Beach plastic is forever

Canadian resarcher Patricia Corcoran said she was studying the mineral components of Hawaiian beaches when she and a colleague noted large amounts of plastic debris on the shore, during a survey of Lydgate Beach on Kaua'i.

(Image: Plastic marine debris on a Kaua'i beach.)

“We wondered if the plastics on Lydgate Beach were derived from land-based or ocean-based sources. We also wondered how long the plastics would remain on the beach,” she said in an email to RaisingIslands. Corcoran is with the Department of Earth Sciences, University of Western Ontario, in London, Ontario, Canada.

She launched a study, using plastics from various Kaua'i beaches, treating the plastic particles in the same way she would have treated mineral sand particles. One finding: the stuff gets smaller and smaller, but it never goes away.

Her study, “Plastics and beaches: A degrading relationship,” with University of Western Ontario co-authors Mark Biesinger and Meriem Grifi, was published in the Marine Pollution Bulletin.

They found that while most of the plastic debris and particles on beaches is originally from the land, most used the ocean as the method of transport for getting onto beaches.

Also, there is more plastic on East Kaua'i beaches than on other shores. That may be a function of current patterns that drive marine debris onto shorelines from the east.

One technique for studying them was inspecting them using a Scanning Electron Microscope.

“I was able to recognize distinct textures related to chemical and mechanical weathering. Combining the textural images with compositional results determined from Fourier Transform Infrared Spectroscopy (FTIR), enabled us to recognize how both chemical and mechanical weathering contributed toward the degradation of plastic particles,” Corcoran said.

Some of the shapes were rounded, some angular, and some mere flakes. They showed evidence of both chemical and mechanical erosion, from exposure to ultraviolet radiation and from having been rubbed against sand grains during wind or wave action.

And the two kinds of degradation seem to support each other. Mechanical erosion from collisions with sand particles create fractures that are favorable spots for chemical weathering. And ultraviolet radiation increases brittleness, which makes mechanical breakdown easier.

“It...made me realize that beach environments are possibly the best natural settings in which plastics can be broken down, although they may remain in the environment in microscopic form indefinitely,” she said.

That's the bad news. The plastic gets smaller and smaller, until you don't see it, but it's always still there.

“We will be returning to Kauai in the coming year to conduct a more rigorous sampling approach of the plastic debris in order to determine which plastic types are most common (provides clues concerning sources), and which polymers degrade most rapidly under weathering conditions,” Corcoran said.


©2008 Jan TenBruggencate

The greening of Lehua Island

No one alive knows what the environment on Lehua Island was like before the rats and rabbits arrived.

These critters began eating virtually every seed and seedling, leaving it an eroded crescent of earth, rock and cinder.

But there is enough evidence to make educated guesses about what the island was like before human interference, and restoration teams will now try to recreate the prehistoric Lehua.

(Image: Lehua from the air. Credit: NASA image via Google Earth.)

A supplemental environmental assessment for the restoration project has been completed by the U.S. Fish and Wildlife Service and the state Department of Land and Natural Resources' Division of Forestry and Wildlife. It updates a 2005 environmental assessment, changing the timing of rodent control efforts to reduce threats to birds, and building on information developed during a similar program at an islet off Molokai.

Lehua is a gorgeous speck of land, even without restoration. An ancient tuff cone, it sits just north of Ni'ihau, visible on a good day from west Kaua'i, 20 miles distant.

Sixteen species of seabirds use its 310 acres. Seals haul out on its rocky shelves.

It is surrounded by deep, clear waters favored by dive tourists. One arm of its curved shape has a deep vertical crack that extends down into the sea. Some folks call it the Keyhole. Multicolored corals and reef fishes cruise the steep-bottomed and sheltered arc of its bay.

But the land is mostly shades of volcanic brown. Little vegetation survives on the island.

As the environmental assessment says, it's been clear at least in the scientific literature since 1931 that rats and rabbits were the main problem. It's taken more than 70 years to move from that recognition to doing something about it.

