Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Tag Archive: ocean

  1. Offshore Drilling Plan Under Fire: Law may have been violated, Senator says

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    • The administration plan calls for opening 90 percent of the U.S. coasts to oil and gas drilling, and scheduling 47 lease sales between 2019 and 2024. With states opposed and potential legal challenges, can it succeed?
  2. Climate change drives collapse in marine food webs

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    • Increased ocean temperatures reduce the vital flow of energy from the primary food producers at the bottom (e.g. algae), to intermediate consumers (herbivores), to predators at the top of marine food webs.

    January 9, 2018 University of Adelaide read full ScienceDaily article here

    A new study has found that levels of commercial fish stocks could be harmed as rising sea temperatures… drive the collapse of marine “food webs.” [The research shows] that increased temperatures reduce the vital flow of energy from the primary food producers at the bottom (e.g. algae), to intermediate consumers (herbivores), to predators at the top of marine food webs.

    Such disturbances in energy transfer can potentially lead to a decrease in food availability for top predators, which in turn, can lead to negative impacts for many marine species within these food webs.

    “Healthy food webs are important for maintenance of species diversity and provide a source of income and food for millions of people worldwide…

    …”Whilst climate change increased the productivity of plants, this was mainly due to an expansion of cyanobacteria (small blue-green algae),” said Mr Ullah. “This increased primary productivity does not support food webs, however, because these cyanobacteria are largely unpalatable and they are not consumed by herbivores.”

    ….Most research on ocean warming involves simplified, short-term experiments based on only one or a few species. “If we are to adequately forecast the impacts of climate change on ocean food webs and fisheries productivity, we need more complex and realistic approaches, that provide more reliable data for sophisticated food web models,” said project leader Professor Nagelkerken.

    Hadayet Ullah, Ivan Nagelkerken, Silvan U. Goldenberg, Damien A. Fordham. Climate change could drive marine food web collapse through altered trophic flows and cyanobacterial proliferation. PLOS Biology, 2018; 16 (1): e2003446 DOI: 10.1371/journal.pbio.2003446

  3. Strong support globally for ocean protection

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    January 10, 2018 University of California – San Diego read full ScienceDaily article

    People around the world strongly support ocean conservation measures, according to a new study of public perceptions of marine threats and protection.

    The public widely believes that the marine environment is under threat from human activities, and supports actions to protect the marine environment in their region, according to a new study to be published in the February issue of the journal Ocean and Coastal Management.

    The study, conducted by an international team of researchers, reviews a set of public perception surveys of marine issues that reached over 32,000 people in 21 countries. It provides one of the first systematic comparisons of the public perceptions of marine threats and protection around the world.

    The researchers found that 70% of respondents believe that the marine environment is under threat from human activities, and 45% believe the threat is high or very high. Survey respondents identified the greatest threats as pollution and fishing, followed by habitat alteration, climate change, and biodiversity loss….

    Heike K. Lotze, Haley Guest, Jennifer O’Leary, Arthur Tuda, Douglas Wallace. Public perceptions of marine threats and protection from around the world. Ocean & Coastal Management, 2018; 152: 14 DOI: 10.1016/j.ocecoaman.2017.11.004

  4. Warming ocean water is turning 99 percent of northern Great Barrier Reef sea turtles female; population viability threatened

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    • Rising temperatures are skewing population ratios toward extreme imbalance
    • Green sea turtle embryos develop as male or female depending on the temperature at which they incubate in sand
    • In the cooler southern Great Barrier Reef, 67 percent of hatched juveniles were female. But more than 99 percent of young turtles hatched in sand soaked by warmer waters in the northern Great Barrier Reef were female — with one male for every 116 females.
    By Laurel Hamers January 8, 2018  Read full ScienceNews article here

    Warming waters are turning some sea turtle populations female — to the extreme. More than 99 percent of young green turtles born on beaches along the northern Great Barrier Reef are female, researchers report January 8 in Current Biology. If that imbalance in sex continues, the overall population could shrink.

