A recent survey of The Canyons Marine Conservation Zone provided noteworthy records of several crustacean species, which are presented here. The geographic or bathymetric ranges of several species are considerably extended, while the genus Rhachotropis, which has not previously been reported from British waters, is represented by two species. Other species that were previously only known in British waters from very few, often historical, records are also reported.

Species of Anisakis typically infect the stomach of cetaceans worldwide, often causing ulcerative lesions that may compromise the host's health. These nematodes also cause anisakiasis or allergic reactions in humans. To assess the risks of this emerging zoonosis, data on long-term changes in Anisakis infections in cetaceans are necessary. Here, we compare the prevalence and severity of ulcerative lesions caused by Anisakis spp. in five cetacean species stranded along the north-west Spanish coast in 2017–2018 with published data from 1991–1996. Open ulcers were found in 32/43 short-beaked common dolphins, Delphinus delphis; 3/5 striped dolphins, Stenella coeruleoalba; 1/7 bottlenose dolphins, Tursiops truncatus; and 1/3 harbour porpoises, Phocoena phocoena meridionalis; a single individual of long-finned pilot whale, Globicephala melas, was found uninfected. In common dolphins, the mean abundance of open ulcers per host was 1.1 (95% confidence interval: 0.8–1.3), with a maximum diameter (mean ± standard deviation) of 25.4 ± 16.9 mm. Stomachs with scars or extensive fibrosis putatively associated with Anisakis were detected in 14 and five animals, respectively. A molecular analysis based on the mitochondrial cytochrome c oxidase II gene using 18 worms from three cetacean species revealed single or mixed infections of Anisakis simplex sensu stricto and Anisakis pegreffii. Compared with the period 1991–1996, we found a strong increase of prevalence, abundance and extension of ulcerative lesions in most cetacean species. Anisakis populations could have increased in the study area over the last decades, although we cannot rule out that a higher environmental stress has also boosted the pathological effects of these parasites.

A new species of Terebellidae, Loimia ramzega sp. nov., has been identified from North Brittany beaches (English Channel). This new species is characterized by its gigantic size (max 650 mm, live), two pairs of lateral lappets on segments 1 and 3; first pair more ventral, second pair more developed and lateral but oblique, with wavy edge. Nine ventral pads from segment 2 (fused on segments 2 and 3), first three pads swollen, next ones subsequently decreasing in size. Three types of notochaetae, asymmetrically bilimbate, symmetrically bilimbate and capillary. Uncini pectinate with 6 teeth (some with 5 teeth) slightly decreasing in size, in one vertical row. Pygidium with about 14 long conical marginal papillae surrounding anus.

A survey of publications and collections databases reveals a pattern of non-indigenous decapods distribution in the 13 seas around Russia and adjacent countries. No alien species were reported from Russian territorial waters and exclusive economic zone in the Japan, Okhotsk, west Bering and most of the Siberian shelf Seas. From the seas and their basins in East Europe, 13 alien species have been recorded, with seven of these yet to become established. Established or commonly occurring species can be categorized as: ‘global invaders’ (Chinese mitten crab, Eriocheir sinensis in the White, Baltic, Black, Azov and Caspian Seas; and Harris mud crab, Rhithropanopeus harrisii in all mentioned seas, except the White Sea); ‘regional aliens’ (Palaemon adspersus and P. elegans in the Caspian Sea and the latter species in the Baltic); and ‘Arctic invaders’ (Kamchatka king crab Paralithodes camtschaticus and snow crab Chionoecetes opilio). Eriocheir sinensis is the most widely occurring alien decapod species, but there are no indications of an established population in East Europe. For this and other mentioned crab species, invasion history, distribution and important biological data are reviewed. In the seas where few or no native crab species have been present, Harris mud crab (in the Azov and Caspian Seas), Kamchatka crab (in the Barents Sea) and snow crab (in the Barents and Kara Seas) have shown rapid establishment (within two decades) of an invasive population throughout an entire basis or its significant part.

Malmgrenia louiseae sp. nov. is described from both the western Mediterranean in the Gulf of Lions, and the north-east Atlantic from off Portugal and the Bay of Biscay. The species was found in muddy sediments in shallow water and is possibly associated with echiurids or synaptid holothurians. Malmgrenia louiseae sp. nov. can be clearly distinguished from all other known Malmgrenia species by the presence of an infra-acicular process in addition to the supra-acicular process on the acicular lobe of the neuropodia, the lack of microtubercules on the elytra, two kinds of notochaetae (stout with blunt tip and slender with fine pointed tip), and exclusively unidentate neurochaetae. An identification key to the north-east Atlantic and Mediterranean Malmgrenia species is provided.

