Habitats

Biological diversity does not come easily near the intersection of Olympic Boulevard and Hoover Street. The neighborhood just west of downtown is one of the most crowded in Los Angeles County, with 25,352 people per square mile. It's chock-full of buildings and has lots of pavement, little landscaping and many economically disadvantaged families. In that setting, Leo Politi Elementary School wanted only to make a dreary corner of campus more inviting to its 817 students. Workers ripped out 5,000 square feet of concrete and Bermuda grass three years ago and planted native flora.

Biological diversity does not come easily near the intersection of Olympic Boulevard and Hoover Street. The neighborhood just west of downtown is one of the most crowded in Los Angeles County, with 25,352 people per square mile. It's chock-full of buildings and has lots of pavement, little landscaping and many economically disadvantaged families. In that setting, Leo Politi Elementary School wanted only to make a dreary corner of campus more inviting to its 817 students. Workers ripped out 5,000 square feet of concrete and Bermuda grass three years ago and planted native flora.

The thousands of students, tourists, fishermen and hungry people who visit the Little Corona del Mar tide pools are loving the area to death. Some marine animals are disappearing from the craggy rocks of Orange County's most popular tide pools, and wildlife biologists are alarmed by the steady degradation of the spot at the south end of Corona del Mar State Beach.

Even in territory as well-traversed as California, biologists can discover new creatures. The latest? A species of scorpion in Death Valley National Park. Wernerius inyoensis is tiny — just over half an inch long — and may live underground. Matthew Graham, a doctoral student at the University of Nevada, Las Vegas, discovered it during a nighttime search of the park, using a special ultraviolet light that made the animal glow in the dark. Scorpions have chemicals in their exoskeletons that fluoresce under UV light.

The federal government has announced plans to set aside more than 2,500 acres of the fast-developing Central Coast as critical habitat for an endangered snail. Most of the land being mapped out for the tiny Morro shoulderband snail is in Montana de Oro State Park near San Luis Obispo, but 615 adjacent acres are in private hands. The designation of critical habitat, which will take effect next year, does not prohibit development.

A group of Riverside County residents who claim they needlessly lost their homes in the recent fires are teaming up with local developers to campaign for changes in federal laws designed to protect endangered animals and plants. About half a dozen burned-out families in the Winchester area of south Riverside County say their homes might have been saved if government officials had given them permission to clear the brush and build firebreaks around their property earlier this year.

Regarding "All Aflutter," by Emily Green (June 26): You should be aware of two butterfly resources located on the Westside: The UCLA Botanical Gardens has recently featured its butterfly and hummingbird section in its newsletter; and the Kenneth Hahn State Recreation Area has transformed a canyon into a butterfly-hummingbird habitat. Mike Hillman Culver City

Manatees may rank lower than traditional military menaces like torpedoes or air-to-sea missiles. But a proposal to protect additional habitat for the deceptively gentle, sea-grass-munching creatures could, according to the U.S. Navy, end up reducing habitat for destroyers, aircraft carriers and nuclear submarines. The U.S. Fish and Wildlife Service soon will make a decision on whether to expand what's called critical habitat for the manatee in Florida and southern Georgia, in response to a petition from several environmental groups.

Recent news articles reported a search for natural habitats that could be improved or built to offset the destruction of wetlands by the ports of Los Angeles and Long Beach. Among habitats being considered are new artificial reefs off the local coastline, but such reefs do not meet federal and state criteria and do not compete with tide pools in the production of flora and fauna. The best habitat to reconstruct is the beach, tidal and sub-tidal areas in the Abalone Cove-Portuguese Bend landslide areas.

Specifications of a 182,000-acre habitat for the arroyo toad were published in the Federal Register on Wednesday, ensuring protection for the endangered species in parts of eight Central and Southern California counties. Approval had been held up briefly by the Bush administration's review of last-minute federal actions taken during President Bill Clinton's tenure.

A federal plan to preserve more than 9,000 acres of river habitat so that the threatened Santa Ana sucker fish can fulfill its complex life cycle has run into stiff resistance from critics who say it jeopardizes development and water supplies in the Inland Empire. Two cities and 10 water districts have sued the U.S. Fish and Wildlife Service in U.S. District Court over the agency's decision to preserve the habitat. They say that it imposes restrictions on water conservation, groundwater recharge and flood control operations that affect water supplies for 1 million residents, and that it threatens plans to sell Santa Ana River water to thirsty communities elsewhere.

