The Monterey Bay Aquarium Research Institute (MBARI) have developed an aquatic robot capable of collecting algal cells from the ocean and extracting the genetic information needed to identify them. The robot, which can accurately be described as a seafaring mobile analytical laboratory, can also extract toxins from the algae samples, thereby allowing scientists to assess the risk to humans and wildlife.

The MBARI-designed robot, formally known as the Environmental Sample Processor, or ‘ESP,’ for short, has now been successfully used by scientists from NOAA’s National Centers for Coastal Ocean Science to conduct the first remote detection of an algal species and its toxin below the ocean’s surface.

The global distribution, frequency, duration and severity of harmful algal blooms are believed to be on the increase and the new robot will make it much easier for scientists to assess the situation and relay accurate information to coastal managers and public health officials.

“Our public health monitoring program is one of the many groups that can benefit directly from the ESP technology and ability to provide an early warning of impending bloom activity and toxicity,” said Gregg Langlois, director of the state of California’s Marine Biotoxin Monitoring Program. “This is critical information for coastal managers and public health officials in mitigating impacts on the coastal ecosystem, since the toxicity of these algae can vary widely from little or no toxicity to highly toxic.”

The information obtained by ESP is transmitted to the laboratory via radio signals.

More details about the project can be found in the June issue of the journal Oceanography.

Pictures by mbari

The famous Sharktooth Hill Bone Bed near Bakersfield has tantalized the imagination of scientists and laymen alike since it was first discovered in the 1850s. How did a six-to-20-inch-thick layer of fossil bones, gigantic shark teeth and turtle shells three times the size of today’s leatherbacks come to be?

Was this a killing ground for C. megalodon, a 40-foot long shark that roamed the seas until 1.5 million years ago? Perhaps a great catastrophe like a red tide or volcanic eruption led to animal mass-death in the region? Or is this simply the result of Sharktooth Hill being used as a breeding ground for generations of marine mammals throughout the millennia?

A research team consisting of palaeontologists from the United States and Canada are now offering their take on the Bone Bed, suggesting it is not the result of a sudden die-off or a certain predator. Instead, the North American team sees it as a 700,000-year record of normal life and death, kept free of sediment by unusual climatic conditions between 15 million and 16 million years ago.

The research team bases its hypothesis on a new and extensive study of the fossils and the geology of Sharktooth Hill. Roughly 3,000 fossilized bone and teeth specimens found in various museums, including the Natural History Museum of Los Angeles County (NHM) and UC Berkeley’s Museum of Paleontology (UCMP), have been scrutinized, and the researchers also cut out a meter-square section of the bone bed, complete with the rock layers above and below.

“If you look at the geology of this fossil bed, it’s not intuitive how it formed,” says Nicholas Pyenson, a former UC Berkeley graduate student who is now a post-doctoral fellow at the University of British Columbia. “We really put together all lines of evidence, with the fossil evidence being a big part of it, to obtain a snapshot of that period of time.”

The existence of a 700,000-year window through which we can catch a glimpse of the past is naturally magnificent news for anyone interested in evolution and Earth’s history.

When the Central Valley was a sea

When the Sharktooth Hill Bone Bed formed between 15,900,000 and 15,200,000 years ago, the climate was warming up, ice was melting and the sea level was much higher than today. What is today California’s Central Valley was an inland sea with the emerging Sierra Nevada as its shoreline.

After closely examining the geology of the Sharktooth Hill area, the research team was able to confirm that it had once been a submerged shelf inside a large embayment, directly opposite a wide opening to the sea.

Several feet of mudstone interlaced with shrimp burrows is present under the bone bed, which is typical of ocean floor sediment several hundred to several thousand feet below the surface. Inside the bone bed, most of the bones have separated joints, indicating that they have been scattered by currents.

“The bones look a bit rotten, as if they lay on the seafloor for a long time and were

abraded by water with sand in it“, says UC Berkeley integrative biology professor Jere Lipps.

Many bones also had manganese nodules and growths on them, something which can form when bones sit in sea water for a long time before they are covered by sediment. According to the team, the most likely explanation for this is that the bones have lain exposed on the ocean floor for 100,000 to 700,000 years while currents have carried sediment around the bone bed. The prevailing climatic conditions at the time have made it possible for the bones to accumulate in a big and shifting pile at the bottom of the sea.

“These animals were dying over the whole area, but no sediment deposition was going on, possibly related to rising sea levels that snuffed out silt and sand deposition or restricted it to the very near-shore environment,” says Pyenson. “Once sea level started going down, then more sediment began to erode from near shore.”

