Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Tag Archive: ocean

  1. Seals, birds and humans compete for fish in the Baltic Sea

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    • Increased populations of seals and fish-eating birds in the Baltic have resulted in a sometimes contentious debate over the effects of these animals on the fish stocks.
    • [Some parallels to Point Blue studies off Farallones] Impacts of seals and birds (primarily cormorants) on fish stocks should be considered in future management plans.
    • Both reductions in fishing quotas and wildlife predation rates should be considered when fish stocks decrease so precipitously.

    Posted: 13 Nov 2017 07:47 AM PST  read full ScienceDaily article here

    In Sweden and in other parts of Europe there are concerns that seals and birds compete with humans for fish resources. For the Baltic Sea, an international study now shows that this competition is a reality.

    For some unknown reason, there has been such a dramatic reduction in eel that they are now considered critically endangered. Eel fishing has been drastically reduced and complete bans are being discussed. In this case as well, it is worth noting that the eel consumption by cormorants is at the same level as human fishing.

    …the scientists conclude that the impacts of seals and birds (primarily cormorants) on fish stocks should be considered in future management plans. Both reductions in fishing quotas and wildlife predation rates should be considered when fish stocks decrease so precipitously.

    Sture Hansson et al. Competition for the fish – fish extraction from the Baltic Sea by humans, aquatic mammals, and birds. ICES Journal of Marine Science, 2017 DOI: 10.1093/icesjms/fsx207the increased populations of seals and fish-eating birds in the Baltic have resulted in a sometimes contentious debate over the effects of these animals on the fish stocks.

  2. Prozac in ocean water a possible threat to sea life

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    • crabs living in harbors and estuaries contaminated with fluoxetine are at greater risk of predation and mortality.

    Posted: 20 Oct 2017 09:58 AM PDT  Read full ScienceDaily article here

    Oregon shore crabs exhibit risky behavior when they’re exposed to the antidepressant Prozac, making it easier for predators to catch them, according to a new study.

    …For years, tests of seawater near areas of human habitation have shown trace levels of everything from caffeine to prescription medicines. The chemicals are flushed from homes or medical facilities, go into the sewage system, and eventually make their way to the ocean...

    …”The changes we observed in their behaviors may mean that crabs living in harbors and estuaries contaminated with fluoxetine are at greater risk of predation and mortality…”

    Joseph R. Peters, Elise F. Granek, Catherine E. de Rivera, Matthew Rollins. Prozac in the water: Chronic fluoxetine exposure and predation risk interact to shape behaviors in an estuarine crab. Ecology and Evolution, 2017; DOI: 10.1002/ece3.3453

  3. Climate shifts shorten marine food chain off California

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    • Research counters earlier thinking that food chains remain constant through time
    • A longer food chain is more typical, and reflects a relatively diverse community, while shorter chains occur during extreme environmental conditions and suggest a decline in that diversity.
    • Extreme El Nino conditions shortened the food chain
    October 19, 2017 NOAA Fisheries West Coast Region read full ScienceDaily article here
    Environmental disturbances such as El Niño shake up the marine food web off Southern California, new research shows, countering conventional thinking that the hierarchy of who-eats-who in the ocean remains largely constant over time.
    “We documented for first time marked changes in the pelagic food web length in response to various natural and anthropogenic related stressors,” said lead author Rocio I. Ruiz-Cooley, formerly of NOAA Fisheries’ Southwest Fisheries Science Center and now at Moss Landing Marine Laboratories. “This tells us that the food web is very dynamic, and reveals changes with the ecosystem around it.”The finding helps scientists understand the health and resilience of the ecosystem, she said. A longer food chain is more typical, and reflects a relatively diverse community, while shorter chains occur during extreme environmental conditions and suggest a decline in that diversity.

    During strong climate perturbations such as the 1997-1999 El Niño Southern Oscillation that included the most intense El Niño event of the century, which brought unusual warming to the U.S. West Coast, the food chain in the California Current shortened sharply, the scientists found. That coincided with declines in ocean productivity such as reduced growth of plankton, declines of some fish and birds and expanded ranges of some species such as jumbo squid, perhaps as they searched for scarce food or followed favorable temperatures….

    Rocio I. Ruiz-Cooley, Tim Gerrodette, Paul C. Fiedler, Susan J. Chivers, Kerri Danil, Lisa T. Ballance. Temporal variation in pelagic food chain length in response to environmental change. Science Advances, 2017; 3 (10): e1701140 DOI: 10.1126/sciadv.1701140

  4. Herbivores help protect ecosystems from climate change

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    • In the summer, when temperatures were at their warmest in the intertidal zone, biological communities could fare well even if they were heated, but only if limpets were present

    October 11, 2017 University of British Columbia read full ScienceDaily article here

    Plant-eating critters are the key ingredient to helping ecosystems survive global warming, finds new research that offers some hope for a defense strategy against climate change.

