Invasion of the Atlantic rock crab (Cancer irroratus) at high latitudes

With the increase in global oceanic trade the establishment of non-indigenous marine organisms has become a major environmental and economic problem worldwide. Recently, the Atlantic rock crab (Cancer irroratus) was reported in Icelandic waters, Eastern North Atlantic. This is the first record of this relatively large crab species outside its natural range, i.e. the east coast of North America. The crab was most likely transferred to Iceland as larvae in ballast water and has successfully established a reproducing population in Icelandic waters. The species is distributed along the southwestern- and western-coast of Iceland. Adult specimens are now common in Faxaflói Bay, Southwest Iceland, but with sporadic occurrences in western and northwestern Icelandic waters. The green crab (Carcinus maenas) and the spider crab (Hyas araneus) are the only native brachyuran decapod species commonly found in its new habitat, but despite its recent colonization the rock crab was the most abundant brachyuran in the areas studied in southwest Iceland. Egg bearing rock crab and green crab females were found from June to October, while egg bearing spider crab females were seen from July to December. In Southwest Iceland both rock crab and green crab larvae were abundant in mid-summer but rare in both spring and autumn, which is opposite of what was observed for the spider crab. The size and abundance of adult crabs, their reproductive conditions, and occurrence of all larval stages, indicate that the Atlantic rock crab has successfully colonized Iceland.     

A benthic foraminiferal record of middle to late Pliocene (3.15-2.85 Ma) deep water change in the North Atlantic

Records of benthic foraminifera from North Atlantic DSDP Site 607 and Hole 610A indicate changes in deep water conditions through the middle to late Pliocene (3.15 to 2.85 Ma). Quantitative analyses of modern associations in the North Atlantic indicate that seven species, Fontbotia wuellerstorfi, Cibicidoides kullenbergi, Uvigerina peregrina, Nuttallides umboniferus, Melonis pompilioides, Globocassidulina subglobosa and Epistominella exigua are useful for paleoenvironmental interpretation. The western North Atlantic basin (Site 607) was occupied by North Atlantic Deep Water (NADW) until ~2.88 Ma. At that time, N. umboniferus increased, indicating an influx of Southern Ocean Water (SOW). The eastern North Atlantic basin (Hole 610A) was occupied by a relatively warm water mass, possibly Northeastern Atlantic Deep Water (NEADW), through ~2.94 Ma when SOW more strongly influenced the site. These interpretations are consistent with benthic δ¹⁸O and δ¹³C records from 607 and 610A (Raymo et al., 1992). The results presented in this paper suggest that the North Atlantic was strongly influenced by northern component deep water circulation until 2.90–2.95 Ma. After that there was a transition toward a glacially driven North Atlantic circulation more strongly influenced by SOW associated with the onset of Northern Hemisphere glaciation. The circulation change follows the last significant SST and atmospheric warming prior to ~2.6 Ma.     

Evidence of successful recruitment of non-native pink salmon Oncorhynchus gorbuscha in Iceland

In mid-May 2022, pink salmon Oncorhynchus gorbuscha smolts were caught in the rivers Botnsá, Grímsá, and Langá in Iceland. This observation provides the first evidence of successful spawning and the completion of the freshwater phase of the life cycle in Icelandic rivers. It is the most western record of O. gorbuscha smolts in Europe, further west than Russia, Norway, and the UK. Smolts originating from Iceland potentially support the recruitment of this species in the North Atlantic and may lead to the establishment of a self-sustaining population in Iceland.     

Schizymenia jonssonii sp. nov. (Nemastomatales,Rhodophyta): a relict or an introduction into the North Atlantic after the last glacial maximum?

North-Atlantic records of Schizymenia dubyi extend along the eastern shores of the North Atlantic from Morocco to southern Britain and Ireland, and the species is also recorded from Iceland. A study was undertaken to confirm the identity of the specimens from Iceland that were geographically separate from the main distribution of S. dubyi and in contrast to other species of the genus did not have gland cells. We analyzed rbcL and COI molecular sequence data from Icelandic specimens and compared the results with those for Schizymenia specimens available in GenBank. For both markers, Schizymenia was shown to be a monophyletic genus. The Icelandic specimens were clearly genetically distinct from S. dubyi and formed a well-supported clade with Schizymenia species from the Northern Pacific. Based on these results, we have described a new species, Schizymenia jonssonii, which can be distinguished by molecular phylogeny, its lack of gland cells and by being strictly intertidal. Crustose tetrasporophytes with identical COI and rbcL sequences were found at the same locations as foliose plants. Schizymenia apoda is reported for the first time in the UK, its identity confirmed by rbcL sequence data. In light of these findings, it is likely that by further molecular analysis of the genus Schizymenia in the north-eastern Atlantic and the Mediterranean, a higher diversity of Schizymenia spp. will be discovered in this region.     

