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Invertebrate larvae are often abundant in the surface ocean, which plays a key role in their dispersal and connectivity. Pelagic microhabitats characterized by small‐scale hydrographic variability are complex and ubiquitous in the coastal ocean, but their study is challenging, and they have been largely neglected in meroplankton ecology. Surface convergences, i.e., surface microhabitats featuring convergent horizontal currents, may aggregate the last larval stage of the American lobster and could provide shelter and food for Stage IV postlarvae and thus enhance their condition. We tested these hypotheses by conducting a series of cruises in the southwestern Gulf of Maine in summer 2021, sampling 15 paired sets of potential convergences and off‐convergence unstructured habitat. We measured postlarval abundance, surface hydrography, acoustic backscatter, and circulation. Experiments and image analysis compared condition, color, and morphology of postlarvae sampled inside and outside potential convergences. Potential convergences varied in near‐surface hydrographic patterns, with most displaying consistency among two transects and diverse patterns in salinity and temperature (e.g., across‐convergence gradients with equal or different signs). While the highest postlarval abundances were found in convergences, abundance patterns on and off convergences were not consistent, and another analysis indicated higher abundance in convergences than in a 7‐year untargeted surface ocean data set. Experiments indicated no survivorship differences among convergence and non‐convergence individuals at two temperatures, while image analyses revealed differences in color and size. Physical measurements and qualitative neuston community analyses indicated substantial heterogeneity among potential convergences. Our results reinforce that small‐scale heterogeneities are highly variable but important to the ecology of meroplankton, including the pelagic and neustonic habitats where lobster postlarvae are abundant. [ABSTRACT FROM AUTHOR]

Planned obsolescence is becoming a more frequent motive of litigation in the international sphere, which damages are being claimed by both public authorities and individuals affected by such behaviour, that seek fair retribution. Therefore, this paper aims to analyse different private actions against the technological company, Apple, who has apparently taken advantage of consumers' lack of knowledge of their area of business, to put into practice tactics for ending their products' lifespan and by doing so, increase their demand. Particularly, this paper discusses the substantive juridical grounds alleged by different class actions in the United States in the last years, against Apple, and their connection with planned obsolescence. The results of the research show that there is a clear increase in the litigation of the technological planned obsolescence around the world and that the arguments used in those cases are mainly private, despite the fact that public concerns are also present. [ABSTRACT FROM AUTHOR]

Plankton and nekton may respond passively or actively to large‐amplitude, nonlinear internal waves (NLIW), with periods and wavelengths on the order of minutes and hundreds of meters, and the NLIW can cause direct or indirect changes in distribution. NLIW are ubiquitous in the coastal ocean, but understanding the influence of NLIW on organism response and distribution is challenging, because of NLIW unpredictability, short temporal and spatial scales, and the difficulty in resolving the biological response. Measurements of currents, temperature, and shark acoustic traces in Massachusetts Bay were used to evaluate the short‐term response of individuals as well as the mean effects on the distribution of an aggregation of small sharks, Squalus acanthias. In two NLIW events, we detected 527 and 3240 shark traces. Individuals moved up and down in response to the currents associated with the sinking and rising of the thermocline. However, mean distribution deepened during one of the events, suggesting that organisms did not merely move in concert with the thermocline oscillation, but that sharks instead might have responded actively. Measurements of vertical currents and shark's depth change during one of the NLIW events indicate that with downward currents (sinking of the thermocline), the sharks tend to react passively. However, in response to the fastest upward currents, sharks appeared to swim down, supporting an active response in the rising phase of the wave. NLIW and other high‐frequency processes can have a profound influence on the distribution of pelagic organisms, yet their ecological consequences remain largely unaccounted for. [ABSTRACT FROM AUTHOR]

Although the research supporting this work presents a global overview of Antonio Nariño as an accountant and as a custodian of public resources, the article is a contribution to the historical controversy over the supposed infidelity of Nariño's wife, Magdalena Ortega that generated the publication of the book "El enigma del medallón" (The enigma of the medallion), by Carmen Ortega Ricaurte (2000). The discussion of the evidence uses the method of iconography, i.e. treaty or description of images, portraits, statues, etc. For our case, we studied two original engravings that appeared stuck in a printed booklet of 34 pages, signed by Antonio Nariño in his own hand, with the help of leading experts such as Enrique Santos Molano, the highest authority in Nariño today. The results of the research also present new facets of the Precursor of Colombian Independence in terms of his accounting work in the management of public resources. [ABSTRACT FROM AUTHOR]

