Ecosystem-based fishery science is an important component of effective marine conservation and resource management. Implementation has progressed through large-scale comprehensive ecosystem status reports; however, integrating ecosystem research within the stock assessment process remains elusive. Primary obstacles include the lack of a consistent approach to including ecosystem and socioeconomic information into a stock assessment model and how to test its reliability for identifying future change. We introduce a methodology and reporting framework termed the Ecosystem and Socioeconomic Profile (ESP) to overcome these obstacles. The ESP facilitates the integration of ecosystem and socioeconomic factors within the stock assessment process through four steps that culminate in a focused, succinct, and meaningful communication of drivers for a given stock. The first ESP was produced for Alaska sablefish and we provide the general process to implement the ESP framework using results from the sablefish ESP. We conducted a data synthesis that allowed for the framework to be applied across multiple regions and stocks. ESPs are an efficient testing ground for developing ecosystem-linked stock assessments and provide a set of reporting tools that can be tailored to a variety of audiences in order to effectively merge the ecosystem, socioeconomic, and stock assessment disciplines.

Over the past two decades, numerous ecosystem surveys and process studies have emerged to monitor and assess the large marine ecosystems of Alaska. Several regional collaborative integrated ecosystem research projects (IERPs) were conducted to gain understanding of fish population fluctuations in relation to the surrounding environment. The Gulf of Alaska (GOA) IERP is one example of such an effort. Products of this program include a suite of in situ observations from fully integrated ecosystem surveys, laboratory experiments of physical thresholds for fish condition, and high-resolution oceanographic, planktonic, and habitat distribution models. When coupled, the synthesis products of this program can be utilized to understand system connectivity and highlight the primary ecosystem drivers of the GOA. Much of this information was included in annual GOA ecosystem status reports through individual indicator contributions. However, assimilation of these data into single-species stock assessments has remained limited. We provide a clear and direct avenue for including the products of these IERPs through the new ecosystem and socioeconomic profile (ESP) framework that identifies mechanistic relationships and tests ecosystem linkages within the stock assessment process. We present a case study using a data synthesis of the five commercially and ecologically valuable focal species of the GOAIERP (sablefish, pollock, Pacific cod, arrowtooth flounder, and Pacific ocean perch). Information was organized along the categories of distribution, phenology, and condition by life history stage to develop life history narratives for each species. These narratives identified critical ecosystem processes that could impact survival of each species. We then used habitat distribution models, seasonal phenology, and energy allocation strategies to sequentially reduce two gridded temperature datasets to reflect the life experience of the stock. This method essentially aligns ecosystem information at a spatial and temporal scale relevant to a stock and creates informed indicators that could then be related to a stock assessment parameter of interest, such as recruitment. Informed temperature indicators differed in magnitude and variability when compared to non-informed indicators and demonstrating species and stage-specific thermal preferences. The difference between the informed indicators and the non-informed indicators can also highlight thresholds and trends in habitat preference that could be further investigated with targeted process studies or laboratory experiments. The coordinated nature of the IERP allowed for the creation of these informed indicators that would not be possible with the results of any one process study. Both the stock-specific narratives and the informed indicators can be included into the ESPs for further monitoring and development. This integration ensures that the identified ecosystem linkages are evaluated concurrently with the stock assessment and ultimately transferred to fishery managers in an efficient and effective format for informing management decisions.

We present the results of a study of the connectivity between Pacific cod spawning and nursery areas, and settlement of Pacific cod in the Gulf of Alaska. This work was conducted to address the hypothesis that spatial and temporal patterns of recruitment are related to variability in connectivity between spawning and nursery areas. To examine this hypothesis, we developed a Lagrangian, biophysical, individual-based model of Pacific cod early life history and dispersal using the Dispersal Model for Early Life Stages (DisMELS) framework. This model is driven by currents and scalars such as temperature from a version of the Regional Oceanographic Model System (ROMS) developed for the Gulf of Alaska. Results of our study show connectivity patterns predicted by the model that agree with our understanding (based on genetic analyses) that there is a high degree of localized retention in Pacific cod. The results indicate that the Shumagin Islands and Prince William Sound regions may serve as important collectors of Pacific cod recruits from upstream spawning areas. We also find correlations between individual-based model outputs and several large-scale climate indicators that appear to show settlement in several important nursery areas, and recruitment overall, are positively affected by slower gyre circulation in the Gulf of Alaska. We hypothesize that this is due to enhancement of retention, settlement in the Shumagin Island region, and reduction of transport of young cod out of the Gulf of Alaska to the southwest.

