Holocene fossil pollen records of Douglas fir in northwestern California: reconstruction of past climate

Douglas fir is one of the most important trees in northwestern California. Regional pollen records suggest that it has become prominent only in the late Holocene. The primary cause for this change is probably southward stabilization of the mean airstream.

Wadge Bank trawl fishery studies. Pt. 1. The effect of the 1928 to 1935 commercial trawling on the demersal stock

The demersal fish stock of Wadge Bank is one of the important fish resources for both Sri Lanka and India. Sivalingam and Medcof (1957) have given an account of its history, general features and relative productivity. According to records the total fishing effort on the bank had been fluctuating and very recently the number of boats operating on the bank has suddenly increased, and there is a possibility that still more will begin operating on the bank in the near future (Mendis, 1965). The increased fishing effort with the possibility of still further increase calls for proper management practices by those concerned, in order to obtain the maximum sustained yield from the demersal stock. For this purpose a detailed study of the past performance of the fishery is essential. With this in view all records of commercial operations up to 1960 are being analysed by the present author and are to be published in a series. This is the first paper in the series and gives a detailed analysis of the first commercial trawling operations from 1928 to 1935. Since there had been a major break of about 10 years between this and the present fishery this data is being analysed separately.

A review of the fisheries of the Uganda waters of Lake Albert East Africa, 1928-1965/66, with catch data mainly from 1953

An historical account is given of the development of the Lake Albert fisheries since Worthington's survey in 1928. It is noted that the development of the fisheries was related to, and dependent upon, improvements in the type of gear and canoes, an incFease in the number of canoes and outboard engines in use, improved marketing facilities and better road communications. Summarized data, collected mainly since 1954, has been analysed and tabulated to show annual exports to the Congo, total annual catches 'and annual catches of individual species. A change in the relative abundance of the various species in the annual catches is described. It is noted that this change was caused by a change-over from large to small mesh size gill-nets, and that it was associated with an increased demand within Uganda for the smaller species of fish, such as Aleste's baremose and Hydrocynus forskahlii. A brief description of fish processing and marketing in the Lake Albert region is given, which emphasizes the suitability of salt-cured fish to the social and physical environment of the area. Finally, a summary of a recent survey of the potential fish resources of the lake is given in the discussion, and estimates of the 1965 catch at the north and south ends of the lake are compared with the findings of the survey. This showed that there is little danger of overfishing the Alestes baremose stocks of the Wanseko area at the 1965 rate of exploitation of the species, and that the total catch for 1965 at the south end of the lake was well below the estimated annual sustainable yield from the area.

A redescription of Diogenes senex Heller, 1865, sensu stricto (Decapoda: Anomura: Paguridea: Diogenidae)

Diogenes senex Heller, 1865 sensu stricto is redescribed from specimens collected in Australia, particularly in and around the type locality of Sydney. A neotype has been designated. Comparisons of this material with other specimens identified as D. senex by a number of authors has shown that at present only the Australian material truly represents Heller's taxon.

Yield isopleths of Tilapia esculenta Graham 1928 in Lake Victoria and Tilapia nilotica (Linnaeus) 1757 in Lake Albert

The yield equation given by BEVERTON and HOLT (1957) has several parameters which are difficult to estimate for tropical freshwater fish species. Nevertheless, some simplifying assumptions can be made and the most relevant parameters used to enable the construction of yield isopleths. Tilapia esculenfa has the following parameters: maximum length (L ∞=33.8 c.m. growth rate (K) = 0.32, natural mortality rate (M)=0.17 and the length at maturity (1 m)=22 cm. The optimum yield is obtained by catching the fish at a length of first capture of 26 em and a fishing mortality rate of 0.5. Tilapia nilotica with L ∞=49 cm, 1 m=36 cm, K=0.50 and M= 0.30 gives optimum yield when caught at a length of first capture of 35-36 cm with a fishing mortality rate of 0.5-0.6. The stuned Tilapia nilotica of Lake Albert has L ∞=17 cm, K=2.77,1 m=12 cm and M=3.37. With such a very high natural mortality, maximum yields would be obtained hy using a length of first capture less than 9 cm and a fishing mortality rate exceeding 1.8.

Classification of jinjiang oysters Crassostrea rivularis (Gould, 1861) from China, based on morphology and phylogenetic analysis

The jinjiang oyster Crassostrea rivularis [Gould, 1861. Descriptions of Shells collected in the North Pacific Exploring Expedition under Captains Ringgold and Rodgers. Proc. Boston Soc. Nat. Hist. 8 (April) 33-40] is one of the most important and best-known oysters in China. Based on the color of its flesh, two forms of C rivularis are recognized and referred to as the "white meat" and 11 red meat" oysters. The classification of white and red forms of this species has been a subject of confusion and debate in China. To clarify the taxonomic status of the two forms of C. rivularis, we collected and analyzed oysters from five locations along China's coast using both morphological characters and DNA sequences from mitochondrial 16S rRNA and cytochrome oxidase 1, and the nuclear 28S rRNA genes. Oysters were classified as white or red forms according to their morphological characteristics and then subjected to DNA sequencing. Both morphological and DNA sequence data suggest that the red and white oysters are two separate species. Phylogenetic analysis of DNA sequences obtained in this study and existing sequences of reference species show that the red oyster is the same species as C. ariakensis Wakiya [1929. Japanese food oysters. Jpn. J. Zool. 2, 359-367.], albeit the red oysters from north and south China are genetically distinctive. The white oyster is the same species as a newly described species from Hong Kong, C. hongkongensis Lam and Morton [2003. Mitochondrial DNA and identification of a new species of Crassostrea (Bivalvia: Ostreidae) cultured for centuries in the Pearl River Delta, Hong Kong, China. Aqua. 228, 1-13]. Although the name C. rivularis has seniority over C. ariakensis and C. hongkongensis, the original description of Ostrea rivularis by Gould [1861] does not fit shell characteristics of either the red or the white oysters. We propose that the name of C. rivularis Gould [1861] should be suspended, the red oyster should take the name C. ariakensis, and the white oyster should take the name C. hongkongensis. (C) 2004 Elsevier B.V. All rights reserved.

Piechota na wschodnim teatrze działań wojny secesyjnej

Wydział Historyczny

At sea and in port, or, Life and experience of William S. Fletcher : for thirty years seaman's missionary in Portland, Oregon / compiled from his journal and other authentic sources by H.K. Hines ; with an introduction by Earl Cranston.

http://www.archive.org/details/atseandinportorl00hineiala

Arthur Douglas : missionary on Lake Nyasa, the story of his life

http://www.archive.org/details/arthurdouglasmi00douguoft