Assessment of habitat quality for juvenile California halibut (Paralichthys californicus) in a seasonally arid estuary

We evaluated habitat quality for juvenile California halibut (Paralichthys californicus) in a Pacific Coast estuary lacking in strong salinity gradients by examining density, recent otolith growth rates, and gut fullness levels of wild-caught and caged juveniles for one year. Juveniles <200 mm standard length were caught consistently in the inner, central, and outer sections of the estuary. The density of juveniles was two times higher in the inner estuary during most of the year, consistent with active habitat selection by part of the population. A generalized linear model indicated temperature, sampling time, and the interaction between salinity and temperature were significantly related to density. However, the model explained only 21% of the variance. Gut fullness levels of wild-caught juveniles were highest during the summer, but recent otolith growth rates were not related to temperature. The proportion of individuals feeding successfully indicated that seasonal differences in food availability are more important than spatial variation in prey abundance in driving feeding success. Feeding success of caged fishes was limited, precluding the use of growth rates as indicators of local habitat quality. However, marginal increment widths were reliable indicators of somatic growth at low growth rates over two-week periods. The relatively high growth rates and abundance of small wild-caught juveniles found throughout the estuary indicates that the entire estuary system has the potential for serving as nursery habitat.

Onshore-offshore distribution and abundance of tuna larvae (Pisces: Scombridae: Thunnini) in near-reef waters of the Coral Sea

The on-offshore distributions of tuna larvae in near-reef waters of the Coral Sea, near Lizard Island (14°30ʹS, 145°27ʹE), Australia, were investigated during four cruises from November 1984 to February 1985 to test the hypothesis that larvae of these oceanic fishes are found in highest abundance near coral reefs. Oblique bongo net tows were made in five on-offshore blocks in the Coral Sea, ranging from 0–18.5 km offshore of the outer reefs of the Great Barrier Reef, as well as inside the Great Barrier Reef Lagoon. The smallest individuals (<3.2 mm SL) of the genus Thunnus could not be identified to species, and are referred to as Thunnus spp. We found species-specific distributional patterns. Thunnus spp. and T. alalunga (albacore) larvae were most abundant (up to 68 larvae/100 m2) in near-reef (0–5.5 km offshore) waters, whereas Katsuwonus pelamis (skipjack tuna) larvae increased in abundance in the offshore direction (up to 228 larvae/100 m2, 11.1–18.5 km offshore). Larvae of T. albacares (yellowfin tuna) and Euthynnus affinis (kawakawa) were relatively rare throughout the study region, and the patterns of their distributions were inconclusive. Few larvae of any tuna species were found in the lagoon. Size-frequency distributions revealed a greater proportion of small larvae inshore compared to offshore for K. pelamis and T. albacares. The absence of significant differences in size-frequency distributions for other species and during the other cruises was most likely due to the low numbers of larvae. Larval distributions probably resulted from a combination of patterns of spawning and vertical distribution, combined with wind-driven onshore advection and downwelling on the seaward side of the outer reefs.

A nursery site of the Alaska skate (Bathyraja parmifera) in the eastern Bering Sea

A nursery site for the Alaska skate (Bathyraja parmifera) was sampled seasonally from June 2004 to July 2005. At the small nursery site (~2 km2), located in a highly productive area near the shelf-slope interface at the head of Bering Canyon in the eastern Bering Sea, reproductive males and females dominated the catch and neonate and juvenile skates were rare. Seasonal samples showed summertime (June and July) as the peak reproductive time in the nursery although some reproduction occurred throughout the year. Timeseries analysis of embryo length frequencies revealed that three cohorts were developing simultaneously and the period of embryonic development was estimated at 3.5 years and average embryo growth rate at 0.2 mm/day. Estimated egg case deposition occurred mainly during summertime and hatching occurred during winter months. Protracted hatching times may be common for oviparous elasmobranch species and may be directly correlated with ambient temperatures as evident from a meta-data analysis. Evidence indicates that the Alaska skate uses the eastern Bering Sea outer continental shelf region for reproduction and the middle and inner shelf regions as habitat for immature and subadults. Skate nurseries may be vulnerable to disturbances because they are located in highly productive areas and because embryos develop slowly.

