Monthly Archives: May 2010

05/25/10

Gulf Coast Wetlands Threatened by Oil Spill

We’ve abandoned our amphibian friends for a couple of weeks to write about the Gulf Coast Oil spill, and while I’d hoped to get back to them this week, the latest news about the oil washing up and covering wetlands seemed too important for us to ignore. And it is an issue that relates to amphibians. While few amphibians live in salt-water wetlands, fresh-water wetlands are vitally important to them.

Wetlands are some of the most environmentally productive ecosystems on earth. Some common names for wetlands are marsh, swamp, or bog. To be called a wetland, an area must be soaked with water for part of the year. Louisiana’s wetlands wind through shallow estuaries, inlets, bays, and reefs. So what’s the big deal about these wetlands?

  • Wetlands provide a habitat for a large variety of wildlife and plants
  • Wetlands are a nursery area for fish, shrimps, crabs, oysters and other wildlife—a calm area protected by heavy waves.
  • Wetlands are like a kidney for other ecosystems, filtering out, cleaning, and storing water.
  • Migratory birds nest in the wetlands

What Oil Does to Wetlands

The glue that holds the marsh together is grass. If grasses are repeatedly covered with oil, they will suffocate. It may take years for intertidal salt marshes and sea grass beds to recover from this kind of oiling.

Oil in Louisiana wetlands, copyright Ted Jackson/The Times-Picayune on nola.com

As quoted by Irving Mendelssohn, a Louisiana State University botanist who specializes in wetland plants, in an AOL News article, “Once they’re dead, the soil collapses,” he said. “Then the soil becomes flooded and can’t grow back. The low areas that become ponds, the ponds form lakes and then the wetland disappears.”

How can the marshes be saved? Some suggestions include burning the oil-covered plants, low-pressure flushing, which helps push oil into areas where it can be vacuumed up or absorbed, cutting back vegetation to leave plants intact, and adding nutrients to help speed to degradation of the oil. Louisiana Governor Bobby Jindal has suggested dredging sand from the Gulf of Mexico and building islands to stop the oil from reaching wetlands. None of these methods is considered ideal and all have potentially serious environmental repercussions.

Even if people don’t care about wildlife and biodiversity, they should be concerned about the destruction of the wetlands. Almost all of the sea life that we consume from the Gulf of Mexico begins its life in these sea grass beds and wetlands. Also, the wetlands provide a buffer for storms and hurricanes, absorbing wind and tidal forces—of vital importance in this hurricane-prone area.

05/17/10

How the Gulf Oil Spill May Harm Dolphins

Like sea turtles and birds, dolphins and other marine mammals are extremely vulnerable to the effects of oil. There are 35,000 to 45,000 bottlenose dolphins in the Gulf of Mexico, one of the largest populations of dolphins off the coast of the U.S.

Bottlenose dolphin mother and calf

Unlike fish, dolphins need to come to the surface frequently to breathe. When they surface, they may come in contact with the oil slick that now covers thousands of square miles of the Gulf of Mexico.

Dolphins are smooth-skinned, hairless mammals with extremely sensitive skin—even more sensitive than human skin. Oil can cause chemical burns or skin irritation.

Dolphins may inhale oil and oil vapor. This may lead to damage of the airways, lung ailments, mucous membrane damage, or even death.

Oil may damage a dolphin’s eyes, which can cause ulcers, conjunctivitis, and blindness, making it difficult for them to find food, and sometimes causing starvation.

Ingesting oil can cause ulcers or internal bleeding.

Oil can impair a dolphin’s immune system and may cause secondary fungal or bacterial infections.

Oil may move up through the food chain as dolphins eat contaminated prey. Dolphins feed on fish and squid and spend much of their time in waters close to shore.

Dolphin calves may be poisoned as they can absorb oil through their mothers’ milk

Dolphins may experience stress and behavioral changes due to oil exposure.

