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AimEcosystem-based management requires accurate predictions on how biotic and environmental factors interact to deliver ecosystem services. Biodiversity-ecosystem function (BEF) theory predicts that as diversity increases, the ecosystem will become more productive (positive diversity-productivity relationship – DPR) and more stable (positive diversity-stability relationship – DSR). Support for BEF has been primarily derived from fine-grained, non-harvested systems. The purpose of this study is to examine the robustness of BEF predictions for the DPR and DSR by examining how well fish diversity predicts productivity and stability of fish, shrimp, and flounder at a regional scale.LocationSoutheast coast of United States.Time Period1989 - 2015Major Taxa StudiedMarine FishesMethodsWe used 27 years of the SEAMAP-SA Coastal Trawl Survey database to derive estimates of fish, shrimp, and flounder biomass (i.e., productivity), temporal stability of biomass (i.e., invariability of productivity), and fish community species richness. We pooled trawls into 22 km x 22 km raster cells and 3-year time bins. We controlled for variation in sampling effort using sample-based rarefaction. We compared the ability of fish species richness, water salinity, and water temperature to predict biomass and stability of all fish, shrimp, and flounder using multiple linear regression.ResultsBoth the DPR and DSR exhibited positive log-log linear trends as expected, but the DPR had a much stronger signal. Species richness outperformed the environmental covariates in both the fish and shrimp DPR models. Surface temperature was the most important variable in both flounder models. Overall, our models better explained productivity than stability.Main ConclusionsThe DPR and DSR are relevant at regional scales in a commercially important fishery although support for the DSR is less justified than DPR. Further investigation into the underlying mechanisms driving the DPR and DSR are necessary to design management around BEF theory.

The Gray Triggerfish Balistes capriscus supports fisheries on both sides of the Atlantic Ocean. We utilized fishery-independent samples to assess the age structure, growth, sex ratio, size and age at maturity, spawning season, and spawning frequency of the Gray Triggerfish population off the southeastern U.S. Atlantic coast. From 1991 to 2012, 7,685 samples were collected, ranging in FL from 82 to 578 mm and ranging in age from 0 to 13 years. Our study provides key life history information for an exploited population and is the first to comprehensively describe age, growth, and reproduction for a Balistes species. We documented that the Gray Triggerfish is sexually dimorphic, with adult males attaining larger sizes at age and a larger maximum size than females. Sex-specific growth curves were fitted, yielding the following von Bertalanffy equations: FLt = 419[1 – e–0.54(t + 0.61)] for males and FLt = 352[1 – e–0.94(t + 0.22)] for females. This species is characterized by a medium size at maturity ...

Marine protected areas (MPAs) have been recommended as an essential conservation tool for ecosystems and fisheries, with MPA coverage increasing four-fold globally since 2000. Despite the increased usage of MPAs, empirical results and scientists are divided on the effectiveness of MPAs to reach their conservation and management goals. In 2009, the South Atlantic Fishery Management Council established eight deep-water partially-protected MPAs off the southeast United States (SEUS) Atlantic coast with the goal of protecting long-lived, deep-water, reef-associated fishery species. Data collected during fish trapping from 2000 to 2018 as part of a fisheries-independent survey were used to evaluate the impacts of protection on a subset of fish species in three of these MPAs. There was a modest positive shift to larger fish observed in two of the MPAs and to older fish for one species, Pagrus pagrus (Linnaeus, 1758), in one of the MPAs relative to adjacent fished areas; however, there was either no change or a decrease in managed reef fish abundance in each MPA relative to adjacent fished areas. Based on these metrics, it does not appear that the SEUS MPAs have yet been effective at protecting managed reef fish species. Given that these MPAs have low enforcement, future assessments should examine compliance within the SEUS MPAs to determine if lack of success is due to illegal fishing, species examined, or MPA design before making a final determination if deep-water MPAs are an effective strategy for fisheries managers in the SEUS.

