Tag: marine biology

Sea star die-off spurred trophic cascade in B.C. coastal waters

Northern rainbow star afflicted with sea star wasting disease. This species had virtually disappeared from central California kelp forests as of February 2014. Photo: Steve Lonhart / NOAA MBNMS
Northern rainbow star afflicted with sea star wasting disease. This species had virtually disappeared from central California kelp forests as of February 2014. Photo: Steve Lonhart / NOAA MBNMS.

Booming sea urchin population takes bite out of ocean kelp forests

Staff Report

Some sea star populations along the Oregon coast may be recovering from a massive wasting epidemic that all but wiped out some species of the echinoderms, but that’s not the case in Howe Sound, a scenic fjord-like sound on the coast of British Columbia.

There, the die-off had a clear ecological trickle-down effect, called a trophic cascade by biologists. After the sea stars died, populations of their favorite prey, green sea urchins, quadrupled. The urchins quickly gobbled up kelp, reducing by 80 percent. Undersea kelp forests are critical to near-shore ocean ecosystems, providing cover and food for many marine species.

The findings were reported by Simon Fraser University marine ecologists Jessica Schultz, Ryan Cloutier and Isabelle Côté, who studied the after-effects of the die-off that hit the area in 2013, described as one of the largest  wildlife mass mortality events ever recorded. Continue reading “Sea star die-off spurred trophic cascade in B.C. coastal waters”

Environment: Study tracks recovery of Oregon sea stars after massive wasting disease epidemic

Scientists say some species may recover quickly

Northern rainbow star afflicted with sea star wasting disease. This species had virtually disappeared from central California kelp forests as of February 2014. Photo: Steve Lonhart / NOAA MBNMS
A northern rainbow star afflicted with sea star wasting disease. This species had virtually disappeared from central California kelp forests as of February 2014. Photo courtesy Steve Lonhart / NOAA MBNMS.

Staff Report

Sea stars along the Oregon coast are recovering from a widespread die-off caused by a viral disease, scientists have reported in a new study published May 4 in the journal PLOS ONE.

The researchers took a close look at the sea star wasting epidemic, which affected 20 species from Baja California to Alaska, making it among the largest marine epidemics on record. They found that, in Oregon, the disease occurred during a phase of cool water upwelling along the coast and so wasn’t directly linked with the over-heated “blob” of Pacific Ocean waters that persisted off the West Coast of the U.S. the past few years. Continue reading “Environment: Study tracks recovery of Oregon sea stars after massive wasting disease epidemic”

Do seals compete with commercial fishermen?

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Do seals compete with commercial fisheries? @bberwyn photo.

New UK study tries to answer the age-old question

Staff Report

Like in other countries, some Irish fishermen have been complaining that seals are increasingly eating up valuable commercial fish stocks, but a new scientific study says that’s generally not the case, with the possible exception of wild Atlantic salmon.

The work done by researchers with Queen’s University Belfast, Northern Ireland, shows that seals don’t have a significant impact on herring, mackerel, cod, haddock, whiting and 30 other species caught for commercial purposes along the south and west coasts of Ireland, from counties Galway to Waterford. Continue reading “Do seals compete with commercial fishermen?”

Study offer new clues in sea star wasting epidemic

Northern rainbow star afflicted with sea star wasting disease. This species had virtually disappeared from central California kelp forests as of February 2014. Photo: Steve Lonhart / NOAA MBNMS
A northern rainbow star afflicted with sea star wasting disease. This species had virtually disappeared from central California kelp forests as of February 2014. Photo: Steve Lonhart/NOAA MBNMS.

Unique student research project tracks immune response to virus at genetic level

Staff Report

Biological sleuthing by a group of young marine-disease researchers from around the country may help solve the mystery of a massive sea star die-off along the West Coast.

Millions of the animals have died the past few years. Scientists still don’t why. They suspect a common ocean virus is at fault, and the new study, published this week in PLOS ONE, has contributed key information about the sea stars’ immune response when infected with this virus, which causes the marine creatures to develops white lesions on its limbs and within days dissolve or  into a gooey mass. Continue reading “Study offer new clues in sea star wasting epidemic”

Are hungry seals hampering Scottish cod recovery?

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Atlantic cod.

‘We may have to live with smaller cod stocks if we want to protect our seals’

Staff Report

FRISCO — Efforts to rebuild commercially important cod stocks off the west coast of Scotland have been hampered by hungry seals, scientists said. The research by marine biologists at the  University of Strathclyde suggests that, as fishermen have cut back on their catches by half, predation by seals has rapidly increased.

The seals may be consuming more than 40 percent of the total stock of cod, up to  7,000 tons per year off the west of Scotland, where landed catches now amount to only a few hundred tons. The research paper has been published in the Journal of Applied Ecology. Continue reading “Are hungry seals hampering Scottish cod recovery?”

Are jellyfish taking over Puget Sound?

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A NASA Earth Observatory satellite image shows Puget Sound.

Study shows dramatic shift in marine species

Staff Report

FRISCO — Biologists looking at 40 years of fisheries data from Puget Sound have documented a dramatic shift in marine species. Key fish in the food chain, like herring and smelt, have declined, while the number of jellyfish has increased exponentially, to the detriment of the marine ecosystem.

“On land people see the changes that come with human population increases, but underwater the changes are much harder to discern,” said Correigh Greene, with NOAA Fisheries’ Northwest Fisheries Science Center. “What this tells us is that when you look over time, you can see that the underwater landscape of Puget Sound is changing too,” said Greene, lead author of the new study published in Marine Ecology Progress Series. Continue reading “Are jellyfish taking over Puget Sound?”

Climate: Some fish species may be able to adapt quickly to warming ocean temperatures

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Three-year study to look at transgeneration climate adaptation.

New study to track epigenetic triggers may shed light on adaptation

Staff Report

FRISCO — Numerous recent studies have focused on how warming ocean temperatures caused by global warming negatively affects fish and other marine life.

But some species apparently have the capacity to adapt to higher temperatures quickly, as offspring born to parents that were exposed to higher temperatures are already acclimatised to the warmer conditions. It’s thought that epigenetic changes triggered by the environment are responsible for the fast adaptation, and a new three-year research effort will delve into the details. Continue reading “Climate: Some fish species may be able to adapt quickly to warming ocean temperatures”