Tag Archives: ocean

Dolphins Using Tools to Hunt

photo of a dolphin with a sponge it uses to hunt

Photograph of dolphin with a sponge it uses to hunt, courtesy of Ewa Krzyszczyk, PLoS, high resolution.

Cool open access research from PLoS One, Why Do Dolphins Carry Sponges?

Tool use is rare in wild animals, but of widespread interest because of its relationship to animal cognition, social learning and culture. Despite such attention, quantifying the costs and benefits of tool use has been difficult, largely because if tool use occurs, all population members typically exhibit the behavior. In Shark Bay, Australia, only a subset of the bottlenose dolphin population uses marine sponges as tools, providing an opportunity to assess both proximate and ultimate costs and benefits and document patterns of transmission.

We compared sponge-carrying (sponger) females to non-sponge-carrying (non-sponger) females and show that spongers were more solitary, spent more time in deep water channel habitats, dived for longer durations, and devoted more time to foraging than non-spongers; and, even with these potential proximate costs, calving success of sponger females was not significantly different from non-spongers. We also show a clear female-bias in the ontogeny of sponging. With a solitary lifestyle, specialization, and high foraging demands, spongers used tools more than any non-human animal. We suggest that the ecological, social, and developmental mechanisms involved likely (1) help explain the high intrapopulation variation in female behaviour, (2) indicate tradeoffs (e.g., time allocation) between ecological and social factors and, (3) constrain the spread of this innovation to primarily vertical transmission.

The dolphins use the sponge to push along the ocean floor and disturb fish, that are hidden. Once the fish start swimming away the dolphin abandons the sponge and catches and eats the fish. Then the dolphin goes back and gets the sponge and continues.

2,000 Species New to Science from One Island

photo of squat lobster

Photograph by Dr Tin-Yam Chan, University of Keelung

153 scientists from 20 countries fanned out across the remote South Pacific island of Espiritu Santo, examining mountains, forests, caves, reefs, and water for all living organisms. In five months, they collected 10,000 species. Some 2,000 of these may be new to science.

This squat lobster, found in waters 150 meters (492 feet) deep, is one of the new species. Eighty percent of the world’s species remain to be discovered, notes French scientist Philippe Bouchet, one of the expedition’s leaders.

A World of Crabs from One Tiny Island

About 600 of these were crab species. The two-horn box crab is able to crack and peel open snails’ shells using a sharp “tooth” on its right claw to cut open shells and long, slender “fingers” on the left claw to yank out its prey.

Dealth of Artic Plankton a Warning on Warming

Death bloom of plankton a warning on warming by David Perlman

Vanishing Arctic sea ice brought on by climate change is causing the crucially important microscopic marine plants called phytoplankton to bloom explosively and die away as never before, a phenomenon that is likely to create havoc among migratory creatures that rely on the ocean for food, Stanford scientists have found.
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Phytoplankton throughout the world’s oceans is the crucial nutrient at the base of the food web on which all marine life depends; when it’s plentiful, life thrives and when it’s gone, marine life is impossible.
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“It’s a complex system,” Arrigo said in an interview, “but as the changes in ice cover throw the timing of phytoplankton abundance off, then the birds and animals whose brains have long been programmed to migrate north at specific times of the year will have missed the boat if there’s no nourishment for them when they get there.”

Every spring and summer, phytoplankton in the Arctic blooms richly in explosive pulses, nourished by nitrogen and phosphorous in the seawater, and when those chemicals are consumed, the blooms end, Arrigo said.

Single-Celled Giant Provides New Early-Evolution Perspective

Discovery of Giant Roaming Deep Sea Protist Provides New Perspective on Animal Evolution
Biologist Mikhail “Misha” Matz and his colleagues recently discovered the grape-sized protists and their complex tracks on the ocean floor near the Bahamas. DNA analysis confirmed that the giant protist found by Matz and his colleagues in the Bahamas is Gromia sphaerica, a species previously known only from the Arabian Sea.