There have been past efforts to control the rats and rabbits—reportedly left by European sailors to provide familiar sustenance for shipwrecked sailors. The rabbits were eradicated by hunting during the past three years, and government now proposes to remove the rats as well.

Says the press release announcing the completion of the environmental assessment:

“The project will protect and restore native populations of seabirds, plants, and other wildlife on Lehua by eradicating rats, an invasive species damaging the island’s ecosystem.

“Rats are known to have eliminated many seabird species from islands around the world by eating bird eggs and preying on live birds. They also feed on native plants and insects, suppressing or eliminating populations of these species as well.

“Once the rats are removed, a plant restoration project will follow increasing habitat for native birds and insects.”

The proposal is to use rat baits, both in types and in ways that are unlikely to impact nesting and roosting bird populations—including doing the project in winter, when the fewest nesting seabirds are present.

The rodenticide of choice is diphacinone, which was recently used to remove rats from Mōkapu Island off north Molokai. It is highly toxic to rats, less toxic to birds and at Mōkapu, tests after use did not find traces of the chemical in marine resources next to the island.

Researchers will keep an eye on the island to see what native plants may begin growing in the absence of the rats and rabbits, but also to see whether weeds begin pushing in. They also propose to plant natives that are known from Lehua and similar offshore islets, but which are not not present.

Copies of the environmental assessment are available at the Fish and Wildlife Service website at http://www.fws.gov/pacificislands/, or you can call the Pacific Islands Fish and Wildlife Office at 808-792-9400.

©2008 Jan TenBruggencate

Celebrate diversity in energy; avoid slavish adherence to favorites

There's been a lot of talk lately in the news about what energy technologies won't work, and which ones ought to be adopted to the exclusion of all others.

My own view is that these are both troublesome positions.

At a time when less than 10 percent of our energy in Hawai'i comes from non-fossil fuel sources, it makes little sense to casually toss any technologies out of consideration—either due to assumptions of their pre-eminence or their perceived flaws.

I begin from three assumptions:

1. Every technology has some downsides. Fossil fuel power systems, as folks in Honolulu know, can be disrupted by earthquakes hundreds of miles away, and impacted by fuel price spikes. Wind doesn't work when there's no wind. Solar doesn't work at night. Hurricanes and tsunami threaten anything built at sea. And so forth.

2. Increasingly, one size doesn't fit all. Geothermal may work on Hawai'i, but probably not on Kaua'i. Solar may not make economic sense in areas with a frequent cloud shadow. OTEC may not work effectively on islands without deep, cold water near shore.

3. Technology changes, and advances. Just 20 years ago, a portable phone required a battery the size of a brick. It's safe to assume that the array of energy options will be somewhat different a decade from now.

I recently wrote a post in which I cited arguments for using every workable technology. One correspondent argued that with was stupid—his term—and that just because some energy systems were feasible didn't mean they were appropriate.

I entirely agreed. Some technologies would not make sense from an economic standpoint, some ought to be rejected from environmental perspectives, some might be too fragile and subject to disruption.

Just because you technically can drive a Mack truck as your primary household vehicle doesn't mean it's a workable option: they use a lot of fuel, they're expensive to garage and they're hard to park downtown. A bicycle, a hybrid or a small pickup truck might better suit your personal needs.

It's a dangerous game to insist that any one energy source, whether it's oil/coal, or waves or even OTEC, is all we need to be working on. There is danger in putting all your eggs in one basket.

If an earthquake can knock out an oil-fired power system, it can also probably take out a windmill. If a hurricane can take out oil platforms, it can probably impact OTEC facilities. A tsunami can probably wipe out wave systems. And so forth.

We've been all-fossil-fuel-all-the-time for so long that for many of us it's a stretch to think about distributed power generation scenarios.

I continue to be a fan of diversity in the energy future. And options. Shucks, 10 years from now, solar thermal might trump all our favorite current renewable alternatives. Or suitcase-sized household cold fusion systems. Or some other nascent technology that only now is wiggling out of the premordial energy slime.

The message then, is to embrace diversity. Celebrate systems that work, but avoid rejecting those that—for now—don't seem ready for prime time.