Little is known regarding the importance of early-life transport and dispersion mechanisms in determining recruitment variability for Pacific ocean perch (POP) in the Gulf of Alaska (GOA). These mechanisms influence the degree of, and variability in, connectivity between offshore natal areas (parturition sites) and inshore demersal nursery habitats for young-of-the year juveniles, and may thus play an important role in the "gauntlet" that individuals must survive from parturition to recruitment. As a first attempt to assess interannual variability in connectivity between natal and nursery areas for POP in the GOA in a synthetic manner, we developed a coupled biophysical individual-based model (IBM) for POP early life history and dispersal with simple representations of active vertical movement, passive horizontal movement, growth, and settlement in appropriate nursery habitat to integrate known early-life traits with variability in environmental forcing. We used an oceanographic model for the GOA based on the Regional Ocean Modeling system (ROMS) to provide the underlying daily physical environment to force the IBM for 1996-2011 and simulated hundreds of thousands of individual POP from parturition along the shelf break to settlement in inshore demersal nursery habitats as young-of-the-year. We used the IBM results to assess spatial patterns of annual "maximum potential" connectivity between presumed natal and nursery areas at along shore scales of similar to 150 km, as well as the interannual variability in these patterns. Results showed that, even in the absence of mortality, most ( > 70%) individuals were unsuccessful in dispersing from presumed natal areas along the continental shelf break to inshore nursery areas. For those that were successful, connectivity was directed in a counter clockwise fashion (southeast to northwest) around the GOA following prevailing current patterns. Typical dispersion distances were on the order of 100's of km along shore, much larger than those inferred from genetic sampling. Natal areas from which the highest fractions of successful individuals originated were in the southeast GOA, while the nursery areas most frequently reached by those successful individuals were in the central GOA. POP from natal areas in the western GOA were consistently exported from the system and likely contribute little to the GOA population, although they may contribute to populations in the Aleutian Islands and eastern Bering Sea. We also found that annual indices derived from the connectivity matrices were not very strongly related to any of a suite of basin- and regional-scale environmental indices, reflecting the overall complexity and scale of the pathways POP in the GOA may undertake during their early life stages and suggesting that multiple drivers operating at different spatial and temporal scales influence connectivity patterns. Finally, while our results indicate that interannual variability in physical transport may have a substantial impact on connectivity, we found little support for the hypothesis that this alone drives variability in POP recruitment.

The Gulf of Alaska Integrated Ecosystem Research Program is a multi-disciplinary study examining interactions between physical and biological oceanography to understand how the environment influences the survival and recruitment of early life stages of select commercially and ecologically important groundfish species. Biological and oceanographic surveys in the eastern and western Gulf of Alaska were conducted during spring and summer of 2011 and 2013; we present a synthesis of ichthyoplankton data. The results describe seasonal (spring vs. summer), regional (eastern vs. western Gulf of Alaska), and interannual (2011 vs. 2013) variation in distribution, abundance, and larval sizes of the focal species. In spring, Pacific Cod (Gadus macrocephalus) larvae were more abundant in 2013 than 2011 and occurred primarily in the western Gulf of Alaska near Kodiak Island, over the shelf, and over the continental slope. Walleye Pollock (Gadus chalcogrammus) larvae were also more abundant in the western Gulf of Alaska, with substantially higher abundance in 2013. Larval rockfish (predominantly Pacific Ocean Perch; Sebastes alutus) were collected in deep water or were associated with the slope, troughs and canyons intersecting the slope, and the outer shelf. Rockfish larvae were collected throughout the study region in spring, with no significant differences in abundance between regions or years. In summer, rockfish (predominantly species other than Pacific Ocean Perch) were more widely distributed over the shelf and were more abundant in the eastern Gulf of Alaska both within and across years, indicating species-specific spawning events. Sablefish (Anoplopoma fimbria) larvae, however, were more abundant in the eastern Gulf of Alaska and in 2011 and were predominantly collected near areas of deep water such as Yakutat Canyon. In 2011, Arrowtooth Flounder (Atheresthes stomias) abundances of larvae were higher in the western Gulf of Alaska, whereas in 2013 abundances were higher in the eastern Gulf of Alaska. Arrowtooth Flounder larvae were collected primarily along the slope and near canyons and troughs. The results from individual years presented here can be used in individual-based model validation of connectivity matrices, delineating transport patterns to suitable nursery habitat, and evaluating recruitment bottlenecks for these focal species in the Gulf of Alaska. Future research will examine patterns of community structure and assemblage diversity using the comprehensive ichthyoplankton dataset. The observed ecological patterns provide insight into how environmental forcing may influence early life history aspects of recruitment.