The team discards the breeding-ground hypothesis due to the scarcity of remains from young and juvenile animals. Hungry Megalodon sharks being the main contributors to the bone pile is also unlikely, since few bones bear any marks of shark bites. If the bone bed was the result of mass-death caused by an erupting volcano the absence of volcanic ash in the bed would be very difficult to explain, and the presence of land animals like horses and tapirs that must have washed out to sea make the red-tide hypothesis equally thin.

Amazing remains from the past

The Sharktooth Hill Bone Bed covers nearly 50 square miles just outside and northeast of Bakersfield in California and is one of the richest and most extensive marine deposits of bones in the world. Studied parts of the bone bed average 200 bones per square meter, most of them larger bones. Ten miles of the bed is exposed, and the uppermost part of the bed contains complete, articulated skeletons of whales and seals.

Within the bone bed, scientists have found bones from many species that are now extinct and the bed provides us with invaluable information about the evolutionary history of whales, seals, dolphins, and other marine mammals, as well as of turtles, seabirds and fish. Sharktooth Hill is naturally the sight of some impressive shark findings too, including shark teeth as big as a hand and weighing a pound each.

A small portion of the bone bed was added to the National Natural Landmark registry in 1976 but the rest is in dire need of protection.

A collaborative effort

The research team, who’s study will be published in the June 2009 issue of the journal

Geology, consisted of:

– UC Berkeley integrative biology professor Jere Lipps, who is also a faculty curator in UC Berkeley’s Museum of Paleontology.

– Nicholas Pyenson, a UC Berkeley Ph.D who is now a post-doctoral fellow at the University of British Columbia.

– Randall B. Irmis, a UC Berkeley Ph.D who is now an assistant professor of geology and geophysics at the University of Utah.

– Lawrence G. Barnes, Samuel A. McLeod, and Edward D. Mitchell Jr., three UC Berkeley Ph.D’s who are now with the Department of Vertebrate Paleontology at the Natural History Museum of Los Angeles County.

Bottle nosed dolphins living along the coast of Florida are getting used to supplement their diet by snatching bait from fishing lines or circle recreational anglers practising catch-and-release. Some dolphins have even made a habit out of routinely approaching humans to beg for food.

Scientists at the National Marine Fisheries Service have now been able to show that this behaviour is spread down through generations of dolphins.

“We are able to document lineage, from grandmother to mother to calf, all following fishing boats and taking thrown-back fish,” says Jessica Powell, a National Marine Fisheries Service biologist.

Dolphins begging for food might be an endearing sight, but approaching humans in this fashion means taking a great risk. In 2006, three dead Sarasota Bay dolphins turned out to have fishing lures stuck inside them.

“Whenever animals become reliant on humans for food, it puts them at jeopardy,” says Dr. Randy Wells, director of dolphin research at Sarasota’s Mote Marine Laboratory. “If they are coming to boats or piers to get fish, they are swimming through a maze of lines, hooks and lures and those lines are designed to be invisible under water.”

Some dolphins do however seem to have figure out how to stay clear of harms way. A bottlenose dolphin nicknamed “Beggar” has been soliciting free meals in a narrow stretch of Intracoastal Waterway near Nokomis Beach since he was a juvenile 20 years ago. Despite routinely swimming just inches from boat propellers, the skin of Beggar’s 8 feet long body is free of major scars. Hopefully, the same is true for the inside of his 400 pound body.

As if the menace of razor sharp propeller blades, invisible fishing lines and jagged double hooks weren’t enough, bottlenose dolphins also stand the risk of encountering anglers who may not appreciate having their bait or catch snatched away by a hungry cetacean. A commercial fisherman out of Panama City, Florida has been sentenced to two years in prison after throwing pipe bombs at dolphins trying to steal his catch. Off Panama City, tour operators have been feeding dolphins for years to assure their presence at the popular “swim-with-the-dolphins” tours.

Feeding the Florida dolphins is illegal under both state and federal law, with federal law banning wild dolphin feeding in the early 1990s. Feeding wild dolphins can also be dangerous and the abovementioned “Beggar” dolphin has for instance sent dozens of overfriendly patters to the hospital for stitches and antibiotics.

Hand-feeding aside, a severe red tide in 2005 seems to have made the habit of interacting with humans for food much more widespread than before among the Florida dolphins. The red tide wiped out 75-95 percent of the dolphin’s usual prey fish and the hungry dolphins eventually realised that they could fill their bellies by picking bait fish off fishing lines.

“We suspect that the dolphins were
hungry,” Wells explains. “Their main prey
base was gone. Seeing a fresh pin fish
dangling from a line might look pretty
good to them. And once they learned
that anglers are a source of food, they
don’t forget that very quickly.”