The present study examines vertical distributions of the early life stages of walleye pollock (Theragra chalcogramma) in the Southeastern Bering Sea to assess ontogenetic and diel vertical migration in relation to development and habitat. Walleye pollock demonstrated a decrease in the depth of occurrence following hatching, indicating an ontogenetic change in vertical distribution. Eggs occurred deepest in the water column and early juveniles occurred shallowest. Vertical distributions were related to the date of collection, water column depth, and thermocline depth. Non-feeding stages (eggs and yolksac larvae

Implementing a recall paradigm without hypnosis, we use functional MRI (fMRI) to explore and compare nociceptive and centrally-driven pain experiences. We posit that a trace of a recent nociceptive event can be used to create sensory-re-experiencing of pain that can be qualified in terms of intensity and vividness. Fifteen healthy volunteers received three levels of thermal stimuli (warm, low pain and high pain) and subsequently were asked to recall and then rate this experience. Neuroimaging results reveal that recalling a previous sensory experience activates an extensive network of classical pain processing structures except the contralateral posterior insular cortex. Nociceptive-specific activation of this structure and the rated intensity difference between physical and recalled pain events allow us to investigate the link between the quality of the original nociceptive stimulus and the mental trace, as well as the differences between the accompanying neural responses. Additionally, by incorporating the behavioural ratings, we explored which brain regions were separately responsible for generating either an accurate or vivid recall of the physical experience. Together, these observations further our understanding of centrally-mediated pain experiences and pain memory as well as the potential relevance of these factors in the maintenance of chronic pain.

Using data on ocean circulation with a Lagrangian larval transport model, we modeled the potential dispersal distances for seven species of bathyal invertebrates whose durations of larval life have been estimated from laboratory rearing, MOCNESS plankton sampling, spawning times, and recruitment. Species associated with methane seeps in the Gulf of Mexico and/or Barbados included the bivalve "Bathymodiolus" childressi, the gastropod Bathynerita naticoidea, the siboglinid polychaete tube worm Lamellibrachia luymesi, and the asteroid Sclerasterias tanneri. Non-seep species included the echinoids Cidaris blakei and Stylocidaris lineata from sedimented slopes in the Bahamas and the wood-dwelling sipunculan Phascolosoma turnerae, found in Barbados, the Bahamas, and the Gulf of Mexico. Durations of the planktonic larval stages ranged from 3 weeks in lecithotrophic tubeworms to more than 2 years in planktotrophic starfish. Planktotrophic sipunculan larvae from the northern Gulf of Mexico were capable of reaching the mid-Atlantic off Newfoundland, a distance of more than 3000 km, during a 7- to 14-month drifting period, but the proportion retained in the Gulf of Mexico varied significantly among years. Larvae drifting in the upper water column often had longer median dispersal distances than larvae drifting for the same amount of time below the permanent thermocline, although the shapes of the distance-frequency curves varied with depth only in the species with the longest larval trajectories. Even species drifting for >2 years did not cross the ocean in the North Atlantic Drift.

We examined the influence of environmental conditions on walleye pollock ( Theragra chalcogramma ) early life history in discrete stages at two ecological scales using a 17-year time series from the southeastern Bering Sea. Generalized additive models (GAMs) were used to quantify relationships between walleye pollock stages (eggs, yolksac larvae, preflexion larvae, late larvae, and juveniles), the fine-resolution environment (temperature, wind speed, salinity, and copepod concentration), and the broad-resolution environment (annual spawning stock biomass, temperature, zooplankton biomass, and wind mixing). Early stages (eggs, yolksac larvae, and preflexion larvae) were associated with high spawning stock biomass, while late stages (late larvae and juveniles) were not associated with spawning stock biomass. The influence of temperature increased with ontogeny: high egg abundance was associated with temperatures from −2 to 7 °C and negative annual temperature anomalies and high juvenile abundance was associated with temperatures from 4 to 12 °C and positive temperature anomalies. Winds enhanced the transport of early stages from spawning locations to shallower sampling depths, but did not affect feeding stages (preflexion larvae, late larvae, and juveniles) in a manner consistent with the encounter-turbulence hypothesis. Feeding stages were positively associated with localized copepod concentrations but not zooplankton biomass anomaly, suggesting that the localized measurements of potential prey is a better indicator compared to broad-scale conditions measured in areas where these stages do not necessarily occur. Broad-resolution covariates, however, explained a greater portion of the overall variation than did fine-resolution models. Of the environmental conditions examined, temperature explained more variation in abundance of walleye pollock early life stages than any other covariate. Temperature is likely a major driving force structuring variability in populations of walleye pollock in their first year of life, acting directly upon them and indirectly upon their physical habitat and prey community.