    The herbivores created space for other plants and animals to move in and we saw much more diversity and variety in these ecosystems,” said Rebecca Kordas, the lead author of the study who completed this research as a PhD student in zoology at UBC. “We want variety because we found it helps protect the ecosystem when you add a stressor like heat.”

    …The researchers found that in the summer, when temperatures were at their warmest, communities could fare well even if they were heated, but only if limpets were present. “When limpets were part of the community, the effects of warming were less harsh,” she said….

    …The researchers were studying life in the intertidal zone, the area of the shore between the low tide and high tide. This area is home to a community of starfish, anemones, mussels, barnacles and seaweed. As the tide moves in and out, the plants and animals must cope with huge variation in temperature every day, sometimes as much as 20 to 25 degrees Celsius.

    These creatures are already living at their physiological limits, so a two-degree change –– a conservative prediction of the warming expected over the next 80 years or so — can make a big difference,” said Kordas. “When heat waves come through B.C. and the Pacific Northwest, we see mass mortality of numerous intertidal species.”…

    Rebecca L. Kordas, Ian Donohue, Christopher D. G. Harley. Herbivory enables marine communities to resist warming. Science Advances, 2017; 3 (10): e1701349 DOI: 10.1126/sciadv.1701349

  5. Better managing plastic waste in 10 rivers could stem ~90% of plastics in the ocean

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    • Scientists have found that 10 rivers around the world where plastic waste is mismanaged contribute 88-95% of global load of plastics in the ocean.
    • Halving plastic pollution in these 10 waterways — eight of which are in Asia — could potentially reduce the total contribution by all rivers by 45 percent.

    October 11, 2017 American Chemical Society see full ScienceDaily article here

    Massive amounts of plastic bits that are dangerous to aquatic life are washing into the oceans and into even the most pristine waters. But how it all gets there from inland cities has not been fully understood. Now scientists have found that 10 rivers around the world where plastic waste is mismanaged contribute to most of the oceans’ total loads that come from rivers.

    ..the amount of plastic in rivers was related to the mismanagement of plastic waste in their watersheds. Additionally, the top 10 rivers carrying the highest amounts accounted for 88 to 95 percent of the total global load of plastics in the oceans, according to the researcher’s calculations.

    The researchers say halving plastic pollution in these 10 waterways — eight of which are in Asia — could potentially reduce the total contribution by all rivers by 45 percent.

    Christian Schmidt, Tobias Krauth, Stephan Wagner. Export of Plastic Debris by Rivers into the Sea. Environmental Science & Technology, 2017; DOI: 10.1021/acs.est.7b02368

  6. Ship exhaust makes oceanic thunderstorms more intense

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    September 7, 2017 American Geophysical Union read full ScienceDaily article here

    Thunderstorms directly above two of the world’s busiest shipping lanes are significantly more powerful than storms in areas of the ocean where ships don’t travel, according to new research.

    A new study mapping lightning around the globe finds lightning strokes occur nearly twice as often directly above heavily-trafficked shipping lanes in the Indian Ocean and the South China Sea than they do in areas of the ocean adjacent to shipping lanes that have similar climates.

    The difference in lightning activity can’t be explained by changes in the weather, according to the study’s authors, who conclude that aerosol particles emitted in ship exhaust are changing how storm clouds form over the ocean….

    Joel A. Thornton, Katrina S. Virts, Robert H. Holzworth, Todd P. Mitchell. Lightning Enhancement Over Major Oceanic Shipping Lanes. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL074982

  7. Irma and Harvey — climate change is real

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    September 7 2017  Read full Washington Post Op-Ed here

    ….Hurricanes get their energy from warm ocean waters, and the oceans are warming because of the human-caused buildup of heat-trapping gases in the atmosphere, primarily from the burning of coal, oil and gas. The strongest hurricanes have gotten stronger because of global warming. Over the past two years, we have witnessed the most intense hurricanes on record for the globe, both hemispheres, the Pacific and now, with Irma, the Atlantic.

    We also know that warmer air holds more moisture, and the amount of water vapor in the atmosphere has increased because of human-induced global warming. We’ve measured this increase, and it has been unequivocally attributed to human-caused warming. That extra moisture causes heavier rainfall, which has also been observed and attributed to our influence on climate. We know that rainfall rates in hurricanes are expected to increase in a warmer world, and now we’re living that reality….\

    …Cutting-edge climate science suggests that such stalled weather patterns could result from a slowed jet stream, itself a consequence — through principles of atmospheric science — of the accelerated warming of the Arctic. This is a reminder of how climate changes in far-off regions such as the North Pole can have very real effects on extreme weather faced here in the Lower 48.