Plans for designating a dog beach in Santa Monica were dashed this week when city staff said opposition from the state all but guaranteed there was "no chance" of opening what would be L.A. County's second canine-friendly stretch of seashore. The City Council, urged on by the advocacy group Unleash the Beach, voted last month to work with the state to establish a pilot off-leash dog zone in Santa Monica. But in a meeting between Santa Monica city staffers and representatives of California State Parks, which owns Santa Monica State Beach, "it was made clear that there was no chance for a pilot program to move forward at this time," according to a memo by Barbara Stinchfield, the city's community and cultural services director.

Over the last five years, the Salton Sea's shoreline has been steadily receding into the desert, creating a "bathtub ring" of exposed lake bed around the 360-square-mile body of murky water that straddles Imperial and Riverside counties. Once, it was one of the most productive fisheries and wildlife habitats in the state, but the shrinking Salton Sea has hit hard times. Along with imperiling the fish that live in the hyper-saline water and the migratory birds that stop along their annual journey, the shrinkage exposes a pesticide-laden lake bed that could contribute to the dust storms that have given the region some of the dirtiest air in California.

Modern life has been tough on the southwestern pond turtles that once were populous in the coastal part of San Diego County. Development ravaged the turtle's natural habitat. Then came the rise of invasive species that challenged the pond turtles for food or, in some cases, liked to dine on them. The African clawed frog, red-eared slider and crayfish have been particularly damaging to the turtles, which live in pools within natural streams and sloughs. In 2003 the U.S. Geological Survey's Western Ecological Research Center could find only 120 pond turtles in five locations in the San Diego region.

One of the nation's most ambitious wildlife reintroduction efforts has suffered a setback with the deaths of 104 mountain yellow-legged frogs that had been rescued from the fire-stripped San Gabriel Mountains in 2009, authorities said Tuesday. The federally endangered frogs, which recently metamorphosed from the tadpole stage, died in captive breeding tanks over the last several weeks at the Fresno Chaffee Zoo. "We have two frogs left. We're trying to determine exactly what happened," said Scott Barton, director of the zoo, which is highly regarded for amphibian husbandry.

Beware the lionfish. The pretty-but-voracious aquarium favorite, which has been gobbling other reef fish throughout the Caribbean, is swimming up South Florida's estuaries, invading the Gulf of Mexico and spreading along the South American coast. Scientists say the East Coast has never seen a mass marine invasion of this kind before, and they worry that it will set off a cascade of ecological damage to native fish, coral reef and their delicate habitat. Lionfish have been multiplying in the Caribbean and along the Carolina coast for more than a decade, probably after a few were dumped from somebody's aquarium off the shores of South Florida and their offspring rode north and east on ocean currents.

A contingent of officials, biologists and staff members from two state and federal wildlife agencies visited Ahmanson Ranch on Friday to examine the habitat of a rare flower and an endangered frog on the site of a proposed housing project. The tour of the Ventura County property where a long-debated, 3,050-home development is proposed by Washington Mutual preceded an expected decision by the U.S.

The California gnatcatcher is likely to be added this week to the nation's list of endangered and threatened species. The songbird lives and breeds in a fragile ecosystem called coastal sage scrub. This fragrant, arid mix of native plants has three main components: California sagebrush, black sage and California buckwheat. About 75 other rare plants and animals make their homes there, and many are candidates for endangered species status.

One way or another, sharks do make an impression. Whether it's those formidable teeth — long before "awesome" became an all-purpose adjective, they were regularly referred to as that — or their mythic importance, sharks are not something people are neutral about. Which is perhaps why they occupy such a special place in popular culture. And while everybody may think "Jaws," Juliet Eilperin roams more expansively. In her picaresque book, "Demon Fish: Travels Through the Hidden World of Sharks" she uses Woody Allen to reference perhaps their most mythic attribute: "A relationship, I think, is like a shark," she quotes Alvy Singer in "Annie Hall.

A proposal to replace 835 oak, sycamore and walnut trees with 199,000 new interment spaces at a prominent Hollywood Hills cemetery near Griffith Park is at the heart of a controversy over the future of what little remains of the Los Angeles area's undeveloped wildlife habitat. Forest Lawn Memorial-Parks & Mortuaries wants to develop 120 acres of its grounds because its existing expanse of carefully manicured lawns has nearly run out of room for interments in grassy havens with names like "Ascending Dawn" and "Vale of Hope.