Western North Atlantic Research Articles

Physics-based sizing functions for ocean-to-estuary shallow-water models

Modeling ocean processes requires a discrete representation of the system geometry, which itself contains multiple degrees of freedom, especially for systems of large geographical scale. This paper assesses the unstructured meshing requirements for a large-scale, astronomic-tide model domain of the western North Atlantic Ocean, Gulf of Mexico and Caribbean Sea with telescopic focus of the South Atlantic Bight (United States southeastern seaboard) and its estuaries. The methodologies of localized truncation error analysis (LTEA), which account only for the model interior and LTEA plus complex derivatives (+CD), which account for the model interior and boundary, are exploited due to their foundations stemming directly from tidal physics. LTEA and LTEA+CD are applied for the M2 tidal harmonics resulting from linear and nonlinear solutions of the ADCIRC (advanced circulation) model based on a highly resolved uniform mesh. The resultant target element size distributions are interrogated distinctively for the inshore (estuarine) region of the South Atlantic Bight, the inlet-punctuated coastline, the shelf-slope-rise triad and deep ocean, and the open-ocean boundary. The relatively large size of the LTEA computational molecule makes it the suitable choice for the deep ocean, offshore and shelf regions where the tidal dynamics are predominantly linear and smoothly changing in space. LTEA+CD is the logical choice for the shallows and estuaries because of the spatial coverage afforded by the combined utility of interior and boundary estimators (computational molecules), as well as its accounting for the nonlinearities in the evaluation of local truncation error. The combination of the two methods enables an almost complete coverage of the domain for generating spacing requirements, with LTEA+CD extending beyond the interior-only definition of LTEA to capture the inshore regions and model boundaries. Implementing the approach with LTEA and LTEA+CD to target finer resolution in areas with sharper gradients in the hydrodynamics, while relaxing resolution in areas with smoother hydrodynamics, resulted in a mesh with a far-reduced number of elements (∼1.3M) relative to an overly resolved uniform mesh (>10M elements) that is comparable in accuracy with ±5% tidal amplitude error for 99% of the domain.

Fisheries‐based approach to disentangle mackerel (Scomber scombrus) migration in the Cantabrian Sea

AbstractMackerel is an important commercial pelagic species present in the western and eastern North Atlantic. The Northeast Atlantic Mackerel (NEAM) stock has its southernmost spawning area mainly located western Iberian Peninsula and southern Biscay. This species performs extensive annual migrations. The present study is focused on the distribution of this species along the Cantabrian Sea, an essential area of the South Spawning Component (SSC), and the environmental drivers that can affect its migration phenology. We have used data from Vessel Monitoring System and Logbooks of the hand line fishery to estimate the catch per unit of effort (CPUE) as a proxy of its distribution and abundance. CPUEs data of fisheries targeting NEAM provided us with a tool to discriminate the most important predictors for both its prespawning and the postspawning behavior. Among the drivers that can affect mackerel migration, we have analyzed wind speed and direction, temperature at surface (SST) and at 200 m depth, chlorophylla, mixed layer depth, upwelling intensity, and the most representative geographical variables: depth, slope of the seafloor, and distance to coast. We used generalize additive models to highlight the predictors most closely related to the phenology of the species and to shape the spatial–temporal abundance of NEAM in the southern Bay of Biscay waters. Temperature and wind speed and direction are the most important factors that affect prespawning and postspawning migration of NEAM SSC and shape its niche tracking leading to a gradual advance of the spawning season.

Contrasting Along-Slope vs. Downslope Sedimentation Style on the High-Latitude Eastern Canadian Continental Margin During the Last 40 ka

