No abstract

Eleven rajid species are taken around the Falkland Islands, with four species, Bathyraja griseocauda, Bathyraja albomaculata, Bathyraja brachyurops, and Raja flavirostris dominating commercial catches and generally occurring together. Catch limits for individual species are not used in management because species are not separated in the catch or reported separately. The catch per unit effort for the mixed rajid assemblage was standardised using generalised linear modelling techniques, and two production models were used to estimate stock size and sustainable yield. Maximum likelihood methods were used to demonstrate that there are two distinct rajid communities, one to the north and one to the south of the Falkland Islands, which have different sustainable yields. Changes in species composition over the 10-year course of the fishery confirm theoretical expectations that the larger, later-maturing B. griseocauda is being replaced in catches by the smaller, earlier-maturing B. albomaculata and B. brachyurops. These changes in composition were evident after only 6 years of directed fishing. The current fishery to the north of the Falkland Islands appears to be stable at an annual catch of about 3000 t, which is between 6.5 and 7.6% of the estimated pre-exploitation biomass.

V440 Per is a Population I Cepheid with a period of 7.57 d and low‐amplitude, almost sinusoidal light and radial velocity curves. With no reliable data on the first harmonic, its pulsation mode identification remained controversial. We obtained a radial velocity curve of V440 Per with our new high‐precision and high‐throughput Poznań Spectroscopic Telescope. Our data reach an accuracy of 130 m s−1 per individual measurement and yield a secure detection of the first harmonic with an amplitude of A2= 140 ± 15 m s−1. The velocity Fourier phase φ21 of V440 Per is inconsistent at the 7.25σ level with those of fundamental‐mode Cepheids, implying that the star must be an overtone Cepheid, as originally proposed by Kienzle et al. Thus, V440 Per becomes the longest‐period Cepheid with securely established overtone pulsations. We show that a convective non‐linear pulsation hydrocode can reproduce the Fourier parameters of V440 Per very well. The requirement to match the observed properties of V440 Per constrains the free parameters of the dynamical convection model used in the pulsation calculations, in particular the radiative loss parameter.

An experimental fishery for Patagonian toothfish Di,ssosfichus rlcginoides was opened in Falkland Island waters briefly in 1992 and then from April 1994. One to two longlines per vessel were usually deployed at night, mostly fishing for 12-30 h at depths between 600 and 2000 m. The characteristics of the vessel, gear, fishing activities and the data collection and analyses methods are described. An initial evaluation of the authors' current understanding of toothfish biology and population dynamics in Falkland Island waters is given. A first analysis of toothfish numbers caught in 1994 suggests that these are changing at rates faster than expected from simple demographic processes. Therefore, despite an intensive monitoring of catch and fishing effort of each vessel, it is still not possible to derive reliable estimates for the size of the toothfish population currently exploited around the Falkland Islands. Migration patterns in and out of' the fishery need to be understood before a reliable assessment of the fishery can be made. These results, together with current and future lines of research, are discussed in the light of ddtd available from other toothfish fisheries in austral waters.,V I996 The Fishcrics Socicty 01. tlic Britiali Isles

Abstract. New CCD photometric observations for 225 Henrietta (1995), 360 Carlova (1996, 1997, 1998), 416 Vaticana (1995-96, 1998), 516 Amherstia (1995, 1996, and 1223 Neckar (1995-96) carried out at five observatories are presented. New synodical periods for two asteroids (225, 1223) have been obtained. Using all available lightcurves, the spin vectors, senses of rotation, and triaxial elipsoid models of these five asteroids have been determined or refined.