Four new fish species have been recorded for the first time in the last few years in Galician waters: Physiculus dalwigkii, Neoscopelus microchir, Gaidropsarus granti and Pisodonophis semicinctus. The captures of Physiculus dalwigki, N. microchir and G. granti represent a new northern limit for their distribution in the north-east Atlantic, increasing their geographical range of distribution considerably while the capture of Pisodonophis semicinctus is the second record for the Atlantic European waters.

Concentrations of iron in embryos and yolk sacs of dogfish Scyliorhinuscanicula (Elasmobranchii: Squaliformes) reared in natural and artificial (iron-free and iron-augmented) seawater were measured and compared with the iron content of adult dogfish tissues in order to investigate the iron budget of dogfish embryos. No difference in iron concentration between sexes was observed in adult dogfish. Liver iron concentration (89.6±5.8 μg g−1) showed the highest value among the three tissues investigated and was significantly higher than that measured in muscle (22.6±2.1 μg g−1), or developing eggs from females (40.5±2.5 μg g−1). The iron concentration in the entire contents of early eggcases (27.1±4.8 μg g−1) was lower, but not significantly different from that of eggs taken from the females. Dogfish yolk sacs from eggcases maintained in (a) natural seawater, (b) artificial seawater, and (c) artificial seawater with supplementary iron, for periods of up to six months, did not show any differences in iron content. Developing embryos from the artificial seawater with supplementary iron treatment demonstrated elevated iron concentrations (62.4±12.0 μg g−1) when compared with those from the remaining two treatments (35.8±5.8 and 35.1±2.7 μg g−1 respectively). The results identify maternal investment as the primary contributor to the iron burden of juvenile dogfish, and demonstrate the ability of the embryos to supplement this supply from their environment.

Both the salmon louse Lepeophtheirus salmonis and its close relative Caligus elongatus are ectoparasitic on Salmonidae in salt water in the northern hemisphere. In this study we monitored population dynamics of these parasites on anadromous brown trout, i.e. sea trout, on the Norwegian Skagerrak coast in the winters of 1998–1999 and 1999–2000. The low salinity was expected to reduce sea lice populations as lice do not tolerate sojourns of more than a few weeks, at most, in freshwater. Results confirmed the presence of both parasite species on estuarine sea trout in winter, and showed that the lice populations go through a bottleneck in this period. Prevalences of infection of both parasite species were very different in the two sampling periods, but fell below 10% in March in both winters. Median infection intensity was 1–2 fish−1. Salinity was statistically related to the presence of C. elongatus both winters, and to L. salmonis in 1999–2000. Temperature appeared to be less important for the abundance of lice.

Tributyltin (TBT) and its degradation products, dibutyltin (DBT) and monobutyltin (MBT), together with triphenyltin (TPT), were investigated in eels from the Thames Estuary and the Weston Canal (Merseyside). Within individual eels, the concentrations of organotin (OT) compounds varied considerably between tissues. Tributyltin concentrations were highest in heart and gall bladder and lowest in muscle and gonad. Tributyltin was generally the most predominant of butyltin (BT) compounds present in eel tissues and DBT the least. Phenyltins were detected in eels from both locations, notably the Weston Canal where TPT was present up to 0.367 μg g−1 (as Sn) in liver samples. Concentrations of OTs in liver (and muscle) were independent of weight and length in the eel populations examined. In a survey of OTs in eel populations along the Thames Estuary hepatic TBT levels ranged from 0.066–0.347 μg g−1 dry wt (as Sn) in liver of eels and were generally highest in the mid-section of the estuary, resembling the distribution pattern of TBT in sediment. Proportions of TBT to total BTs were also elevated in eel from this section of the waterway, consistent with continuing inputs in this region, albeit at relatively low levels. Major sewage treatment plants are sited here and may represent a possible source.

The effect of temperature on growth of butterfish, Pholis gunnellus on the west coast of Iceland was studied from September 1995 to March 1997. Butterfish were collected monthly at two sites with different temperature regimes. According to otolith readings butterfish can reach 12 years. The fish in the area with higher sea temperature were larger at all ages but had similar growth rates. Higher temperature seems to result in a shorter incubation time of butterfish eggs and/or higher growth rate of the larvae, leading to larger larvae size at settlement.

The capture of five specimens of Solea (Microchirus) boscanion (Osteichthyes: Soleidae), a species previously unrecorded in the Mediterranean, is reported from the Iberian coast (western Mediterranean). The main morphometric and meristic measurements of this species with data of the other sympatric, and morphologically very similar, soleids Microchirus variegatus and Buglossidium luteum are also given. The record is discussed in relation to climate change and competition between species.

Possible effects of ‘El Niño’ Southern Oscillation (ENSO) components ‘El Niño’ and ‘La Niña’ on populations of southern elephant seals, Mirounga leonina, were analysed. Changes in the cephalopod diet composition of moulting females at King George Island, Antarctic Peninsula were considered. The diet of female elephant seals sampled in 1991–1992 and 1992–1993 (El Niño years) were compared with those taken in 1995–1996 (La Niña year) at the same site and employing the same methodology. The squid Psychroteuthis glacialis constituted the main cephalopod prey of the seals. A reduction in the ‘Index of Biomass Ingested’ by female elephant seals (IBIF) of this prey species was observed in ‘El Niño’ years (1992, 1993) compared with the ‘La Niña’ year (1996). This reduction in biomass applied to all squid species in the seals' prey with the exception of Galiteuthis glacialis, which occurred in low numbers, but was more abundant during El Niño years than in the La Niña year.

The abundance of Calanus finmarchicus is known to have fallen between the present and the late 1950s in north-eastern Atlantic shelf waters. Further west in deeper water, however, long-term abundance of the copepod has risen.

Most krill species undergo diel vertical migration (DVM) which is to some extent influenced by light intensity. During a solar eclipse (11 August 1999) the upward and downward movement of krill, Meganyctiphanes norvegica, inhabiting a Swedish fjord followed closely changes in light intensity. Here the eclipse was partial (77%) and the weather overcast and yet krill at 70–90 m depth were able to detect, and respond to very small changes in light. This observation of an event during mid-day which is not pre-programmed confirms light as an important triggering mechanism for krill DVM.

Two specimens of the Chinese mitten crab Eriocheir sinensis (Crustacea: Decapoda: Brachyura) were caught in the River Tyne, north-east England during 2001. The specimens were brought back to the laboratory, sexed, measured and stored in 95% ethanol. Unconfirmed reports of this species' occurrence in the River Tyne were first circulated in 1997.

The specimens of Melibe fimbriata were found during October 2001 in Stari Grad Bay (Island of Hvar, Croatia) in Cymodocea nodosa and Posidonia oceanica beds on sandy and sandy–muddy bottoms at depths of 2 to 15 m. Presently, this is the northernmost record of this lessepsian immigrant in the Mediterranean basin.

Egg masses of Loligo forbesi were encountered for the first time from a depth of 730 m at Gökova Bay (southern Aegean Sea), extending the known spawning depth in the Mediterranean Sea.

Surface occurrence of ocean sunfish (Mola mola) was recorded during summer (May–September) in the western English Channel off Plymouth over a six-year period between 1995 and 2001. Fifteen individuals of between 0.5–0.7 m estimated total length were sighted during 1651 hours of observation. Nearly all sightings (93%) occurred in June and July in water between 13 and 17°C. Sunfish were mostly associated with frontal and stratified water masses (86%) rather than in cooler, mixed water.