The benthic algal vegetation of the Mjóifjörđur,Eastern Iceland

The benthic algal vegetation of Mjóifjör?ur, situated in the central area of the East Icelandic coast, is described regarding the species distribution from the head to the mouth of the fjord, the main algal associations and zonation patterns. The vegetation gradient along the fjord coast is related to the hydrographic conditionsviz. the influence of freshwater discharge in the inner area and that of the cold water masses of the East Icelandic Current in the outer area. Comparisons are made with the vegetation of other Icelandic fjords investigated during surveys of the Icelandic algal vegetation as a whole.     

Global population genetic structure of the starlet anemone <Emphasis Type="Italic">Nematostella vectensis</Emphasis>: multiple introductions and implications for conservation policy

Distinguishing natural versus anthropogenic dispersal of organisms is essential for determining the native range of a species and implementing an effective conservation strategy. For cryptogenic species with limited historical records, molecular data can help to identify introductions. Nematostella vectensis is a small, burrowing estuarine sea anemone found in tidally restricted salt marsh pools. This species’ current distribution extends over three coast lines: (i) the Atlantic coast of North America from Nova Scotia to Georgia, (ii) the Pacific coast of North America from Washington to central California, and (iii) the southeast coast of England. The 1996 IUCN Red List designates N. vectensis as “vulnerable” in England. Amplified fragment length polymorphism (AFLP) fingerprinting of 516 individuals from 24 N. vectensis populations throughout its range and mtDNA sequencing of a subsample of these individuals strongly suggest that anthropogenic dispersal has played a significant role in its current distribution. Certain western Atlantic populations of N. vectensis exhibit greater genetic similarity to Pacific populations or English populations than to other western Atlantic populations. At the same time, F-statistics showing high degrees of genetic differentiation between geographically proximate populations support a low likelihood for natural dispersal between salt marshes. Furthermore, the western Atlantic harbors greater genetic diversity than either England or the eastern Pacific. Collectively, these data clearly imply that N. vectensis is native to the Atlantic coast of North America and that populations along the Pacific coast and in England are cases of successful introduction.     

Observations on the morphology of some North American nemertines with consequent taxonomic changes and a reassessment of the architectonics of the phylum

A majority of the nemertine species from the western North Atlantic were originally described from life in the nineteenth century. Many of these were established by A. E. Verrill who had ‘an eye for species’ no matter which phylum he was working with, and thus when living nemertines which he described are encountered, they can usually be recognized. The morphology of most of these species has never been reported; some may prove to be species described earlier from the eastern North Atlantic. Morphological observations on the nemertine species from the North East coast of the Pacific are inadequate and have prevented satisfactory comparison with species from Japan and eastern Russia. The morphology of some species collected in the Gulf of Maine and from Cape Cod, as well as a re-examination of some of the slides of type specimens of species from the west coast of North America, indicates that their generic placement must be re-examined. The architectonic plan of the heteronemertines postulated over 100 years ago can not be substantiated and is redescribed. Three new heteronemertean genera are described: Tenuilineus gen.n. Parvicirrus gen.n., Tarrhomyos gen.n.     

Origin and dispersal of Potamophylax cingulatus (Trichoptera: Limnephilidae) in Iceland

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Biodiversity of benthic invertebrates and bioprospecting in Icelandic waters

Iceland is an island in the North Atlantic Ocean, with an exclusive economic zone of 200 nautical miles that is largely unexplored with respect to chemical constituents of the marine biota. Iceland is a geothermally active area and hosts both hot and cold adapted organisms on land and in the ocean around it. In particular, the confluence of cold and warm water masses and geothermal activity creates a unique marine environment that has not been evaluated for the potential of marine natural product diversity. Marine organisms need to protect themselves from other organisms trying to overgrow, and some need to secure their place on the bottom of the ocean. Unexplored and unique areas such as the hydrothermal vent site at the sea floor in Eyjafjordur are of particular interest. In 1992 a collaborative research programme on collecting and identifying benthic invertebrates around Iceland (BIOICE) was established, with participation of Icelandic and foreign institutes, universities and taxonomists on benthic invertebrates from all over the world. Since the programme started almost 2,000 species have been identified and of those 41 species are new to science. Our recent bioprospecting project is directed towards the first systematic investigation of the marine natural product diversity of benthic invertebrates occurring in Icelandic waters, and their potential for drug-lead discovery in several key therapeutic areas.     

