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A new genus and species of axiid shrimp, Carolinaxius kexuae gen. et sp. nov. is described and illustrated based on a single specimen collected from an unnamed seamount in the Caroline Ridge, northwest Pacific. Although both chelipeds are missing, the specimen can be distinguished from other axiid genera by a combination of characteristics: narrowly triangular rostrum; median carina and lateral gastric carina each with one prominent tooth; submedian gastric carinae converging posteriorly, with teeth; cornea weakly pigmented, eyestalk with acute distomesial tooth on dorsal surface; male pleopod 1 two-articled; pleopod 2 with appendix interna and appendix masculina; pleopods 3–5 with appendix interna. The molecular phylogeny suggests the new genus is most closely related to another recently described genus living inside hexactinellid sponges on seamounts in the Indian Ocean, Montanaxius Dworschak, 2016. However, it differs from Montanaxius in the shape of the rostrum, the arrangement of teeth on the carapace, and the shape of the eyestalk. Besides, the significant molecular differences support the two belonging to different genera. [ABSTRACT FROM AUTHOR]

Three deep-sea black corals belonging to the family Schizopathidae, are reported from two seamounts on the Caroline Ridge in the tropical Western Pacific: Umbellapathes parva sp. nov. with depth of 1 488–1 766 m, Telopathes cf. magna MacIsaac & Best, 2013 with depth of 937–1 016 m, and Stauropathes cf. punctata (Roule, 1905) with depth of 942–1 353 m. The latter two species are the first records in the Western Pacific Ocean. U. parva sp. nov. is characterized by monopodial corallum, relatively long unpinnulated stalk with complex pinnulated branches developing from the lowermost primary pinnules and small spines. It differs from two known congeners by much smaller spines and the present of secondary pinnules. T. cf. magna MacIsaac & Best, 2013 has sparsely branched corallum, relatively long and simple pinnules arranged in subopposite or alternate pairs. S. cf. punctata (Roule, 1905) is characterized by the corallum with almost planar pinnulated branches, and pinnules arranged in subopposite pairs. Our results indicate that the corallum size and shape are variable in conspecific specimens particularly those at different growth stages. By contrast, the size of the polypar spines as well as the abpolypar spines have little variation and can be served as a main differing feature for schizopathid species. The phylogenetic analyses using nuclear internal transcribed spacer region (spanning partial 18S rDNA, ITS1, 5.8S, ITS2, and partial 28S rDNA) and two mitochondrial fragments cox3-IGR-cox1 (COI) and trnW-IGR-nad2 (NAD2) showed Telopathes, Stauropathes, and Bathypathes had close relationships, and Umbellapathes formed a sister clade with Alternatipathes. [ABSTRACT FROM AUTHOR]

Trait structure is increasingly used in plankton ecology to understand diversity and biogeography. However, our knowledge of microzooplankton (e.g. planktonic ciliates) trait structure and its variation with hydrography is limited. In this study, we analyzed planktonic ciliate trait structure in waters with different hydrography and deep Chlorophyll a maximum (DCM) layers over three seamounts: Yap, Mariana, and Caroline seamounts. Mariana seamount had a lower surface temperature than the Yap and Caroline seamounts. DCM layers over Mariana and Caroline seamounts were deeper than Yap seamount. There was a weak upwelling in upper 50 m around top of Mariana seamount. The ciliate distribution showed bimodal pattern (high abundance appeared in the surface and DCM layers) over three seamounts. At surface layer, the large size-fraction (>30 µm) abundance proportion to aloricate ciliate over Yap seamount (44.4%) was higher than Mariana (32.8%) and Caroline (36.1%) seamounts. For tintinnid abundance proportion to total ciliate, Mariana (12.0%) and Caroline (11.5%) seamounts at about 100-m depth were higher than that of Yap seamount (6.4%). Vertically, tintinnid could be divided into 4 groups over the three seamounts. At 30-m depth, group I (species occurring from surface to 100 m only) was dominant component over Yap and Caroline seamounts, while group IV (species occurring at every depth) changed into dominant component over Mariana seamount, the weak upwelling might be the reason. Salpingella faurei was the top dominant species, which corresponded to deeper DCM layers over Mariana and Caroline seamounts. Our results showed that the upwelling and the deeper DCM could influence the planktonic ciliate trait structure. [ABSTRACT FROM AUTHOR]