Marine mammals are our closest relatives in the ocean—it’s heartbreaking that we have fouled their habitats and are potentially poisoning large numbers of these beautiful and intelligent animals. You can help by donating to The Institute for Marine Mammal Studies, Gulfpost, MS

Most of this information in this post is from Effects of Maritime Oil Spills on Wildlife, on the Australian government website

05/12/10

How the Gulf Oil Spill May Affect Sea Turtles

During the Age of the Dinosaurs, the sea teemed with marine reptiles. But when the dinosaurs disappeared 65 million years ago, only a few reptiles remained in the sea—sea turtles, sea snakes, saltwater crocodiles, and marine iguanas.

Kemp's Ridley turtle, courtesy of www.turtlejournal.com

These ancient sea creatures have survived unto the 21st century, but most of the seven species of sea turtles are threatened or endangered. One of the most critically endangered sea turtle species—the Kemp’s Ridley—may be most affected by the recent Gulf Oil spill. Kemp’s Ridleys are one of the few sea turtle species that don’t do a lot of roaming. They stay mostly in the Gulf of Mexico.

Kemp’s Ridley (along with Olive Ridleys) are the smallest sea turtles. They are known for their unusual nesting behavior called an arribada, in which hundreds or even thousands come ashore at the same time to lay their eggs. In the 1940s, over 40,000 turtles were filmed coming ashore at one time to lay eggs. By 1980 that number had shrunk to just a few thousand. Causes of their decline are drowning in shrimp trawls, longlines, and gillnets, pollution, egg collection, hunting, degradation of their nesting sites, habitat loss, and other human-caused problems.

Shrimpers are now required by law to attach Turtle Extruder Devices (TEDs) to their nets to prevent entangled turtles from drowning. TEDs are a grid of bars with an opening at the top or bottom fitted into the neck of the shrimp trawl that allows small animals like shrimp to slip through the bars and be caught, while larger animals such as sea turtles strike the bars and are ejected.

In recent years the Kemp’s Ridley sea turtles have made a recovery. In 2009 there were 197 documented nests on the Texas coasts. At Rancho Neuvo and in neighboring Mexico beaches, 8000 females nested. Unfortunately the recent oil spill may cause a severe setback in the recovery of these turtles.

How Oil Harms Turtles*

Like marine mammals, sea turtles need to come to the surface to breathe air. If turtles surface in an oil slick to breathe, oil will affect their eyes and damage airways or lungs. Imagine if you dove into a pool with oil on the surface. When you came up for air, you couldn’t help but swallow and breathe in the oil.

Sea turtles will be affected by oil through contamination of their food supply.

Sea turtles are marine (ocean) animals, but have a crucial tie to the land. Females must come ashore to lay eggs. After they lay the eggs, female turtles cover the nest (a deep hole they have dug in the sand with their flippers) and return to the ocean. The baby turtles hatch from eggs and must fend for themselves as they scramble from the nests to the ocean.

Nesting sites covered with oil can lead to the following problems:

•Digestion/absorption of oil through food contamination or direct physical contact, leading to damage to the digestive tract and other organs.

•Irritation of mucous membranes (such as those in the nose, throat and eyes) leading to inflammation and infection.

•Eggs may be contaminated, either because there is oil in the sand high up on the beach at the nesting site, or because the adult turtles are oiled as they make their way across the beach to the nesting site. Oiling of eggs may inhibit their development.

•Newly hatched turtles, after emerging from the nests, make their way over the beach to the water and may become oiled.

In addition to the oil, thousands of gallons of “dispersants” have been dumped into the Gulf in an effort to break up the oil spill. It is unclear what chemicals are in these dispersants, which will now become part of the food chain—and could contaminate the seafood we eat as well.

So far, scientists have been unable to predict the direction of the spill. It depends on weather/wind patterns, possible storms, and many other variables. If the oil gets into the loop current that swings northeast from the Gulf, it may reach the Florida Keys and eventually the Eastern Seaboard. If this happens, loggerhead turtles that nest on southeastern beaches may also be severly affected by the spill.

