Halimeda opuntia and Diplosoma virens are common marine organisms in the Indo-Pacific. Halimeda grows to dense populations, and the ability of didemnids to overgrow coral has been well documented. In the light of their abundance in the Hikkaduwa Nature Park in Sri Lanka, this study investigated the effect of these two associates on the growth and survival of the commonly occurring staghorn coral, Acropora formosa. The results showed that both affected the growth rates of the host coral colonies significantly (P = 0.11 at 0.15 error level). The two associates also displayed a strong negative correlation between the spreading rate and the host growth rate (−0.71 for H. opuntia and −0.55 for D. virens). The results show that D. virens could have serious implications on coral survival with a population bloom.

We present the result of a milk analysis collected from a dead female of Sotalia guianensis (191 cm) incidentally captured in gill-net fishery together with its calf (70 cm) in November 2002, in Barra de São João, east coast of Rio de Janeiro State, Brazil. The organochlorine pesticides with the highest concentration were endosulfan1 (5.86 ng g–1), followed by p-p′DDT (4.89 ng g–1), dieldrin (2.55 ng g–1) and HCB (2.41 ng g–1). These results show the high environmental persistency of these contaminants, and the transference capacity from the mother to the calf during lactation.

The first record of the non-indigenous Fusinus rostratus in northern Brittany (north-west France) is reported. Seven specimens of this predatory gastropod were found on a muddy maerl matrix at about 10 m depth in the inner part of the bay of Morlaix. This is the first record for the Atlantic coast of France as the species originates from the warmer waters of the Mediterranean, Portugal and northern Spain, and was previously unrecorded in the English Channel. Some biometric measures are given.

A short term survey to quantify the number of marine mammals incidentally caught, and interviews to gain perceptions of local fishers towards issues of by-catch, were conducted. A total of 44 cetaceans was recorded as incidental catches at Chennai, Kakinada and Mangalore fishing harbours during 80 days of observation. Six species of dolphins and one species of porpoise were recorded. The spinner dolphin Stenella longirostris was the most frequently caught (38.6%), followed by the finless porpoise Neophocaena phocaenoides (31.8%). Gill-nets and purse seines operated from motorized boats accounted for the entire by-catch. It is estimated that 9000–10,000 cetaceans are killed by gill-nets every year along the Indian coast. The intricacies and possibilities of reducing cetacean kills by gill-nets are discussed in this paper.

The increased extent of deep-sea oil and gas exploitation puts pressure on the demand for environmental research and monitoring at great depths. Operation of biological and chemical sampling equipment in deep-sea situations is attended with several technical challenges. To overcome problems related to the operation of large bottom mooring weights and floating elements in order to avoid drifting of gear, we have developed a versatile rig unit for deep-water animal collection. The rig can be fitted with a range of sampling gear for collection of organisms at great depths. The retrieval operation is based on acoustic release from the seabed and for tracking purposes the rig is fitted with an acoustic transponder. The equipment can be operated with a small crane and does not require a specialized vessel. The trap was field tested down to 1100 m depth, fitted with three types of baited traps that caught deep-water fish and several invertebrate species.

In this note we present new records of Pontoporia blainvillei stranded along the north-eastern coast of the Rio de Janeiro State from 1999 to 2007. Three dolphins were found in the known distribution of the isolated population on the northern coast of Rio de Janeiro and showed evidence of entanglement in fishing nets. Surprisingly, one dolphin (GEMM 140) was found in Rio das Ostras, only 6.5 km south of the previously known limit of the species' distribution. However, the stranding data presented here support the hypothesis of the discontinuous distribution of this species.

Stellifer rastrifer, a coastal fish species that inhabits the tropical and south-western Atlantic Ocean is reported for the first time from the Uruguayan coast. Its geographical distribution range is extended southward more than 1200 km. Population descriptors such as a length–frequency distribution (LFD) and a length–weight relationship are presented. Some warm circulation events are suggested as a putative factor explaining the occurrence of the fish in the area.