Little is known about the mechanism of transport that enables age-0 sablefish (Anoplopoma fimbria) to reach suitable nursery sites from spawning locations far offshore, or the strength of the connection between individual spawning sites and nursery areas, or how variability in the strength of these connections may impact recruitment success. Using a model for the early life stages of sablefish, we explored the variability in connectivity between spawning and recruitment sites that can arise solely from interannual variability in environmental forcing and its impact on transport. Our major findings are that 1) the model indicates young sablefish settling in nursery areas in the Gulf of Alaska were most likely spawned in the eastern Gulf; 2) sablefish spawned in the western Gulf of Alaska are unlikely to settle anywhere in the Gulf, and are more likely to be advected farther west, perhaps to settle in the Aleutian islands or Bering Sea (to contribute to the Alaska population, they would have to undergo an active return migration as they mature); 3) total connectivity between all spawning sites and nursery areas showed stronger correlation with recruitment estimates than the strength of connections to or from specific regions; and 4) transport to St. John Baptist Bay, a known sablefish nursery area, was not the most probable end point for sablefish spawned throughout our Gulf of Alaska model domain. This suggests that young individuals arrive at this persistent nursery area due to directional swimming behavior, highly localized spawning, or small-scale currents not captured in the hydrographic model. The fact that no single correlate in our analysis had a very strong relationship to sablefish recruitment indicates that recruitment variability arises from complex interactions between the environment and the individual, and a possible disconnect in spatial scales between the Gulf of Alaska sablefish IBM and the broader sablefish stock assessment, which includes both the GOA and the Eastern Bering Sea, as well as possible contributions from Canadian stocks to the south. Our analyses determined that although the timing and extent of this transport shows significant interannual variability, both the location of likely sablefish spawning (source) areas and the comparative strength of connectivity between spawning and nursery sites appear to be relatively consistent year-to-year.

