deepseanews

Octopus Sex at Hydrothermal Vents

deepseanews:

In the video below, deep-sea octopus expert Janet Voight with the Field Museum, discusses sex in octopods focusing on Vulcanoctopus hydrothermalis. This ghostly looking octopus is only known from hydrothermal vents at 2600-2650m on the East Pacific Rise at 13 degrees north. The ethereal appearance comes from a combination of the eyes being reduced and … → Read More: Octopus Sex at Hydrothermal Ventsimage http://dlvr.it/44qrq0

This is awesome. Watch the video.

Just on one arm? Or all the arms

The pathways traveled by >14 million modeled coral larval over a one-year period using the Connectivity Modeling System developed by Dr. Claire Paris at the University of Miami. Note the empty no-man’s-land that larvae have difficulty breaching — this is the East Pacific Dispersal Barrier.
The study, published in Global Ecology and Biogeography, is the first to recreate the oceanic paths along which corals disperse globally, and will eventually aid predictions of how coral reef distributions may shift with climate change.
Coral reefs are under increasing threat from the combined pressures of human activity, natural disturbances and climate change. It has been suggested that coral may respond to these changing conditions by shifting to more favourable refuges, but their ability to do this will depend on the ocean currents.
Sally Wood, a Ph.D. candidate at UB, explains: “Dispersal is an extremely important process for corals. As they are attached to the seafloor as adults, the only way they can escape harmful conditions or replenish damaged reefs is by releasing their young to the mercy of the ocean currents.”
…
Some of the results yielded by the team were surprising. While the majority of simulated larvae settled close to home, others travelled as far as 9,000 km., almost the entire width of the Pacific Ocean. When considered over multiple generations, this means that corals are able to cross entire ocean basins, using islands and coastlines as ‘stepping stones.’ However, a few places proved too distant for all but the hardiest of larvae: Coral in the tropical eastern Pacific are almost entirely cut off from those on islands of the central Pacific by a daunting 5000 km of open ocean. Geographically isolated reefs such as these may be particularly vulnerable, as they are not stocked with external recruits as frequently.
The model captured the start of the coral larvae’s journey to its survival, and further work is ongoing to complete the story. Even after overcoming the trials of the open ocean, coral larvae arriving at a suitable location must first negotiate a ‘wall of mouths’ to settle on the reef face, and then compete fiercely for the space to thrive and grow.
Source
Paper: ’Modeling dispersal and connectivity of broadcast spawning corals at the global scale’, by S. Wood, C.B. Paris, A. Ridgwell, & E.J. Hendy. Global Ecology and Biogeography (2013).

The pathways traveled by >14 million modeled coral larval over a one-year period using the Connectivity Modeling System developed by Dr. Claire Paris at the University of Miami. Note the empty no-man’s-land that larvae have difficulty breaching — this is the East Pacific Dispersal Barrier.

The study, published in Global Ecology and Biogeography, is the first to recreate the oceanic paths along which corals disperse globally, and will eventually aid predictions of how coral reef distributions may shift with climate change.

Coral reefs are under increasing threat from the combined pressures of human activity, natural disturbances and climate change. It has been suggested that coral may respond to these changing conditions by shifting to more favourable refuges, but their ability to do this will depend on the ocean currents.

Sally Wood, a Ph.D. candidate at UB, explains: “Dispersal is an extremely important process for corals. As they are attached to the seafloor as adults, the only way they can escape harmful conditions or replenish damaged reefs is by releasing their young to the mercy of the ocean currents.”

Some of the results yielded by the team were surprising. While the majority of simulated larvae settled close to home, others travelled as far as 9,000 km., almost the entire width of the Pacific Ocean. When considered over multiple generations, this means that corals are able to cross entire ocean basins, using islands and coastlines as ‘stepping stones.’ However, a few places proved too distant for all but the hardiest of larvae: Coral in the tropical eastern Pacific are almost entirely cut off from those on islands of the central Pacific by a daunting 5000 km of open ocean. Geographically isolated reefs such as these may be particularly vulnerable, as they are not stocked with external recruits as frequently.