Terebellides stroemii Sars, 1835, the type species of the genus, was originally described from the south-west coast of Norway. Over the past 170 plus years this species has been reported from around the world often without a detailed description; in some cases, schematic illustrations of the anterior end with the distinctive branchiae were given. Identifications were likely based mainly on the branchiae consisting of 4–5 lobes but recent work has shown that this character alone has led to misidentifications and confusion of a number of morphologically similar species. Michael Sars (1835) did not designate type specimens for this species. In order to provide an accurate definition of the genus it is necessary to redescribe and characterize the type species including the designation of a neotype. This will provide a baseline against which the potentially undescribed sibling species in the area can be compared and fully described. A large collection of specimens identified as T. stroemii from locations along the coasts of Norway was studied in the Natural History Museum, University of Oslo. This has prompted us to locate material collected by M. Sars (1835) from the vicinity of the type locality and to designate a neotype and provide a comprehensive description of the type species of the genus.

During the Capbreton cruises (1987–1990), samples of bathyal benthic macrofauna were taken at 37 stations situated along the continental slope (480–1113 m depth) of the Capbreton Canyon (Bay of Biscay, north-east Atlantic). Ten species of polychaetes belonging to six genera (Melinna, Eclysippe, Amphicteis, Anobothrus, Glyphanostomum and Tanseimaruana) of the family Ampharetidae Malmgren, 1866 were collected at 13 of these stations. Most of these species are reported for the first time in the area. Amphicteis aff. wesenbergae is reported for the first time after its recent description and a new species belonging to the genus Glyphanostomum is here described. Moreover, the finding of Melinna monoceroides represents the northernmost record of the species; Tanseimaruana vestis is recorded for the second time from the East Atlantic after its recent finding in Icelandic waters; Anobothrus aff. gracilis is reported for the second time from the Iberian Peninsula, representing, the southernmost record of the species in the Atlantic Ocean. The potential identification of two fragments of an Ampharetinae indet as Anobothrus laubieri, a deep water Arctic species, is discussed.

Peaks in northern bottlenose whale, Hyperoodon ampullatus, strandings are found between August and September in the UK and August and November in The Netherlands, consistent with a hypothesized southward migration. However, results on diet suggest that several whales stranded during these months were not travelling from northern latitudes prior to stranding. We analysed the stomach contents of ten whales stranded in the north-east Atlantic (Scotland, N = 6, England, N = 1, Ireland, N = 2 and The Netherlands, N = 1). All but one of the analysed whales (live-stranded in the River Thames in January 2006) stranded between August and October. Food remains consisted almost entirely of cephalopod mandibles. Twenty-one cephalopod species (16 families) were recorded, the most abundant taxa being Gonatus spp., Teuthowenia spp. and Taonius pavo. No fish and few crustacean remains were found. Small amounts of cephalopod flesh were found in three of the stomachs and none in the others. Given that cephalopod beaks can remain within the stomach for several days, and that there was no evidence of inshore feeding (no coastal species were present among the prey), the whales may not have fed for several days prior to stranding. Three whales had remains of warm-temperate water cephalopods (e.g. Vampyroteuthis infernalis, Heteroteuthis sp.) in their stomachs, while three individuals showed a high diversity of prey in their stomachs, suggesting that several of the whales could have been either travelling north or consistently feeding in temperate latitudes prior to stranding. As previously recorded in other deep diving teuthophagous cetaceans, two animals had ingested small amounts of plastic debris.

The occurrence of the hoplonemertean Emplectonema neesii in the north-east Atlantic has been reported from Iceland to France. This paper provides the first record of E. neesii in Galicia (north-west Spain), possibly the most southern location, if the previous records under this name from the Mediterranean referred to a different species. Morphological data and pictures of this species are provided.

Benthic dinoflagellates collected in spring–summer 2010 and 2011 from intertidal sandy sediments of the shore of Wimereux (north-east English Channel, France) were examined by light microscopy, and some of them by scanning electron microscopy. High dinoflagellate species richness, 70 species, was evidenced when compared to the plankton observed in the coastal waters of the north-east English Channel. The greatest difficulty in performing accurate species identification mainly concerned the heterotrophic species of Amphidinium sensu lato, the laterally flattened species of Amphidiniopsis, as well as some heterotrophic species of Thecadinium. Several undescribed species are here illustrated, mainly within these genera. The differences in size between species of Herdmania and Sabulodinium suggest the occurrence of at least a second species for these monotypic genera. The species Amphidiniopsis hexagona, A. rotundata, A. uroensis and Sinophysis minima are reported for the first time in the Atlantic Ocean and on European coasts. Although these species were only previously known from the Pacific Ocean, they should not necessarily be considered as newcomers or invasive species due to the scarce coverage of the previous studies on sand-dwelling dinoflagellates.