Synthesis of four decades of Gulf of Alaska ichthyoplankton data indicates that species diversity and total abundance peaks during spring, a common pattern in temperate and sub-arctic ocean regions due to synchrony with the spring peak in plankton production. Nevertheless, fish larvae occur in the plankton at all times of year and peak abundance periods vary significantly by species and habitat. Larval size at hatching and at transformation to the juvenile stage is also highly variable and associated with a variety of larval durations and temporal supply of larval cohorts to pelagic habitats. This phenological diversity represents variability in exposure and adaptation to seasonal cycles in the ocean. Water temperature, winds and currents, and availability of suitable zooplankton prey vary significantly on a seasonal scale affecting degrees of synchrony among larval species with optimal environmental conditions for growth, transport and survival. This synchrony is also affected by interannual shifts in the oceanographic environment, and different early life phenologies among species generate different sensitivities to such interannual variability. Early life history strategies and synchronies are evaluated here and environmental sensitivities are proposed for the numerically dominant species of fish larvae occurring in Gulf of Alaska plankton, including commercially and ecologically important species. For winter to early spring spawners, cold temperatures are an advantage in terms of slowing development so that larvae do not use up all their lipid reserves prior to optimal availability of suitable larval zooplankton prey. Interannual variability in winter temperature may therefore be a good indicator of survival outcomes, especially as influenced by the timing of the switch to exogenous feeding. Variability in temperature-influenced larval growth during late spring and summer months may be less consequential in maintaining synchrony with larval food availability for spring summer spawners. Rapid growth in association with warm summer conditions facilitates access to a wide size range of prey organisms and minimizes critical periods of vulnerability to trophic mismatch. The Gulf of Alaska is a highly advective environment; storms and alongshore winds promote onshore advection of surface waters. This onshore Ekman transport is strongest during winter and spring when deep water spawned larvae are most abundant over the slope and require access to the shelf. Enhanced shoreward transport of larvae in the canyons intersecting the slope is also an important mechanism. Interannual variability in such transport mechanisms may be critical in determining early ontogeny survival for these species. During all seasons, but especially spring and summer, there are species of larvae for which retention nearshore is vital for survival and mesoscale oceanographic features as well as larval behavioral abilities may be crucial. Annual patterns in phytoplankton and zooplankton production and abundance indicate high-amplitude variation in the composition of prey fields available to larvae, including variability in abundance and the size spectrum of organisms that larvae might encounter and consume. Food limitation seems less likely for larval species that are most abundant in spring summer than for species with peak abundance in winter-spring. It is probable that the more selective a species is in terms of zooplankton prey, the more susceptible that species is to atrophic mismatch. Species-specific intrinsic rates and morphological development during early ontogeny also influence the interaction of larvae with their environment, and larval growth trajectories can be quite different even among species with identical early life phenology. This insight clearly indicates that although phenology is critical, timing is not everything and all fish larvae are not equal. For the 23 species and two genera of fish in this study, a synoptic overview is provided of their early ontogeny environmental synchronies and proposed sensitivities. This ecological synthesis of phenologies helps us characterize vulnerability and resilience factors for intervals of the planktonic phase in the pelagic environment. It also identifies environmental signals that could be tested as species-specific ecosystem indicators of population trends for fish stocks in the Gulf of Alaska. Further, understanding seasonal dynamics in the ichthyoplankton is considered important for gauging food availability and energy flow more broadly in this and other pelagic ecosystems, as well as to understanding environmental forcing on the fish populations themselves.

Little is known regarding the early life transport and dispersion mechanisms, from offshore spawning areas to inshore nursery habitats, that potentially underlie recruitment variability for arrowtooth flounder in the Gulf of Alaska (GOA). We developed a biophysical individual-based model (IBM) for arrowtooth flounder early life history and dispersal with simple representations of swimming behavior, growth, and survival to explore the variability in connectivity between spawning and recruitment sites that can arise due solely to interannual variability in environmental forcing and its impact on transport. Results of our simulations for 1996-2011 show that, even in the absence of mortality, most (> 80%) individuals were unsuccessful in dispersing from presumed spawning areas along the continental shelf break to inshore nurseries in the GOA. For those that were successful, connectivity was directed in a counterclockwise fashion (southeast to northwest) following prevailing current patterns, with typical dispersion distances of 100 s of km alongshore. The most productive spawning areas were in the southeastern GOA (areas off Sitka and Cross Sound), while the most effective nursery areas were in the central and western GOA (Prince William Sound and North Kodiak areas). Arrowtooth flounder from spawning areas in the western GOA were exported from the system and likely contribute little to the population in the GOA, but may provide recruits to populations in the Aleutian Islands or eastern Bering Sea. We developed a suite of potential recruitment indices based on the connectivity results; however, none of these appeared to reflect estimated (age-1) recruitment to the population from a stock assessment model.

