Renewal after catastrophe

By Nadine Lymn, ESA Director of Public Affairs Extreme events such as the eruption of Mount St. Helens and the severe fires in Yellowstone National Park initially seemed to have left behind wastelands.  Yet ecologists and other researchers discovered that in both cases, plants and other life rebounded much more quickly than anticipated.  Now a new study of sandy beaches finds surprising resilience following the 8.8 magnitude earthquake and tsunami that rocked coastal Chile in February of 2010. The Maule earthquake was the 6th largest event recorded by modern seismology and unleashed a tsunami, killing nearly 500 people.  Communities in coastal areas around the world have been erecting seawalls for centuries in an effort to stem beach erosion and protect themselves against storms and tsunamis.  Researchers from Southern University of Chile and the University of California, Santa Barbara had been researching the effects of such structures on plant and animal life on nine coastal beaches in Chile just prior to the earthquake.  After it struck, they resurveyed the now dramatically altered areas. As they had predicted, their pre-earthquake surveys found that species that live in the upper and mid-intertidal areas of sandy beaches are more affected by seawalls than those living in the lower shore areas.  The upper intertidal zone is mostly terrestrial except during high tides and the mid intertidal zone is regularly exposed and submerged by tides.  The low intertidal areas are only exposed during very low tides.  Seawalls physically cover up part of the beach and cause sand in front of the walls to be lost until the beach eventually “drowns.” The earthquake and tsunami brought about tremendous physical changes, drowning some beaches while creating sandy beach habitat in other areas. According to a press release by the National Science Foundation, which helped fund the study, the research team found that intertidal species were destroyed in the drowned beaches while newly widened beaches saw the return of life that had previously “vanished due to the effects of coastal armouring.” From previous studies in California and Chile, said lead author Eduardo Jaramillo of the Universidad Austral de Chile, “…we knew that building coastal defense structures, such as seawalls, decreases beach area, and that a seawall results in the decline of intertidal diversity.  But after the earthquake, where significant continental uplift occurred, the beach area that had been lost due to coastal armoring has now been restored,” said Jaramillo.  “And the re-colonization of the mobile fauna [such as crabs] was underway just weeks afterward.” Jaramillo E, Dugan JE, Hubbard DM, Melnick D, Manzano M, Duarte C, Campos C, & Sanchez R (2012). Ecological Implications of Extreme Events: Footprints...

Read More

Wildlife damage from Japan’s tsunami

Most people have heard about the damage caused by last week’s massive magnitude 9 earthquake that sent a tsunami—at times reaching 33 feet—onto the island nation of Japan. The situation in Japan is dire. According to CBS News, “An estimated 452,000 people are living in shelters following the earthquake and tsunami. Japan’s police agency currently puts the death toll at 6,900 with 10,700 more people still missing.” Meanwhile, the threat of a nuclear meltdown is looming. The effects of the tsunami are devastating and far-reaching. From around the world, search teams, medics and volunteers work tirelessly to locate and help victims of the quake and floods. While the world’s attention is rightly focused on aiding the people of Japan, other nearby island countries are trying to recover from severe damage to their infrastructure as well. One example is the Charles Darwin Foundation (CDF) and Research Station on the Galapagos island of Santa Cruz. As described in a recent Southern Fried Science post, “The tsunami hit the island at high tide on March 11, and the resulting 1.7 meter flood destroyed essential equipment and shut the research station down for the foreseeable future.” Despite extensive flooding in the Marine Laboratory, the animals at the Research Station were relocated in time to be saved. “Lonesome George, the iconic last Giant Tortoise from Pinta island, had been moved to high ground prior to the tsunami as a precautionary measure,” reported the World Heritage Convention. According to the Galapagos Conservancy, the island’s animal and plant life  may have suffered significant damage: “With regard to the flora and fauna, the impacts are being assessed. According to Galapagos National Park reports, some marine turtle nests at Garrapatero Beach on Santa Cruz were destroyed. We had significant damage to the vegetation along the shore of the Research Station. The marine iguana nests that we have been monitoring within the area…seem fine.” In Japan, the wildlife casualties are more severe than in the Galapagos. As described in the U.S. Fish and Wildlife website, “A tsunami generated by a powerful earthquake off the coast of Japan struck Midway Atoll National Wildlife Refuge at 11:36 PM on Thursday, March 10th and continued for the next few hours…Fortunately, no one was injured and no major damage occurred to the island’s infrastructure…” “The short-tailed albatross nest was washed over again, but the [first short-tailed albatross] chick [to hatch on Midway in decades] was found unharmed about 35 [meters] away and returned unharmed to its nest area. A minimum of 1,000 adult/subadult, and tens of thousands of Laysan Albatross chicks, were lost. Thousands of Bonin petrels were buried alive. Spit Island [was]...

Read More