©2008 Jan TenBruggencate

Renewable energy? Diversity is key

The acronym DREP is a new one, but Diverse Renewable Energy Portfolio makes nothing but sense.

(Image: A 2002 shot of an active sun, a key factor in any renewable energy picture. Credit: NOAA Space Weather Prediction Center.)

The DREP concept, as I understand it, builds on the recognition that there are perils in choosing one energy source for the future to the exclusion of others. Look at where fossil fuels have gotten us.

Instead, DREP envisions a plan for the future that calls into play multiple sources: air power like wind; water power like wave and ocean thermal and hydroelectric; solar power like photovoltaics and solar thermal; biofuels; and others.

The message for the renewable energy community: lots of eggs in lots of baskets. Don't try to solve the energy problem only with wind, or only with biofuels, or only with solar, or only with ocean thermal. Prepare for the diverse renewable energy future by planning for a Diverse Renewable Energy Portfolio.

The term came up at a remarkable venue last week, a three-day, high-speed planning session for Kaua'i Island's Lihu'e district. It was guided by a Sustainable Design Assessment Team from the American Institute of Architects' Center for Communities by Design program. The team calls itself an SDAT.

Here, a team of architects from around the country, unpaid, arrive to help a community envision its future and work toward putting flesh on the vision. After intense sessions with community members, the team developed an outline—to be expanded in the coming months.

A piece of the Lihu'e vision, described in outline at an evening session Nov. 14, 2008, dealt with energy. The energy component had four main pieces: conservation, education, demonstration and transformation.

Conservation: The first and key piece of any energy strategy is to remove the inefficiencies inherent in the system—building conservation strategies and promoting efficient practices. Included is the commitment to write building codes, and design guidelines to support the energy goal.

Education: To get the community to buy in to the idea—community workshops, training sessions, community events that use energy as central themes, and education programs in schools.

Demonstration: New systems won't be adopted by a large component of folks until they know they work, and preferably until they've seen them work. The local government needs, the SDAT group said, to “walk the walk.” County buildings should be retrofitted or, when built new, built to the highest energy standards. County fleets need to be as energy efficient as possible. The community needs to provide assistance to businesss and individuals in the form of an information clearing house and personnel capable of holding folks by the hand or giving them a helpful push as they move forward.

Transformation: Ultimately, the community adopts every workable technology—solar water heating, alternative fuels for transportation and all the rest—as it moves forward with its DREP.

There weren't many new pieces in this energy discussion, but they were put together in interesting ways. Said former mayor and current County Council member JoAnn Yukimura, the sessions were “provocative—by that I mean stimulating a lot of thinking.”

Learn more about the SDAT program at the American Insitute of Architects' Center for Communities by Design site, http://www.aia.org/liv_sdat.

Word Merchant's Note: I was surprised, on Googling and Yahooing DREP after hearing it at the Lihu'e SDAT session, to find it wasn't there.

DREP is an acronym for a number of other things, some of which even have something to do with energy—among them Decentralized Rural Electrification Project and Colorado's Desert Rock Energy.

But the Diverse Renewable Energy Portfolio is a concept that need to be at the forefront in the discussion of the energy future, for Hawai'i and the world.

©2008 Jan TenBruggencate

Hurtling in reverse on greenhouse emissions

In the headlong international race to get control over climate change, you might wonder about pace.

Are we careening forward, creeping forward, barely moving?

Actually, we're hurtling in reverse.

(Image: The Keeling Curve, showing atmospheric CO2 levels continue to rise. Credit: NOAA Earth System Research Laboratory.)

Whatever starting line you choose is disappearing in the distance over the dashboard.

Japan's carbon dioxide emissions just hit a new record. Higher than they've ever been.

To be fair, Japan's arguably been doing at least a reasonable job, keeping emissions stable since 1995 at between 1.2 and 1.4 million tonnes of carbon dioxide. But they haven't been dropping, and they are not approaching the nation's Kyoto targets.

Nor are carbon dioxide global production figures.

The classic Keeling Curve, in which atmospheric carbon dioxide levels are measured at high elevation at the Mauna Loa Observatory, shows no change in the upward slope.