Floristical and ecological characterization of the polar desert zone of Greenland

Abstract. Species composition and biomass of four plant communities were investigated in two coastal polar desert areas in eastern North Greenland, bordering the North East Water Polynya - an ice-free sea area kept open by upwelling - and compared with inland areas in North Greenland. Herb barren, the poorest type, has a species richness of 6 species/m², a cover of 0.7 %, and an aboveground biomass of 0.6 g/m² (vascular plants). The richest type, Saxifraga oppositifolia snowbed, has 10 species/m², 5.0 % cover, and 11.2 g/m² biomass. A floristic and vegetation boundary exists a few kilometres from the coast. The coastal areas bordering the North East Water Polynya had an impoverished flora and vegetation compared to areas near the ice-covered sea, possibly caused by very low summer temperatures and high frequency of clouds. A new delimitation of the polar deserts of Greenland is proposed on the basis of the number of vascular plant species, the occurrence of species with a specific inland distribution in North Greenland and the dominating life forms. At present the polar desert zone includes only areas within a zone up to ca. 15 km from the outer coast of high arctic Greenland - north of ca. 80° N. Large areas formerly classified as polar deserts in eastern North Greenland, as well as in Washington Land in western North Greenland, are excluded. New floristic data confirm that Greenland is correctly included in the Canadian province of the arctic polar deserts, whereas there is no reason for subdividing the polar deserts of the Canadian province.     

Dietary variation within and between populations of northeast Atlantic killer whales,Orcinus orca,inferred from δ13C and δ15N analyses

Epidermal skin samples from eastern North Atlantic killer whales, Orcinus orca, were analyzed for carbon and nitrogen stable isotope ratios. From those, comparisons within a data set of 17 samples collected from Tysfjord, Norway, in November suggested that diet is relatively specialized during this time period at this location. There were significant differences between a small set of samples from Iceland and those collected from Norway, which had all been assigned to the same population by a previous population genetics study. The results would be consistent with matrilines feeding on either the Norwegian or Icelandic stocks of Atlantic herring (Clupea harengus). There was no significant difference within Icelandic samples between those assigned to the population known to feed upon herring and those assigned to a population hypothesized to follow Atlantic mackerel (Scomber scombrus). The greatest differences were between the epidermal samples analyzed in this study and tooth and bone collagen samples from the North Sea that were analyzed previously, which also showed significantly more variation in isotopic ratios than found for skin samples. These differences could reflect differences in turnover rate, differences in diet‐tissue fractionation and discrimination due to the amino acid composition of the different tissues, and/or greater competition promoting dietary variation between groups in the North Sea.     

Conclusive evidence for panmixia in the American eel

Eels are unique species in the biological world. The two North Atlantic eel species, the American eel (Anguilla rostrata) and the European eel (A. anguilla), occupy a broad range of habitats from the Caribbean to Greenland in the western Atlantic and from Morocco to Iceland in the eastern Atlantic, respectively. North Atlantic eels have a catadromous life cycle, spawning only in the Sargasso Sea and spending the majority of their lives in continental (fresh, brackish and coastal) waters. Despite such a wide distribution range, North Atlantic eels have been regarded as a textbook example of panmictic species. In contrast with the large amount of population genetic studies testing the panmixia hypothesis in the European eel, a relatively modest effort has been given to study the population structure of the American eel. In this issue of Molecular Ecology, Côté et al. ( 2013 ) present the most comprehensive American eel data set to date, which includes samples of different life stages obtained throughout all its distribution range in North America. Results show a total lack of genetic differentiation among samples and provide decisive evidence for panmixia in the American eel.     