Species of the rougheye rockfish complex: resurrection of Sebastes melanostictus (Matsubara, 1934) and a redescription of Sebastes aleutianus (Jordan and Evermann, 1898)(Teleostei: Scorpaeniformes)

The widespread and commercially important rougheye rockfish, Sebastes aleutianus (Jordan and Evermann, 1898), has been considered a single variable species, with light- and dark-colored forms, found on the outer continental shelf and upper slope of the North Pacific Ocean. Genetic analysis of 124 specimens verified the presence of two species in new specimens collected from Alaska to Oregon, and the two species were analyzed for distinguishing color patterns and morphological characters. Characters distinguishing the two were extended to an analysis of 215 additional formalin-fixed specimens representing their geographic ranges. Sebastes aleutianus is pale, often has dark mottling on the dorsum in diffuse bands, and does not have distinct dark spots on the spinous dorsal fin; it ranges from the eastern Aleutian Islands and southeastern Bering Sea to California. Sebastes melanostictus (Matsubara, 1934), the blackspotted rockfish, ranges from central Japan, through the Aleutian Islands and Bering Sea, to southern California. It is darker overall and spotting is nearly always present on the spinous dorsal fin. Sebastes swifti (Evermann and Goldsborough, 1907) is a synonym of S. aleutianus; S. kawaradae (Matsubara, 1934) is a synonym of S. melanostictus. The subgenus Zalopyr is restricted to S. aleutianus and S. melanostictus. Nomenclatural synonymies, diagnoses, descriptions, and distributions are provided for each species.

Factors influencing cannibalism and abundance of walleye pollock (Theragra chalcogramma) on the eastern Bering Sea shelf, 1982–20

Cannibalism is thought to be an inf luential top-down process affecting walleye pollock (Theragra chalcogramma) recruitment in the eastern Bering Sea (EBS). In summer, many age-1 pollock occupy the same depths as those of adult walleye pollock, making them vulnerable to cannibalism. We examine factors that inf luence the occurrence and amount of cannibalism, as well as the abundance and co-occurrence of predator and prey walleye pollock. Large walleye pollock were generally found in deeper waters and avoided cold temperatures; whereas, age-1 walleye pollock were found in broader bottom depth and temperature ranges. The occurrence of cannibalism was highest in the area where predator and prey walleye pollock co-occurred and the amount of cannibalism was highest on the middle and outer EBS shelf. Both the occurrence and amount of cannibalism were influenced by location, bottom temperature and bottom depth, and the abundance of prey walleye pollock. The abundance of both large and small walleye pollock decreased during the 1982–2006 survey period in the EBS and, hence, the occurrence and amount of cannibalism also decreased. The occurrence and amount of cannibalism observed in the diet samples from the summer survey were good indicators of year class strength, as estimated by the stock assessment model. There was more cannibalism of age-1 walleye pollock when predicted recruit abundance was highest, indicating that summer cannibalism on age-1 walleye pollock, a top-down process, does not control walleye pollock recruitment in the EBS.

Biodiversity as an index of regime shift in the eastern Bering Sea

Data collected from an annual groundf ish survey of the eastern Bering Sea shelf from 1975 to 2002 were used to estimate biomass and biodiversity indexes for two fish guilds: f latfish and roundfish. Biomass estimates indicated that several species of f latfish (particularly rock sole, arrowtooth flounder, and f lathead sole), several large sculpins (Myoxocephalus spp.), bigmouth (Hemitripterus bolini), and skates (Bathyraja spp.) had increased. Declining species included several f latfish species and many smaller roundfish species of sculpins, eelpouts (Lycodes spp.), and sablefish (Anoplopoma fimbria). Biodiversity indexes were calculated by using biomass estimates for both guilds from 1975 through 2002 within three physical domains on the eastern Bering Sea shelf. Biodiversity trends were found to be generally declining within the roundfish guild and generally increasing within the f latfish guild and varied between inner, middle, and outer shelf domains. The trends in biodiversity indexes from this study correlated strongly with the regime shift reported for the late 1970s and 1980s.

