The research, led by fish expert Milton S. Love, a research biologist with UCSB's Marine Science Institute, entailed collecting a total of 196 fish –– 18 kelp bass (Paralabrax clathratus), 80 kelp rockfish (Sebastes atrovirens), and 98 Pacific sanddab (Citharichthys sordidus) –– from five offshore oil platforms and 10 natural areas during 2005 and 2006. Samples were taken at 19 sites between the Santa Barbara Channel in the north and Long Beach in the south. Three of the offshore islands –– Santa Cruz, Anacapa, and Catalina –– provided some of the natural sites.
Platform Gilda in the Santa Barbara Channel hosts a variety of marine life.
Credit: Scott Gietler
Of 63 elements, 42 were excluded from statistical comparisons because they were not detected during analysis, were detected at concentrations too low to yield reliable quantitative measurements, or were deemed unlikely to accumulate to potentially toxic concentrations. None of the remaining 21 elements consistently exhibited higher concentrations at oil platforms than at natural areas.
For one species of fish, the Pacific sanddab, small fish around oil platforms had lower levels of three elements, selenium, titanium, and vanadium, whereas larger platform fish tended to have higher levels of these three elements. In addition, larger fish tended to have more tin at natural areas but more copper at platforms. "We are mystified and have no explanation for that," said Love. "It may have to do with different feeding habits between juveniles and adults, but we just don't know."
Twenty-seven active and seven decommissioned offshore platforms are located within the study area. There is great debate about what to do with decommissioned platforms. The study says that while decommissioned oil platforms in Southern California have historically undergone complete removal, "recent ecological studies indicate that platforms provide artificial structure for marine life, including many fish species of recreational and commercial importance, and may contribute to rebuilding overfished stocks."
According to Love, the federal government, which oversees most of the platforms off California, is looking down the road to the time when these platforms become uneconomical to operate. "No one knows when that will be," he said, "it is a purely economic decision, much of it driven by the price of oil." This study, sponsored by the Bureau of Ocean Energy Management, gives the federal government important information in the decision-making process for future decommissioning.
"The State of California has a law that says that complete removal may not be necessary," explained Love. "It's possible that the state will require owners to cut the platforms below the waterline and leave the rest as reefs. In that process, there are questions that have arisen over and over again: Are these fish polluted in some way? Are we leaving a structure filled with polluted fish?"
This study begins to answer that question. The findings do not support the hypothesis that oil platforms off California are major sources of trace element contamination in resident marine fish.
"In science, nothing answers anything definitively," said Love. "Because you can never know the truth; all you can do is approach the truth. All we can say is that based on this one study, heavy metal pollution does not seem to be an issue around the platforms we sampled."
Julie Cohen | EurekAlert!
Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy