Growth, mortality and yield-per-recruit of the poor cod, Trisopterus minutus capelanus, from the Strait of Sicily

Length-based methods (LBMs) were used to study the growth of Trisopterus minutus capelanus in the Strait of Sicily (Messina Strait). A total of 16,304 'merluzzetto' or poor cod collected by experimental trawling off the southern coast of Sicily during spring, summer, autumn 1986 and winter 1987 were measured in order to estimate the length structure of the population. Length-frequency distribution were analyzed and normal components were discriminated. Von Bertalanffy growth parameters were derived from the mean length of the normal components. The growth parameters obtained by weighted non-linear regression were: K=0.462 (yr super(1)), L sub( infinity )=222.3 (TL,mm) and t sub(o)=-0.679 yr. The resulting growth performance index ( Phi ') was 4.36, a value slightly lower than those derived for Western Mediterranean (mean Phi '=4.45) and Adriatic ( Phi '=4.58) populations and slightly higher than that derived for Hellenic waters ( Phi '=4.27). On the basis of the von Bertalanffy parameters estimated, an array of age-specific instantaneous natural mortality rate (M sub(t)=0.5-1.1) and an average value of total natural mortality rate (Z=2.1 yr super(1)) were estimated and used in the Thompson and Bell yield per recruit (Y/R) analysis in order to evaluate the status of the fishery and forecast the effects of changes in the fishing pattern. Results indicate that this resource is overexploited and that Y/R could be increased by postponing the age at first capture from 0.5 to 1.0 yr. Even a slight reduction in fishing mortality could improve the performance of the fishery. At the present level of exploitation, and assuming a constant recruitment, the spawning stock biomass per recruit (SPR) is well below the conservative threshold of 30% of the pristine or unexploited SPR.

Viability of seeds in food products proposed for field trips in Galapagos

Seeds of 14 plant species extracted from food products proposed for field trips in Galapagos were tested for viability. Strawberry Fragaria ananasa and Blackberry Rubus glaucus jams (Snob and Gustadina brands) contained no viable seeds. Schullo brand granola contained inviable Sesame Sesamum indicum seed, but Sesame in granolas prepared in Galapagos was viable. Sesame seed in bread was viable but Flax Linum usitatissimum seed in bread was not. Brown Rice Oryza sativa and Sunflower seeds Helianthus annuus were both viable. Fresh Apple Malus domestica, Naranjilla Solanum quitoense, Cucumber Cucumis sativus, Pineapple Ananas comosus, Pear Pyrus communis, Bell Pepper Capsicum annuum, Tomato Solanum lycopersicum, Grape Vinis vinifera all contained viable seeds. We recommend prohibiting any product with viable seeds from field trips to uninhabited areas. CDF Contribution Number 1009.

The Coleopteran fauna of exposed riverine sediments on the River Dane, Cheshire: A survey report

This is the Coleopteran Fauna of ERS on the river Dane, Cheshire: a survey report produced by the Environment Agency in 2003. A comprehensive survey of the Exposed Riverine Sediment (ERS) on the River Dane, Cheshire was undertaken between mid-April and mid-June 2003. 6 locations were selected and subsequently examined to determine the importance of the constituent invertebrate fauna. Appropriate sampling techniques (i.e. pitfall trapping, hand searching and excavations) were directed towards the target group (Coleoptera). All adults from the chosen taxa were identified to species level. The relative value of the fauna was assessed using species richness, conservation status, fidelity score and a site quality index.