Prevalence, intensity, and effect of a nematode (Philometra saltatrix) in the ovaries of bluefish (Pomatomus saltatrix)

Examination of 203 adult bluefish (Pomatomus saltatrix) from Long Island, New York, in 2002 and 2003 and 66 from the Outer Banks, North Carolina, in 2003 revealed the presence of dracunculoid nematodes (Philometra saltatrix) in the ovaries of female fish. Percent prevalence reached 88% in July and then decreased after the peak of the spawning season. Bluefish contained up to 100 parasites per fish. Infection was associated with a range of disorders, including hemorrhage, inf lammation, edema, prenecrotic and necrotic changes, and follicular atresia, that may prevent proper development of oocytes and probably affect bluefish fecundity. Historical occurrences, life cycle, and geographical distribution of this nematode remain largely unknown, but may play important roles in recruitment processes of bluefish.

Patterns of growth, mortality, and size of the tropical damselfish Acanthochromis polyacanthus across the continental shelf of the Great Barrier Reef

Age-based analyses were used to demonstrate consistent differences in growth between populations of Acanthochromis polyacanthus (Pomacentridae) collected at three distance strata across the continental shelf (inner, mid-, and outer shelf) of the central Great Barrier Reef (three reefs per distance stratum). Fish had significantly greater maximum lengths with increasing distance from shore, but fish from all distances reached approximately the same maximum age, indicating that growth is more rapid for fish found on outer-shelf reefs. Only one fish collected from inner-shelf reefs reached >100 mm SL, whereas 38−67% of fish collected from the outer shelf were >100 mm SL. The largest age class of adult-size fish collected from inner and mid-shelf locations comprised 3−4 year-olds, but shifted to 2-year-olds on outer-shelf reefs. Mortality schedules (Z and S) were similar irrespective of shelf position (inner shelf: 0.51 and 60.0%; mid-shelf: 0.48 and 61.8%; outer shelf: 0.43 and 65.1%, respectively). Age validation of captive fish indicated that growth increments are deposited annually, between the end of winter and early spring. The observed cross-shelf patterns in adult sizes and growth were unlikely to be a result of genetic differences between sample populations because all fish collected showed the same color pattern. It is likely that cross-shelf variation in quality and quantity of food, as well as in turbidity, are factors that contribute to the observed patterns of growth. Similar patterns of cross-shelf mortality indicate that predation rates varied little across the shelf. Our study cautions against pooling demographic parameters on broad spatial scales without consideration of the potential for cross-shelf variabil

Sexual differentiation and gonad development in striped mullet (Mugil cephalus L.) from South Carolina estuaries*

This study examined the sexual differentiation and reproductive dynamics of striped mullet (Mugil cephalus L.) in the estuaries of South Carolina. A total of 16,464 specimens were captured during the study and histological examination of sex and maturity was performed on a subsample of 3670 fish. Striped mullet were sexually undifferentiated for the first 12 months, began differentiation at 13 months, and were 90% fully differentiated by 15 to 19 months of age and 225 mm total length (TL). The defining morphological characteristics for differentiating males was the elongation of the protogonial germ tissue in a corradiating pattern towards the center of the lobe, the development of primary and secondary ducts, and the lack of any recognizable ovarian wall structure. The defining female characteristics were the formation of protogonial germ tissue into spherical germ cell nests, separation of a tissue layer from the outer epithelial layer of the lobe-forming ovarian walls, a tissue bud growing from the suspensory tissue that helped form the ovary wall, and the proliferation of oogonia and oocytes. Sexual maturation in male striped mullet first occurred at 1 year and 248 mm TL and 100% maturity occurred at age 2 and 300 mm TL. Female striped mullet first matured at 2 years and 291 mm total length and 100% maturity occurred at 400 mm TL and age 4. Because of the open ocean spawning behavior of striped mullet, all stages of maturity were observed in males and females except for functionally mature females with hydrated oocytes. The spawning season for striped mullet recruiting to South Carolina estuaries lasts from October to April; the majority of spawning activity, however, occurs from November to January. Ovarian atresia was observed to have four distinct phases. This study presents morpholog ical analysis of reproductive ontogeny in relation to size and age in South Carolina striped mullet. Because of the length of the undifferentiated gonad stage in juvenile striped mullet, previous studies have proposed the possibility of protandric hermaphrodism in this species. The results of our study indicate that striped mullet are gonochoristic but capable of exhibiting nonfunctional hermaphroditic characteristics in differentiated mature gonads.