    Green sea turtle embryos develop as male or female depending on the temperature at which they incubate in sand. Scientists have known that warming ocean waters are skewing sea turtle populations toward having more females, but quantifying the imbalance has been hard.

    The sex ratio in the overall population is “nothing out of the ordinary,” with roughly one juvenile male for every four juvenile females, says study coauthor Michael Jensen, a marine biologist with the National Oceanic and Atmospheric Administration in La Jolla, Calif.

    But breaking the data down by the turtles’ region of origin revealed worrisome results. In the cooler southern Great Barrier Reef, 67 percent of hatched juveniles were female. But more than 99 percent of young turtles hatched in sand soaked by warmer waters in the northern Great Barrier Reef were female — with one male for every 116 females. That imbalance has increased over time: 86 percent of the adults born in the area more than 20 years ago were female….

    Michael Jensen, et al. Environmental Warming and Feminization of One of the Largest Sea Turtle Populations in the World.  Current Biology. Volume 28, Issue 1, p154–159.e4, 8 January 2018 DOI: http://dx.doi.org/10.1016/j.cub.2017.11.057/

    “Combining our results with temperature data show that the northern GBR green turtle rookeries have been producing primarily females for more than two decades and that the complete feminization of this population is possible in the near future.”

  5. We are creating a new class of extreme weather events, with dire results

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    • the 2016 global heat record, a deadly heat wave in Southeast Asia, and “marine hot spots” that led to devastating coral bleaching could not have occurred without the influence of human-caused global warming.
    • we are manufacturing our own extremes according to scientists at the 2017 American Geophysical Union’s Annual Meeting in New Orleans

    by Andrew Freeman December 14 2017  read full Mashable article here

    ….Global warming is bringing us newly possible extremes, from the 2016 global average surface temperature milestone (it was number one, baby), to a stifling heat wave in Southeast Asia that set numerous all-time high temperature records.

    The reason we know this tipping point in extreme weather and climate events has been passed is because of a growing sub-field within climate science, known as detection and attribution research. Scientists who work in this field are the climate equivalent of CSI investigators, probing for clues about what may have led to an extreme event soon after it occurs. …

    …..Scientists tend to shy away from bold pronouncements. But this year’s report is different…..On Wednesday, at the American Geophysical Union’s Annual Meeting in New Orleans, ….. contributors to 2016’s edition threw much of that typical caution to the increasingly gusty wind.

    The message of the 2016 attribution issue is that a sea change has occurred in our understanding of what we, by burning fossil fuels for energy, are doing to our weather. In short, we’re now manufacturing our own extremes, scientists said.

    It can no longer be said that we are simply raising the odds of particular events, or making them more severe, or both. In fact, we’re now pushing the climate into new territory entirely, researchers said.

    In other words, instead of realizing the sci-fi fantasy of controlling our weather, we’ve done everything possible to push the atmosphere toward a new, more malevolent form of chaos. 

    Out of the 27 extreme events examined in the peer reviewed report, investigators looking into three of them — the 2016 global heat record, a deadly heat wave in Southeast Asia, and “marine hot spots” that led to devastating coral bleaching — concluded that the events could not have occurred without the influence of human-caused global warming. In other words, take away global warming, and these things probably wouldn’t have happened. …

    …Regarding the 2016 global temperature record, scientists concluded that at least part of the warmth was due to a strong El Niño event, but that most of the warm temperature record was due to human-caused climate change during the past 100 years.

    …Another study in the BAMS issue found that extreme heat in Southeast Asia, particularly India and Thailand, near the end of 2016 “would not have been possible without climate change.” ….

     

     

  6. ‘Zero tolerance’ plan for plastic pollution considered by UN environment ministers

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    • Governments are being asked to move towards a legal treaty banning plastic waste from entering the sea.
    • At the moment ships are prohibited from dumping plastic overboard but there’s no international law against plastics flooding into the sea from the land.