This article shows that the legacy of classical rhetoric in defense of General Nariño before the first Colombian Senate in 1823 had Thomistic origins, that is, it proceeds from the political thought of scholasticism. The documentary evidence is examined through the critical analysis of the discourse to make explicit the implicit: the defense of the honor of Nariño as a Statesman. In consideration of this masterpiece of Colombian parliamentary oratory, this work proposes that the scholastic tradition of the Independence was a determining factor in the construction of the State's identity. It is concluded that this defense laid the rhetorical foundations in the configuration of the historical personality of Colombia, a nation in a trance. [ABSTRACT FROM AUTHOR]

We assessed the effects of large‐scale oceanic disturbances on the settlement rate of an abundant intertidal barnacle. Daily or weekly settlement, nearshore temperature, currents, and abundance of early‐stage barnacle nauplii and Chthamalus fissus cyprids were measured in La Jolla, California, from the inception of the large‐scale warm‐water anomaly known as the "Blob" in 2014, to 1 yr following the 2015/2016 El Niño. We also measured over 2 yr of weekly settlement rates during the 1997/1998 El Niño in La Jolla and in two Mexican sites. Settlement was low during the Blob and the 2015/2016 El Niño, but increased dramatically after its end, and rates remained high through spring 2017. Barnacle nauplii and C. fissus cyprid abundances were also low during the Blob and El Niño. Nearshore water column thermal stratification and variability of the high‐frequency cross‐shore currents, a measure of internal wave activity, declined during the Blob and El Niño, but increased at the end of El Niño. Similarly, settlement rates in the Mexican sites were low during the 1997/1998 El Niño. The reduction in settlement during the Blob and El Niño may be related to two factors: a decrease in water column stratification, which can influence internal bore larval transport and the cross‐shore distribution of larvae, and also to reduced early‐stage larval abundance, potentially related to lower reproductive output or high nauplii mortality during the disturbances. [ABSTRACT FROM AUTHOR]

The phase retrieval process is mainly affected by local shadows, irregular surface brightness and fringe discontinuities. To overcome these problems, image-processing strategies are carried out such as binary masks, interpolation techniques, and filtering. Similarly, many unwrapping algorithms have been developed to handle phase unwrapping errors in two-dimensional regions. The presence of error-prone areas can be visualized during the acquisition stage avoiding the use of image processing strategies and sophisticated phase unwrapping algorithms, which in many cases represent high computational costs and long execution times. To help overcome these problems, we propose a Fringe Quality Map based on a phase residue analysis to estimate error-prone areas during acquisition. The software was fully implemented in LabVIEW, and we provide the software as supplementary material. Experimental results demonstrate that the proposed method estimates areas with poor contrast, which lead to unwrapping errors, as well as phase errors in a more complex 3D shape. [ABSTRACT FROM AUTHOR]

The article analyzes the dissuasive capacity of the system to protect free competition in Colombia by studying its two legal facets: regulatory standards and the institutional component. The dissuasive capacity of the system implemented in Colombia is examined based on the Model Law on Competition of the United Nations Conference on Trade and Development, and on the regulatory implementation of dissuasive policies on competition in third-party systems for the defense of free competition. The article also evaluates the above-mentioned dissuasive power of the Office of the Superintendent of Industry and Commerce, based primarily on its organizational qualities and structure. [ABSTRACT FROM AUTHOR]

The paper analyses two state aid investigations of the European Commission that involve prominent clubs in the Spanish football, through the exposure of the factual circumstances that caused them and the substantial elements that are needed to solve them. Thus, paper's goal is comparing the theoretical and practical matters about anticompetitive state aid, through the Spanish football case. After the review of them, the document pulls out different conclusions than the European Commision ones on it's resolution about the case. [ABSTRACT FROM AUTHOR]