Late Pleistocene Labrador Sea depositional systems developed in front of ice streams and glacier outlets from the Laurentide Ice Sheet (LIS) are documented by Huntec and 3.5 kHz seismic profiles and piston cores. Due to efficient grinding by the LIS, massive amounts of fine-grained sediments and meltwater in addition to the icebergs linked to the Heinrich events (H events) of the last glaciation were delivered to the neighboring Labrador Sea. The position of the Hudson Strait ice stream during the periodic expansion and contraction on the Labrador margin allowed fine-grained sediments and meltwater direct delivery on the lower shelf and upper slope. These discharges were then transported southward by the Labrador Current and western boundary current. In contrast to the lower shelf and upper slope, sediments delivered on the mid to the lower Labrador Slope were transported by the Northwest Atlantic Mid-Ocean Channel to distal sites. The nepheloid flow layer at or near the sea bottom or at mid-water depths developed from meltwater loaded with an excessive charge of fine-grained sediments. Contrastingly, the non-discriminatory ice rafting process delivered detritus of all sizes, but its total contribution to the sediment column was only minor, notwithstanding its paleoclimatic significance during H events. Heinrich H1, H2, and H4 layers were identified by their characteristic nepheloid flow layer deposits, that is, alternating coarse silt and clay-sized laminae with thin ice-rafted debris interspersed by coarse- to fine-grained dropstone. Furthermore, the progressive thinning and eventual disappearance of the fine-laminae (i.e., coarse and fine silt/clay) in H layers at the distal sites suggest the exhaustion and raining out of fines due to long-distance transport. However, the H3 layer was identified by a combination of nepheloid flow layer deposits (upper slope) and finely laminated mud turbidites (lower slope and deep basin) at proximal sites. In the lower Labrador Slope and Basin, the H3 stratigraphic equivalent layer was identified by exorbitantly thick finely laminated carbonate-rich mud turbidites. The divergent sedimentation style (i.e., reflected by the sediment facies) and the thickness of the H3 layer compared to other H events suggest that the Hudson Strait ice stream position was different from other H events. Therefore, our data imply that the divergence in the H3 layer between the eastern and western North Atlantic might lie with the position of the Hudson Strait ice stream on the Labrador continental margin.

High prevalence of Ichthyophonus sp. infections in Northeast Atlantic mackerel (Scomber scombrus).

High prevalence of Ichthyophonus sp. infections in Northeast Atlantic mackerel (Scomber scombrus).

The common bottlenose dolphin (Tursiops truncatus) ecotypes of the western North Atlantic revisited: an integrative taxonomic investigation supports the presence of distinct species

Abstract Integrative taxonomy can help us to gain a better understanding of the degree of evolutionary divergence between taxa. In the western North Atlantic (wNA), two ecotypes (coastal and offshore) of common bottlenose dolphin, Tursiops truncatus, exhibit some external morphological differences, and previous genetic findings suggested that they could be different species. However, their taxonomy remains unsettled. Using an integrative approach comparing traditional and geometric morphometrics, mitochondrial and nuclear DNA, we evaluated evolutionary relationships between these ecotypes. We observed congruence among these lines of evidence, strongly indicating that the wNA ecotypes are following distinct evolutionary trajectories. Based on mitochondrial DNA analyses, we detected significant divergence (Nei’s dA = 0.027), unshared haplotypes and one fixed difference leading to complete diagnosability (percentage diagnosable = 100%) of the wNA coastal ecotype. We found morphological diagnosability and negligible nuclear gene flow between the wNA ecotypes. Integration of these multiple lines of evidence revealed that the wNA coastal ecotype is an independent evolutionary unit, appearing to be more closely related to coastal dolphins in the Gulf of Mexico and Caribbean Sea than to their parapatric offshore neighbours, while the offshore dolphins form a relatively cohesive worldwide unit, T. truncatus. We propose that this coastal ecotype is recognized as a distinct species, resurrecting the name Tursiops erebennus.

Trends in the Climatology of Winter Wind Wave Heights in a Back-Barrier Bay in Western North Atlantic Ocean

Trends in the Climatology of Winter Wind Wave Heights in a Back-Barrier Bay in Western North Atlantic Ocean

Super East Asian monsoon Mei-yu in June and July 2020 tied to dissimilar-shifting upper-level westerlies

