid were larger than the year prior by about 25-30 per cent, and they were beginning to repopulate their old grounds.

Gilly suspects that each new generation of squid may lead them to rediscover the rich lantern fish feeding grounds of their ancestors and the average squid will grow a little larger.

Whether the descendants of the squid that moved north will remain around the Midriff Islands and spawn a new and stable squid fishery remains unknown. The food brought up by the tidal upwelling is mostly krill -- much smaller and probably less nutritious than the usual lantern fish -- so it takes a lot more krill to help a Humboldt squid reach its full physical potential.

A revival of the lantern fish may eventually attract most of the squid back down south and reunite the whole squid Diaspora.