The model captured the start of the coral larvae’s journey to its survival, and further work is ongoing to complete the story. Even after overcoming the trials of the open ocean, coral larvae arriving at a suitable location must first negotiate a ‘wall of mouths’ to settle on the reef face, and then compete fiercely for the space to thrive and grow.

Source

Paper: ’Modeling dispersal and connectivity of broadcast spawning corals at the global scale’, by S. Wood, C.B. Paris, A. Ridgwell, & E.J. Hendy. Global Ecology and Biogeography (2013).

fortheocean

h4ilstorm:

Birth of a Sea Turtle (by O.Blaise)

…except the turtle isn’t laying her eggs in a nest. She could be dumping them after a failed nesting attempt and the load being too much to bear. Those eggs wouldn’t survive. However, turtles can lay multiple nests during the season, so all is not necessarily lost!

The arribada is very much on the bucket list.

Study finds Loggerhead turtles depend on broader range of habitat than previously thought

A new US Geological Survey study suggests that the threatened loggerhead sea turtle may require broader habitat protection during the nesting season.
"This is the first study to locate and quantify in-water habitat use by female loggerheads in the Northern Gulf of Mexico subpopulation during their reproductive periods," said lead author Kristen Hart, a USGS research ecologist. "Our tracking results show they depend on a much broader range of habitat during this critical part of their lives than was previously thought to be required."
The study reveals detailed loggerhead movements during “inter-nesting” periods, showing patterns that vary for individual turtles. Generally, this period begins when a female returns from open seas around May and lasts roughly until September. Up until now, efforts to protect the species generally centered on beaches with high nesting activity under the assumption that once turtles had nested on those beaches, they either remained in their immediate vicinity or migrated back out to sea. 
Satellite data and researchers observations confirm that the loggerheads nest at multiple beaches and sometimes these beaches are hundreds of miles apart. 
…
"These data show it is not sufficient to just protect habitat around high density nesting beaches … because many turtles that nest on the Peninsula use the entire region from the eastern Florida Panhandle to Louisiana," said Lamont.
"We are working towards defining areas where sea turtles concentrate their activities at sea, effectively building a map of in-water turtle hotspots," said Hart. "The more we know about their habitat use, the more questions are raised about their behavior and ability to adapt."
Source: Environmental News Network
Photo source

Study finds Loggerhead turtles depend on broader range of habitat than previously thought

A new US Geological Survey study suggests that the threatened loggerhead sea turtle may require broader habitat protection during the nesting season.

"This is the first study to locate and quantify in-water habitat use by female loggerheads in the Northern Gulf of Mexico subpopulation during their reproductive periods," said lead author Kristen Hart, a USGS research ecologist. "Our tracking results show they depend on a much broader range of habitat during this critical part of their lives than was previously thought to be required."

The study reveals detailed loggerhead movements during “inter-nesting” periods, showing patterns that vary for individual turtles. Generally, this period begins when a female returns from open seas around May and lasts roughly until September. Up until now, efforts to protect the species generally centered on beaches with high nesting activity under the assumption that once turtles had nested on those beaches, they either remained in their immediate vicinity or migrated back out to sea. 

Satellite data and researchers observations confirm that the loggerheads nest at multiple beaches and sometimes these beaches are hundreds of miles apart. 

"These data show it is not sufficient to just protect habitat around high density nesting beaches … because many turtles that nest on the Peninsula use the entire region from the eastern Florida Panhandle to Louisiana," said Lamont.

"We are working towards defining areas where sea turtles concentrate their activities at sea, effectively building a map of in-water turtle hotspots," said Hart. "The more we know about their habitat use, the more questions are raised about their behavior and ability to adapt."