Extreme precipitation anomalies over the East Asia–western Pacific exhibited an unusually similar pattern in June and July 2020, with catastrophic Mei-yu floods in the Yangtze River Valley and severe droughts in southern China and the Bay of Bengal–the western North Pacific (BOB–WNP). However, the corresponding atmospheric circulation anomalies showed distinct characteristics, especially the meridional shifts of the East Asian westerly jet (EAWJ). In June 2020 the EAWJ displaced northward in response to a high-latitude Rossby wavetrain originated from the western North Atlantic, whereas in July 2020 the EAWJ shifted southward due to a robust Pacific–Japan (PJ) wavetrain. The linchpins of the PJ wavetrain are the rapid sea surface warming and the resultant strong convection over the Arabian Sea and the tropical eastern Indian Ocean in July, which considerably enhanced the divergence and sinking motion over the Philippine Sea and the convergence and rising motion over Korea and Japan, favorable for triggering the PJ wavetrain. Meanwhile, the enhanced WNP subtropical high was located further northward to Japan in July compared to June, transporting abundant moisture to Korea and Japan and further strengthening the Mei-yu/Baiu in July, which in turn maintained the PJ wavetrain.

Population genomic dynamics of mesopelagic lanternfishes Diaphus dumerilii, Lepidophanes guentheri, and Ceratoscopelus warmingii (Family: Myctophidae) in the Gulf of Mexico

Assessing the impacts of the Deepwater Horizon oil spill (DWHOS) on deep-sea fish assemblages of the Gulf of Mexico (GOM) has been hindered by an absence of baseline (pre-spill) data concerning the population genetic dynamics of these fishes. The lanternfishes (Myctophidae) are a speciose, yet understudied, taxonomic group, that comprise a significant portion of the global deep-sea biomass, making them integral members of meso- and bathy-pelagic food webs. Herein, we used a genomic approach (double digest restriction site associated DNA sequencing) to investigate the temporal genetic dynamics of three species of lanternfishes within the northern GOM in the region of the oil spill: Ceratoscopelus warmingii (N = 65, SNP = 1804), Diaphus dumerilii (N = 42, SNP = 2577), and Lepidophanes guentheri (N = 44, SNP = 3462). Fishes were sampled in 2011, and then again in 2015, and 2016, and genotyped using single nucleotide polymorphisms (SNP) markers. An additional 22 C. warmingii samples collected in 2014 from the western North Atlantic were used to assess genetic connectivity between these two regions. Overall, all three species were characterized by low levels of genetic diversity and high inbreeding coefficients, and within two of the three species (C. warmingii and L. guentheri), little (if any) evidence of population genetic structure was found within northern GOM waters. Conversely, significant intra-GOM genetic population structure was found for D. dumerilii, highlighting the need for a more robust population genetic survey of these fishes within the GOM to understand how populations of these fishes may respond to future environmental perturbations. In addition, significant genetic population structure was also found between sub-populations of C. warmingii from the northern GOM and western North Atlantic; with evidence of a mixture of two genetic populations co-occurring within the western North Atlantic. Given the potential for future environmental perturbations caused by expanding oil and gas extraction and climate change on GOM mesopelagic communities, rigorous population genetic assessments are required to understand the population dynamics of fishes and to safeguard the genetic diversity and resilience of this functionally important group of deep-sea fishes.

Global-Scale Environmental Niche and Habitat of Blue Shark (Prionace glauca) by Size and Sex: A Pivotal Step to Improving Stock Management