In the first description of the population structure of the cockle Cerastoderma glaucum, a preliminary stock assessment and spatial distribution have been investigated in the Bou Ghrara Lagoon. The main results collected about this species in the coastal zone of the lagoon from 2003 through to 2004 have been recapitulated. A total of 671 cockles was collected, treated and the demographic structure of this species was studied. In terms of geographical occupation, maps of the population distributions were drawn. They showed that this population has a significant fluctuation in the colonized surface, which was roughly divided into five sites. The consequence was a remarkable biomass which represented 220 tons of fresh weight (average 15.53 g m−2) and high abundance levels reaching over 156 million individuals. The distribution of the species has also been investigated in consideration with the size which varies markedly according to location, while the shell length ranged between 6 and 29 mm. Additional factors influencing the population distribution are discussed and it is concluded that bottom characteristics, food potential (organic matter content of the sediment, phytoplankton rates and seagrass organic matter) and physicochemical factors were the fundamental factors controlling the spatial distribution of C. glaucum.

The geographical distribution of the pipefish Anarchopterus tectus in the western South Atlantic is clarified based on three museum specimens and an underwater photograph. The known range for this reef pipefish is extended by ~4000 km southwards in a straight line and by ~5500 km of coastline.

A rare soleid species, Klein's sole Synapturichthys kleinii, has been observed during night dives near the French seashore of the Mediterranean Sea. It is the first report on the behaviour, the predation and the parasites of Klein's sole in the wild.

In the last decade, a growing amount of evidence incorporated by several authors as signals of global changes, defined a trend of expansion of thermophilic species in the Mediterranean. This phenomenon is markedly shown by the spread of some non-indigenous fish beyond their natural limits and by their success in the new colonized areas. The incidence of those non-indigenous fish in the catch composition of the artisanal fishery of Tyre (south Lebanon) was investigated for the first time using both official data and daily landing site surveys. The investigatory fleet consisted of 250 small vessels (4–10 m length) with old and not very powerful engines, and about 400–550 fishermen at the end of 2005. Most of the fleet used different types of bottom standing gear, such as trammel nets, set gill-nets and bottom longlines, whereas purse seines and other fishing gear (floating longlines and traps) were used less frequently. Landings comprised a great number of species, many of which were lessepsian migrants. We recorded a total of 25 lessepsian species, representing 17 families and comprising 37% of the total landing by weight. Some of these non-indigenous species have become important components of local fisheries in the area.

Two preserved specimens of Alopias superciliosus are conserved in the small collection of the Hydrobiological Station of Rhodes. Being caught in the Dodecanese waters (south-eastern Aegean Sea, eastern Mediterranean) during the 1950s, they probably represent the oldest samples of the bigeye thresher shark captured in Mediterranean waters.

The black striped mussel Mytilopsis sallei, originally described from Guatemala, is reported for the first time from the Mediterranean Sea. In the late 20th Century the species was transported to south-east Asia, where it has caused economic and ecological damage. Its recent discovery in Haifa Harbour, Israel, suggests that the vessel-transported species has been established in the Mediterranean as well.

Five opisthobranch species (Pleurobranchus testudinarius, Caloria elegans, Dondice banyulensis, Janolus cristatus and Flabellina babai) unrecorded up-to-date in the Greek seas along with Scyllaea pelagica and Notarchus punctatus species reported after more than a century from their first finding in the Mediterranean (southern Aegean—Milos and Serifos Islands) by Forbes (1844), and zoogeographical and ecological details, are presented in this study. Scyllaea pelagica, N. punctatus and F. babai seem to have a narrow distribution in Greek waters while the rest of the species seem well established similar to what has been reported from other seas in the western Mediterranean or the Atlantic.