A new method to autonomously collect larvae and environmental variables such as temperature, salinity, and circulation is described. A large volume in situ pumping system, recently developed for discrete biogeochemical sample collection in deep-sea environments, was adapted and mounted to the autonomous underwater vehicle (AUV) REMUS 600 for autonomous larval and environmental sampling in coastal waters. To assess the performance of this system, the distribution of barnacle larvae was assessed in March 2014 with two transects perpendicular to the coastline (~ 9.9 and 11.2 km) in Buzzards Bay, Massachusetts, USA. The second transect included a complex sampling mission through a relatively deeper channel, and sampling at discrete depth intervals. In this deployment, nearshore and surface waters were fresher, with distinct vertical stratification due to salinity. Barnacle larvae were classified into early nauplii, late nauplii, and cyprid stages, and the mitochondrial COI barcode marker was sequenced to identify individual larvae of different stages. In an analysis of 164 barcode sequences, larvae belonging to Amphibalanus sp., Semibalanus balanoides , and Chthamalus fragilis were found, with Amphibalanus sp. the most abundant larval taxon overall. In the second deployment, early and late nauplii were relatively more abundant near the bottom. However, there was no obvious pattern relative to depth with cyprids, and there were no clear cross-shore distributional patterns for nauplii and cyprids. While additional deployments are necessary to corroborate these observations, the results demonstrate the feasibility of this approach. Autonomous vehicle based sampling has the potential to collect larvae of other invertebrates as well as zooplankton, and together with genetic identifications, overcomes many existing limitations and will provide valuable new insight in understanding larval distributions and transport dynamics. [ABSTRACT FROM AUTHOR]

As part of the debate on the fundamental objective of defending competition, this article compares the concepts in the Chicago School doctrine on the subject --in defense of economic efficiency-- and the Harvard School doctrine, which attributes a social function to protecting the competitive ecosystem that goes beyond the economic argument. The inflexible relationship that exists between consumer protection and antitrust laws is assessed, and the scope of making consumer protection the ultimate and universal purpose of the law on competition is calculated. Thanks to the regulations that have emerged in the United States, the European Union and Colombia, and in light of case law, the article confirms the priority of lawmakers and those who hand down rulings or judgments in the selected regions is to safeguard the interests of consumers through antitrust rules and regulations. [ABSTRACT FROM AUTHOR]

As part of a competitive environment increasingly widespread, under which anticompetitive conducts, with a public or private source, are able to impact the markets in locations beyond state borders where they have been generated; this work expounds the basic characteristics of state aids, because of the skills these have been shown to distort the competitive environment. Explaining also, the importance of structuring an internal antitrust regulatory framework, and a supranational one, which in use of tools, as Free Trade Agreements, discipline the exercise that closer partners can give to these kinds of aids. Using the international precedents that link together countries which recently have strengthened trade ties with Colombia, this work refers to solutions that were raised to curb state subsidies on bilateral relationships that tie up those members, and suggests similar bounds to adhere to the agreements signed between Colombia and those major economies. [ABSTRACT FROM AUTHOR]

El autor presenta la emergencia del territorio como concepto político (las ciudades griegas, los imperios, el feudalismo no funcionan según nuestra idea de correspondencia absoluta entre espacio de producción de lo práctico y territorio), su universalización progresiva, su hegemonía afirmada, en particular por la colonización y luego descolonización que han podido respetar los modos locales de organización de lo político. Lo que es artificial en África, comenta Bertrand Badie, no es el trazado de fronteras, sino el sentido que reviste, en contra de las solida ridades constitutivas de un político particular. En la segunda parte, el autor analiza las crisis que sacuden el principio de territorialidad desde mediados los años sesenta. En la última parte estudia los modos de regulación posible de esta crisis del territorio. En efecto, el territorio no ha representado nunca todos los espacios de lo político, e incluso cuando el discurso político aparenta hablar de geografía no habla necesariamente de territorio: cuando los israelitas evocan la tierra de Israel, ¿hablan de un territorio, de un espacio heredado, de cultura? Parece incluso que bajo la apariencia de un Estado homogéneo, territorialmente definido (Somalia, por ejemplo), perduran otras lógicas lo suficientemente arraigadas para impedir el funcionamiento de instituciones estatales. Dicho en otras palabras, casi en todo, y sin duda cada vez más, se oponen a la lógica del territorio (contorno y límites de lo político en nuestra concepción occidental), y especialmente en la lógica de una política pensada a través de múltiples espacios, de múltiples identidades, no reducibles a la geografía territorial. [ABSTRACT FROM AUTHOR]

In summer 2010, a bleaching event decimated the abundant reef flat coral Stylophora pistillata in some areas of the central Red Sea, where a series of coral reefs 100-300 m wide by several kilometers long extends from the coastline to about 20 km offshore. Mortality of corals along the exposed and protected sides of inner (inshore) and mid and outer (offshore) reefs and in situ and satellite sea surface temperatures (SSTs) revealed that the variability in the mortality event corresponded to two spatial scales of temperature variability: 300 m across the reef flat and 20 km across a series of reefs. However, the relationship between coral mortality and habitat thermal severity was opposite at the two scales. SSTs in summer 2010 were similar or increased modestly (0.5°C) in the outer and mid reefs relative to 2009. In the inner reef, 2010 temperatures were 1.4°C above the 2009 seasonal maximum for several weeks. We detected little or no coral mortality in mid and outer reefs. In the inner reef, mortality depended on exposure. Within the inner reef, mortality was modest on the protected (shoreward) side, the most severe thermal environment, with highest overall mean and maximum temperatures. In contrast, acute mortality was observed in the exposed (seaward) side, where temperature fluctuations and upper water temperature values were relatively less extreme. Refuges to thermally induced coral bleaching may include sites where extreme, high-frequency thermal variability may select for coral holobionts preadapted to, and physiologically condition corals to withstand, regional increases in water temperature. [ABSTRACT FROM AUTHOR]

The acorn barnacle, Semibalanus balanoides, is thought to release larvae in response to phytoplankton blooms, but there is evidence that another, unidentified cue for release may exist. We conducted high-frequency sampling in Little Harbor, Massachusetts, USA, to determine whether early-stage larval abundance was related to several environmental variables, and to characterize vertical distributions of the larvae. Larval concentrations peaked at 2.52 and 1.02 individuals l during two storms. Larvae were more abundant near the surface than near the bottom. We suggest the hypothesis that turbid conditions and upward-swimming behavior may protect newly-released larvae from predation and cannibalism. Future studies should test this hypothesis with barnacles and other invertebrates. [ABSTRACT FROM AUTHOR]

Abstract: Marine broadcast spawners have two-phase life cycles, with pelagic larvae and benthic adults. Larval supply and settlement link these two phases and are crucial for the persistence of marine populations. Mainly due to the complexity in sampling larval supply accurately, many researchers use settlement as a proxy for larval supply. Larval supply is a constraining variable for settlement because, without larval supply, there is no settlement. Larval supply and settlement may not be well correlated, however, and settlement may not consistently estimate larval supply. This paper explores the argument that larval supply (i.e., larval abundance near settlement sites) may not relate linearly to settlement. We review the relationship between larval supply and settlement, from estimates and biases in larval supply sampling, to non-behavioral and behavioral components, including small-scale hydrodynamics, competency, gregarious behavior, intensification of settlement, lunar periodicity, predation and cannibalism. Physical and structural processes coupled with behavior, such as small-scale hydrodynamics and intensification of settlement, sometimes result in under- or overestimation of larval supply, where it is predicted from a linear relationship with settlement. Although settlement is a function of larval supply, spatial and temporal processes interact with larval behavior to distort the relationship between larval supply and settlement, and when these distortions act consistently in time and space, they cause biased estimates of larval supply from settlement data. Most of the examples discussed here suggest that behavior is the main source of the decoupling between larval supply and settlement because larval behavior affects the vertical distribution of larvae, the response of larvae to hydrodynamics, intensification of settlement, gregariousness, predation and cannibalism. Thus, larval behavior seems to limit broad generalizations on the regulation of settlement by larval supply. Knowledge of the relationship is further hindered by the lack of a well founded theoretical relationship between the two variables. The larval supply–settlement transition may have strong general consequences for population connectivity, since larval supply is a result of larval transport, and settlement constrains recruitment. Thus, measuring larval supply and settlement effectively allows more accurate quantification and understanding of larval transport, recruitment and population connectivity. [Copyright &y& Elsevier]

We study a topological Abelian gauge theory that generalizes the Abelian Chern–Simons one, and that leads in a natural way to the Milnor's link invariant $\bar\mu(1,2,3)$ when the classical action on-shell is calculated. [ABSTRACT FROM AUTHOR]

Late stage larvae (cyprids) of the barnacle Semibalanus balanoides frequently encounter freezing conditions along the northwest Atlantic coast. S. balanoides cyprids survived for more than 4 weeks embedded in sea ice, and a significant fraction of larvae held in ice up to 2 weeks successfully settled and metamorphosed after thawing. Larvae that completed metamorphosis continued to develop and reproduce. In settlement experiments with cyprids of known age and where settled cyprids were removed every other day from the experimental containers, cyprids held in ice for 2 weeks settled and metamorphosed more than nonfrozen larvae. Mean time to metamorphosis was longer for frozen cyprids than for nonfrozen ones, and maximum time to metamorphosis was 38 d for cyprids held in sea ice for 2 weeks and 26 d for cyprids in nonfrozen treatments. Larval tolerance to freezing conditions greatly expands the environmental tolerance repertoire of marine invertebrates and may help explain the ecological success of this widespread intertidal species. [ABSTRACT FROM AUTHOR]