Blue shark (Prionace glauca) is amongst the most abundant shark species in international trade, however this highly migratory species has little effective management and the need for spatio-temporal strategies increases, possibly involving the most vulnerable stage or sex classes. We combined 265,595 blue shark observations (capture or satellite tag) with environmental data to present the first global-scale analysis of species’ habitat preferences for five size and sex classes (small juveniles, large juvenile males and females, adult males and females). We leveraged the understanding of blue shark biotic environmental associations to develop two indicators of foraging location: productivity fronts in mesotrophic areas and mesopelagic micronekton in oligotrophic environments. Temperature (at surface and mixed layer depth plus 100 m) and sea surface height anomaly were used to exclude unsuitable abiotic environments. To capture the horizontal and vertical extent of thermal habitat for the blue shark, we defined the temperature niche relative to both sea surface temperature (SST) and the temperature 100 m below the mixed layer depth (Tmld+100). We show that the lifetime foraging niche incorporates highly diverse biotic and abiotic conditions: the blue shark tends to shift from mesotrophic and temperate surface waters during juvenile stages to more oligotrophic and warm surface waters for adults. However, low productivity limits all classes of blue shark habitat in the tropical western North Atlantic, and both low productivity and warm temperatures limit habitat in most of the equatorial Indian Ocean (except for the adult males) and tropical eastern Pacific. Large females tend to have greater habitat overlap with small juveniles than large males, more defined by temperature than productivity preferences. In particular, large juvenile females tend to extend their range into higher latitudes than large males, likely due to greater tolerance to relatively cold waters. Large juvenile and adult females also seem to avoid areas with intermediate SST (~21.7-24.0°C), resulting in separation from large males mostly in the tropical and temperate latitudes in the cold and warm seasons, respectively. The habitat requirements of sensitive size- and sex-specific stages to blue shark population dynamics are essential in management to improve conservation of this near-threatened species.

The distribution of manta rays in the western North Atlantic Ocean off the eastern United States

In 2018, the giant manta ray was listed as threatened under the U.S. Endangered Species Act. We integrated decades of sightings and survey effort data from multiple sources in a comprehensive species distribution modeling (SDM) framework to evaluate the distribution of giant manta rays off the eastern United States, including the Gulf of Mexico. Manta rays were most commonly detected at productive nearshore and shelf-edge upwelling zones at surface thermal frontal boundaries within a temperature range of approximately 20–30 °C. SDMs predicted highest nearshore occurrence off northeastern Florida during April, with the distribution extending northward along the shelf-edge as temperatures warm, leading to higher occurrences north of Cape Hatteras, North Carolina from June to October, and then south of Savannah, Georgia from November to March as temperatures cool. In the Gulf of Mexico, the highest nearshore occurrence was predicted around the Mississippi River delta from April to June and again from October to November. SDM predictions will allow resource managers to more effectively protect manta rays from fisheries bycatch, boat strikes, oil and gas activities, contaminants and pollutants, and other threats.

A new species of Bathynomus Milne-Edwards, 1879 (Isopoda: Cirolanidae) from the southern Gulf of Mexico with a redescription of Bathynomus jamesi Kou, Chen and Li, 2017 from off Pratas Island, Taiwan

ABSTRACT Bathynomus jamesi Kou, Chen and Li, 2017 from Zhengbin fishing port in Keelung, Taiwan, was identified by the shape of the distolateral corner of the uropodal endopod, the shape of the clypeus, and the nucleotide sequences of the COI (cytochrome c oxidase subunit 1) and 16S rRNA genes. Only two species of Bathynomus have previously been recorded from Taiwan, B. doederleini Ortmann, 1894 and B. decemspinosus Shih, 1972. Bathynomus kensleyi, previously known from the South China Sea as well as the south-east Swain Reefs, Coral Sea, was primarily differentiated by the elongate and upturned pleotelson spines, but that character is now shown to also occur in mature Bathynomus jamesi. Two specimens from the Gulf of Mexico (obtained from the Enoshima Aquarium in Japan) were compared to species of Bathynomus from the western North Atlantic. Sequence data showed that one of two samples was not B. giganteus Milne-Edwards, 1879, as had been assumed, and it did not match any other species of Bathynomus. That specimen was collected off the Yucatán Peninsula and is morphologically distinct from both B. giganteus (in the relative length of the antennal flagellum and the length:width ratio of the pleotelson) and B. maxeyorum Shipley, Brooks, and Bruce in Shipley et al., 2016 (the number of pleotelson spines is seven and the distolateral corner is produced on the uropodal exopod). Therefore, it is here described as B. yucatanensis sp. nov. Bathynomus is currently a very minor fisheries resource in Taiwan and Japan, but this find demonstrates the continuing importance of the fishing industry to marine biological exploration. http://www.zoobank.org/urn:lsid:zoobank.org:pub:399605D3-356E-402D-9ED1-E36A649A3F1B