Study on the activation mechanism of BCL-2 related ovarian killer (BOK)

BCL-2 family proteins are key regulators of the mitochondrial apoptotic machinery, controlling the mitochondrial outer membrane (MOM) permeabilization (MOMP). BCL-2 related Ovarian Killer (BOK) is a poorly understood pro-apoptotic member of this protein family. It has been reported that BOK localizes predominantly (although not exclusively) at membranes of the endoplasmic reticulum and of the Golgi apparatus. However, it is unclear whether BOK also operates at the MOM to promote apoptosis, as other pro-apoptotic BCL-2 family members do. Basing on the fact that the other two BAX-like pro-apoptotic members have been reported to oligomerize in order to induce MOMP, site-directed mutagenesis was used to generate two point mutations that predictably eliminated BOK’s oligomerization capacity. Then, the effect of such mutations on BOK’s membrane activity was examined using fluorescence spectroscopy.

The activity view of inner speech

We distinguish two general approaches to inner speech (IS) the "format" and the "activity" views and defend the activity view. The format view grounds the utility of IS on features of the representational format of language, and is related to the thesis that the proper function of IS is to make conscious thinking possible. IS appears typically as a product constituted by representations of phonological features. The view also has implications for the idea that passivity phenomena in cognition may be misat-tributed IS. The activity view sees IS as a speaking activity that does not have a proper function in cognition. It simply inherits the array of functions of outer speech. We argue that it is methodologically advisable to start from this variety of uses, which suggests commonalities between internal and external activities. The format view has several problems; it has to deny "unsymbolized thinking"; it cannot easily explain how IS makes thoughts available to consciousness, and it cannot explain those uses of IS where its format features apparently play no role. The activity view not only lacks these problems but also has explanatory advantages: construing IS as an activity allows it to be integrally constituted by its content; the view is able to construe unsymbolized thinking as part of a continuum of phenomena that exploit the same mechanisms, and it offers a simple explanation for the variety of uses of IS

Dinâmica de colonização de uma planície hipersalina por espécies de mangue em Guaratiba, RJ

Alterações na frequência e amplitude das inundações pelas marés são fatores reguladores da dinâmica das florestas de mangue. Tais alterações podem estar relacionadas à elevação do nível médio relativo do mar (NMRM), que vem sendo atribuída como fator de impacto decorrente das mudanças climáticas globais atuando sobre os ecossistemas costeiros. Durante a década de 90, o Núcleo de Estudos em Manguezais da Universidade do Estado do Rio de Janeiro observou, em Guaratiba (RJ), um processo de colonização de uma planície hipersalina por espécies de mangue, e começou a monitorá-lo. Após seis anos os dados indicaram a consolidação da colonização e juntamente com o desenvolvimento de outros estudos neste sistema, a elevação do NMRM foi atribuída como principal causa deste processo. Os dados gerados por tal monitoramento, de 1998 até o ano de 2011, constituem a base de dados da presente dissertação, que teve como objetivo analisar o desenvolvimento do processo de colonização e verificar suas relações com fatores meteorológicos locais. No ano de 1998 foram demarcadas seis parcelas justapostas, no sentido floresta-planície hipersalina, até onde era percebida a presença das plantas de mangue. Todos os indivíduos foram identificados com etiquetas numeradas e tiveram suas alturas medidas ao longo de todo monitoramento, da mesma forma que novos indivíduos (recrutas). Quando recrutas eram encontrados em áreas mais distantes da floresta, novas parcelas eram incluídas no monitoramento. No ano de 2011, a colonização já havia avançado 75 m de distância da floresta e as treze parcelas monitoradas indicaram diferentes estágios sucessionais: mais próximas à floresta apresentam consolidação do processo de colonização, com redução de densidade e maior desenvolvimento estrutural; intermediárias, com altas densidades, encontra-se em fase menos avançada da colonização; mais externas caracterizam o início da colonização da área por poucos indivíduos. Notou-se, ainda, que o processo de colonização se dá por meio do estabelecimento de coortes, que demonstram variabilidade nos padrões de desenvolvimento estrutural ao longo dos anos (densidade, distribuição e taxa de crescimento), relacionada às condições ambientais distintas (padrões climatológicos). Quanto à disponibilidade hídrica (entre 1985 e 2011), Guaratiba apresentou predomínio de déficit hídrico, com tendência de amenização ao final do período. Períodos de maior disponibilidade de água no sistema coincidiram com marcação de novas parcelas, bem como com picos de recrutamento e elevadas taxas de crescimento das coortes. Assim, foi possível observar que o desenvolvimento das coortes esteve relacionado às condições de disponibilidade de espaço e luz, além de responderem aos processos meteorológicos, relacionados à disponibilidade de água na região.