Source: Environmental News Network

Photo source

Travels of Pregnant Great White Sharks Revealed
by Douglas Main
For the first time, migrating great white sharks have been tagged and their movements around the oceans tracked for years, as opposed to the few months they have previously been tracked, according to a researcher.
Scientists used special satellite tags that tracked several sharks from a specific great white population for up to three years off the coast of Mexico. The study found that adult female sharks complete a two-year breeding cycle and avoid male sharks whenever possible, said study author Michael Domeier, a researcher and the president of the Marine Conservation Science Institute.
Published recently in the journal Animal Biotelemetry, the study followed four female great white sharks from their mating grounds off Mexico’s Guadalupe Island until they returned 24 months later, Domeier said. During the first 18 months, the females followed an ambling path through the open ocean, he said.
They then arrived in off Baja California to give birth to shark pups, putting themselves at risk of running into shipping traffic on their voyage along the shore, the study found.
"During the time the females are giving birth along the Baja Peninsula they are exposed to an array of commercial fishing activities that put them at risk," Domeier told OurAmazingPlanet in an email. "Of course, the baby white sharks are at even more risk since they spend the first years of their life in coastal waters and their small size makes them even more susceptible to capture."
Once the young sharks are born, the females return to Guadalupe Island to mate again.
The study found a high prevalence of bite marks on the sharks. Male sharks “bite the head, flank or pectoral fin of females during the mating ritual, but certainly these sharks are biting each other out of aggression as well,” Domeier added. “Males may be battling it out for access to females or preferred hunting grounds.”  
While the females return to mate every two years, the males only return every other year. When they’re not mating, both males and females may range as far afield as the waters off Hawaii, Domeier said.
The researchers tag the great white sharks by affixing the device to the tip of the animal’s dorsal fin, during which time they are very close to the predators.
"It’s surreal and humbling," Domeier said. "It is also stressful since the shark’s life is in our hands during the short time it takes us to capture and tag each individual."
Source: Live Science
Photo Credit: Neil Hammerschlag

Travels of Pregnant Great White Sharks Revealed

by Douglas Main

For the first time, migrating great white sharks have been tagged and their movements around the oceans tracked for years, as opposed to the few months they have previously been tracked, according to a researcher.

Scientists used special satellite tags that tracked several sharks from a specific great white population for up to three years off the coast of Mexico. The study found that adult female sharks complete a two-year breeding cycle and avoid male sharks whenever possible, said study author Michael Domeier, a researcher and the president of the Marine Conservation Science Institute.

Published recently in the journal Animal Biotelemetry, the study followed four female great white sharks from their mating grounds off Mexico’s Guadalupe Island until they returned 24 months later, Domeier said. During the first 18 months, the females followed an ambling path through the open ocean, he said.

They then arrived in off Baja California to give birth to shark pups, putting themselves at risk of running into shipping traffic on their voyage along the shore, the study found.

"During the time the females are giving birth along the Baja Peninsula they are exposed to an array of commercial fishing activities that put them at risk," Domeier told OurAmazingPlanet in an email. "Of course, the baby white sharks are at even more risk since they spend the first years of their life in coastal waters and their small size makes them even more susceptible to capture."

Once the young sharks are born, the females return to Guadalupe Island to mate again.

The study found a high prevalence of bite marks on the sharks. Male sharks “bite the head, flank or pectoral fin of females during the mating ritual, but certainly these sharks are biting each other out of aggression as well,” Domeier added. “Males may be battling it out for access to females or preferred hunting grounds.”  

While the females return to mate every two years, the males only return every other year. When they’re not mating, both males and females may range as far afield as the waters off Hawaii, Domeier said.

The researchers tag the great white sharks by affixing the device to the tip of the animal’s dorsal fin, during which time they are very close to the predators.

"It’s surreal and humbling," Domeier said. "It is also stressful since the shark’s life is in our hands during the short time it takes us to capture and tag each individual."

Source: Live Science

Photo Credit: Neil Hammerschlag