The continental shelf around Kodiak Island is incised with numerous submarine canyons, which play an important role in the cross-shelf transport of heat, salt, and nutrients, and the transport of ichthyoplankton of deep-spawning fish from the slope region into the shallow nursery grounds surrounding Kodiak Island. To explore the pathways and variability of flow, and the extent of tidal mixing within the canyons, moorings were placed in the Chiniak, Barnabas, and Amatuli troughs, and off the shelf from Resurrection Bay (Seward Line) and the Kenai Peninsula (Gore Point). In the troughs, intensified flow was evident near the trough walls, and flow was directed by bathymetry with inflow along the upstream (northern) side and outflow along the downstream (southern) side. The presence of mesoscale eddies in the gulf had no unique influence on currents or salinity in the troughs. Tidal mixing was strongest in Chiniak Trough, and this introduced cold, nutrient-rich bottom waters into the upper water column. Intensified bottom flow associated with the Alaskan Coastal Current was evident along the Seward Line and Gore Point, and directed toward the Kennedy-Stevenson Entrances, which are also regions of strong tidal mixing. Observations of tidal mixing were consistent with model results and satellite images showing cooler, phytoplankton-rich water in summer in the nursery grounds that surround Kodiak Island. Patterns of flow within the troughs and in Shelikof Strait were consistent with the springtime advance of ichthyoplankton across the shelf.

In recent decades, Arrowtooth Flounder (Atheresthes stomias) has been the most abundant groundfish in the Gulf of Alaska and an apex predator with trophic links to many pelagic and benthic species. Its abundance and trophic status implies that a small change in survival may result in substantial uncertainty in the ecosystem, with potentially large effects across multiple species. A synthesis of Arrowtooth Flounder ecology in the Gulf of Alaska was undertaken to determine exposure to the environment during different life history stages, and to develop hypotheses regarding population response to environmental forcing. Historical data sets were used to identify mechanisms of interaction with the pelagic environment during the egg and larval phase, assess habitat utilization and trophic interactions from early settlement through adult life, and evaluate sensitivity and potential response of the population to climate-induced variability in the Gulf of Alaska ecosystem. Modeling approaches include Individual-Based Modeling of the planktonic drift phase from spawning to settlement, Generalized Additive Modeling to examine the effects of location, bottom temperature, and depth on the distribution and density of different size categories of fish, and Habitat Suitability Modeling which integrates presence-absence and environmental data to develop predictive maps of suitable habitat for early juveniles, late juveniles, and adults. A strategy of high endurance characterizes the early ontogeny phase. Spawning and hatching occur during winter in deep water where predation risk is relatively low, and cold temperatures along with intrinsically low metabolic rates ensure extended availability of yolk reserves, lowering the risk of larval starvation in a food-poor environment. Larval duration and drift is protracted, contributing to widespread delivery of larvae to coastal, continental shelf and slope waters throughout the Gulf of Alaska, as well as expected transportation into the Bering Sea through the Aleutian Island Passes. Connectivity between spawning and settlement areas is less directed and juveniles are more ubiquitous across depths than previously understood. Juvenile and adult Arrowtooth Flounder are habitat and prey generalists, with some ontogenetic shifts apparent. Based on this comprehensive ecological synthesis, a preliminary climate-related vulnerability assessment indicates low risk, high resilience overall for this species in the Gulf of Alaska. However, some stage-specific sensitivity is hypothesized primarily relating to the potential for exacerbated temporal mis-match between early larvae and suitable zooplankton prey with increased temperatures. Density-dependent effects during the juvenile to adult stage may constrain further increases in Arrowtooth Flounder biomass in the Gulf of Alaska. This comprehensive ecological approach to assessing environmental sensitivities across life history stages for a commercially and ecologically important fish species has substantial merit for furthering the ecosystem approach to fisheries management, especially in marine ecosystems where there are robust sampling programs across trophic levels.

A synthesis of nearly four decades of ichthyoplankton survey data from the Gulf of Alaska was undertaken to provide the most comprehensive information available on the early life history ecology of five focal species: Pacific Cod (Gadus macrocephalus), Walleye Pollock (Gadus chalcogrammus), Pacific Ocean Perch (Sebastes alutus), Sablefish (Anoplopoma fimbria), and Arrowtooth Flounder (Atheresthes stomias). This analysis of historical data, along with information from published studies, is presented here in the form of ecological reviews of the species during their planktonic phase. The reviews include descriptions of temporal and spatial patterns of exposure to the environment, and interpretation regarding associated sensitivities to environmental forcing. On a temporal scale, patterns in abundance of eggs and larvae are synthesized that characterize seasonal exposure to the pelagic environment, and interannual variation that is presumed to incorporate responses to long-term environmental forcing. Spatial patterns are synthesized to identify horizontal and vertical extent of egg and larval distributions, delineate areas of primary larval habitat, and illuminate egg and larval drift pathways. The observed patterns are discussed with respect to characterizing species early life history strategies, identifying long-term adaptations to the Gulf of Alaska environment, and associated resilience and vulnerability factors that may modulate early life responses to environmental forcing in this region. For each species, gaps in knowledge are identified and are concerned primarily with the period of transition between the larval and juvenile stage, and feeding habits and ecology across seasons, habitats and sub-intervals of early ontogeny. These early life history reviews advance our ecological understanding of the pelagic phase, and fine-tune our focus for the investigation of potential response mechanisms to environmental forcing at appropriate, species-specific temporal and spatial scales.