During an expedition to a seamount at Caroline Plate in the tropical western Pacific, a new species of Tritonia was sampled from the upper bathyal zone at depth of 970–1 262 m. This new species, Tritonia iocasica sp. nov., represents the first tritoniid nudibranch known to feed on octocoral of the family Melithaeidae. The species is up to 120 mm in length, pinkish in color; with the rhinophoral sheath divided into several petaliform extensions; veil with about 18 elongate digitiform processes; notal margin with 17–19 pairs of secondary gills; anus located below the 5th and 6th secondary gills, and the genitalia below the 3rd secondary gill on the right side of the body. Based on these external features, T. iocasica sp. nov. can be clearly distinguished from all previously described members of the genus. Phylogenetic analyses of two mitochondrial (COI, 16S rRNA) and a nuclear (H3) genes using Bayesian inference, maximum likelihood, and species delimitation analysis also support the separation of T. iocasica sp. nov. from its congeners. [ABSTRACT FROM AUTHOR]

A new species of bubblegum coral, Paragorgia papillata sp. nov., discovered from a seamount located on the Caroline Ridge at the water depth of 858 m, is studied using morphological and molecular approaches. The new gorgonian is white-colored, uniplanar with prominent autozooids, and measures about 670-mm high and 690-mm wide. The genetic distance and phylogenetic analysis showed that P. papillata sp. nov. was closely related to P. coralloides Bayer, 1993, but the former differs morphologically from the latter by its prominent calyces (diameter 2.0–4.0 mm and height 1.5–3.0 mm vs. both diameter and height about 1 mm), white cortex (vs. pink), regular 8-radiates in surface cortex (vs. mostly 8-radiate derived globular radiates) and highly ornate medullar spindles (length 185–100 µm vs. no more than 150 µm). P. papillata sp. nov. is the third known white-colored species of the genus, and the fifth species found in the tropical Western Pacific. [ABSTRACT FROM AUTHOR]

Two new species of Chrysogorgia Duchassaing & Michelotti, 1864 collected from the Caroline seamounts in the tropical Western Pacific Ocean are described. Chrysogorgia pinniformis sp. nov. belongs to Versluys' group C (Squamosae typicae) with only scales in polyp body wall and tentacles. C. pinniformis sp. nov. is characterized by large branches pinnately branched and forming multiple fans with its small branches regularly and quasi-dichotomous branched, and scales and rods present in the polyp mouth area. It is most similar to C. pinnata Cairns, 2007 by the pinnate trait, but differs from the latter by its group C pattern (vs. group A, Spiculosae) and having sclerites present in the polyp mouth area (vs. absent). Chrysogorgia varians sp. nov. belongs to the Chrysogorgia group A (Spiculosae) with rods distributed in the polyp body wall and tentacles. It is characterized by warty rods and elongated scales in the tentacles, many warts and ridges on the scales, conspicuously toothed margins at the rounded ends in the pinnules, and small rods with ridge-like warts in the polyp mouth area. This species was frequent and abundant in the Caroline seamounts during our cruises and its morphological variability in growth period was obvious. The phylogenetic analyses based on mtMutS and 28S rDNA regions supported the assignment of the new species to the genus Chrysogorgia. However, the mtMutS marker showed very limited usefulness for species delimitation and inner relationship inference of Chrysogorgia. In contrast, the 28S rDNA showed much higher level of genetic variation, and it may be a potential barcode for this genus. In the 28S rDNA trees, the two new species clustered together. Additionally, compilation of our data showed that 42 of 78 (ca. 54%) Chrysogorgia species were found in the Indo-West Pacific convergent region, indicating that this area may be a hotspot of deep-water Chrysogorgia species. [ABSTRACT FROM AUTHOR]

The genus Munidopsis has high biodiversity in seamount habitats. In this study, two new Munidopsis species, Munidopsis ahyongi sp. nov. and Munidopsis carolinensis sp. nov. from the Caroline Ridge in the tropical western Pacific Ocean were described. M. ahyongi sp. nov. is very similar to a group of species in the M. serricornis complex, but can be readily distinguished from the related species in having the oblique posterior orbital margins, 2 spines on the lateral carapace margin, and a relatively longer rostral median spine. M. carolinensis sp. nov. is different from two related species primarily in having oblique frontal margins, blunt outer orbital angles, straight lateral margins of the rostrum, scale-like rugae on sternites 5–7, and less spinose pereopod 1 (chelipeds, P1) merus and carpus. Aside from the morphological comparisons, DNA barcode analysis and phylogenetic analysis based on the cytochrome c oxidase subunit I gene (COI) were employed for the identification of these new species. [ABSTRACT FROM AUTHOR]