A Seesaw Variability in Tropical Cyclone Genesis between the Western North Pacific and the North Atlantic Shaped by Atlantic Multidecadal Variability

AbstractVariabilities in tropical cyclone (TC) activity are commonly interpreted in individual TC basins. We identify an antiphase decadal variation in TC genesis between the western North Pacific (WNP) and North Atlantic (NA). An inactive (active) WNP TC genesis concurs with an enhanced (suppressed) NA TC genesis. We propose that the transbasin TC connection results from a subtropical east–west “relay” teleconnection triggered by Atlantic multidecadal oscillation (AMO), involving a chain atmosphere–ocean interaction in the North Pacific. During a negative AMO phase, the tropical NA cooling suppresses local convective heating that further stimulates a descending low-level anticyclonic circulation in the tropical NA and eastern North Pacific as a Rossby wave response, inhibiting the NA TC genesis. Meanwhile, the anomalous southwesterly to the western flank of the anomalous anticyclonic circulation tends to weaken the surface evaporation and warm the SST over the subtropical eastern North Pacific (southwest–northeast-oriented zone from the tropical central Pacific to the subtropical west coast of North America). The SST warming further sustains a cyclonic circulation anomaly over the WNP by local atmosphere–ocean interaction and the Bjerknes feedback, promoting the WNP TC genesis. This transbasin linkage helps us interpret the moderate amplitude of variations in TC genesis frequency in the Northern Hemisphere.

Correlation Between Sea-Level Rise and Aspects of Future Tropical Cyclone Activity in CMIP6 Models.

Future coastal flood hazard at many locations will be impacted by both tropical cyclone (TC) change and relative sea‐level rise (SLR). Despite sea level and TC activity being influenced by common thermodynamic and dynamic climate variables, their future changes are generally considered independently. Here, we investigate correlations between SLR and TC change derived from simulations of 26 Coupled Model Intercomparison Project Phase 6 models. We first explore correlations between SLR and TC activity by inference from two large‐scale factors known to modulate TC activity: potential intensity (PI) and vertical wind shear. Under the high emissions SSP5‐8.5, SLR is strongly correlated with PI change (positively) and vertical wind shear change (negatively) over much of the western North Atlantic and North West Pacific, with global mean surface air temperature (GSAT) modulating the co‐variability. To explore the impact of the joint changes on flood hazard, we conduct climatological–hydrodynamic modeling at five sites along the US East and Gulf Coasts. Positive correlations between SLR and TC change alter flood hazard projections, particularly at Wilmington, Charleston and New Orleans. For example, if positive correlations between SLR and TC changes are ignored in estimating flood hazard at Wilmington, the average projected change to the historical 100 years storm tide event is under‐estimated by 12%. Our results suggest that flood hazard assessments that neglect the joint influence of these factors and that do not reflect the full distribution of GSAT change may not accurately represent future flood hazard.

On the relationship between paleomagnetic secular variation and excursions – Records from MIS 9 and 10 - ODP Leg 172

This paper summarizes paleomagnetic secular variation (PSV) and excursions recorded from MIS 9–10 (300–374 ka) shipboard measurements of sediments from the western North Atlantic Ocean at ODP Sites 1060, 1061, 1062, and 1063. We have identified 33 inclination features, 31 declination features, and 12 paleointensity features that are reproducible among the four ODP Sites. We have dated these records based on estimates of Milankovich carbonate cyclicity in Grutzner et al. (2002). We also dated these records by comparison with the PISO-1500 global paleointensity record (Channel et al., 2009). The two methods give comparable age estimates for this time interval.. We have also recovered a 9-m PSV record from u-channel studies of Hole 1062H. This record is almost identical to the shipboard paleomagnetic results from Site 1062. All records show evidence for the Calabrian Ridge Excursion (329 ± 3 ka); Sites 1062 and 1063 contain the most consistent and high-resolution paleomagnetic records of the excursion. The Calabrian Ridge excursion is associated with a narrow (~12 ky) interval of high angular dispersion and low paleointensity. We have also carried out a statistical study of the PSV records after removing all true excursional directions (Lund, 2018). There is significant PSV directional variability over 104 yr time scales that is common to all four sites. The pattern of angular dispersion variability is bimodal with most time spent with low (~10°) dispersion, with two shorter intervals of high (~25°) dispersion. The high-dispersion intervals are associated with low intensity intervals and excursions.

