Marine Pollution Bulletin 64 (2012) 1985–1988

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Marine Pollution Bulletin

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News

Do beavers benefit Scottish wild salmon?

Reintroduced European beavers could have an overall positiveimpact on wild salmon populations in Scotland, according to a studyby the University of Southampton.

Representatives of recreational fisheries interests north and south ofthe border are concerned that beavers can harm economically impor-tant fish stocks due to their dam building activities and potential toblock migratory life phases. However, results of a study conducted byscientists at the University of Southampton, funded by Scottish NaturalHeritage, indicate that beavers can also have substantial beneficialeffects which may outweigh those that are negative.

Dr Paul Kemp, a researcher in freshwater fish ecology and fisheriesmanagement from the University’s International Centre for Ecohydrau-lics Research, who led the study, considers that the positive findingswere more frequently based on quantitative evidence, while discussionof negative impacts was often speculative.

Beaver reintroduction has been a contentious issue in Scotland eversince a total of 16 individuals from Norway were released in Argyll in2009 and 2010 as part of a scientific trial conducted by the ScottishWildlife Trust, The Royal Zoological Society of Scotland, and the hostpartners, the Forestry Commission Scotland.

Even more controversy surrounds the establishment of a breedingpopulation of escaped beavers on the River Tay. This has had ramifica-tions south of the border as the Angling Trust has requested that trap-ping and destruction of the beavers be urgently undertaken to preventtheir spread to England where it is claimed they could damagefisheries.

When researchers carried out a critical view of over 100 sources ofpeer-reviewed information the negative effects were found to relate tothe construction of beaver dams which can temporarily impede themovement of some fish, particularly in narrow rivers and streams,and the effects of siltation which can cause loss of spawning habitatimmediately upstream of dams. However, beavers were also found tohave beneficial effects on fish by increasing the variety and area ofhabitats in streams, and, due to the presence of dams and ponds, byincreasing the abundance of invertebrates which form the main com-ponent of the diet of many stream-dwelling fish. The dams and pondswere also seen to provide refuges during periods of high or low waterflows.

In fact, of 49 fisheries managers, scientists, and beaver ecologyexperts, from Europe and North America, more than half (58%) believedthat the overall impact of beavers on fish populations was positive.

Source: University of Southampton

Antarctica research on potential king crab invasion

Climate change could cause a major ecological upheaval in theshallow marine waters of the continental shelf of Antarctica. This isthe outlook according to Professor Richard Aronson, head of the FloridaInstitute of Technology Department of Biological Sciences. His researchfinds predatory crabs poised to return to warming Antarctic waters and

http://dx.doi.org/10.1016/j.marpolbul.2012.09.001

disrupt the primeval marine communities that have lived there formillions of years.

A $760,000 grant from the National Science Foundation (NSF) willsupport two oceanographic cruises, planned for the 2013–2014 and2014–2015 austral-summer seasons, to chart the progress of theinvasion.

The king crabs are predators that eat most types of hard-shelledprey. If the crabs make it onto the Antarctic shelf, it is highly likely theywill disrupt the unique seafloor communities, which currently live justa few hundred metres shallower than the massed crab populations.Although king crabs are commercially harvested elsewhere, Antarcticais too remote and the crabs are too small for a viable fishery.

The shell-cracking crabs, fish, sharks and rays that dominate bottomcommunities in temperate and tropical zones have been shut out ofAntarctica for millions of years because it is simply too cold for them.

But, according to Aronson, this situation is about to change.

Populations of predatory king crabs are already living in deeper waterand increasing ship traffic is introducing exotic invaders all the time.When ships unload ballast water in the Southern Ocean that surroundsAntarctica, larvae from all over the world get introduced to theecosystem.

Antarctica’s coastal waters are warming rapidly. Temperatures atthe sea surface off the western Antarctic Peninsula went up 1�C inthe last 50 years, making it one of the fastest-warming regions of theWorld Ocean.

The crabs’ invasion would be set to devastate Antarctica’s uniqueshallow-marine fauna, and the communities will lose their uniquestructure and come to look like seafloor communities everywhere elsemaking the world’s marine ecosystems less diverse.

Source: Florida Institute of Technology

Darwin right about eastern Pacific barrier and coral species

A coral species that is found in abundance from Indonesia eastwardto Fiji, Samoa, and the Line Islands rarely crosses the Eastern PacificBarrier toward the coast of the Americas, according to a team ofresearchers from Penn State University.

Darwin hypothesized in 1880 that most species could not disperseacross that marine barrier, and this study is the first comprehensivetest of that hypothesis. The researchers used coral as the test organism.The results of the study have important implications for climate-change research, species-preservation efforts, and the economic stabi-lity of the eastern Pacific region, including the Galàpagos, Costa Rica,Panama, and Ecuador.

The Eastern Pacific Barrier (EPB), an uninterrupted 4,000-milestretch of water with depths of up to 7 miles, separates the central fromthe eastern Pacific Ocean. In his writings, Darwin had termed this bar-rier ‘‘impassable’’ and, since Darwin’s time, scientists have confirmedthat many species of marine animals cannot cross this oceanic divide.However, until now, researchers had not performed a comprehensiveanalysis of the impact of the barrier on coral species.

1986 News / Marine Pollution Bulletin 64 (2012) 1985–1988

Coral adult colonies reproduce by making small coral larvae that stayin the water column for some time moving, often long distances, withthe currents. However, the EPB is a formidable barrier because the timeit would take to cross it probably exceeds the life span of a larva.

To test whether or not coral larvae are able to travel across thebarrier, the research team chose a strong species called Porites lobata.This species harbours symbionts in its larvae that can provide foodduring a long journey. In addition, the adults seem to survive moreextreme temperatures, as well as more acidic conditions.

The team members collected coral samples of the Porites lobata spe-cies from both sides of the Eastern Pacific Barrier and performed genetictests using microsatellite markers to distinguish individuals. For themost part, samples found to the east were genetically dissimilar to thosefound to the west. This research confirms that coral larvae originating inthe central Pacific are not making it across the ocean to the Americas.

The only exception, the team found, was a relatively smallpopulation of Porites lobata living near Clipperton Island, which islocated just north and west of the Galàpagos.

The team’s findings about the ability of coral to travel across themarine barrier have important implications for the economic stabilityof the eastern Pacific, the region’s species-conservation efforts and,more broadly, for the impact of climate change on tropical ecosystems.In the event of any large-scale coral crisis, coral populations in the east-ern Pacific are very unlikely to be replenished by larvae from the westand vice versa.

Source: Penn State University

Viruses could be the key to healthy corals

Corals are an invaluable part of the marine ecosystem, fostering bio-diversity and protecting coastlines. But they are also increasingly en-dangered. Pathogenic bacteria, along with pollution and harmfulfishing practices, are one of the biggest threats to the world’s coral po-pulations today. One of the solutions to the crisis may lie in humanmedicine.

Researchers from Tel Aviv University have developed a treatmentfor coral infected by Thalassomonas loyana, otherwise known as WhitePlague disease. This deadly bacterium infects 9% of Favia favus corals onthe Eilat coral reef in the Red Sea and readily transmits the disease tonearby healthy corals.

Their treatment uses viruses, bacteriaphages, that infect bacteria byinjecting some of their own genetic material into the bacterium. Thistherapy was originally developed as a means of treating bacterial infec-tions in humans. In this case, the researchers isolated a bacteriaphagecalled BA3 and discovered that it had the ability to kill off White Plaguedisease. Field experiments in the Gulf of Eilat demonstrated that thetreatment stopped the progression of the disease in infected corals andprevented the spread of the disease to surrounding healthy corals as well.

Treating bacterial infections in corals is difficult as they do not pro-duce antibodies like humans and therefore cannot be immunizedagainst a particular disease. Also, pharmaceutical antibiotics are not aviable option because the treatment releases the drugs into the sea,possibly harming the marine environment.

The researchers applied their treatment to two groups of diseasedcoral, each surrounded by a circle of healthy corals. After 24 hours,the difference in the outcome was highly significant. In the test group,the infection of the diseased coral ceased its progression, and the dis-ease did not spread to the surrounding healthy corals. In the controlgroup, however, the White Plague disease progressed rapidly in the ori-ginal infected coral and spread to seven out of ten of the surroundinghealthy corals.

One of the most surprising discoveries during the course of theirresearch was that some corals naturally possess the same beneficialvirus and are already resistant to infection by the pathogen WhitePlague disease. When the researchers tested the three corals in thecontrol group that remained uninfected, they discovered that the viruswas already present in their biological composition. Therefore, theirintervention was enhancing a natural process that goes on all the time.

The next step is to develop an effective way to spread the virusesover large areas of an infected coral reef. Also, as reefs in differentregions of the world are infected with different pathogens, it will beessential to determine regionally specific bacteriaphages. Sufficientamounts of these viruses can be easily manufactured in the laboratory.

Source: Tel Aviv University

Fuelling nuclear power with seawater

The U.S. Department of Energy’s Pacific Northwest National Labora-tory (PNNL) and Oak Ridge National Laboratory (ORNL) are investigatingthe viability of extracting uranium from sea water for use as nuclear fuel.

Uranium occurs in Earth’s oceans in trace amounts of just 3 partsper billion, but it adds up. Combined, the oceans hold up to 4.5 billiontons of uranium, enough to potentially fuel the world’s nuclear powerplants for 6,500 years.

Countries such as Japan have examined the ocean as a uraniumsource since the 1960s, but previous approaches have been too expen-sive to extract the quantities needed for nuclear fuel. Now researchersat the PNNL are revisiting the concept with the goal of making extrac-tion more efficient and cost-competitive.

Japan developed an adsorbent that attaches the uranium-lovingchemical group amidoxime to a plastic polymer. ORNL examined thebinding process between the plastic and chemical groups and used thatknowledge to enhance the uranium-grabbing characteristic of the ami-doxime groups on the adsorbent material’s surface.

PNNL tested the adsorbent’s performance at its Marine SciencesLaboratory in Washington State, DOE’s only marine research facility.Using filtered seawater from nearby Sequim Bay, PNNL established alaboratory testing process to measure the effectiveness of both Japan’sand ORNL’s adsorbent materials. Initial tests showed ORNL’s adsorbentcan soak up more than two times the uranium than the material fromJapan.

Source: U.S. DOE

Marine research in Brazilian rainforest

A recent study carried out by scientists from Brazil, U.S.A and led byThorsten Dittmar of the Max Planck Institute for Marine Microbiology,has shown that the common practice of slash and burn practised in theBrazilian Amazonas in the 1970s left huge amounts of charcoal in thesoil. This charcoal is washed out by rainfall and transported by riversinto the Atlantic Ocean. The soluble fraction of charcoal is composedof extremely stable carbon compounds.

Slash and burn during the centuries reduced the size of the Brazilianforest from 1.3 million km2 in the 19th century to just 100,000 km2.What was left was 200–500 million tons of charred carbon in the soils.These remnants are complex and extremely stable carbon compounds.During the rainy seasons the water elutes the soluble fractions and trans-ports the carbon to the Atlantic Ocean, affecting biogeochemical cyclesfor centuries and millenia.

According to Dittmar, the detection of telltale carbon compoundstypical for burnt plant material and charcoal dissolved in ocean watersuggested that the pre-harvest burning of sugar cane plantations and for-est fires in Brazil was a major source. This information was combinedwith data from colleagues in Brazil, who had taken soil and water sam-ples for years around the Paraiba do Sul river with surprising results.

It was found that substantially more carbon compounds were dis-charged by the river than the annual procedure of pre-harvest burningof sugar cane plantations could produce. When the results from thesamples were plotted against time and the pattern compared withthe amount of precipitation and the occurrence of fires, the relation be-came obvious. The charred carbon must have originated from the slashand burn period from much earlier times.

This assumption was confirmed by further experiments and data.The still practiced pre-harvest burning of the sugar cane plantationsproduces only 190–740 tons of charred carbon annually, but theamount found in the river was three to sixteen times higher. The scien-

News / Marine Pollution Bulletin 64 (2012) 1985–1988 1987

tists extrapolated 50,000 to 70,000 tons for the annual load carried byrivers from the total area of the relict rain forest into the Atlantic Ocean.

Source: Max Planck Institute for Marine Microbiology

Arctic sea ice reaches lowest extent ever recorded

The blanket of sea ice floating on the Arctic Ocean melted to itslowest extent ever recorded since satellites began measuring it in1979, according to the University of Colorado Boulder’s National Snowand Ice Data Centre. On August 26th 2012, the Arctic sea ice extent fellto 4.10 million km2 which is 70,000 km2 below the record low daily seaice extent set on September 18th, 2007.

Since the summer, Arctic sea ice minimum normally does not occuruntil the melt season ends in mid- to-late September. The CU-Boulderresearch team expects the sea ice extent to continue to dwindle for thenext two or three weeks.

While a large Arctic storm in early August appears to have helped tobreak up some of the 2012 sea ice and helped it to melt more quickly,the decline seen in recent years is well outside the range of naturalclimate variability. Most scientists believe the shrinking Arctic sea iceis tied to warming temperatures caused by an increase in human-produced greenhouse gases pumped into Earth’s atmosphere.

CU-Boulder researchers consider that the old, thick, multi-year icethat used to dominate the Arctic region has been replaced by young,thin ice that has survived only one or two melt seasons. This ice nowmakes up about 80% of the ice cover. Since 1979, the September Arcticsea ice extent has declined by 12% per decade.

This has led the researchers to believe that the Arctic may be ice-free in the summers within the next several decades. The years from2007 to 2012 are the six lowest years in terms of Arctic sea ice extentin the satellite record. In the big picture, 2012 is just another year in thesequence of declining sea ice. There has been a trend toward decreasingminimum Arctic sea ice extents for the past 34 years, and there’s noreason to believe this trend will change.

The Arctic sea ice extent, as measured by scientists, is the total areaof all Arctic regions where ice covers at least 15% of the ocean surface.

Scientists consider that the Arctic sea ice is important because itkeeps the polar region cold and helps moderate global climate. Whilethe bright surface of Arctic sea ice reflects up to 80% of the sunlightback to space, the increasing amounts of open ocean there, which ab-sorb about 90% of the sunlight striking the Arctic, have created a posi-tive feedback effect, causing the ocean to heat up and contribute toincreased sea ice melt.

Source: University of Colorado

Are methane hydrates dissolving?

Huge amounts of methane hydrates are stored in the sea bed of thetransitional zones between shallow shelf seas and the deep sea at con-tinental slopes. These specific, ice-like compounds only form at lowtemperatures and under high pressure. When the water temperaturedirectly above the sea bed rises, some of the methane hydrates coulddissolve and release the previously bound methane. With the averagetemperatures of the atmosphere and oceans rising, this scenario couldlead to two problems. Firstly, that enormous amounts of methane, avery powerful greenhouse gas, will be released into the atmosphere,and secondly that the continental slopes may become unstable. Thisresearch is being carried out by researchers from GEOMAR, theHelmholtz Centre for Ocean Research, Kiel.

A new expedition on the German research vessel Maria S. Merianhas now set out to investigate these issues further. They will analysethe sea off the western shore of Spitsbergen in order to find outwhether the first methane hydrates in the sea bed are indeed dissolvingand what the consequences might be.

The expedition builds on research conducted by marine scientistsfrom Kiel who worked in this area of the sea in 2008. Back then theyfound over 250 places where gas was escaping from the sea bed. Theycame from spots which lay directly on the border of the area of stable

hydrates. It would appear that the hydrates are dissolving from the riminwards.

During the upcoming expedition, the scientists from Kiel will beworking together with colleagues from Bremen, Switzerland, GreatBritain and Norway to discover whether the gas emanation shows signsof dissolved hydrates and whether this is due to warmer sea beds.

Parallel to this, geophysicists from GEOMAR will investigate theslopes under the gas outlet spots for signs of instability using acousticand seismic methods.

Source: GEOMAR

Cloud control could tame hurricanes

In a bid to tame the hurricane, scientists propose using cloud seed-ing to decrease sea surface temperatures where hurricanes form. It isclaimed, in a recent paper published in Atmospheric Science Letters, thatthe technique could reduce hurricane intensity by a category.

The scientists focused on the relationship between sea surface tem-perature and the energy associated with the destructive potential ofhurricanes. Rather than seeding storm clouds or hurricanes directly,the idea is to target marine stratocumulus clouds, which cover an esti-mated quarter of the world’s oceans, to prevent hurricanes forming.

Using a technique known as Marine Cloud Brightening (MCB), theauthors propose that unmanned vehicles could spray tiny seawaterdroplets, a good fraction of which would rise into the clouds above, in-creasing their droplet numbers and thereby the cloud reflectivity andduration. In this way, more sunlight is bounced back into space, there-by reducing sea surface temperature.

The team’s calculations, based on a climate ocean atmosphere cou-pling model (HadGEM1) suggest this could reduce the power of devel-oping hurricanes by one category. Somewhat different cloud-seedingprojects, designed to directly influence rainfall amounts, already existaround the world and were most famously used in China during the2008 Beijing Olympics.

The calculations show that when targeting clouds in identified hur-ricane development regions the technique could reduce an average seasurface temperature by up to a few degrees, greatly decreasing theamount of energy available to hurricane formation.

One potential drawback to the idea is the impact of cloud seeding onrainfall in neighbouring regions. The team noted concerns that seedingin the Atlantic could lead to a significant reduction of rainfall in theAmazon basin and elsewhere. However, if different patterns of seedingwere used, such rainfall reductions were not found over land.

Source: University of Leeds

Silicone anti-fouling coatings for quagga and zebra mussels

Silicone anti-fouling coatings may be an important tool for mitigat-ing invasive quagga and zebra mussels’ impacts to water and hydro-power infrastructures. The American Bureau of Reclamation hastested more than 50 coatings and metal alloys over three years at Par-ker Dam on the Colorado River.

The silicone anti-fouling coatings were found to reduce the rate ofmussel settlement, and any attached mussels were easy to remove. Inmany cases, it was found water flowing at 0.03m per second providedsufficient force to remove mussel colonies.

Parker Dam provided an excellent field test site to evaluate coatingsin still and flowing water because the quagga and zebra mussels infest-ing this location reproduce throughout the year and have a high growthrate.

The coatings and metal alloys tested can be divided into six broadcategories: conventional epoxies (no fouling control), anti-fouling coat-ings, antifouling coatings, fluorinated powdered coatings, metallic coat-ings and metal alloys. The coatings were tested in still water andflowing water.

However, one problem with silicone anti-fouling coatings is thatthey are not that durable. Initial research found the silicone anti-fouling coatings were soft and were easily damaged by floating debris

1988 News / Marine Pollution Bulletin 64 (2012) 1985–1988

or mechanical abrasion. Further research is already underway to find asilicone anti-fouling technology that will meet the abuse coatings onfacilities must take.

Source: U.S. Department of the Interior, Bureau of Reclamation

Increased sediment and nutrients delivered to Chesapeake

Reservoirs near the mouth of the Susquehanna River just above Che-sapeake Bay are nearly at capacity in their ability to trap sediment. As aresult, large storms are already delivering increasingly more suspendedsediment and nutrients to the Bay, which may negatively impact re-storation efforts.

Too many nutrients in the Bay remove oxygen needed for the aqua-tic organisms and, along with sediment, cloud the waters, disturbingthe habitat of underwater plants crucial for aquatic life and waterfowl.

The upstream reservoirs have served previously to help reduce nu-trient pollutant loads to the Chesapeake Bay by trapping sediment andthe pollutants attached to them behind dams. Now that these reser-voirs are filling to capacity with sediment, they have become much lesseffective at preventing nutrient-rich sediments from reaching the Bay.

According to a new United States Geological Survey (USGS) report,the Susquehanna River delivered more phosphorus and sediment tothe Bay during 2011 storms than from any other year since monitoringbegan in 1978.

According to the report, from 1996–2011 total phosphorus movinginto the Bay has increased by 55%, and suspended sediment has in-creased by 97%. Over this time period, total nitrogen decreased byabout 3% overall, although showing increases during large floodingevents. The latter reflects successful efforts to clean up the waters en-tering the reservoirs.

While the reservoirs are filling, they are a trap for sediment and thenutrients attached to that sediment. As a reservoir approaches its sedi-ment storage capacity, it cannot hold as much sediment. When reser-voirs are near capacity, significant flow events, such as flooding fromTropical Storm Lee, have greater potential to cause scour, or the suddenremoval of large amounts of sediment, allowing that sediment and at-tached nutrients to flow out of the reservoirs and into the Bay.

Additionally, as the reservoir becomes filled, the channel that waterflows through gets smaller. As a result, for any given amount of flow,the water moves through the channel faster, further increasing the like-lihood of scour. Higher velocities also result in lower rates of settling,decreasing the amount of sediment that will be deposited.

Source: USGS

Hundreds of sensors to be set in Savannah River

Hundreds of sensors are being deployed along the Savannah Riverby a team of researchers from Clemson University and Coastal CarolinaUniversity (CCU) to monitor and gather data for a $4-million IntelligentRiver project. The sensors will collect and transmit real-time informa-tion about the quality and quantity of water in the 312-mile river.

The Intelligent River environmental data-collection system or‘‘macroscope’’ will include a network of remote sensors to collect, storeand send data on river conditions ranging from water quality and flowto storm-water runoff and pollution discharges. Wireless transmitterswill send data on temperature, water clarity, dissolved oxygen andother environmental indicators to Clemson, where the information willbe processed and posted on the Internet. Anyone anywhere in theworld can monitor the well-being of the river.

CCU’s Centre for Marine and Wetland Studies, who are collaboratingwith Clemson University, has extensive experience in deploying andoperating a wide range of scientific instrumentation in diverse environ-ments and has expertise in making scientific measurements in challen-ging locations, ranging from studies collecting sediment cores from anicebreaker in the Arctic Ocean to chemically tracing fluids seeping fromthe bottom of the Gulf of Mexico on a research submarine.

Source: Clemson University

U.S. Navy settles hazardous waste violations at facility inVirginia Beach

The U.S. Navy has agreed to pay a civil penalty to settle alleged vio-lations of hazardous waste regulations and underground storage tank(UST) regulations at the Joint Expeditionary Base Little Creek-Fort Storyfacility in Virginia Beach, according to the US Environmental ProtectionAgency (EPA).

EPA cited the U.S. Navy for violating the Resource Conservation andRecovery Act (RCRA), the federal law governing the treatment, storage,and disposal of hazardous waste. RCRA is designed to protect publichealth and the environment, and avoid costly cleanups, by requiringthe safe, environmentally sound storage and disposal of hazardouswaste. In addition, RCRA regulates underground storage tanks withthe emphasis on preventing releases from USTs which can cause ser-ious contamination to groundwater.

The U.S. Navy facility, which provides housing and training for U.S.expeditionary forces, allegedly violated RCRA by failing to determine ifthe waste was hazardous; storing hazardous waste at the facility; fail-ing to label containers with date and contents; failing to have function-ing spill and over fill equipment for two USTs; and failing to notify thestate when a new oil-containing UST was installed.

The settlement penalty reflects the Navy’s compliance efforts, andits cooperation with EPA in the investigation and resolution of this mat-ter. The facility has made significant improvements to come into com-pliance including the removal of an underground storage tank,providing personnel training and implementing better managementpractices. As part of the settlement, the U.S. Navy has neither admittednor denied liability for the alleged violations, but has certified its com-pliance with applicable RCRA requirements.

Source: U.S. EPA

News-in-Brief

Honolulu

Authorities have initiated an enforcement action under the SafeDrinking Water Act against Christian Marston and Tahiti Nui Enter-prises, Inc. LLC for failing to close three large capacity cesspools in Ha-nalei, Kauai. Marston’s property had been inspected multiple times andMarston was notified that his establishment was in violation of the fed-eral regulations. By 2012 Marston had failed to comply with Act and asa result of the continued noncompliance, EPA is now seeking penaltiesof up to $177,500, in addition to prompt closure and replacement of thecesspools with an approved wastewater system.

Canada

A new study of Canadian lakes shows that microcystin, a toxin pro-duced by cyanobacteria, is present in lakes in every province. This toxincan be a threat to health.

Microcystins are well-established as potent liver toxins to humansand other mammals, and are classified as possible human carcinogens.The study is the first to report on microcystin prevalence at a nationalscale in 246 bodies of water across Canada.

China

The first reading of a draft amendment to the Environmental Protec-tion Law has been announced in China. The new draft adds a clause thatcalls for governments and environmental protection departments to re-lease information concerning environmental quality, pollution-relatedaccidents and the collection and use of pollutant discharge fees to thepublic, as well as allowing the public to request related information.

The draft also calls for controls over the total amount of major pol-lutants discharged. Regions that exceed pollutant discharge limits orfail to meet environmental standards will face suspensions for newprojects that could cause more pollution.