The Gram-stain-negative, rod-shaped, aerobic strain, designated YC1039T, was isolated from a seamount northern Mariana Trench in the tropical western Pacific. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain YC1039T was related to the genus Mesoflavibacter and had highest 16S rRNA gene sequence similarities to Mesoflavibacter sabulilitoris GJMS-9T (98.3%) and Mesoflavibacter zeaxanthinifaciens TD-ZX30T (98.2%). The predominant cellular fatty acids were iso-C15:1 G and iso-C15:0. The polar lipid profile contained phosphatidylethanolamine, two unidentified phospholipids, and 13 unidentified lipids. The respiratory quinone was MK-6. The genomic DNA G+C content of strain YC1039T was 29.8 mol%. On the basis of the evidence presented in this study, strain YC1039T represents a novel species of the genus Mesoflavibacter, for which we propose the name Mesoflavibacter profundi sp. nov. (type strain YC1039T = KACC 19026T = CGMCC 1.16329T). [ABSTRACT FROM AUTHOR]

Mass occurrences of large sponges, or ‘sponge grounds’, are found globally in a range of oceanographic settings. Interest in these grounds is growing because of their ecological importance as hotspots of biodiversity, their role in biogeochemical cycling and bentho-pelagic coupling, the biotechnological potential of their constituent sponges, and their perceived vulnerability to physical disturbance and environmental change. Little is known about the environmental conditions required for sponges to persist and for grounds to form, and very few studies have explicitly characterised and interpreted the importance of oceanographic conditions. Here, results are presented of the first observational oceanographic campaign at a known sponge ground on the Schultz Massif Seamount (SMS; Arctic Mid-Ocean Ridge, Greenland / Norwegian Seas). The campaign consisted of water column profiling and short-term deployment of a benthic lander. It was supported by multibeam echosounder bathymetry and remotely operated vehicle video surveys. The seamount summit hosted several environmental factors potentially beneficial to sponges. It occurred within relatively nutrient-rich waters and was regularly flushed from above with slightly warmer, oxygen-enriched Norwegian Arctic Intermediate Water. It was exposed to elevated suspended particulate matter levels and oscillating currents (with diurnal tidal frequency) likely to enhance food supply and prevent smothering of the sponges by sedimentation. Elevated chlorophyll a concentration was observed in lenses above the summit, which may indicate particle retention by seamount-scale circulation patterns. High sponge density and diversity observed on the summit is likely explained by the combination of several beneficial factors, the coincidence of which at the summit arises from interaction between seamount geomorphology, hydrodynamic regime, and water column structure. Neighbouring seamounts along the mid-ocean ridge are likely to present similarly complex oceanographic settings and, as with the SMS, associated sponge ground ecosystems may therefore be sensitive to changes over a particularly broad range of abiotic factors. [ABSTRACT FROM AUTHOR]

During research cruise M71/1 of German FV METEOR in winter 2006, meiofauna sampling was undertaken on the eastern Mediterranean Anaximenes Seamount at six sites (the summit, northern slope, north-western slope, north-western base, north-eastern slope and eastern base). Analysis of the benthic Copepoda (i.e. Harpacticoida and Canuelloida) revealed a highly diverse fauna. This is in contrast to what is generally considered an impoverished bathyal and abyssal fauna in the surrounding eastern Mediterranean Sea: It is regarded as one of the most oligotrophic regions of the world’s oceans. This is attested to by comparison of the seamount fauna with that of a remote deep-sea (“Far-field”) site in the Rhodes Basin, which presented a clearly impoverished fauna with respect to abundance, higher-taxon diversity and species diversity. Comparison of sites across the seamount found no overall “seamount community” of benthic Copepoda. Instead, three different assemblages could be detected, with abundance and species diversity comparable to north-eastern Atlantic seamounts and islands. Regarding species composition, however, only four of the recorded species are shared with other Mediterranean and Atlantic elevations. The benthic copepod fauna at Anaximenes Seamount is composed mostly by “typical” deep-sea and eurybathic species, whilst “typical” shallow-water species were absent. Thus, it is concluded that Anaximenes Seamount does not play a role in the dispersal of shallow-water benthic Copepoda. Nonetheless, it appears important for the establishment of abundant and diverse deep-sea communities. Moreover, it constitutes no barrier for the dispersal of deep-sea benthic Copepoda in the Mediterranean. [ABSTRACT FROM AUTHOR]

Seamounts are considered hot spots of biodiversity and can aggregate pelagic predators and their prey. Passive acoustic monitoring was conducted over 3 mo in 2012 to document the occurrence of odontocetes near a seamount chain in the central equatorial Pacific in relation to oceanographic changes over time. Beaked whale echolocation signals were most frequently encountered. The main beaked whale signal was an unknown type, BW38, which resembled signals produced by Blainville's beaked whales. It had high occurrence during high sea surface temperature and low sea surface salinity. Cuvier's beaked whales were the second most detected. They had an opposite pattern and were encountered more often when sea surface temperature was low and net primary productivity was high. Risso's dolphins and short-finned pilot whales had high acoustic densities, and echolocated predominantly at night. Risso's dolphins occurred more often during low sea surface height deviation. False killer whales were less frequently detected and mostly occurred during the day. Sperm whale detections were fewer than expected and associated with high chlorophyll a. Short duration Kogiidae encounters occurred on average every third day. These types of long-term site studies are an informative tool to comparatively assess species composition, relative abundance, and relationship to oceanographic changes. [ABSTRACT FROM AUTHOR]

Concentrations of V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Cd and Pb were determined in muscle, liver and gonads of two ecologically contrasting fishes, Helicolenus dactylopterus (benthic) and Pagellus bogaraveo (benthopelagic). Elevated concentrations of As, Se and Cd found in tissues of both species appear to mirror the contribution of volcanic activity to the natural inputs of elements to Azorean waters. Results showed different element accumulation between the two species. Whereas higher concentrations were found in the liver of P. bogaraveo , elevated values were observed in the muscle of H. dactylopterus . Differences in accumulation are most likely related to metabolic rates, diet specificities and habitat. Concentrations in gonads varied up to four orders of magnitude, being higher and more variable in P. bogaraveo than H. dactylopterus . Elevated values of Cd were detected in gonads of both species despite its non-essential role on metabolic functions, presumably related to elimination. [ABSTRACT FROM AUTHOR]

Senghor Seamount is located in the north-east (NE) Atlantic Ocean, 550 km west of Senegal, Africa, in the Cape Verde Archipelago. Macrofaunal sampling was undertaken from the summit (~100 m depth) to the base of the seamount (~3300 m depth) during the RV Meteor cruise (November 2009). The Chrysopetalidae fauna represents the first record for the family from a tall seamount habitat and is composed of East Atlantic continental margin and deep-sea species. Dysponetus sp. 1 is present at the summit and Dysponetus caecus at base depths. Thrausmatos is recorded for the first time in the Atlantic Ocean, as Thrausmatos senghorensis sp. nov., and is found at mid-slope depths only. The taxon with the largest number of individuals, Arichlidon reyssi, is most evident at the summit, with one record mid-slope. All Senghor species belong to the only three chrysopetalid genera that possess epitokous, swimming neurochaetae. Adults of A. reyssi from the Senghor Seamount and planktonic metatrochophore larvae from the NE Atlantic coast are compared and described in detail. The West Atlantic benthic nectochaete larvae of Arichlidon gathofi are also described in the interest of recognising and separating the two cryptic Atlantic Arichlidon species. [ABSTRACT FROM AUTHOR]

Highlights: [•] We developed a Seamount Ecosystem Evaluation Framework (SEEF) and database. [•] Only 0.4–4.0% of the world estimated seamount population have been sampled. [•] Seamounts present heterogeneous geophysical settings. [•] The diversity of seamount morphology and functioning have management implications. [•] SEEF constitutes a tool to identify features playing a key role in the deep-sea. [ABSTRACT FROM AUTHOR]

Ninety-two individuals of a deep-sea harrimaniid enteropneust were imaged between 1675 m and 3225 m off the California coast. Of these, about three-fourths were positioned with their posterior regions buried in sediment or hidden by rocks, and the rest were completely exposed on the substratum. When visible, the posterior end of each worm was typically associated with a dense tangle of fecal strands. One specimen was captured and is described here as the holotype of Saxipendium implication. In life, it was 22 cm long, and the color of its dome-shaped proboscis, narrow collar, and anterior trunk was medium orange. No wing-like folds of the body wall protruded anywhere along the length of the worm. The proboscis complex included a stomochord and glomeruli, but neither a heart nor a pericardial cavity could be detected. Most of the dorsal collar nerve runs along an open invagination in the dorsal midline of the collar and is only roofed over very briefly at the posterior extremity of the collar. Another unusual feature is the exaggerated posterior extension of the horns of the proboscis skeleton, which projected into the anterior extremity of the trunk. The trunk commenced anteriorly with a pharyngeal/esophageal region that included a tract of ovaries on either side of the dorsal midline. The ripest ovaries contained a single oocyte approximately 700 μm in diameter (presumably this species is gonochoric, although no males have yet been collected). The gill skeleton lacked synapticles. More posteriorly, the trunk housed a long, darkly pigmented hepatic intestine without sacculations and a short, lightly pigmented post-hepatic intestine. The geographic range of S. iniplicatum appears to be restricted to the Davidson, Guide, and Taney Seamounts region in the eastern Pacific offshore of Central California. [ABSTRACT FROM AUTHOR]

Ptilocrinus amezianeae n. sp. is a new species of stalked crinoid attributed to the family Hyocrinidae. Forty-five specimens were collected from seamounts north of the Ross Sea, and one specimen from the Kerguelen Plateau at depths ranging from 450 to 1,680 m. The collection from Admiralty and Scott seamounts constitutes the first example of a hyocrinid population known both from in situ photographs and from numerous collected specimens ranging from small juvenile to large adult. Variation in theca and stalk articulation characters throughout ontogeny is congruent with the molecular data and indicates that all the specimens examined belong to a single species. Tegmen and pinnule architecture, brachial arrangement, and stalk articular facets indicate that Ptilocrinus amezianeae n. sp. has close affinities with P. clarki and P. pinnatus from the northeastern Pacific and displays the most derived characters among these three species. Two cases of true arm division into two unequal branches suggest that Ptilocrinus and Calamocrinus are closely related. The picture and video transects on Admiralty seamount show a patchy distribution of living specimens with patches of mean density ca. 2.6 individuals m-2. In situ photographs also document predation by a sea urchin and a sea star on tegmen and proximal arms. The COI gene sequences analyzed in 25 specimens from Admiralty and Scott seamounts display low pairwise distances, low nucleotidic diversity, and intermediate haplotype diversity. These results, together with disarticulated ossicles and attachment disks observed on in situ photographs, indicate that the population investigated here is in decline. [ABSTRACT FROM AUTHOR]

Demersal fishes were sampled using a large fish trawl during two surveys carried out in February and March 2004 and 2008 in the Ross Sea, and around seamounts and islands just to the north at 66°S. The distribution and abundance of 65 species collected in these surveys were examined to determine if demersal fish communities varied throughout the area, and what environmental factors might influence this. Species accumulation with sample frequency did not reach an asymptote, but the rate of new species was low suggesting data were adequate for describing the main components of the communities. Three broad assemblages were identified, in the southern Ross Sea (south of 74°S), central-northern Ross Sea (between latitudes 71°-74°S), and the seamounts further north (65°-68°S) where some species more typical of sub- Antarctic latitudes were observed. Multivariate analyses indicated that environmental factors of seafloor rugosity (roughness), temperature, depth, and current speed were the main variables determining patterns in demersal fish communities. [ABSTRACT FROM AUTHOR]

Aim To determine if Kōko Seamount submerged below sea level before Kure Island and Pearl and Hermes Reef formed, resulting in a period in which there were no extant islands. A period with no islands would eliminate prior terrestrial and shallow marine biotas that could migrate from island to island and require a restart of colonization from distant shores to populate the younger islands of the Hawaiian volcanic chain. Location Emperor Seamount Chain, north-central Pacific Ocean. Methods We estimate subsidence rates for Kōko Seamount using ages determined from fossil large foraminifera and Sr-isotopes, and maximum depths using palaeodepth estimates based on coralline algae. These data are combined with palaeolatitude changes as the Pacific Plate moved northwards, sea level variations, and sea surface temperature variations at the seamount through time to reconstruct the time and causes of submergence. Results Rounded carbonate clasts include three facies: zooxanthelate corals, bioclastic packstones to rudstones, and rhodolith floatstones. Two rudstones contain relatively deep-water, coralline algal rhodoliths and large foraminifera indicative of Aquitanian (20.4–20 Ma) and Burdigalian (20–16 Ma) stages of the Early Miocene, consistent with Sr-isotope ages of algae and one sample of large foraminifera. Corals grew on Kōko Seamount from c. 50 to 27.1 ± 0.4 Ma, the youngest Sr-isotope age of a coral sample. These shallow, warm-water coral reefs came under increasing stress as the volcano subsided at 0.012 ± 0.003 mm yr−1, and migrated northwards, and as global climate cooled. The summit submerged and shallow coral reef growth ceased before 29 Ma, probably around 33 Ma. The volcano continued its slow subsidence, and deep-water carbonates accumulated until they too were unable to keep pace, dying out at c. 16 Ma. Main conclusions The final submergence of the summit of Kōko Seamount by about 33 Ma confirms that biota on older Hawaiian–Emperor Islands could not have migrated from island to island along the entire chain to eventually colonize the present Hawaiian Islands. There was a period between at least 33 and 29 Ma in which no islands existed, and distant colonization had to repopulate the younger portion of the Hawaiian chain, which began to emerge between about 29 and 23 Ma. [ABSTRACT FROM AUTHOR]

The identification of biodiversity hotspots and their management for conservation have been hypothesized as effective ways to protect many species. There has been a significant effort to identify and map these areas at a global scale, but the coarse resolution of most datasets masks the small-scale patterns associated with coastal habitats or seamounts. Here we used tuna longline observer data to investigate the role of seamounts in aggregating large pelagic biodiversity and to identify which pelagic species are associated with seamounts. Our analysis indicates that seamounts are hotspots of pelagic biodiversity. Higher species richness was detected in association with seamounts than with coastal or oceanic areas. Seamounts were found to have higher species diversity within 30-40 km of the summit, whereas for sets close to coastal habitat the diversity was lower and fairly constant with distance. Higher probability of capture and higher number of fish caught were detected for some shark, billfish. tuna, and other by-catch species. The study supports hypotheses that seamounts may be areas of special interest for management for marine pelagic predators. [ABSTRACT FROM AUTHOR]

Abstract: This study explores the relationship between a seamount located in the Cantabrian Sea known as Le Danois Bank (El Cachucho fishing ground), the first offshore Marine Protected Area (MPA) in Spain, and the Spanish albacore (Thunnus alalunga) surface fishery that operates during the summer and autumn months. The geographical distribution of catch per unit effort (CPUEs), expressed by number, showed that August and September were the months with the highest catches in the El Cachucho area, however, annual variability existed. Nominal CPUE series obtained from both logbook data and fishing interviews revealed that higher CPUEs were achieved inside the MPA during some fishing seasons, but there was no consistency in the data, since spatial and temporal variability were shown. The spatial distribution of monthly CPUE data was characterized by means of geostatistical analysis. Albacore schools tended to aggregate in mesoscale patches of similar dimensions but the location of these aggregations was non-stationary both in space and time. This supports the hypothesis that albacore are not randomly spatially distributed, but that they concentrated in certain areas where they find suitable conditions of food availability. [Copyright &y& Elsevier]

The deep ocean greater than 1 km covers the majority of the earth's surface. Interspersed on the abyssal plains and continental slope are an estimated 14000 seamounts, topographic features extending 1000 m off the seafloor. A variety of hypotheses are posited that suggest the ecological, evolutionary, and oceanographic processes on seamounts differ from those governing the surrounding deep sea. The most prominent and oldest of these hypotheses, the seamount endemicity hypothesis (SMEH), states that seamounts possess a set of isolating mechanisms that produce highly endemic faunas. Here, we constructed a faunal inventory for Davidson Seamount, the first bathymetric feature to be characterized as a 'seamount', residing 120 km off the central California coast in approximately 3600 m of water (Fig 1). We find little support for the SMEH among megafauna of a Northeast Pacific seamount; instead, finding an assemblage of species that also occurs on adjacent continental margins. A large percentage of these species are also cosmopolitan with ranges extending over much of the Pacific Ocean Basin. Despite the similarity in composition between the seamount and non-seamount communities, we provide preliminary evidence that seamount communities may be structured differently and potentially serve as source of larvae for suboptimal, non-seamount habitats. [ABSTRACT FROM AUTHOR]