Identification of western North Atlantic odontocete echolocation click types using machine learning and spatiotemporal correlates.

A combination of machine learning and expert analyst review was used to detect odontocete echolocation clicks, identify dominant click types, and classify clicks in 32 years of acoustic data collected at 11 autonomous monitoring sites in the western North Atlantic between 2016 and 2019. Previously-described click types for eight known odontocete species or genera were identified in this data set: Blainville’s beaked whales (Mesoplodon densirostris), Cuvier’s beaked whales (Ziphius cavirostris), Gervais’ beaked whales (Mesoplodon europaeus), Sowerby’s beaked whales (Mesoplodon bidens), and True’s beaked whales (Mesoplodon mirus), Kogia spp., Risso’s dolphin (Grampus griseus), and sperm whales (Physeter macrocephalus). Six novel delphinid echolocation click types were identified and named according to their median peak frequencies. Consideration of the spatiotemporal distribution of these unidentified click types, and comparison to historical sighting data, enabled assignment of the probable species identity to three of the six types, and group identity to a fourth type. UD36, UD26, and UD28 were attributed to Risso’s dolphin (G. griseus), short-finned pilot whale (G. macrorhynchus), and short-beaked common dolphin (D. delphis), respectively, based on similar regional distributions and seasonal presence patterns. UD19 was attributed to one or more species in the subfamily Globicephalinae based on spectral content and signal timing. UD47 and UD38 represent distinct types for which no clear spatiotemporal match was apparent. This approach leveraged the power of big acoustic and big visual data to add to the catalog of known species-specific acoustic signals and yield new inferences about odontocete spatiotemporal distribution patterns. The tools and call types described here can be used for efficient analysis of other existing and future passive acoustic data sets from this region.

Incidence of microplastic fiber ingestion by Common Terns (Sterna hirundo) and Roseate Terns (S. dougallii) breeding in the Northwestern Atlantic

Ingestion of microplastics has been documented across marine species, but exposure remains sparsely described in many seabird species. We assess microplastic (between 0.2 and 5.0 mm) ingestion in two Northwestern Atantic - breeding species for which exposure to microplastics is entirely or largely undescribed: Common Terns (Sterna hirundo) and Roseate Terns (S. dougallii). Common Tern microplastic load did not vary between life stages (p = 0.590); microplastic load did differ in Common Tern adults breeding at two of three colonies explored (p = 0.002), with no other regional differences observed. Roseate Terns ingested significantly more microplastics than Common Terns (p = 0.007). Our results show that microplastic ingestion by terns varies regionally and interspecifically, but not by life stage, trends potentially explained by dietary differences. We provide the first quantification of microplastic fiber ingestion by terns in the Northwestern Atlantic and identify trophic dynamics related to microplastic ingestion, representing an important step toward understanding the risk of the pollutant to terns across regions, as well as toward the use of terns as potential bioindicators of microplastics.

Legacy and emerging flame retardants in sharks from the Western North Atlantic Ocean

Following the discontinuation of commercial polybrominated diphenyl ether (PBDE) mixtures, a variety of alternative flame retardants (FRs) have been developed and employed. To understand the contamination status of these emerging FRs in marine fish and wildlife, we investigated their bioaccumulation in four shark species, including shortfin mako shark (Isurus oxyrhinchus; n = 26), porbeagle (Lamna nasus; n = 4), sandbar shark (Carcharhinus plumbeus; n = 6), and common thresher (Alopias vulpinus; n = 4), from coastal and offshore waters of the western North Atlantic Ocean. Median concentrations of emerging FRs, including dechlorane analogues (i.e., dechlorane plus, Dec-602, −603, and − 604), tetrabromo-o-chlorotoluene (TBCT), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), and hexabromobenzene (HBBZ), ranged from 1.4–7.4, 10.2–22.4, 1.0–16.7, and 4.1–17.7 ng/g lipid weight (lw), respectively. Although concentrations of emerging FRs were generally 1–2 orders of magnitude lower than those of legacy FRs (i.e., PBDEs, 312–800 ng/g lw and hexabromocyclododecane or HBCDD, 17.2–99.3 ng/g lw), they were detected in more than 80% of the shark livers. Analysis of available biological data indicated that fork length significantly correlated with the concentrations of ΣPBDEs, HBCDD, ΣDechloranes or TBCT in shortfin mako livers. This indicates that longer-term exposure likely results in elevated FR concentrations in sharks. Our findings suggest likely exposure of western North Atlantic fish and wildlife to several emerging FRs, including dechloranes, BTBPE, HBBZ, and TBCT. Additional studies are needed to better elucidate their potential risks to fish and wildlife as well as the variety of environmental and biological factors influencing these risks.