Matz says the protists probably move by sending leg-like extensions, called pseudopodia, out of their cells in all directions. The pseudopodia then grab onto mud in one direction and the organism rolls that way, leaving a track. Hr says the giant protists’ bubble-like body design is probably one of the planet’s oldest macroscopic body designs, which may have existed for 1.8 billion years.

“I personally think now that the whole Precambrian may have been exclusively the reign of protists,” says Matz. “Our observations open up this possible way of interpreting the Precambrian fossil record.”

He says the appearance of all the animal body plans during the Cambrian explosion might not just be an artifact of the fossil record. There are likely other mechanisms that explain the burst-like origin of diverse multicellular life forms.

Single-Celled Giant Upends Early Evolution

Slowly rolling across the ocean floor, a humble single-celled creature is poised to revolutionize our understanding of how complex life evolved on Earth.

A distant relative of microscopic amoebas, the grape-sized Gromia sphaerica was discovered once before, lying motionless at the bottom of the Arabian Sea. But when Mikhail Matz of the University of Texas at Austin and a group of researchers stumbled across a group of G. sphaerica off the coast of the Bahamas, the creatures were leaving trails behind them up to 50 centimeters (20 inches) long in the mud.

The trouble is, single-celled critters aren’t supposed to be able to leave trails. The oldest fossils of animal trails, called ‘trace fossils’, date to around 580 million years ago, and paleontologists always figured they must have been made by multicellular animals with complex, symmetrical bodies.

Friday Fun: Penguin Evades Orcas

A penguin takes sanctuary on a boat while killer whales circle.

Scientists With Lots of Monitors Onboard Ship

photo of computer monitors onboard ship

Fun blog by Linds, a geophysicist, with fun name and tagline: PhD = Pretty huge Dork There’s no crying in grad school! I enjoy including some posts on scientists at work (and plan on trying to intentionally do more of that). The photo shows her office onboard ship – pretty impressive. I thought this monitor was cool.

The boat is a steel monster about 400 feet long. There’s three decks, with cabins, the galley and mess hall, a few different labs, a movie room, reading room and a weight room with white padded walls. It’s all very “Life Aquatic“, if you get the reference. [those that don’t follow the link its a crazy movie – John]
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We have been in transit for the past three days, getting our computers and systems up and running. We arrive at our first deployment spot tomorrow morning at 5:30 am. That is when we’ll put our first ocean bottom seismometer (OBS) down. The OBS itself is a sphere about 16 inches in diameter made of inch thick glass–these suckers are heavy! It’s vacuum sealed with the instrumentation inside and attached to an anchor. When we are done with the survey, the sphere is timed to detach from the anchor and it’ll float to the surface of the water. Our boat will pull up alongside it and we’ll scoop it out with a net and crane.
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woke up today at 3am to get ready for my first watch. We definitely have the worst seas that we have had so far. We are definitely pitching and rolling out here! We deployed our first OBS at 5am and are doing about 1 instrument/hr for the next 24 hours.

Those snippets are from various posts on the blog. Another from earlier:

But there is recent good news: that lone female professor (who is an amazing researcher and is highly respected in the field, chairs many committees both nationally and within the department and was president of the Geological Society of America in the 90’s) has been named the new department chair. I think this move is important in encouraging talented women scientists to apply for positions within the department and shows dedication on the part of the higher-ups to highlighting ‘diversity’ as a priority.

Marine Plankton From 100 Million Years Ago Found in Amber

photo of foraminifer in amber

Marine microorganisms have been found in amber dating from the middle of the Cretaceous period. The fossils were collected in Charente, in France. This completely unexpected discovery will deepen our understanding of these lost marine species as well as providing precious data about the coastal environment of Western France during the Cretaceous. This work was carried out by researchers at the GÃ©osciences Rennes laboratory, together with researchers from the PalÃ©obiodiversitÃ© et PalÃ©oenvironnement laboratory in Paris and the Centre de GÃ©ochimie de la Surface in Strasbourg.

Amber is a fossil resin with a reputation for preserving even the most minute details of insects and other terrestrial arthropods (spiders, scorpions, mites) that lived in resiniferous trees. The forest-based provenance of amber in theory makes it impossible for marine animals to be trapped in the resin. Nonetheless, researchers from the GÃ©osciences Rennes laboratory have discovered various inclusions of marine plankton in amber from the Mid-Cretaceous (100 to 98 million years ago). These micro-organisms are found in just a few pieces of amber among the thousands that have been studied, but show a remarkable diversity: unicellular algae, mainly diatoms found in large numbers, traces of animal plankton, such as radiolaria and a foraminifer, spiny skeletons of sponges and of echinoderms.

Foraminifera (the photo shows one in Amber) are amoeboid protists with reticulating pseudopods, fine strands of cytoplasm that branch and merge to form a dynamic net.[1] They typically produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in structure.[2] These shells are made of calcium carbonate (CaCO3) or agglutinated sediment particles. About 275,000 species are recognized, both living and fossil.[citation needed] They are usually less than 1 mm in size.”

Carried out together with researchers at the MusÃ©um national d’histoire naturelle, the study of diatoms pushed back by 10 to 30 million years the known date for the appearance of certain marine forms of this type of algae. This new information, taken together with recent data on molecular phylogeny, marks a huge advance in our understanding of the complex evolutionary history of diatoms.

The presence of these marine organisms in the amber is an ecological paradox. How did these marine species become stuck and then trapped in the conifers’ resin? The most likely scenario is that the forest producing the amber was very close to the coast, potentially shrouded by plankton-bearing mist or flooded by sea water during storms.

The preservation of marine organisms in amber is an exceptional asset, allowing us to deepen our understanding of these lost species and to have a clear idea about the coastal environment of Western France during the Cretaceous.

press release

Atlantic Hurricane Season 2008

photo of hurricane evacuation sign

Here is a nice post on weather and understanding data – Atlantic Hurricane Season 2008

A well-accepted metric which convolves storm frequency, intensity, and duration is called accumulate cyclone energy (ACE) and is calculated very simply: take the maximum sustained winds reported by the NHC every 6-hours for all storms (> 34 knots), square this value, and sum over the entire lifetime, then divide by 10,000. In 2007, even though there were also 15 storms, the ACE was only 72 compared to 132 for 2008 with the same number of named storms. This is partially because the storms in 2008 were much longer lived especially Bertha.
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When encapsulated in the recent active period in North Atlantic activity (1995-2007), 2008 experienced normal or expected activity as measured by ACE. In terms of a long-term climatology, either the last 30 or 65 years, 2008 is clearly an above average year.

Data can’t lie but mistaken assumptions can lead you to form mistaken impressions. If you believe the number of named storms = hurricane activity and then are surprised that in fact there was many more days of hurricane activity it is not because the data lied but because you didn’t understand what the data represented.

Friday Fun: Octopus Juggling Fellow Aquarium Occupants

photo of Otto the Octopus

Otto the octopus wreaks havoc

Otto is constantly craving for attention and always comes up with new stunts so we have realised we will have to keep more careful eye on him – and also perhaps give him a few more toys to play with.

“Once we saw him juggling the hermit crabs in his tank, another time he threw stones against the glass damaging it. And from time to time he completely re-arranges his tank to make it suit his own taste better – much to the distress of his fellow tank inhabitants.”

Staff believe that the octopus called Otto had been annoyed by the bright light shining into his aquarium and had discovered he could extinguish it by climbing onto the rim of his tank and squirting a jet of water in its direction. The short-circuit had baffled electricians as well as staff at the Sea Star Aquarium in Coburg, Germany, who decided to take shifts sleeping on the floor to find out what caused the mysterious blackouts.

Virgin Birth for Another Shark Species

Virgin shark birth in Virginia

The first time it happened, scientists thought it might be a fluke. A female hammerhead shark residing at a zoo in Omaha, Neb., had not been in contact with male sharks for at least three years and yet experienced a “virgin birth.” She delivered a single pup.

But it has happened again, according to today’s issue of the Journal of Fish Biology. This time, a blacktip shark… had spent nearly her entire eight years at either the Virginia Aquarium without any male companionship from her kind.