We investigated the effect of the daily sea breeze on the surface flow at Bahia Salsipuedes, Baja California, Mexico. Drifter-tracking experiments were conducted over a 2-week period in July, 1999. Surface drifters were deployed daily and their trajectories tracked from a small boat for 3–7 h. Wind speed and direction, as well as the vertical distribution of temperature and current velocities were measured throughout the observation period. Our results indicate that strong winds associated with the daily sea breeze at the study area can produce onshore surface currents with velocities of up to 10 cm s-1 (net transport of up to 2 km in a diurnal cycle). There was a hyperbolic relationship between onshore wind stress and net onshore transport of the drifters. A decrease in stratification and more consistent pattern of onshore transport were associated with sustained winds >6 m s-1 towards the end of the study. Progressive vector diagrams computed from near-surface currents failed to predict the trajectory of drifters, especially on days where wind forcing was more consistent in terms of direction and magnitude. We discuss the implications of these results regarding the collection of settlement data and their interpretation in terms of larval supply to coastal populations. [Copyright &y& Elsevier]

Barnacle settlement was monitored in two sites 100 km apart along the coast of Alta and Baja California. In five periods of observations completed between 1991 and 1996, Chthamalus spp., Pollicipes polymerus, and Balanus glandula settlement was consistently higher in the northern site, La Jolla (LJ), than in the southern site, La Salina (LS). For Chthamalus, the most abundant settler, settlement was higher in LJ in 58 out of 60 paired dates, by a mean factor of 141. In 1996, time series of temperature in about 15 m of water showed that the stratification was 72% higher, on average, and that the thermocline was shallower in LJ than in LS. Spectra of temperature showed that internal motions of tidal and higher frequencies were more energetic and closer to the surface in LJ compared to LS. In LJ changes in settlement were positively correlated with changes in stratification. These results suggest that high-frequency internal motions are important in the onshore transport of larvae. Low-frequency cooling events recorded in LJ apparently caused the energetic semidiurnal temperature variability to migrate from the bottom towards the surface, leading to the surface manifestation of the internal tide and surface internal tidal bores, which indicates that the surface nearshore bores occur in response to the shallowing of the thermocline. Tidal and higher frequency internal motions were more energetic when the thermocline was shallow during the low-frequency cooling events, than when it was deep and relatively weak during ordinary conditions. The major cooling event in LJ correlated with the local wind, suggesting local wind-driven upwelling. On the other hand, correlation of LS temperature with LJ temperature, winds, and sea level suggest propagation from the South. These results suggest that the low-frequency drops in temperature that modulate the nearshore internal tidal bores are caused by a combination of the local wind and events that propagate poleward, possibly as coastally trapped waves. [Copyright &y& Elsevier]

An introduction is presented in which the editor discusses changes in front cover of the journal for emphasizing scientific framework of the journal, inclusion of a section in the journal which provides academic reviews and display of paintings done by artist Héctor Miguel-Rincón.

The calibration methods most used in fringe projection profilometry are based on models of least squares adjustment and stereo vision techniques. However, the geometric distortions of the projector and camera lenses introduce imprecision in certain regions of the 3D reconstruction. In this paper, we perform a comparative study between the second order polynomial adjustment method and the stereo calibration method applying lens distortion compensation. The experimental results show that in the stereo calibration the incidence of the distortions in the 3D reconstruction is significant. In contrast, in the proposed polynomial calibration, reconstruction errors are associated with the calibrated volume, typically low within the calibration volume. [ABSTRACT FROM AUTHOR]

Blythe, J. N., da Silva, J. C. B., and Pineda. J. 2011. Nearshore, seasonally persistent fronts in sea surface temperature on Red Sea tropical reefs. – ICES Journal of Marine Science, 68: 1827–1832.Temperature variability was studied on tropical reefs off the coast of Saudi Arabia in the Red Sea using remote sensing from Aqua and Terra satellites. Cross-shore gradients in sea surface temperature (SST) were observed, including cold fronts (colder inshore) during winter and warm fronts (warmer inshore) during summer. Fronts persisted over synoptic and seasonal time-scales and had a periodic annual cycle over a 10-year time-series. Measurements of cross-shore SST variability were conducted at the scale of tens of kilometres, which encompassed temperature over shallow tropical reef complexes and the continental slope. Two tropical reefs that had similar reef geomorphology and offshore continental slope topography had identical cold fronts, although they were separated by 100 km along the Red Sea coast of Saudi Arabia. Satellite SST gradients across contours of topography of tropical reefs can be used as an index to flag areas potentially exposed to temperature stress. [ABSTRACT FROM PUBLISHER]