Despite all the talk, we're producing more and more carbon dioxide.

The average growth rate in parts per million of CO2 in the atmosphere was less than 1 in the 1960s. It was between 1 and 2 in the 1970s. It exceeded 2 parts per million in three years of the 1980s, and continued to grow in the 1990s.

In this decade, the rate of growth has exceeded 2 parts per million on average. (See http://www.esrl.noaa.gov/gmd/ccgg/trends/)

The United States, long the leader in greenhouse gas production, has dropped to number-two. But that's not because of remarkable conservation in this country. Rather, it's that China is growing its economy and building coal-fired industrial facilities so fast that it has overtaken the U.S.

Both presidential candidates in the recent U.S. elections asserted their plans to do something about climate, but at some level, this is Nero fiddling as Rome burns. It takes more than something. It takes a great deal.

The oceans are measurably acidifying as the result of rising CO2, and the list of climate effects on the surface is endless.

We are living the reputed Chinese curse: “May you live in interesting times.”

© 2008 Jan TenBruggencate

Cold freshwater plumes deliver nutrients to the reef

There are special places in the salty ocean off the Islands, where you can swim through plumes of cold, fresh water.

Early residents in arid areas would carry gourds to such areas, and collect drinking water, amazingly, in the ocean.

(Image: Bird's-eye perspective view of the submarine groundwater discharge exiting from Kaloko-Honokohau National Historical Park and Honokoko Harbor in West Hawai'i. The waters are made “visible” using advanced thermal infrared techniques from low flying aircraft. The huge volumes of groundwaters exiting West Hawaii are plumes of cold nutrient-rich waters that float on top of normal seawater. The flow rates and concentrations of the major nutrients (white inset) of the plume are determined by the scientist’s oceanographic studies, which are then incorporated into the large-scale surface temperature maps. The inset of the Kona coast shows the position of only the largest groundwater plumes throughout the region. Credit: Craig Glenn/ SOEST/ University of Hawai'i.)

Scientists are now learning much more about these oceanic freshwater oases, using advanced imaging techniques.

A recent paper in the journal Geophysical Research Letters reviews some of the techniques and the results. The paper, “Aerial infrared imaging reveals large nutrient-rich groundwater inputs to the ocean,” was written by Adam Johnson, Craig Glenn and Paul Lucey of the University of Hawai'i's School of Ocean and Earth Science and Technology, and William Burnett and Richard Peterson of Florida State University's Department of Oceanography.

They used low-altitude infrared photography to identify places where water temperature was different. The fresh water that flows out of the island aquifers is much colder than the ambient ocean temperature, and shows up in aerial infrared images as cool plumes that emerge from the island and eventually disperse in the warmer salty sea. Since fresh water tends to float on top of denser salty water, these sites are easy to distinguish from the air using temperature sensing equipment.

The researchers found that this is more than just a fresh water addition to the ocean. It is also an injection of nutrients into the nutrient-deprived Hawaiian ocean—which helps support marine life along the coast. In addition to using infrared techinques to check the water temperature, the authors tested the nutrient contents of water from water samples from the coastal ocean as well as from fresh and brackish wells near the shore.

Groundwater tends to have high levels of nitrogen and phosphorous, which can act as fertilizers to the nearshore marine habitats.

In areas without regular surface rivers or streams, like the dry kona coasts of the islands, the impact is even greater than where there are rivers.

“The input of nutrients to coastal environments via (submarine groundwater discharge) is disproportionately large due to its elevated nutrient load,” the authors write.

And the impact is also changing with the changing face of the landscape.

As human development of the coast expands, more and more nutrients make their way into the groundwater—and eventually into the nearshore waters. The increased nutrient load comes from things like fertilizers and septic systems.

The researchers worked in the dry Kona coast of the Big Island, where groundwater “is the only significant source of freshwater to the coastal ocean.” They found more than 30 major plumes of fresh water into the coastal ocean.