We investigated the hypothesis that synchronous recruitment is due to a shared susceptibility to environmental processes using stock–recruitment residuals for 52 marine fish stocks within three Northeast Pacific large marine ecosystems: the Eastern Bering Sea and Aleutian Islands, Gulf of Alaska, and California Current. There was moderate coherence in exceptionally strong and weak year-classes and correlations across stocks. Based on evidence of synchrony from these analyses, we used Bayesian hierarchical models to relate recruitment to environmental covariates for groups of stocks that may be similarly influenced by environmental processes based on their life histories. There were consistent relationships among stocks to the covariates, especially within the Gulf of Alaska and California Current. The best Gulf of Alaska model included Northeast Pacific sea surface height as a predictor of recruitment, and was particularly strong for stocks dependent on cross-shelf transport during the larval phase for recruitment. In the California Current the best-fit model included San Francisco coastal sea level height as a predictor, with higher recruitment for many stocks corresponding to anomalously high sea level the year before spawning and low sea level the year of spawning. The best Eastern Bering Sea and Aleutian Islands model included several environmental variables as covariates and there was some consistent response across stocks to these variables. Future research may be able to utilize these across-stock environmental influences, in conjunction with an understanding of ecological processes important across early life history stages, to improve identification of environmental drivers of recruitment.

For Gulf of Alaska (GOA) fish populations, ordination by principal component analysis of a matrix of species by early life history and ecological traits resulted in distribution of species along three primary gradients. These are synonymous with phenology of egg and larval production, quantity of production, and ubiquity of larvae, the latter representing temporal and spatial extent of distribution in the pelagic environment. GOA species were assigned to categories that shared similar positions in ordination space relative to the three primary gradients. From this comparative analysis, a conceptual framework is proposed for species’ early life histories representing trade-offs in adaptation to prevailing environmental conditions and associated vulnerability and resilience factors that may modulate species’ recruitment responses to environmental variability. The utility of this framework for evaluating response to environmental forcing was supported by the analysis of a 27-year time series of GOA late spring larval fish abundance. The hypothesis for this ongoing research is that we can utilize similarities in reproductive and early life history characteristics among species to identify (i) ecologically determined species groups that are predisposed to respond to environmental forcing in similar ways and (ii) plausible environmental predictors of recruitment variation attributable to aspects of early life history.