Water temperatures in the southeastern Bering Sea influence the density of walleye pollock Theragra chalcogramma early life stages, potentially influencing spatial distributions and the phenology of reproduction and development. We quantified stage-specific changes in spatial and temporal distributions under cold- and warm-water conditions using generalized additive models. Analyses showed that walleye pollock egg and yolksac larval spatial distributions are unaffected by temperature, suggesting that spawning locations are stable. Preflexion larvae, late larvae, and juveniles shift onto the shelf under warm conditions, similar to spatial shifts observed in distributions of sub-adults and adults. Temporal distributions were used to address the hypo - thesis that timing of the density peak at each stage is delayed under cold conditions. Differences in the timing of density peaks supported the hypothesis that the timing of spawning, hatching, lar- val development, and juvenile transition are temperature-dependent. The current analysis repre- sents the best support available for the importance of temperature to walleye pollock in determin- ing early life stage development and population trends in the eastern Bering Sea. Our data indicate that future changes in water temperatures could influence the early life stages of an eco- logically dominant member of the Bering Sea community by changing phenology and habitat use in the first several months of life.

Coordination of gametogenesis and spawning during restricted breeding seasons increases availability of mates, fertilization rates, and often success of offspring. Orton’s Rule predicts water temperature as the dominant environmental cue for gametogenesis or spawning in temperate invertebrates. Crisp’s Rule predicts that species producing planktotrophic larvae will time their reproduction to ensure optimal nutrition for the larvae. Owenia collaris (Annelida: Oweniidae) is a temperate polychaete that produces planktotrophic larvae that remain in the water column for several weeks. Reproductive phenology and its relationship to the environment were investigated in an estuarine population of O. collaris using field and laboratory studies. Owenia collaris produced mature gametes between March and September each year during the productive season between the spring and fall transitions when day lengths were 12 h or more, alkalinity was 8.1 or higher, and temperature was 11 °C or higher. Gamete production was not related to seasonal changes in salinity or benthic phytoplankton concentrations and gametes were present prior to the spring phytoplankton bloom. In laboratory experiments, production of gametes was influenced somewhat by manipulating day lengths but not adult food. The association with predictable and stable environmental cycles (day length) and a broad spawning season suggest that this species is unlikely to mis-match with larval food availability which would lead to reduced availability of recruits in any given year, supporting Crisp’s Rule. Our data do not support the hypothesis that reproductive timing in this species is driven by access to excess energy required by adults to initiate the production of gametes. Our data also do not support Orton’s premise that temperature is the primary controlling factor of reproduction in this temperate marine invertebrate.

We report observations on spawning and early development in bone-eating worms of the genus Osedax. Individual females of Osedax rubiplumus were observed at 1820 m depth freely spawning hundreds of oocytes, and females of an undescribed species, Osedax “orange collar”, were observed spawning in laboratory aquaria. Cytological and molecular analysis of the spawned oocytes of two Osedax species revealed no evidence for the bacterial endosymbionts that the female worms require for their nutrition, suggesting that the bacteria must be acquired later from the environment, as they are in other siboglinids. Individual O. “orange collar” females released an average of 335 (±130) eggs per day, but the number of oocytes spawned per day varied greatly, suggesting that not all the females spawned daily. Fertilization rates of the spawned oocytes varied from 0 to 100%, though most females showed nearly 100% fertilization rates. Oocytes spawned in the laboratory at 4–6°C were negatively buoyant. If fertilized, these oocytes extruded polar bodies and then after at least four hours cleaved unequally. Subsequent cleavages occurred in a spiral pattern at roughly 2-h intervals, resulting in free-swimming trochophore larvae after 24 h. These lecithotrophic trochophores swam for 9–16 days before settling with several hooked chaetae, similar to those of dwarf Osedax males. The larval life span of the Osedax species studied in the laboratory appears to be shorter than in closely related Vestimentifera. Osedax rubiplumus, on the other hand, has much larger oocytes and so may have greater dispersal potential than these other Osedax species. The high fecundity and apparently continuous reproduction of Osedax boneworms permits the opportunistic exploitation of sunken vertebrate bones.