Long-term studies in the abyssal north-east Atlantic (1989–2005) have revealed large-scale changes in the benthic ecosystem and especially in some megafaunal invertebrate taxa over the period 1996–2002, termed the ‘Amperima Event’. Holothurians dominated the megafaunal samples. Temporal patterns in the abundance of holothurians showed a wide spectrum of responses, possibly related to the feeding and reproductive characteristics of the various species. One of the holothurians, the synallactid Paroriza prouhoi, is a simultaneous hermaphrodite, providing a distinct comparison with dioecious reproductive patterns more typical of deep-sea holothurian species. The reproductive biology and abundance/biomass patterns of P. prouhoi were investigated over the period 1989–2005. Paroriza prouhoi produces oocytes with a maximum diameter of ~370 µm. It has asynchronous patterns of gametogenesis both at the individual and population levels. Mean oocyte diameter and the ratio between previtellogenic and vitellogenic oocytes showed no significant differences between the periods prior to and after the Amperima Event. There were no significant differences in abundance or biomass over the time series. We conclude that the energy investment into gamete production by this hermaphrodite did not change over the 16 years examined. It is hypothesized that the feeding characteristics of P. prouhoi lead to a slow, steady and consistent production of gametes despite large-scale changes in organic matter supply to the seabed evident at the time series locality.

A comparison is made of sponge diversity and abundance in nine cold-water coral reef locations situated in four regions of the north-east Atlantic, Rockall Bank (two reef locations, both deep, oceanic), Porcupine Bank (two locations, both deep, oceanic), Mingulay (two reef locations, both shallow, near-shore), Skagerrak (three reef locations, all shallow, near-shore). Literature data from two reefs were used to supplement our own data from seven reef locations. Geographical distance between the regions may be summarized as Rockall Bank < Porcupine << Mingulay <<< Skagerrak. The first three regions are all situated west of the British Isles, and prevailing current patterns and bottom conditions would make direct larval transport between all three a distinct possibility. The fourth region, Skagerrak, is situated away from the Atlantic regions, with larval contact hampered by long distances over predominantly shallow sedimented sea bottoms. Accordingly, we expected the largest taxon turnover to be between the three Atlantic regions and the Skagerrak localities. However, cluster analysis and multidimensional scaling clearly show, that shelf reefs at Mingulay were faunistically closer to the geographically- distant shelf reefs at Skagerrak than to the geographically closer bathyal reefs of the Porcupine–Rockall area. Further research is necessary to determine whether depth is a proxy for other abiotic factors such as oceanic circulation or trophic conditions.

A description of a specimen of Cynoscion nebulosus caught in the Spanish waters of the Gulf of Cadiz, in the north-east Atlantic is presented. This is the first record of this species at this longitude.

Long-term monitoring programmes of a comparatively small area complement larger scale, but temporally limited surveys and can provide extensive datasets on seasonal occurrence and fine-scale habitat use of multiple species. A marine mammal monitoring programme, involving year-round, land-based observations, has been conducted in Broadhaven Bay candidate Special Area of Conservation, north-west Ireland, during 2002, 2005 and 2008–2011. Nine cetacean and two seal species have been recorded, with grey seal, harbour porpoise, common and bottlenose dolphins, and minke whale present throughout the year. Generalized additive models, taking into account observer effort, sighting conditions (sea state) and interannual variation, did not reveal any significant seasonal patterns in the occurrence of grey seals, bottlenose dolphins and minke whales. On the other hand, common dolphin presence in Broadhaven Bay was highest during autumn and winter. Bottlenose dolphins could be separated spatially from both common dolphins and minke whales in a classification tree by their preferential use of the shallower inshore areas of the bay (<30 m depth). However, common dolphins and minke whales, which occurred mainly in the deeper outer section of Broadhaven Bay, could not be spatially distinguished from each other, and grey seals were distributed over the entire bay. Broadhaven Bay represents an important marine mammal habitat with respect to overall species diversity and the regular occurrence of bottlenose dolphin, harbour porpoise, grey and harbour seals (all listed under Annex II of the EU Habitats Directive).

The ectoparasite community of the blackspot seabream, Pagellus bogaraveo, was studied in different locations in Portuguese waters of the north-east Atlantic Ocean. This is the first study to focus on the ectoparasites of this commercially important sparid fish. Nine ectoparasite species were detected. Gnathia sp., Aega deshaysiana, A. antillensis, Rocinela danmoniensis and Argulus sp. are reported for the first time on this host. Significant differences were detected among the sampling locations, with monogeneans being more prevalent in mainland waters, and crustaceans being more prevalent in the Atlantic islands of Madeira and Azores. Fish from Madeira showed significantly higher infection levels of all ectoparasites, especially crustaceans, and particularly high prevalence of Hatschekia pagellibogneravei. The potential impact of the species detected on captive fish is also discussed, since the blackspot seabream is a promising new species for marine aquaculture.