The purpose of this study was to examine the distribution, abundance and characteristics of plastic particles in plankton samples collected routinely in Northeast Pacific ecosystems, and to contribute to the development of ideas for future research into the occurrence and impact of small plastic debris in marine pelagic ecosystems. Plastic debris particles were assessed from zooplankton samples collected as part of the National Oceanic and Atmospheric Administration’s (NOAA) ongoing ecosystem surveys during two research cruises in the Southeast Bering Sea in the spring and fall of 2006 and four research cruises off the U.S. west coast (primarily off southern California) in spring, summer and fall of 2006, and in January of 2007. Nets with 0.505 mm mesh were used to collect surface samples during all cruises, and sub-surface samples during the four cruises off the west coast. The 595 plankton samples processed indicate that plastic particles are widely distributed in surface waters. The proportion of surface samples from each cruise that contained particles of plastic ranged from 8.75 to 84.0%, whereas particles were recorded in sub-surface samples from only one cruise (in 28.2% of the January 2007 samples). Spatial and temporal variability was apparent in the abundance and distribution of the plastic particles and mean standardized quantities varied among cruises with ranges of 0.004–0.19 particles/m3, and 0.014–0.209 mg dry mass/m3. Off southern California, quantities for the winter cruise were significantly higher, and for the spring cruise significantly lower than for the summer and fall surveys (surface data). Differences between surface particle concentrations and mass for the Bering Sea and California coast surveys were significant for pair-wise comparisons of the spring but not the fall cruises. The particles were assigned to three plastic product types: product fragments, fishing net and line fibers, and industrial pellets; and five size categories: <1 mm, 1–2.5 mm, >2.5–5 mm, >5–10 mm, and >10 mm. Product fragments accounted for the majority of the particles, and most were less than 2.5 mm in size. The ubiquity of such particles in the survey areas and predominance of sizes <2.5 mm implies persistence in these pelagic ecosystems as a result of continuous breakdown from larger plastic debris fragments, and widespread distribution by ocean currents. Detailed investigations of the trophic ecology of individual zooplankton species, and their encounter rates with various size ranges of plastic particles in the marine pelagic environment, are required in order to understand the potential for ingestion of such debris particles by these organisms. Ongoing plankton sampling programs by marine research institutes in large marine ecosystems are good potential sources of data for continued assessment of the abundance, distribution and potential impact of small plastic debris in productive coastal pelagic zones.

We examined the patterns of abundance and distribution of Alaska plaice, Pleuronectes quadrituberculatus, eggs, larvae and pelagic juveniles over the southeastern Bering Sea shelf to better understand factors controlling transport and recruitment of flatfish in the Bering Sea. Ichthyoplankton data were derived from plankton surveys conducted in 1997, 1999, 2002, 2003, and 2005. Temperature, salinity, depth, and abundance of micro-zooplankton were measured concurrently. Eggs and larvae were primarily collected from depths <200 m, with the majority occurring over bottom depths ranging 50-100 m. Eggs were present throughout the water column, though densities of preflexion stage larvae were concentrated at depths 10-20 m. There was no evidence of vertical migration for pre-flexion stages. Spawning in Alaska plaice occurs primarily east of Port Moller in April and May, and eggs and larvae appear to drift to the north and northeast, an observation based on satellite-tracked drifter information, model output, and collections of older, later-stage postlarvae. Connectivity between spawning areas and nursery habitats is likely influenced by wind forcing, so climate-mediated changes to dispersal trajectory or timing is expected to have significant impacts on recruitment in this species, though entrainment in consistent, directional currents may modify these effects. Published by Elsevier B.V.

The present study investigates ecological patterns and relationships to environmental variables among a time-series of larval fish species abundance from late spring surveys (1981–2003) in the northwest Gulf of Alaska (GOA). Links between interannual variation in species abundance and the physical environment were explored using generalized additive modeling (GAM). Trends in larval abundance and connections with physical variables displayed patterns that indicate unique and complex responses among species to environmental forcing during the larval period. In particular, the observed patterns suggest that ontogenetic-specific responses, representing sub-intervals of early life, are important. In addition, a notable degree of synchrony in larval abundance trends, and similarity in links with physical variables, were observed among species with common early life history patterns. The deepwater spawners, northern lampfish, arrowtooth flounder, and Pacific halibut, were most abundant in the study area during the 1990s, in association with enhanced wind-driven onshore and alongshore transport. Years of high abundance for Pacific cod, walleye pollock, and northern rock sole were associated with cooler winters and enhanced alongshore winds during spring. High larval abundance for spring–summer spawning rockfish species and southern rock sole seemed to be favored by warmer spring temperatures later in the time-series. This apparent exposure–response coupling seems to be connected to both local-scale and basin-scale environmental signals, to varying degrees depending on specific early life history characteristics. Understanding such ecological connections contributes to the evaluation of vulnerability and resilience among GOA species’ early life history patterns to fluctuating climate and oceanographic conditions. This investigation also provides crucial information for the identification of “environmental indicators” that may have a broad-spectrum effect on multiple species early life history stages, as well as those that may be more species-specific in exerting control on early life history survival. Of particular interest was the emergence of the EP–NP (East Pacific–North Pacific) teleconnection index as the top-ranked variable in the GAM models exploring the connections between late spring larval abundance and the physical environment. The EP–NP index represents an important and often primary mode of spring–summer atmospheric variability in the northeast Pacific, with a strong expression in the GOA, and its connection with species in this study implies that it may be a climate mode of significant ecological importance.