New species and records of Caulleriella, Chaetocirratulus and Chaetozone (Annelida, Cirratulidae) from continental shelf and slope depths of the Western North Atlantic Ocean

Seventeen species of cirratulid polychaetes, 13 new to science, are reported from continental shelf and slope depths of the western North Atlantic Ocean. The samples were collected as part of deep-water offshore reconnaissance surveys from New England to the Carolinas and long-term monitoring programs in Boston Harbor, Massachusetts Bay, and Georges Bank off Massachusetts. The new species are included in the genera Caulleriella (C. cryptica n. sp.), Chaetocirratulus (C. hessleri n. sp., C. sandersi n. sp., and C. tomaculus n. sp.), and Chaetozone (C. adunca n. sp., C. artaspinosa n. sp., C. brychiata n. sp., C. castouria n. sp., C. donerae n. sp., C. lophia n. sp., C. novagracilis, n. sp., C. paucispinosa n. sp. and C. profunda n. sp. In addition, Chaetozone gayheadia Hartman, 1965 is redescribed based on type-material and additional collections and transferred to the genus Chaetocirratulus. Chaetozone benthaliana McIntosh, 1985 is designated a species inquirendum because it was described from a posterior fragment that cannot be confirmed as belonging to any known cirratulid genus or species. Updated descriptions and new records are provided for Chaetozone anasima, C. diodonta, and C. hystricosa all originally described by Doner Blake (2006).

A bowhead whale in the eastern North Pacific.

Bowhead whales occur in the Arctic year‐round. Their movements are largely correlated with seasonal expansions and reductions of sea ice, but a few recent extralimital sightings have occurred in the eastern and western North Atlantic and one was also documented in the western North Pacific over 50 years ago. Here we present details of a juvenile bowhead whale that was photographed and filmed from above and below the water while it was skim‐feeding in Caamaño Sound, BC, Canada on May 31, 2016. This sighting occurred over 2000 km southeast from the nearest known range for this species in the Bering Sea at a time that most bowhead whales in that region would have been migrating northeast. This sighting represents the first and only documentation of a bowhead whale in the eastern North Pacific to date.

Seasonal Prediction of Tropical Cyclones over the North Atlantic and Western North Pacific

AbstractIn this study, tropical cyclones (TCs) over the western North Pacific (WNP) and North Atlantic (NA) basins are analyzed in seasonal forecasting models from five European modeling centers. Most models are able to capture the observed seasonal cycle of TC frequencies over both basins; however, large differences for numbers and spatial track densities are found. In agreement with previous studies, TC numbers are often underestimated, which is likely related to coarse model resolutions. Besides shortcomings in TC characteristics, significant positive skill (deterministic and probabilistic) in predicting TC numbers and accumulated cyclone energy is found over both basins. Whereas the predictions of TC numbers over the WNP basin are mostly unreliable, most seasonal forecast provide reliable predictions for the NA basin. Besides positive skill over the entire NA basin, all seasonal forecasting models are skillful in predicting the interannual TC variability over a region covering the Caribbean and North American coastline, suggesting that the models carry useful information, including for adaptation and mitigation purposes ahead of the upcoming TC season. However, skill in all forecast models over a smaller region centered along the Asian coastline is smaller compared to their skill in the entire WNP basin.