Breeding populations of seabirds in California, 1989-1991. Volume I - population estimates

In 1989-1991, the U.S. Fish and Wildlife Service surveyed breeding populations of seabirds on the entire California coast. This study was sponsored by the Minerals Management Service in relation to outer continental shelf oil and gas leasing. At 483 nesting sites (excluding terns and skimmers in southern California), we estimated 643,307 breeding birds of 21 seabird species including: 410 Fork-tailed Storm-petrel (Oceanodroma furcata); 12,551 Leach's Storm-petrel (O. leucorhoa); 7,209 Ashy Storm-petrel (O. homochroa); 274 Black Storm-petrel (O. melania); 11,916 Brown Pelican (Pelecanus occidentalis); 10,037 Double-crested Cormorant (Phalacrocorax auritus); 83,394 Brandt's Cormorant (P. penicillatus); 14,345 Pelagic Cormorant (P. pelagicus); 888 Black Oystercatcher (Haemotopus bachmani); 4,764 California Gull (Larus californicus); 61,760 Western Gull (L. occidentalis); 2,838 Caspian Tern (Sterna caspia) (excluding southern California); 3,550 Forster's Tern (S. forsteri) (excluding southern California); 272 Least Tern (S. albifrons) (excluding southern California); 351,336 Common Murre (Uria aalge); 15,470 Pigeon Guillemot (Cepphus columba); 1,821 Marbled Murrelet (Brachyramphus marmoratus); 1,760 Xantus' Murrelet (Endomychura hypoleuca); 56,562 Cassin's Auklet (Ptychoramphus aleuticus); 1,769 Rhinoceros Auklet (Cerorhinca monocerata); and 276 Tufted Puffin (Fratercula cirrhata). The inland, historical or hybrid breeding status of American White Pelican (P. erythrorynchus), American Oystercatcher (H. palliatus), Heermann's Gull (L. heermanni), Ring-billed Gull (L. delawarensis), Glaucous-winged Gull (L. glaucescens) and Black Tern (Chlidonias niger) are discussed. Estimates for Gull-billed Tern (S. nilotica), Royal Tern (S. maxima), Elegant Tern (S. elegans) and Black Skimmer (Rhynchops niger) will be included in the final draft of this report. Overall numbers were slightly lower than reported in 1975-1980 surveys (summarized in Sowls et al. 1980. Catalog of California seabird colonies. U.S. Dept. Int., Fish Wildl. Serv., Biol. Serv. Prog., FWS/OBS 37/80). Recent declines were found or suspected for Fork-tailed Storm-petrel, Leach's Storm-petrel, White Pelican, Black Tern, Caspian Tern, Least Tern, Common Murre and Marbled Murrelet. Recent increases were found or suspected for Brown Pelican, Double-crested cormorant, California Gull, Western Gull, Forster's Tern and Rhinoceros Auklet. Similar numbers were found for other species or trends could not be determined without additional surveys, studies and/or more in-depth comparisons with previous surveys. The status of terns and skimmers in southern California has not yet been finalized.

The California flooding rains during February, 1986 [abstract]

After an unusually strong and persistent pattern of atmospheric circulation over the United State[s] in Fall 1985, it became quite changeable (although high amplitude anomalies still prevailed). Following a fall that was cold in the West and warm in the East with heavy precipitation, a high pressure ridge set in over the West during December, with generally light precipitation over most of the country. Throughout the winter, the central North Pacific was very active, with large negative atmospheric pressure anomalies centered at about 45°N, l60°W. This activity may have been encouraged by an enhanced meridional eastern North Pacific sea surface temperature (SST) gradient, with positive SST anomalies in the subtropics and negative anomalies in midlatitudes. However, in January, the western high pressure ridge remained strong and temperatures were remarkably warm, increasing the threat of drought in California after the two previous dry winters. However, in February, storms from a greatly expanded and southerly displaced Aleutian Low broke into the West Coast. An unusual siege from February 11 to February 20 flooded central and northern California, with very heavy precipitation and record to near-record runoff. Upwards of 50 percent of annual average precipitation fell on locations from the upper San Joaquin to the Feather River drainage basins, and the largest flow since observations began in the early 1900's was recorded on the Sacramento River at Sacramento. The atmospheric pattern that was responsible for this remarkable stormy spell developed when the western high pressure retrograded to the northwest into the Aleutians, accompanied by the strengthened and southerly extended storm tract that moved into California. Although exact details vary from case to case, this episode displayed meteorological conditions similar to those in several other historical California winter flood events. These included a long duration of very strong westerly to southwesterly winds over a long subtropical fetch into California. Much of the precipitation during this series of storms was orographically induced by the moisture laden flow rising over the Sierra ranges. Due to the warm air mass, snow levels were relatively high (about 7500 feet) during the heaviest precipitation, resulting in copious runoff.

Extreme tides and sea levels in California [abstract]

During the winter of 1982-1983, a combination of high tides, higher than normal sea level and storm-induced waves were devastating to the coast of California. Damage estimates for public and private property destruction in the coastal counties of California totaled over $100,000,000. Much higher than average sea levels played a very important contributory role in the flooding damage. These unusually high sea levels were due to a combination of higher than normal mixed layer temperature associated with a strong, 2-year El Nino, storm surge due to low atmospheric pressure and persistent winds, and the cumulative effect of steady, "global" rise in relative sea level. Higher than average high tides coincided to an unusual extent with the peak sea levels reached during the numerous storms between November 1982 and March 1983. Important cyclical variations occur in California's mixed tide regime and the consequences of these on extreme tides have not been properly considered previously. In fact, erroneous "predictions" of much higher tides in the 1990's appearing in the popular press during the 1982-83 flooding, caused much public apprehension.

The quest for temperature records in California free of urban heat island effects [abstract, figures, and tables]

EXTRACT (SEE PDF FOR FULL ABSTRACT): The data of this paper differ from the Jones and Bradley papers [of 1982-1986] in that it represents an attempt to select thermal pollution free records rather than to include all available records. The specific long-term trends that this paper is trying to avoid are those illustrated by the heat islands of fast growing urban locations. One other major difference in this paper is that all of the records reported of this study are complete for the entire study period.

400 years of precipitation variability in central and southern California reconstructed from tree-rings [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Precipitation variability at 31 stations hanging from San Diego to San Francisco and from the coast to the Sierras was characterized ...