Another species of marine mammal is on the verge of extinction. The Vaquita (Phocoena sinus), a small porpoise endemic to the northern Gulf of Mexico, is reportedly just 30 individuals away from being lost forever. The name vaquita is Spanish for “little cow,” and it looks somewhat like a panda mixed with a dolphin. Because individuals suffer high mortality when trapped in illegal gill nets used by fishermen, the vaquita populations have plummeted since 1997. Mexico has spent millions trying to stop the illegal practice of using gill nets, but to date has not been able to prevent it completely. Continue reading Vaquita: The World’s Rarest Marine Mammal Is In Trouble
The Future of Renewable Energy
With regulatory and market forces chipping away at the profit margins for coal-fired and oil-fired power plants, will the next few decades usher in a surge in more cost competitive renewable energy projects throughout the United States? Not likely. The reason is that most renewable energy sources are also facing similar challenges in addition to technological barriers.
Currently, renewable energy sources make up only 13% of the power generation in the U.S., with hydroelectric power being the largest renewable energy source at 63%. By 2040, renewable energy as a percentage of total power production is only expected to reach 16%, while coal is expected to drop from 42% to 35%. Natural gas will replace the lost coal capacity and is expected rise from 25% to 30%. Why is there not a larger growth in renewable energy as a percentage of total energy production?
Take wind power for instance. Many of the best locations for wind generated electricity are off-shore where the wind gusts are frequent and strong enough to keep the blades turning profitably. The problem is that offshore turbines need maintenance to keep them running, which requires specialized equipment and procedures. Also, salt water increases corrosion and can wreak havoc on the electronics. That makes off shore maintenance a costly endeavor. The U.S. Energy Information Agency states that less than 2% of global wind capacity is located offshore, likely because of the high capital cost to build in the ocean.
One potential solution is to build the wind turbines on shore and construct them in places like the Great Plains where the wind is plentiful and maintenance costs are low. In fact, one-fifth of the United States possible wind resource is located in North and South Dakota (Bret Harper, 2005). Here the issue is that there are not enough transmission lines to carry the power to the places where it is needed. No company is willing to build wind turbines in a location where there are no transmission lines or build transmission lines where there is no power being generated. There are a few locations that are both near transmission lines and where there is sufficient wind, but the best locations are being snapped up quickly, leaving new projects to compete for less desirable locations.
Lastly, the love affair with wind power is rapidly becoming limited to those who don’t have to live anywhere near them. The public is more aware of the complaints from wind farm neighbors concerning turbine noise, its impact on birds and bats, and the amount of land it takes to collect enough wind to make a project worth doing. The result is that it is becoming increasingly more difficult to get projects approved in a reasonable time period.
Solar power is hardly worth even talking about in terms of a viable solution to the energy needs in the United States, at least with the current technology. Who by now has not heard about the number of solar power companies that have gone under due to high production costs and low wage competition from China. Even if we can get cheaper solar panels from overseas, solar power is very expensive to produce, whether being generated by giant light collecting mirrors harnessing sunlight to boil water to make electricity or using solar panels to make electricity directly. The places where sunlight is plentiful tend to be places that are dusty and hot. A thin layer of dust that is barely perceptible to the human eye can reduce the light power 20% or more. Also, high temperatures tend to cause problems with solar panels that are made with semiconductor devices that are sensitive and unreliable when temperatures get too hot. And, as with wind, there is the chicken and egg problem, because some of the best locations for generating solar power are not on the grid.
Biomass is a catchall that can refer to burning plant or animal derived materials to make power and includes municipal garbage. When biomass is burned it has the benefit of lowering the amount that needs to be landfilled and is considered a renewable resource. While biomass power plants are more easily located near transmission lines and fuel sources, they typically have other challenges that make them less competitive with fossil fuel-fire power plants. Most biomass plants are operated on a much smaller scale than traditional power plants, which means that they don’t produce enough power to keep the lights on without the aid of fossil fuel burning plants. Among the reasons is that biomass fuels do not have the same energy density (i.e. the amount of energy that can be generated per unit mass) as fossil fuels. In addition, air emissions such as acid gases can be comparable to a similar sized coal plant. Wood burning power plants, in fact, tend to have higher nitrous oxide and methane emissions when compared to a similar sized coal plant. Nitrous oxide and methane are 31 to 300 times more potent in absorbing heat than carbon dioxide. The fact that wood-fired biomass plants emit more potent greenhouse gases (GHG) makes Environmental Protection Agency’s statement of the benefits of renewable energy posted on their website somewhat awkward:
“Environmental and economic benefits of using renewable energy include: generating energy that produces no anthropogenic GHG emissions and reduces some types of air pollution”
For more information on renewable energy resources see the following links:
Are Green sea turtle populations increasing along the Texas gulf coast? Along the Texas Gulf Coast there appears to be an uptick in the number of sightings of Green Sea Turtles (Chelonia mydas) and Green Sea Turtle nests on North Padre Island. While reported sightings are not uncommon, experts do appear to agree that in 2012 and the beginning of 2013 there has been an increase in the number of sighting reports. Also increasing, is the number of turtles requiring rehabilitation due to injuries from boat encounters that too often result in the immediate death of turtles, or more frequently, leave deep disfiguring wounds that are prone to infection.
The increased sightings have some scratching their heads as to what might be occurring. A few people have suggested that there are more turtles due to the reopening of Packery Channel between Mustang Island and Padre Island. These islands form a barrier between the Texas coastline and the Gulf of Mexico, cutting off Corpus Christi Bay from the ocean and giving rise to a shallow water body known as the Laguna Madre that stretches the Texas coastline from Corpus Christi into northern Mexico. Padre Island is the longest barrier island in the world and because it separates the Laguna Madre from the ocean there is only limited mixing with ocean water, which also means limited ways for sea turtles to get in. Now that Packery Channel is open, perhaps Green Sea turtles, whose favored habitat is shallow coastal areas, are visiting more frequently than was possible before.
The turtles may also be attracted by the large gardens of sea grass that grow in the Laguna Madre. Sea grass populations have grown in the upper Laguna Madre and, because the Laguna Madre has an average depth of 3.6 feet (1.1 m), there is plenty of light from the sun and nutrients in the sandy bottoms to allow healthy growth of sea grass. In fact, 75% of all of the sea grass cover along the entire Texas coast is found in the Laguna Madre. Three species of grass dominate with shoal grass being the most abundant, followed by a moderate distribution of manatee grass and a small distribution of turtle grass. There is speculation that all of this grass is just too tempting for the vegetarian Green Sea turtle to pass up, especially in light of the fact that sea grass beds in and around other gulf coast areas have disappeared from both natural causes and human activities.
Whether the increased number of sightings is the result of an increase in the Green Sea Turtle population or more sea turtles getting in through Packery Channel may never be known. Measuring any sea turtle population is a challenge, not just because there are not enough resources to make accurate estimates, but because making the measurements often requires disturbing turtles that may lead them to abandon their nesting grounds never to return. A second difficulty is that Green Sea Turtles that do come to shore are primarily females looking for good places to build nests. Adult males and juvenile turtles tend to stay out in the open water making population estimates unreliable.
For more information on the Green Sea Turtle and other species of sea turtle, see the associated links.