One of the classic views is at the Honokohau Small Boat Harbor. The inner part of the harbor is dominated with cold fresh water, which grows warmer and more brackish as it moves seaward. The propellers of the many boats that operate there pull warm water out of the depths and drag is to the surface, and these warm trails are visible on aerial infrared pictures.


©2008 Jan W. TenBruggencate

Where the fish? Maybe we already caught them.

There's a human tendency to blame someone else's behavior for problems that may have complex causes, but a new study suggests that in declining fish populations, the obvious conclusion is the right one.

(Image: Ulua cruising. Credit: Dr. Anthony R. Picciolo, NOAA NODC.)

The key player in the decline of Hawai'i reef fish...is fishing, says the study—the largest-ever assessment of reef fish populations in the main Hawaiian Islands.

And the proofs are pretty clear.

The study, published in the journal Environmental Conservation, is entitled, “Assessing the importance
of fishing impacts on Hawaiian coral reef fish assemblages along regional-scale human population gradients.”

Its authors are Ivor Williams of the Hawai'i Cooperative Fishery Research Unit at the University of Hawaii and the state Division of Aquatic Resources; Alan Friedlander of the Oceanic Institute and NOAA National Ocean Service; William Walsh and Kosta Stamoulis of the Hawaii Division of Aquatic Resources; and Robert Schroeder and Benjamin Richards of the University of Hawai'i's Joint Institute for Marine and Atmospheric Research.

One of the key proofs is this: Across the state, where there is heavy fishing, the population of the kinds of fish anglers are seeking is down far more than the ones they don't target.

“This study shows that the reef fishes most coveted by fishers, such as uhu, ulua and redfish, are severely depleted, and it points to fishing as the main driver of those declines,” Williams said.

Over the years, evidence to this effect has been piling up. This study is a major advance. It looked at coastal areas across the state, sampling fish populations at 89 locations. A number of pieces of the fishery puzzle came to light.

This is important because you can't solve a problem if you don't clearly understand its causes, just as you can't fix a backfiring car until you know whether it's a fuel issue, a spark issue or some other problem. A mechanic's first challenge is to narrow down the causes.

In reef fish populations, there are lots of potential problems: sediment that chokes corals, oil spills, chemical runoff, physical damage from dredging and dragging anchors, and, of course, fishing, are among them.

“Humans can impact coral reef fishes directly by fishing, or indirectly through anthropogenic degradation of habitat. Uncertainty about the relative importance of those can make it difficult to develop and build consensus for appropriate remedial management,” the study authors said in their paper summary.

One assumption of the study was that large-scale environmental problems should affect most of the different fish stocks. When the results showed that only the fished fish like uhu and ulua were down, and other species like hawkfish, small triggerfish, surgeon fish and others were still doing okay, that tended to implicate fishing.

“If the chief cause of fish declines was habitat loss or environmental degradation related to development and pollution, then we would have seen fish declines across the board. Instead, fish declines along human population trends were only really apparent for species preferred by fishers,” Williams said.

Other pieces of information: Targeted fish populations tended to be reduced in places where there are lots of people fishing—meaning urban areas compared to very rural areas. But also, the target species tend to be healthier—even in urban areas—where it's difficult for anglers to get to the water.

“It did not seem that proximity to human populations by itself was associated with fish population declines, but rather that the crucial factor was proximity to human populations who were able to readily access, and therefore fish, nearshore waters,” the authors wrote.

How bad is it?

“We found that herbivores are enormously depleted. The biomass on Oahu reefs is only about three percent of that in remote parts of the state. Parrotfishes are massively impacted by fishing,” Williams said. Herbivores are plant-eaters like uhu or parrotfish, as distinguished from carnivores or meat-eaters like ulua or jacks.

The paper doesn't give coastal pollution a pass. It says that reefs impacted by uncontrolled urban activity result in degraded reefs that support fewer fish. But overfishing makes problems worse.

“Where significant habitat or environmental degradation occurs around heavily populated locations, its likely effects will be to exacerbate already severe impacts of intensive fishing, rather than being the main driver of any local declines in target fish stocks,” the paper says.

©2008 Jan W. TenBruggencate