Atlantic snake pipefish (<Emphasis Type="Italic">Entelurus aequoreus</Emphasis>) extends its northward distribution range to Svalbard (Arctic Ocean)

Ecological forecasts predict the immigration of boreal species into Arctic waters as one consequence of rising sea temperatures. Here, we report the finding of Atlantic snake pipefish (Entelurus aequoreus) off the western coast of Spitsbergen at 79°N in August 2006. This syngnathid fish species, which was presumed to be confined to waters south of Iceland, has dramatically increased in population size in its core distribution area in the northeastern Atlantic since 2002, probably in response to greater reproduction success due to higher water temperatures. We conclude that our finding is an indication of the predicted northward extension of the distribution range of boreal species.     

NORTH CAROLINA MARINE ALGAE. IX. ONSLOWIA ENDOPHYTICA GEN. ET SP. NOV. (PHAEOPHYTA,SPHACELARIALES) AND NOTES ON OTHER NEW RECORDS FOR NORTH CAROLINA1

Four benthic algae are reported here for the first time in the North Carolina flora. The new brown algal genus and species, Onslowia endophytica Searles, is described as an endophyte of Halymenia floridana from the North Carolina continental shelf. New records of Boodleopsis pusilla and Naccaria corymbosa from North Carolina constitute range extensions of these tropical species on the American coast north from Florida. Blastophysa rhizopus, an endophyte and epiphyte known from the North Atlantic coast of Europe and America as well as the Caribbean is reported from North Carolina for the first time and in a new host, Predaea feldmannii.     

Composition,abundance, and diversity of peracarid crustaceans on a transect of the Kolbeinsey Ridge,north of Iceland

Composition, abundance, and diversity of Crustacea Peracarida were investigated on a transect across the Kolbeinsey Ridge, north of Iceland in summer 1992 during the M21/5 expedition with RV Meteor. This ridge is influenced by both the cold East Greenland Current as well as the warmer East Iceland Current, mixing with warmer Atlantic water. Sampling has been performed using an epibenthic sledge modified after Rothlishberg & Pearcy (1977). Being one of the most important components of the macrobenthic epi- and suprafauna, composition, abundance, and diversity of peracarids was significantly different on western and eastern sides of the slope. Isopoda and Amphipoda were most frequent at all stations, followed by Cumacea and Tanaidacea. Mysidacea have only been sampled on the eastern slope. Abundance and diversity were highest on the two eastern stations in depths of 830–940 meters, values decreased on the deepest eastern station in 1100 meter depth and were also low on both western stations in 830 and 860 meters depth. These differences are probably due to sediment composition and to quality and quantity of organic carbon reaching the seafloor, rather than to differences in salinity or in hydrographic regimes. The high abundance of peracarid crustaceans, especially of epibenthic species, capable of burrowing within the first centimeters of sediment, indicate their high potential of bioturbation and also their importance for benthic carbon cycling.     

The biogeography of the beachflea, Orchestia gammarellus (Crustacea, Amphipoda, Talitridae), in the North Atlantic with special reference to Iceland: a morphometric and genetic study

The beachflea [Orchestia gammarellus (Pallas)] is a trans‐Atlantic amphipod inhabiting the littoral fringe. In Iceland, its distribution is temperature‐limited; it has recently colonized Iceland's relatively warm south‐western coast, and in the cooler north‐west, several small populations inhabit isolated warm springs. We address two questions: (i) Do the warm spring populations show evidence of long‐term residence in Iceland, or of recent colonization? (ii) For the new south‐western Icelandic populations, can the source population be determined? We sequenced COI for 22 populations in Iceland, Nova Scotia, the Faroe Islands, the British Isles, Norway and Sweden. Morphometric analysis of a subset of populations assessed 16 continuous and five discrete characters. Genetically, we found a star phylogeny: a common haplotype was found at all sites except two neighbouring warm spring populations, and all haplotypes were within two base pairs of this common haplotype. Morphometrically, almost all populations examined differed significantly in some characters; however, the warm spring populations differed slightly more from each other than did other populations. Although the origins of the Icelandic populations could not be well resolved, our data are consistent with a recent European origin.     