Abstract: The Oyashio shelf region and the seasonally ice-covered areas north of Hokkaido are highly productive, supporting a wide range of species including marine mammals, seabirds and commercially important species in the western subarctic Pacific. The fishes include gadids, such as walleye pollock and Pacific cod, and subarctic migratory pelagic fishes such as chum salmon and pink salmon. It is also an important summer feeding ground for subtropical migrants such as the Japanese sardine, Japanese anchovy, Pacific saury, mackerels, Japanese common squid, whales and seabirds. In recent decades, some components of the Oyashio ecosystem (i.e., phytoplankton, mesozooplankton, gadid fish, and subtropical migrants) have shown changes in species abundance or distribution that are correlated with environmental changes such as the 1976/1977 and 1988/1989 regime shifts. The First Oyashio Intrusion moved northward from the mid-1960s until the late 1970s, when it moved southward until the 1980s, after which it returned to the north again after the mid-1990s. The sea-surface temperature in spring decreased after the late 1970s, increased after the late 1980s, and remained high during the 1990s. The extent of ice cover in the Sea of Okhostk also decreased during the latest warming in the 1980–1990s but has increased again since the late 1990s. This and other variabilities affect the Oyashio ecosystem and the surrounding region. [Copyright &y& Elsevier]

Despite rather broad definitions, global analysis showed that seamount fishes, particularly seamount-aggregating fishes, had higher intrinsic vulnerability than other groups of fishes. The pattern was similar when considering only commercially exploited species. Biological characteristics leading to greater vulnerability included a longer life span, later sexual maturation, slower growth and lower natural mortality. The results supported the contention that seamount fishes, especially those that aggregate on seamounts, are highly vulnerable to exploitation and that fishing on seamounts may not be sustainable at current levels and with current methods. A number of seamount populations have already been depleted; more depletion, extirpations, and even species extinctions may follow if fishing on seamounts is not reduced. [ABSTRACT FROM AUTHOR]

Aim We evaluated the applicability of Rapoport's rule (RR) to the marine molluscs of the Americas. The biogeographical pattern predicted by RR has been the subject of a large number of studies, some supporting it and some not. In this exercise, we attempted to generate results free of biases in taxonomy or geographical scale. Location The study area encompassed the Pacific and Atlantic sides of the entire North and South American continents. Methods Our analysis was based on secondary data. We tested the relationship of the geographical range to gradients of latitude and depth, using the methodologies of Stevens (1989) and midpoint (Rohde et al., 1993). By Spearman's correlation, we related the mean amplitude of the geographical distribution to each gradient. We compared all known molluscan species together, and performed a second analysis limited to certain taxonomically well- known groups. Results Our results were generated from a databank encompassing 4067 species. The analyses corroborated RR on both the Pacific and Atlantic coasts. In applying the pattern to the Atlantic coast, certain methodological issues had to be considered, such as the exclusion of deep-water species and taxonomically biased groups. Regional features, such as the size of a biogeographical province, seemed to strongly affect the form of the pattern. The results also supported the association of RR with a depth gradient. [ABSTRACT FROM AUTHOR]

Partially linearly polarized light is abundant in the oceans. The natural light field is partially polarized throughout the photic range, and some objects and animals produce a polarization pattern of their own. Many polarization-sensitive marine animals take advantage of the polarization information, using it for tasks ranging from navigation and finding food to communication. In such tasks, the distance to which the polarization information propagates is of great importance. Using newly designed polarization sensors, we measured the changes in linear polarization underwater as a function of distance from a standard target. In the relatively clear waters surrounding coral reefs, partial (%) polarization decreased exponentially as a function of distance from the target, resulting in a 50% reduction of partial polarization at a distance of 1.25–3 m, depending on water quality. Based on these measurements, we predict that polarization sensitivity will be most useful for short-range (in the order of meters) visual tasks in water and less so for detecting objects, signals, or structures from far away. Navigation and body orientation based on the celestial polarization pattern are predicted to be limited to shallow waters as well, while navigation based on the solar position is possible through a deeper range. [ABSTRACT FROM AUTHOR]

This study used hard-part analyses from scats (n = 117) and stomachs (n = 3) to investigate the diet of high Arctic harbour seals (Phoca vitulina L., 1758) living on Prins Karls Forland, Svalbard, in early autumn. Additionally, it compared the results of fatty-acid analyses of the seals' blubber versus that of potential prey with the findings of the more traditional diet assessment method. Svalbard harbour seals appear to be opportunistic, polyphagous feeders similar to the situation in other parts of their range. Members of the cod-family, and secondarily the sculpin-family, dominated the diet of harbour seals on Svalbard. Small fish comprised most of the diet of the harbour seals; invertebrates appeared to be insignificant. Atlantic cod (Gadus morhua L., 1758) was the most important species in the diet in terms of biomass, whereas polar cod (Boreogadus saida (Lepechin, 1774)) was the most frequently consumed prey. Our comparison between hard-part diet analyses and fatty acids is far from definitive, but it indicates a general influence of the diet on the fatty-acid composition of the inner blubber layer. However, it also suggests systematic selective processes in the incorporation of fatty acids into the blubber. Observed differences between the fatty-acid composition of the different blubber layers and possible differences between sex and age classes warrant further investigation. [ABSTRACT FROM AUTHOR]