    A plan for zero tolerance of plastic pollution of the oceans may be agreed by nations at a UN environment summit…..

    Experts say ocean plastics are an obvious subject for a global treaty: plastics present a large-scale threat….Plastic pollution doesn’t recognise international borders. Delegates in Nairobi preparing the way for the UN’s environment ministers meeting next week are said to be in broad agreement on the need for tougher action to combat the plastics crisis.

    Plastic on a beach

    …China – the world’s biggest plastics polluter – is said to be cautious about being bound by global rules. Other big polluters like India and Indonesia are said to be generally supportive about the resolutions….

    India’s Prime Minister Narendra Modi recently applauded the clean-up of plastic from a beach in Mumbai, saying: “It is our duty to protect the environment for our future generations.”

    Eirik Lindebjerg from WWF said the Nairobi meeting could prove a turning point in the plastics crisis. He told BBC News: “The treaties on climate change and biodiversity were initiated in this forum – so it has a track record of making things happen.”….

    …The meeting will also discuss pollution of the air and water. A global ban on lead in paints may be approved.

  7. Deep ocean bacteria discovered to play large role in carbon capture

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    • Nitrite-oxidizing bacteria contribute to the capture of carbon dioxide in deep, unlit ocean waters
    November 27, 2017 Bigelow Laboratory for Ocean Sciences
    Marine bacteria that live in the dark depths of the ocean play a newly discovered and significant role in the global carbon cycle, according to a new study.
    The “dark ocean” — everything that lies below 200 meters — makes up 90 percent of the ocean. Very little is known about the microscopic life in this realm and its critical role in transforming carbon dioxide to cell material, proteins, carbohydrates and lipids. This freshly produced organic material can then be consumed by other marine organisms enhancing the productivity of the ocean…
    …”We experimentally demonstrated the major role of nitrite oxidizers in capturing carbon dioxide in the dark ocean and illuminated a group of microbes which has not yet received adequate attention for their impact in the oceanic carbon cycle.”

    Maria G. Pachiadaki, Eva Sintes, Kristin Bergauer, Julia M. Brown, Nicholas R. Record, Brandon K. Swan, Mary Elizabeth Mathyer, Steven J. Hallam, Purificacion Lopez-Garcia, Yoshihiro Takaki, Takuro Nunoura, Tanja Woyke, Gerhard J. Herndl, Ramunas Stepanauskas. Major role of nitrite-oxidizing bacteria in dark ocean carbon fixation. Science, 2017; 358 (6366): 1046 DOI: 10.1126/science.aan8260

  8. Consumption of chinook salmon increases with recovery of West Coast marine mammals

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    November 20, 2017 Oregon State University

    The researchers estimate that from 1975 to 2015, the yearly biomass of chinook salmon consumed by pinnipeds (sea lions and harbor seals) and killer whales increased from 6,100 to 15,200 metric tons, and from five to 31.5 million individual salmon.

    ….While the recovery of marine mammals represents a conservation success, it creates complex tradeoffs for managers also charged with protecting the salmon they prey on, the study concludes. The U.S. Marine Mammal Protection Act of 1972 protects all marine mammals, including whales and pinnipeds (seals and sea lions) within the waters of the United States. and the Endangered Species Act protects nine West Coast populations of chinook salmon….

    While the recovery of marine mammals represents a conservation success, it creates complex tradeoffs for managers also charged with protecting the salmon they prey on. Credit: © Lori Pagel / Fotolia

    Brandon E. Chasco, Isaac C. Kaplan, Austen C. Thomas, Alejandro Acevedo-Gutiérrez, Dawn P. Noren, Michael J. Ford, M. Bradley Hanson, Jonathan J. Scordino, Steven J. Jeffries, Kristin N. Marshall, Andrew O. Shelton, Craig Matkin, Brian J. Burke, Eric J. Ward. Competing tradeoffs between increasing marine mammal predation and fisheries harvest of Chinook salmon. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-14984-8

  9. 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.

  10. 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