The understanding of the stock structure of a species is essential to effectively manage fisheries. Otolith shape analysis has been successfully applied in stock identification using the elliptic Fourier analysis. This method was used to assess possible differences in the otolith shape of Helicolenus dactylopterus caught around the Azores, Madeira and mainland Portugal. A total of 294 individuals ranging from 23 to 29 cm in total length, equally distributed by sex and area, were analysed. The multivariate analysis of variance performed on the otolith normalized elliptic Fourier descriptors (NEFDs) revealed significant differences for both area and sex, but no interaction was found between the two factors. In the canonical discriminant analysis an overall classification success of 69.4% and 66.7% was achieved for females and males respectively. These results suggest the usefulness of otolith shape analysis for stock differentiation of bluemouth from Portuguese waters.

In this work, we report for the first time the presence of the amphipod Perioculodes aequimanus from the north-east Atlantic. Specimens were collected in Zostera meadows located in the O grove inlet (north-western Iberian Peninsula), where the species is well established and is one of the numerically dominant peracarid species. Some morphological differences were found in comparison to Mediterranean individuals but those are regarded as due to intraspecific variation. This species can be distinguished from other Atlantic species according to the features of the propodus of the first gnathopod, the first coxa, the pereiopod 7 basis and the antennal peduncle.

We address the effect of spatial scale and temporal variation on model generality when forming predictive models for fish assignment using a new data mining approach, Random Forests (RF), to variable biological markers (parasite community data). Models were implemented for a fish host-parasite system sampled along the Mediterranean and Atlantic coasts of Spain and were validated using independent datasets. We considered 2 basic classification problems in evaluating the importance of variations in parasite infracommunities for assignment of individual fish to their populations of origin: multiclass (2–5 population models, using 2 seasonal replicates from each of the populations) and 2-class task (using 4 seasonal replicates from 1 Atlantic and 1 Mediterranean population each). The main results are that (i) RF are well suited for multiclass population assignment using parasite communities in non-migratory fish; (ii) RF provide an efficient means for model cross-validation on the baseline data and this allows sample size limitations in parasite tag studies to be tackled effectively; (iii) the performance of RF is dependent on the complexity and spatial extent/configuration of the problem; and (iv) the development of predictive models is strongly influenced by seasonal change and this stresses the importance of both temporal replication and model validation in parasite tagging studies.

In the first seven months of 2008, eighteen Cuvier's beaked whales (Ziphius cavirostris), four Sowerby's beaked whales (Mesoplodon bidens), five unidentified beaked whales and twenty-nine long-finned pilot whales (Globicephala melas) were reported stranded in the UK and Ireland. Decomposition of those animals investigated puts the predicted time of death at mid-January. Concerns that an unusual mortality event had taken place prompted further investigations. Most carcasses were too decomposed for necropsy. A summary of findings is presented here. Although the initial stranding of five Cuvier's beaked whales in Scotland shared some similarities with atypical mass stranding events linked in time and space to mid-frequency naval sonars, there were two important differences with the remaining strandings during this period. First, the geographical range of the event was very wide and second, the strandings occurred over a prolonged period of several months. Both of these factors could be related to the fact that the mortalities occurred offshore and the carcasses drifted ashore. The cause(s) of this high number of strandings of mixed offshore cetacean species during this period remain undetermined.

In order to understand how marine ecosystems function, it is essential to study the trophic interactions among the community members, particularly from poorly known regions. In this study, the feeding ecology and diet of conger eels, Conger conger, an abundant fish species with commercial interest, was examined in the north-east Atlantic, off Algarve (southern Portugal) between May 2005 and August 2006. The diet was characterized by species composition, size and mass of prey. Conger eels are opportunistic feeders, cannibalistic, feeding on benthopelagic/pelagic prey (67% by mass and 71% by number) but also benthic prey (32% by mass and 29% by number). Fish (67.8±4.7% in mass) are the main prey of conger eels, followed by cephalopods (16.5±3.8%) and crustaceans (15.6±3.7%). The most numerous (identifiable) fish consumed were Capros aper, occurring in 90% of the stomach samples that contained food and representing 1.4% in mass, and Scomber japonicus, the most important fish in mass (21.1%), which occurred in 4.2% of the stomach samples that contained food. The present study shows that octopodids can play a more important role in the diet of conger eels than previously thought. Of the species preyed upon by conger eels, six species (21% of the total prey taxa) are caught commercially (Trachurus trachurus, Scomber japonicus, Micromesistius poutassou, Helicolenus dactylopterus and Conger conger) by local fisheries. As discards by local trawl and longline fisheries do not correspond with the diet of C. conger, it is likely that most prey of C. conger in rocky areas were caught actively in that study region.