Several years ago, I saw a loggerhead sea turtle lay her eggs on a beach on the east coast of Florida in the shadow of Cape Canaveral—an awesome experience  I will never forget. I witnessed something that had been happening for millions of years. Humans have been around for a tiny fraction of the time that sea turtles have inhabited this planet. It is our responsibility to help protect them, especially now, in the face of this potentially devastating oil spill.

The Sea Turtle Restoration Project has daily updates about sea turtles and the oil spill, and includes suggestions for how you can help.

The Carribean Conservation Corporation: Sea Turtle Survival also has good information about how oil affects sea turtles, and has lots of general information about sea turtles. I have adopted several turtles from this organization.

*Note: most of the information about sea turtles and oil came from the Australian government website, Effect of Maritime Oil Spills on Wildlife.
05/6/10

How the Gulf Oil Spill Threatens Birds

The BP oil spill in the Gulf of Mexico, caused by an explosion and fire that destroyed a drilling rig about 50 miles offshore, has cost 11 oil workers’ lives. The oil spill also endangers the livelihood of the area fishermen/women, potentially harms tourism and local businesses, and is another blow to an already beleaguered area.

In addition, the oil spill is a potential environmental tragedy that may have devastating effects on the area’s wildlife. Birds will be among the first to experience the effects of the spill. In separate posts, we will also cover sea turtles, dolphins, bluefin tuna, and other animals, including amphibians, that may be potentially harmed by the spill.

Why is oil so terrible for birds?

According the International Bird Rescue and Research Center (IBRRC), even a dime-sized glob of oil can kill a bird. A bird is kept waterproof, not by the natural oils in its feathers, which serve more as a conditioner, but by the position of the birds’ feathers. When a bird preens, it carefully aligns each feather—made up of a shaft, veins, and tiny barbs—that connect the veins in a tightly woven unit. This keeps water out and provides the bird with buoyancy and insulation.

A bird can’t preen with oil on its feathers, which mat and separate, exposing birds to hypothermia (too cold) or hyperthermia (too warm). The bird will instinctively try to preen, and will ingest oil, which causes severe damage to its internal organs. Because they are frantically trying to rid their feathers of oil, they are not hunting as much and so suffer from starvation, anemia, and so on.

According to IBRRC, washing an already stressed bird could cause its death.  It is more important to give these birds needed nutrition, hydration, and medical treatment first. Once stable, the oiled birds go through a series of tub washes alternating between one percent solution dishwashing liquid in water, and clean water. After being washed, they are put in cages with warm air dryers, then gradually acclimated to being released in the wild.

According to the National Audubon Society website, these birds may be affected by the spill:

Brown Pelicans
The state bird of Louisiana, Brown Pelicans nest colonially on barrier islands and feed on fish in nearshore waters. They have just begun their breeding season, and many pairs are already incubating eggs. Brown Pelicans were removed from the U.S. endangered species list only late last year, but they remain vulnerable to storms, habitat loss and other pressures. Their reproductive rate is relatively low, and a disruption to their breeding cycle this year could have serious effects on the population.

Least terns and other beach-nesting terns and gulls
These birds nest and roost in groups on barrier islands and beaches. Some species have begun nesting or building pair bonds in preparation for nesting. They feed on fish and other marine life. Because they roost and nest directly on the sand and plunge-dive into the water to catch fish, they are extremely vulnerable both to oil on the surface of the water and oil washing ashore.

Reddish Egrets are large, strictly coastal egrets known for wild dance-like behavior as they hunt for prey in the surf. Their numbers have dwindled due to habitat loss and disturbance, and because they are specialized residents of coastal environments, they have nowhere else to go if their feeding and nesting grounds are fouled by oil.

Large wading such as herons and egrets and other species feed in marshes and along the coast, and they nest in large colonies called rookeries. They are vulnerable if oil comes ashore in areas where they nest and feed. The central Gulf Coast region hosts continentally significant populations of many of these birds.

Other birds affected include migratory shorebirds (plovers, sandpipers), migratory songbirds (warblers, orioles, buntings, flycatchers, swallows, and others), and ocean-dwelling birds, including the Magnificent Frigatebird.

The National Audubon Society suggests ways you can help the birds.