After the sinking of the oil carrier ‘Prestige’, which occurred in November 2002, approximately 60,000 mt of heavy oil (type M-100) were spilled into the ocean. Immediately after the accident, a series of management measures were applied to fisheries in the area, resulting in the establishment of various closed areas. Four of the most important fleets operating in the north and north-east of the Iberian Peninsula were affected (otter trawl, pair trawl, purse seine and hand line fishing gears). These fleets exploit important fisheries resources, some of them currently beyond their biological security limits. Reductions in effort were observed in all of them, particularly in the first three months of the ban and in the north-eastern area. However, apart from the hand line fleet, this did not involve a considerable reduction in the total effort produced by each of the fleets in 2003. The pair trawlers perform two trip types, but no differences in the specific composition were observed in any of them during the three years under analysis. Five types of trawling trip were identified, but important reductions were only observed for Norwegian lobster, with the fleet targeting this species as well as hake, megrim and monkfish.

Uruguayan mussel beds are located along the estuarine gradient caused by the interaction of the Río de la Plata run-off and the Atlantic Ocean, changing in species composition across this gradient. In the oceanic portion of the gradient, the exotic Perna perna showed a sequence of local extinction–colonization episodes since at least the second half of the 20th Century, thus altering the dominance relationships within the mussel beds. Owing to its larger size, this species may have caused profound effects on the spatial structure of the mussel beds and consequently on its associated macrofauna. In this vein, we analysed patterns in zonation, abundance and dominance of mussel species in a mussel bed located in the oceanic portion of the Uruguayan coast in relation to tidal and exposure level. We also evaluated if these factors could affect the dominance patterns between mussel species. The main results showed that the dominance of the native mussel Brachidontes rodriguezii was consistent across all tidal levels in all sites in terms of absolute and relative abundance, with the exception of the shallow subtidal at the intermediate site, where P. perna dominated over this species in terms of relative abundance. This suggests that the effect of an invasive mussel is highly dependent on the receptive assemblage, and that the outcome of interspecific competition can also be modulated by small-scale factors.

The inter-relationship between the pea crab Pinnotheres sinensis and its bivalve host Septifer virgatus was studied from July 2002 to December 2004. The infested bivalve generally contained a single crab (72.4–94.7%), but multiple infestation was also observed in some cases (5.3–27.6%). Seasonal fluctuations in the prevalence rate, sex ratio and ovigerous rate were examined. The prevalence rate and sex ratio increased in autumn and decreased from spring to summer. By contrast, the rate of the ovigerous female increased in summer and decreased in autumn. The carapace width of females was larger than that of males, and seasonal fluctuation in the carapace width was observed in the female crabs. All the females had a soft carapace whereas most males had a hard carapace. No females were observed outside the host, though a small number of males were observed outside it. Mating probably took place inside the host where females remained stationary, with males visiting different bivalves as well as spending much time outside the bivalves.

In recent years there has been an increasing interest in the effects of water temperature changes on the structure of marine populations. During the 1970s the burrowing starfish Astropecten jonston was present in large numbers along the south-east of Sardinia (Italy). When investigations were resumed in 1999 fewer active individuals could be found than in the 1970s, with anecdotal evidence suggesting an increase in sightings of dying animals on the sand surface. These observations, combined with a hitherto unknown susceptibility to handling stress, caused us to investigate the effect of water temperature, salinity and individual size on A. jonstoni survival. Results indicated that significantly fewer starfish were affected by a wasting disease when kept at 12°C compared with individuals maintained at 20°C and 25°C regardless of salinity (28 or 35 ppt) and that smaller starfish were less affected. Microbiological analysis revealed that, amongst other species, bacteria of the genus Vibrio, which have been associated with diseases of stressed marine invertebrates, were present in both field and laboratory animals.

The capture of two females of Ocythoe tuberculata during the summer of 2006, in the north-east Atlantic is reported. This pelagic cephalopod species are rare beyond subtropical waters and were caught at the sea surface by two live-bait boats. The appearance of this species in the area is related with an anomalous sea warming.

On 23 July 2007 a very rare specimen of the live sharksucker Echeneis naucrates was caught in the Ombla River near Dubrovnik, in the south-eastern Adriatic. First data on biometric lengths and morphology of this species are presented for the eastern Adriatic.