Atlantic paleobathymetry, paleoproductivity and paleocirculation in the late Albian: the benthic foraminiferal record

Spatial distribution patterns of benthic foraminifers in upper Albian sediments from 25 DSDP/ODP sites and 31 onshore sections of the North and South Atlantic Ocean are used to generate paleobathymetric reconstructions and to identify areas of high primary production such as coastal and equatorial upwelling zones. New paleobathymetric estimates are provided for DSDP/ODP sites and onshore locations that are not situated on oceanic crust. Paleobathymetric reconstructions indicate shallow water exchange between the North and South Atlantic but show the existence of a deep-water connection between the western and eastern Tethys (>2500 m) through the Gibraltar Gateway. Strikingly, there is no evidence for a strong latitudinal gradient in deep-water benthic foraminiferal distribution during the late Albian: South Atlantic assemblages show close affinity to North Atlantic and Tethyan assemblages, exhibiting only a minor degree of provincialism. Biogeographic patterns reveal a distinct asymmetry in late Albian paleoproductivity for the North Atlantic. As for the present day, the eastern margins of the Atlantic were generally more productive than the western margins, and a belt of enhanced carbon flux export to the seafloor can be traced around the north African coast, which probably corresponded to a zone of vigorous coastal upwelling. By contrast, assemblage composition in the South Atlantic generally reflects mesotrophic to oligotrophic conditions. Benthic foraminiferal distribution patterns, thus, provide robust proxy data to test predictions from paleocirculation and paleobathymetric models for the mid-Cretaceous Atlantic Ocean and adjacent margins.     

Feeding ecology of mackerel and dietary overlap with herring in Icelandic waters

The Northeast Atlantic mackerel (Scomber scombrus) has been extending its summer feeding distribution north and west, including around Iceland, since around 2006. The objective of this study is to quantify the weight gain and total food consumption of mackerel and to evaluate the food competition between mackerel and herring (Clupea harengus) feeding in the marine ecosystem around Iceland during the summers 2009–2011. Mackerel feeding in Icelandic waters gained around 43% on average in weight during these summers. Based on swept-area abundance estimates of mackerel from an international survey in 2011 and available estimates of food conversion efficiency in mackerel, the weight gain in Icelandic waters in 2011 corresponded to a total consumption of around 3.4 (2.4?4.5) million tonnes. Overall, 98% of 2314 mackerel, 91% of 398 Icelandic summer-spawning herring and 96% of 424 Norwegian spring-spawning herring stomachs, collected over the summers 2009?2011, contained food. The mean weight of the stomach content of mackerel was higher than for herring in all the years. While the stomach content weight of mackerel was generally highest in southeastern and southwestern areas, it was highest for herring in western, eastern and northern areas. Analysis of stomach contents showed that Copepoda were the most important food of mackerel in most areas, while Copepoda and Euphausiacea were the most important food items for herring. Fish prey contributed a higher proportion in stomachs of mackerel than herring, although relatively low for both species.     

Carbon and nitrogen stable isotopic inventory of the most abundant demersal fish captured by benthic gears in southwestern Iceland (North Atlantic)

Stable isotopes (δ¹³C and δ¹⁵N) were used to examine the origin of organic matter for the most representative demersal species of the SW Icelandic fishery, accounting for over 70% of landings of those species in the North Atlantic. Samples were collected during a 2-week period in early September 2004 from landings and directly during fishing cruises. Stable isotopes showed that particulate organic matter and sedimentary organic matter were at the base of the food web and appeared to fill two different compartments: the pelagic and the benthic. The pelagic realm was composed of only capelin and sandeel; krill and redfish occupied an intermediate position between pelagic and benthic realms; while anglerfish, haddock, cod and ling resulted as the true demersal species while tusk, rays and plaice were strongly linked to the benthic habitat.     

Parallel Evolution,not Always so Parallel: Comparison of Small Benthic Charr, <Emphasis Type="Italic">Salvelinus alpinus</Emphasis>, from Grímsnes and Thingvallavatn,Iceland

Synopsis Iceland is unique in terms of geologically young freshwater systems and rapid adaptations of fresh water fishes to diverse habitats, e.g. lava with ground water flow. Iceland has six species of freshwater fishes, including Arctic charr, Salvelinus alpinus. Previous research has shown great diversity within this species. Four different morphs of Arctic charr are found in one lake, Thingvallavatn, including a small benthivorous charr. Similar populations of small benthic charr are known from several other Icelandic freshwater locations, including Nautavakir in Grímsnes. Our comparison of the small benthic charr morphs in Thingvallavatn and in Grímsnes showed that they are similar in morphology but distinguishable in several characteristics. Small benthic charr in Grímsnes and Thingvallavatn demonstrate similar adaptations and are an example of parallel evolution. However, subtle morphological differences between them indicate further specialized adaptations at each location.