We analyzed the spatial distribution, concentration, and characteristics of plastic micro-debris in neuston samples from the CalCOFI region off the southern Californian coast from winter cruises in 1984, 1994, and 2007 By sorting archived CalCOFI zooplankton samples we were able to separate micro-debris particles and characterize particle size, circularity, and surface area using digital image analysis by ZooScan Our results suggest that plastic micro-debris is widespread in the California Current system off the southern California coast Fifty-six to 68% of the CalCOFI stations hid detectable plastic micro-debris The avenge concentrations and misses of the particles were not significantly different over the three decades Median concentrations of plastic micro-debris ranged from 0 011-0 033 particles/m(3) in different years, with a maximum of 3 141 particles/m(3) Our results also suggest that not only is plastic micro-debris widely distributed, it has been present in the northeast Pacific Ocean water column for at least 25 years

Analyses of ichthyoplankton samples collected in the vicinity of Kodiak Island, Alaska, during the period October 1977-March 1979 provide new information on the spawning strategy and early life history of capelin in the Gulf of Alaska. Seasonal variation in abundance, length, and distribution of capelin larvae indicates that capelin populations in this area in 1978 spawned inshore during summer and autumn, and that spawning activity peaked during June-July. Distribution patterns of capelin larvae suggest that, subsequent to hatching and emergence into the plankton, larvae are transported from the bays and coastal zone around Kodiak Island into adjacent shelf waters, probably by tidal flushing and wind-induced surface currents. Mixing processes on the shelf seawards of Kodiak Island, reflecting variable current patterns there, are likely to enhance the dispersal of larvae as indicated by the uniformity observed among distribution patterns of several length categories. A comparison of larval abundance and length between bongo and neuston samples suggests that capelin larvae >30 mm standard length actively migrate to the surface layer. The observations represent a picture of capelin early life history during a period of abundance of adult capelin that has been linked to a cold phase in the oceanographic environment of the Gulf of Alaska. (C) 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd. All rights reserved.

The coastal regions of the northeast Pacific support large, economically valuable fishery resources and provide nursery areas for many fish species. Over the last few decades, there have been dramatic shifts in species abundance and composition in this area. In this paper, we examine the springtime spatial patterns in the ichthyoplankton of three oceanographically different regions, the Southeast Bering Sea, the Gulf of Alaska and the U.S. West Coast. The data examined are a subset of a larger database (comprising data from cruises conducted from 1972 to 1997) that is being used to investigate spatial, seasonal and interannual patterns in ichthyoplankton of the northeast Pacific in relation to environmental conditions. Ichthyoplankton were collected during seven cruises using 60-cm bongo nets. Spatial patterns of ichthyoplankton were examined using both classification and ordination techniques. Relative Bray-Curtis dissimilarity coefficients calculated from the log(10) (n+1) of abundance data were used as input to the numerical classification of species and stations. Nonmetric multidimensional scaling was also applied to the abundance data to examine geometric patterns in the data. The numerical analyses of the species abundance data sets for each cruise revealed spatial patterns in the ichthyoplankton that suggest the occurrence of geographically distinct assemblages of fish larvae in each region. For all three sampling regions, the assemblage structure is primarily related to bathymetry, and Shelf, Slope, and DeepWater assemblages are described. This shallow to deep-water gradient in species occurrence and abundance reflects the habitat preference and spawning location of the adult fish. Another degree of complexity is superimposed on this primary assemblage structure in each region and seems to be related to local topography and the prevailing current patterns. The patterns in ichthyoplankton assemblages of the three regions in the northeast Pacific Ocean described here form the basis for future investigations of spatial and temporal patterns in the ichthyoplankton of the subarctic Pacific. (C) 2002 Published by Elsevier Science Ltd.