The leatherback sea turtle, Dermochelys coriacea (Vandelli, 1761), has the most extensive range of any reptile, migrating from tropical and subtropical nesting areas to distant foraging habitats, including those in temperate and even boreal waters. This implies flexible thermal functioning. It has been inferred that leatherbacks support active foraging by keeping warm in cold water, rather than becoming lethargic as other marine turtles do. However, data consistent with this view have come from captive turtles in unnatural and stressful conditions. In the present case, foraging leatherbacks were captured at sea off Nova Scotia and their body temperature recorded within 10 min, before such large animals could change their body temperatures appreciably. Mean excess temperature over that of the sea surface (15.0–16.7 °C) averaged 8.2 °C. These results attest to, but underestimate, the capacity of free-swimming leatherbacks to keep warm in northern waters, as data from another turtle that was instrumented to record ocean temperature while diving revealed that leatherbacks foraging in this area at the same time of year may spend 40% of their time diving to waters cooler than the surface. [ABSTRACT FROM AUTHOR]

Many shallow-water organisms are subjected to regular, frequent and considerable changes in their environment imposed by the tides. Such changes range from complex alterations in local conditions, as in the intertidal zone, to simpler variations in current speed and direction offshore. To take advantage of the opportunities these changes provide, many animals undertake regular vertical and/or horizontal migratory movements in synchrony with the tidal cycle. Others use tidal currents selectively for transport to new habitats. Such movements vary in extent from a few mm to several km and may be modulated by the diel cycle of light intensity. This paper reviews the existence of tidal migration in marine animals from various taxa and habitats. Crustacean and fish examples illustrate the various functions of tidal migration, including transport, feeding, predator avoidance and reproduction. These functions are not necessarily mutually exclusive and may change throughout ontogeny. The mechanisms involved in migration are discussed in terms of direct reactions to environmental stimuli and the interaction of these responses with endogenous rhythms of activity and responsiveness. [ABSTRACT FROM AUTHOR]

Marine litter has been defined as solid materials of human origin discarded at sea, or reaching the sea through waterways. The effect of marine debris on wildlife, tourism and human health is well documented and there is considerable scientific literature about plastic litter in the sea and over the seabed, mostly highlighting the possible impact on marine mammals and tourism. Dispersal of marine and terrestrial organisms on floating objects has biogeographical and ecological interest. For some species, extension of their geographical range is more likely to be related to transport of mature individuals on floating rafts than to the active or passive dispersal of reproductive propagules. Variability and variety of rafting materials has increased dramatically in recent years and marine litter has been used widely as a raft by `hitch-hiking' species. This paper reports on the benthic invertebrates living on marine debris transported by wind and surface currents over the western Mediterranean Sea. Plastics accounted for the major item of debris because of poor degradability, however glass, cans, fishing nets and polyurethane containers, were also found. Macro-benthos living on raft material comprised mainly molluscs, polychaetes and bryozoans. Large fish were found commonly below large plastic bags. Estimations of the distances that may be covered by hitch-hiking species and the contribution of rafting to the theoretical dispersal of species is provided. [ABSTRACT FROM AUTHOR]

The tolerance to Cd2+ and possible mechanisms of Cd2+ detoxification by 178 free-living bacteria isolated from sea water, associated with marine animals (a mussel Crenomytilus grayanus, a scallop Patinopecten yessoensis), and eelgrass Zostera marina collected in The Sea of Japan and The Sea of Okhotsk have been studied. The concentrations of 25 and 50 mg Cd2+/L were highly toxic and inhibited the growth from 54% to 78% of the total bacteria studied. The free-living bacteria isolated from seawater samples (up to 50%) were tolerant to high concentrations of cadmium. Marine gamma-proteobacteria tolerated Cd2+ by the activation of different detoxifying mechanisms. The strain Halomonas sp. KMM 734 isolated from seawater prevented the uptake of Cd2+ into bacterial cells. The chromosomal cadmium resistance system of Pseudoalteromonas citrea KMM 461 and Marinobacter sp. KMM 181 was found to be similar to class III metallothioneins (also known as phytochelatins). [ABSTRACT FROM AUTHOR]