Cross-shelf and seasonal variation in larval fish assemblages on the southeast United States continental shelf off the coast of Georgia

Seasonal and cross-shelf patterns were investigated in larval fish assemblages on the continental shelf off the coast of Georgia. The influence of environmental factors on larval distributions also was examined, and larval transport processes on the shelf were considered. Ichthyoplankton and environmental data were collected approximately every other month from spring 2000 to winter 2002. Ten stations were repeatedly sampled along a 110-km cross-shelf transect, including four stations in the vicinity of Gray’s Reef National Marine Sanctuary. Correspondence analysis (CA) on untransformed community data identified two seasonal (warm weather [spring, summer, and fall] and winter) and three cross-shelf larval assemblages (inner-, mid-, and outer-shelf ). Five environmental factors (temperature, salinity, density, depth of the water column, and stratification) were related to larval cross-shelf distribution. Specifically, increased water column stratification was associated with the outer-shelf assemblage in spring, summer, and fall. The inner shelf assemblage was associated with generally lower temperatures and lower salinities in the spring and summer and higher salinities in the winter. The three cross-shelf regions indicated by the three assemblages coincided with the location of three primary water masses on the shelf. However, taxa occurring together within an assemblage were transported to different parts of the shelf; thus, transport across the continental shelf off the coast of Georgia cannot be explained solely by twodimensional physical factors.

Fishery-independent Bottom Trawl Surveys for Deep-water Fishes and Invertebrates of the U.S. Gulf of Mexico, 2002–08

From 2002 through 2008, the Mississippi Laboratories of the NMFS Southeast Fisheries Science Center, NOAA, conducted fishery-independent bottom trawl surveys for continental shelf and outer-continental shelf deep-water fishes and invertebrates of the U.S. Gulf of Mexico (50–500 m bottom depths). Five-hundred and ninety species were captured at 797 bottom trawl locations. Standardized survey gear and randomly selected survey sites have facilitated development of a fishery-independent time series that characterizes species diversity, distributions, and catch per unit effort. The fishery-independent surveys provide synoptic descriptions of deep-water fauna potentially impacted by various anthropogenic factors.

The Status of the United States Population of Night Shark, Carcharhinus signatus

Night sharks, Carcharhinus signatus, are an oceanic species generally occurring in outer continental shelf waters in the western North Atlantic Ocean including the Caribbean Sea and Gulf of Mexico. Although not targeted, night sharks make up a segment of the shark bycatch in the pelagic longline fishery. Historically, night sharks comprised a significant proportion of the artisanal Cuban shark fishery but today they are rarely caught. Although information from some fisheries has shown a decline in catches of night sharks, it is unclear whether this decline is due to changes in fishing tactics, market, or species identification. Despite the uncertainty in the decline, the night shark is currently listed as a species of concern due to alleged declines in abundance resulting from fishing effort, i.e. overutilization. To assess their relevance to the species of concern list, we collated available information on the night shark to provide an analysis of its status. Night shark landings were likely both over- and under-reported and thus probably did not reflect all commercial and recreational catches, and overall they have limited relevance to the current status of the species. Average size information has not changed considerably since the 1980’s based on information from the pelagic longline fishery when corrected for gear bias. Analysis of biological information indicates night sharks have intrinsic rates of increase (r) about 10% yr–1 and have moderate rebound potential and an intermediate generation time compared to other sharks. An analysis of trends in relative abundance from four data sources gave conflicting results, with one series in decline, two series increasing, and one series relatively flat. Based on the analysis of all currently available information, we believe the night shark does not qualify as a species of concern but should be retained on the prohibited species list as a precautionary approach to management until a more comprehensive stock assessment can be conducted.