FIRST ESTIMATES OF VAQUITA ABUNDANCE

The abundance of the only population of vaquitas, Gulf of California harbor porpoise ( Phocoena sinus ), is estimated from four surveys conducted in Mexico between 1986 and 1993, using a variety of methods. A line-transect approach was applied, using some parameters estimated from a related species, the harbor porpoise ( Phocoena phocoena ). Vaquita abundance is estimated as 503 (CV = 0.63) from 1986–1988 boat surveys, 885 (CV = 0.50) from 1988–1989 aerial surveys, 572 (CV = 1.43) from a 1991 aerial survey, and 224 (CV = 0.39) from a 1993 ship survey. A weighted log-linear regression indicates a rate of population change (decline) of −17.7% per year (95% CI =−43.2% to +19.3%) between 1986 and 1993. All of these estimates of vaquita abundance indicate that the species is at a critically low level.     

Predicting bycatch hotspots for endangered leatherback turtles on longlines in the Pacific Ocean

Fisheries bycatch is a critical source of mortality for rapidly declining populations of leatherback turtles, Dermochelys coriacea. We integrated use-intensity distributions for 135 satellite-tracked adult turtles with longline fishing effort to estimate predicted bycatch risk over space and time in the Pacific Ocean. Areas of predicted bycatch risk did not overlap for eastern and western Pacific nesting populations, warranting their consideration as distinct management units with respect to fisheries bycatch. For western Pacific nesting populations, we identified several areas of high risk in the north and central Pacific, but greatest risk was adjacent to primary nesting beaches in tropical seas of Indo-Pacific islands, largely confined to several exclusive economic zones under the jurisdiction of national authorities. For eastern Pacific nesting populations, we identified moderate risk associated with migrations to nesting beaches, but the greatest risk was in the South Pacific Gyre, a broad pelagic zone outside national waters where management is currently lacking and may prove difficult to implement. Efforts should focus on these predicted hotspots to develop more targeted management approaches to alleviate leatherback bycatch.     

山东青岛沿海岛屿耐冬山茶濒临灭绝的原因及其就地保护问题

耐冬山茶(Camellia japonica)是山茶花耐寒的原始种,著名的观赏植物,天然分布于我国的东部和日本、朝鲜一带,黄海岛屿是其在我国分布的北缘。由于人为严重的破坏,天然分布的范围日益狭窄,已陷入了濒临灭绝的境地。本文对其现况、濒危的原因和挽救措施作了详细的调查,提出了建设性的意见。     

Biography of a "Feathered Pig": The California Condor Conservation Controversy

In the early 20th century, after hundreds of years of gradual decline, the California condor emerged as an object of intensive scientific study, an important conservation target, and a cultural icon of the American wilderness preservation movement. Early condor researchers generally believed that the species' survival depended upon the preservation of its wilderness habitat. However, beginning in the 1970s, a new generation of scientists argued that no amount of wilderness could prevent the condor's decline and that only intensive scientific management - including captive breeding - could save the species from certain extinction. A bitter and highly politicized battle soon developed over how to best preserve the condor. For 5years the condor was extinct in the wild; however, by the time that officials released the first captive-bred birds the condor recovery program had garnered widespread public support, even among its former critics. Today, condor advocates from the scientific and activist communities work together to manage the species and protect its habitat. The condor's story illustrates some of the tensions, problems, and successes that have accompanied the rise of conservation biology as a scientific field and environmental movement in the United States.     

Report of the Alpine Section, 1958

Background: Over 10,000 island endemic angiosperms are highly threatened by extinction. Yet, few of these species have the temporal change in their range documented and quantified, particularly within a potentially informative context of a long period of botanical study.

Aim: Here, we used Roussea simplex a mono-specific genus endemic to Mauritius, itself an island with long botanical history and advanced habitat destruction extent, to investigate how the distribution and population of this model oceanic island plant changed through time.

Methods: All known localities and population size estimates were compiled from published literature, herbarium specimens, surveys and personal communications to estimate changes in population size, extent of occurrence and area of occupancy and investigate main distribution patterns.

Results: Roussea simplex survives in nine high elevation sites. Since the 1930s, its range halved relative to its maximum known distribution and its population size decreased much faster than direct habitat loss would predict. It now qualifies as Endangered according to the IUCN Red List categories.

Conclusions: Even in an extremely deforested island, endemic plant population decline may be driven more by diminishing habitat quality than diminishing habitat extent. This renders habitat protection alone insufficient, therefore addressing ecological interactions is vital to stem population decline.