Abstract: The effects of the 1997–1998 and 2002–2004 El Niño on the upper waters in the continental shelf and slope regions off northwestern Baja California are explored with data from eight cruises taken in late spring from 1998 to 2004 and the summers of 1997 and 1998. Geostrophic velocities were calculated referenced to a specific volume anomaly surface separating the generally southward flowing California Current waters from the waters advected to the north by the California Undercurrent. The resulting fields show equatorward flow near the surface except in the summer of 1997, when a poleward jet was found in the upper 40dbar. This shallow jet advected anomalously warm and salty waters characteristic of the 1997–1998 El Niño, with its core found within 20–30km from the coast. By spring of 1998, the waters brought into the region by the jet had mixed across the pycnoline with the salty California Undercurrent waters below, resulting in high salinity levels on the density surfaces corresponding to the otherwise fresh California Current waters (25–26). By contrast, the 2002–2004 El Niño stands out for the very fresh and cold waters found on the same density surfaces in late spring of 2003 and 2004, marking a pronounced presence of subarctic waters. The fresh conditions found on the latter years represent a nearshore expression of the anomalous intrusion of subarctic waters observed 50–150km from the coast of Southern California and Punta Eugenia, reported from July 2002 until April 2003. Our results suggest that the presence of this intrusion has continued to influence the region at least until May 2004. [Copyright &y& Elsevier]

Shows how estimates of quasi-extinction of the harbor seal depend on model assumptions about the exact level of immunity, population growth rate, the variance in population growth and the action of density dependence. Discussion on the sampling error and quasi-extinction probability; Population rate of increase; Inclusion of immunity.

Video microscopy has a long history of providing insight and breakthroughs for a broad range of disciplines, from physics to biology. Image analysis to extract quantitative information from video microscopy data has traditionally relied on algorithmic approaches, which are often difficult to implement, time-consuming, and computationally expensive. Recently, alternative data-driven approaches using deep learning have greatly improved quantitative digital microscopy, potentially offering automatized, accurate, and fast image analysis. However, the combination of deep learning and video microscopy remains underutilized primarily due to the steep learning curve involved in developing custom deep-learning solutions. To overcome this issue, we introduce software, DeepTrack 2.0, to design, train, and validate deep-learning solutions for digital microscopy. We use this software to exemplify how deep learning can be employed for a broad range of applications, from particle localization, tracking, and characterization, to cell counting and classification. Thanks to its user-friendly graphical interface, DeepTrack 2.0 can be easily customized for user-specific applications, and thanks to its open-source, object-oriented programing, it can be easily expanded to add features and functionalities, potentially introducing deep-learning-enhanced video microscopy to a far wider audience. [ABSTRACT FROM AUTHOR]

The article presents a study on barnacle distributions in two adjacent coastal lagoons of Bahía Honda, a bay on the Pacific coast of Panama. It discusses details of the experiments to determine the probable causes for differences in the two lagoons and the role of season and salinity in barnacle distribution. It highlights the effects of natural stressors on population and community dynamics of nearshore species with a two-phase life cycle.

Abstract: Patterns of vertical distribution in marine invertebrate larvae interact with coastal hydrodynamics to determine cross-shore distributions, dispersal ranges, and scales of connectivity among populations. We present observations on the vertical distribution of barnacle larvae from southern California, collected from 3 depth intervals every 2h and over a 48-h period at a fixed nearshore station. Larvae were identified to species and stage of development, and their vertical distributions were tested for day/night and between-stage differences within each species, as well as for correlations with environmental variability. Stage-specific patterns of vertical distribution were distinct and consistent across species. Nauplii were most abundant near the surface at all times, and were numerically dominated by Chthamalus spp. (78% of Nn =1835). Cyprids were substantially less abundant than nauplii in our samples (Nc =146) and corresponded mostly to the subtidal barnacle Balanus nubilus (84%). Despite the lower counts and different species composition, our data suggest that cyprids remain within the mid-depth and bottom layers, and that changes in their mean depth of distribution (MDD) may track changes in pycnocline depth. Temporal changes in nauplii MDD were not correlated with water-column variability, wind forcing, or tidal height. The apparent vertical segregation of nauplii and cyprids may be related to previously documented differences in the cross-shore distribution of these stages. [Copyright &y& Elsevier]