Reef fish species naturally fluctuate in abundance over various temporal and spatial scales, but recent broad-scale declines in abundance have been observed worldwide and attributed to various anthropogenic influences. We used 25 years of fishery-independent trap data (N = 11,237 trap hauls) to examine the spatial and temporal variability in temperate reef fish abundance along the southeast coast of the USA, a relatively understudied region with many economically important reef fish species. Overall, 441,298 individuals from 118 species were caught in the trap survey. Number of species and total number of individuals caught in the trap survey declined over the 25 years, but when separated, nontargeted fish species declined more than fishery-targeted species. For instance, traps caught a median of 18 nontargeted individuals and a median of 2–3 nontargeted reef fish species in the early 1990s, but by the 2010s, traps caught a median of fewer than three nontargeted individuals and a median of one nontarget species. Using generalized additive models, we found that the catch of fishery-targeted and nontargeted species was positively related to bottom water temperature, while depth influenced nontargeted and fishery-targeted species in opposite ways. The substantial and consistent decline in nontargeted fish species suggests that more research and management attention should be given to these often ignored species. These results suggest that the temperate reef fish community in the southeast USA is influenced by more than just fishing, perhaps including invasive species (e.g., lionfish Pterois volitans), decadal-scale environmental variability, or climate change.

The accurate detection and enumeration of Mycobacterium immunogenum in metalworking fluids (MWFs) is imperative from an occupational health and industrial fluids management perspective. We report here a comparison of immunomagnetic separation (IMS) coupled to flow-cytometric enumeration, with traditional centrifugation techniques for mycobacteria in a semisynthetic MWF. This immunolabeling involves the coating of laboratory-synthesized nanometer-scale magnetic particles with protein A, to conjugate a primary antibody (Ab), specific to Mycobacterium spp. By using magnetic separation and flow-cytometric quantification, this approach enabled much higher recovery efficiency and fluorescent light intensities in comparison to the widely applied centrifugation technique. This IMS technique increased the cell recovery efficiency by one order of magnitude, and improved the fluorescence intensity of the secondary Ab conjugate by 2-fold, as compared with traditional techniques. By employing nanometer-scale magnetic particles, IMS was found to be compatible with flow cytometry (FCM), thereby increasing cell detection and enumeration speed by up to two orders of magnitude over microscopic techniques. Moreover, the use of primary Ab conjugated magnetic nanoparticles showed better correlation between epifluorescent microscopy counts and FCM analysis than that achieved using traditional centrifugation techniques. The results strongly support the applicability of the flow-cytometric IMS for microbial detection in complex matrices.

Despite the wide variety of larval forms among polychaetes, most are clearly derived from the canonical spiralian trochophore. Within the genus Owenia (family Oweniidae), however, the mitraria larva lacks the characteristic ciliary bands of the trochophore, and those it has are monociliated, typically a deuterostome characteristic. Adult Owenia spp. also possess a monociliated epidermis and deuterostome-like nephridia. This study is the first detailed account of early embryology for any member of the Oweniidae. Light, confocal, and scanning electron microscopy were used to investigate organogenesis from fertilization through metamorphosis in Owenia collaris. Equal spiral cleavage yields an embryo with an unusually large blastocoel for a spiralian. The embryo undergoes gastrulation by invagination, and begins swimming 24 h after fertilization. Three important events deviate markedly from stereotypical polychaete embryogenesis. First, at the 8-cell stage the micromeres are larger than the macromeres, as in nemerteans. Second, the blastopore becomes the anus, as in some deuterostomes, while the stomodeum may form secondarily. Third, the cells that would form the prototroch in a canonical spiralian trochophore (1q(2) descendants) never undergo cleavage arrest, and the primary ciliated band of the mitraria never contains large, multiciliated cells. The mitraria larva thus represents a mixture of protostome and deuterostome developmental traits, suggesting that spiralian development is not so rigidly constrained as it might appear.