    These linkages are preliminary, and scientists are still actively studying them. But they are a reminder that surprises may be in store — and not welcome ones — when it comes to the unfolding effects of climate change….

  8. Eclipse Days Bring High Tides; Extra-High Tides Are a Preview of Sea Level Rise

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    Post your photos here- iSeeChange August 21 2017 

    Rising sea levels are already starting to flood our coastal communities. You can spot signs of change on days when the tides are extra high – as they will be on August 21, 2017, the day of a total solar eclipse.

    Extra-High Tides Are a Preview of Sea Level Rise

    Enhanced high tides happen when the sun, Earth, and moon are in near-perfect alignment, as they are every month during the full and new moon phases. At those times, the moon and Sun’s gravity add up to an extra “pull” on the Earth, making our planet’s oceans bulge more than normal. Those extra-high tides can cause flooding in homes and streets along the coast, giving us a preview of how sea-level rise will affect our communities in the future.

    How You Can Help

    Take pictures of high tides and flooding on August 21. Where do you see flooding? How does flooding affect your routine?

  9. Atlantic/Pacific ocean temperature difference fuels drought and wildfires in CA and Southwest US; multi-year predictions possible

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    • New study shows that the large-scale difference between a warm Atlantic and relatively cold Pacific ocean temperatures plays a fundamental role in causing droughts, and enhancing wildfire risks in California and the southwest.
    • the Atlantic/Pacific temperature difference shows pronounced variations on timescales of more than 5 years. Like swings of a very slow pendulum, this implies that there is predictability in the large-scale atmosphere/ocean system, which we expect will have a substantial societal benefit.
    July 26, 2017 Institute for Basic Science Read full ScienceDaily article here
    A new study shows that difference in water temperature between the Pacific and the Atlantic oceans together with global warming impact the risk of drought and wildfire in southwestern North America.
    …”we were able to show that without anthropogenic effects, the droughts in the southwestern United States would have been less severe.”
    ..The new findings show that a warm Atlantic and a relatively cold Pacific enhance the risk for drought and wildfire in the southwestern US. “According to our study, the Atlantic/Pacific temperature difference shows pronounced variations on timescales of more than 5 years. Like swings of a very slow pendulum, this implies that there is predictability in the large-scale atmosphere/ocean system, which we expect will have a substantial societal benefit,”…
    …”we can use our climate computer model to determine whether on average the next year will have drier or wetter soils or more or less wildfires. Our yearly forecasts are far better than chance.”…

    Yoshimitsu Chikamoto, Axel Timmermann, Matthew J. Widlansky, Magdalena A. Balmaseda, Lowell Stott. Multi-year predictability of climate, drought, and wildfire in southwestern North America. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-06869-7

  10. Since 1950s, 8.3 billion tons of plastics produced; 79% discarded into landfills and environment; only 9% recycled

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    • Humans have created 8.3 billion metric tons of plastics since large-scale production of the synthetic materials began in the early 1950s, and most of it now resides in landfills or the natural environment, according to a study.

    Posted: 19 Jul 2017 11:09 AM PDT  read full ScienceDaily article here

    …The researchers found that by 2015, humans had generated 8.3 billion metric tons of plastics, 6.3 billion tons of which had already become waste. Of that waste total, only 9 percent was recycled, 12 percent was incinerated and 79 percent accumulated in landfills or the natural environment.

    If current trends continue, roughly 12 billion metric tons of plastic waste will be in landfills or the natural environment by 2050. Twelve billion metric tons is about 35,000 times as heavy as the Empire State Building.

    Most plastics don’t biodegrade in any meaningful sense, so the plastic waste humans have generated could be with us for hundreds or even thousands of years,” said Jenna Jambeck, study co-author and associate professor of engineering at UGA. “Our estimates underscore the need to think critically about the materials we use and our waste management practices.“…

    They estimated that 8 million metric tons of plastic entered the oceans in 2010….

    “Roughly half of all the steel we make goes into construction, so it will have decades of use — plastic is the opposite,” said Roland Geyer, lead author of the paper and associate professor in UCSB’s Bren School of Environmental Science and Management. “Half of all plastics become waste after four or fewer years of use.”

    “I think we need to take a careful look at our expansive use of plastics and ask when the use of these materials does or does not make sense.” ….

    Roland Geyer et al. Production, use, and fate of all plastics ever made. Science Advances, July 2017 DOI: 10.1126/sciadv.1700782