Chemical contaminants, pathogen exposure and general health status of live and beach-cast Washington sea otters (Enhydra lutris kenyoni)

Analyses of blood and liver samples from live captured sea otters and liver samples from beachcast sea otter carcasses off the remote Washington coast indicate relatively low exposure to contaminants, but suggest that even at the low levels measured, exposure may be indicated by biomarker response. Evidence of pathogen exposure is noteworthy - infectious disease presents a potential risk to Washington sea otters, particularly due to their small population size and limited distribution. During 2001 and 2002, 32 sea otters were captured, of which 28 were implanted with transmitters to track their movements and liver and blood samples were collected to evaluate contaminant and pathogen exposure. In addition, liver samples from fifteen beachcast animals that washed ashore between 1991 and 2002 were analyzed to provide historical information and a basis of reference for values obtained from live otters. The results indicate low levels of metals, butyltins, and organochlorine compounds in the blood samples, with many of the organochlorines not detected except polychlorinated biphenyls (PCBs), and a few aromatic hydrocarbons detected in the liver of the live captured animals. Aliphatic hydrocarbons were measurable in the liver from the live captured animals; however, some of these are likely from biogenic sources. A significant reduction of vitamin A storage in the liver was observed in relation to PCB, dibutyltin and octacosane concentration. A significant and strong positive correlation in vitamin A storage in the liver was observed for cadmium and several of the aliphatic hydrocarbons. Peripheral blood mononuclear cell (PBMC) cytochrome P450 induction was elevated in two of 16 animals and may be potentially related to aliphatic and aromatic hydrocarbon exposure. Mean concentration of total butyltin in the liver of the Washington beach-cast otters was more than 15 times lower than the mean concentration reported by Kannan et al. (1998) for Southern sea otters in California. Organochlorine compounds were evident in the liver of beach-cast animals, despite the lack of large human population centers and development along the Washington coast. Concentrations of PCBs and chlordanes (e.g., transchlordane, cis-chlordane, trans-nonachlor, cis-nonachlor and oxychlordane) in liver of Washington beach-cast sea otters were similar to those measured in Aleutian and California sea otters, excluding those from Monterey Bay, which were higher. Mean concentrations of 1,1,1,- trichloro-2,2-bis(p-chlorophyenyl)ethanes (DDTs) were lower, and mean concentrations of cyclohexanes (HCH, e.g., alpha BHC, beta BHC, delta BHC and gamma BHC) were slightly higher in Washington beach-cast otters versus those from California and the Aleutians. Epidemiologically, blood tests revealed that 80 percent of the otters tested positive for morbillivirus and 60 percent for Toxoplasma, the latter of which has been a significant cause of mortality in Southern sea otters in California. This is the first finding of positive morbillivirus titers in sea otters from the Northeast Pacific. Individual deaths may occur from these diseases, perhaps more so when animals are otherwise immuno-compromised or infected with multiple diseases, but a population-threatening die-off from these diseases singly is unlikely while population immunity remains high. The high frequency of detection of morbillivirus and Toxoplasma in the live otters corresponds well with the cause of death of stranded Washington sea otters reported herein, which has generally been attributable to infectious disease. Washington’s sea otter population continues to grow, with over 1100 animals currently inhabiting Washington waters; however, the rate of growth has slowed over recent years. The population has a limited distribution and has not yet reached its carrying capacity and as such, is still considered at high risk to catastrophic events. (PDF contains 189 pages)

Changes in the size structure of the yellowfin tuna population of the tropical eastern Pacific Ocean from 1947 to 1955

ENGLISH: Morphometric studies by Godsil (1948), Godsil and Greenhood (1951), Royce (1953) and Schaefer (1952, 1955) have indicated that the yellowfin tuna of the Eastern Pacific are distinct from those of the Central Pacific. Tagging of yellowfin tuna by the California Department of Fish and Game, and by the Inter-American Tropical Tuna Commission in the Eastern Pacific, and by the Pacific Oceanic Fishery Investigations in the Central Pacific, have not yet revealed any migrations between these areas. Shimada and Schaefer (1956) have compared changes in population abundance and fishing intensity, considering the population in the Eastern Pacific as a separate entity. They conclude " ... the amount of fishing has had a real effect upon the stock of Eastern Pacific yellowfin tuna, taken in the aggregate, over the period studied. The evidence suggests also that for this species the intensity of fishing in some recent years has reached and might have even exceeded the level corresponding to the maximum equilibrium yield." Tagging experiments by the California Department of Fish and Game and by the Inter-American Tropical Tuna Commission have yielded returns in the order of one to five percent (Roedel 1954, and unpublished data of both agencies), a level much lower than that at which fishing intensity would be expected to noticeably affect the population size. These results are probably a reflection of the inadequacies of the present tagging methods, but they could lend doubt to the conclusions of Shimada and Schaefer. It is desirable, therefore, to examine other, independent, evidence as to the effects of fishing on the population. At the high levels of fishing intensity suggested by Shimada and Schaefer, in addition to changes in quantity, measurable changes would be expected to have occurred in the quality of the yellowfin tuna stocks, because the average age and size of the fish would have been reduced by the high mortality rates accompanying high fishing intensities. A continuing regular program of sampling catches and determining their length composition, to assess changes in the size composition of the stocks, was initiated by the Commission in 1954 but direct measurements are not available for the earlier, more dynamic period of growth of the fishery. Consequently, other, more general indications of possible changes in the size composition were sought. SPANISH: Los estudios morfométricos efectudos por Godsil (1948), Godsil y Greenhood (1951), Royce (1953) y Schaefer (1952, 1955), han demostrado que el atún aleta amarilla del Pacífico Oriental es distinto del que habita el PacÍfico Central. Los experimentos del Departamento de Pesca y Caza de California y de la Comisión Interamericana del Atún Tropical en el Pacífico Oriental, así como los de las Investigaciones Pesqueras del Océano Pacífico en el Pacífico Central,consistentes en la marcación de atunes aleta amarilla, aún no han puesto de manifiesto movimientos migratorios entre dichas áreas. Shimada y Schaefer (1956) han hecho estudios comparativos sobre la abundancia de la población y la intensidad de la pesca, considerando a la población del Pacífico Oriental como una entidad separada. Su conclusión es que " ... la intensidad de la pesca ha tenido un definido efecto sobre la población del atún aleta amarilla del Pacífico Oriental, tomada en conjunto, a lo largo del período estudiado. La evidencia de que se dispone sugiere así mismo que, por lo que hace a esta especie, la intensidad de la pesca en los últimos años ha alcanzado y quizás aún sobrepasado el nivel correspondiente a la máxima pesca de equilibrio". Los experimentos de mar•cación del Departamento de Pesca y Caza de California y de la Comisión Interamericana del Atún Tropical han producido recuperaciones ,entre el uno y el cinco por ciento (Roedel 1954 y datos inéditos de ambos organismos), lo que constituye un nivel mucho más bajo de aquél en que la intensidad de la pesca podría considerarse que afectaría notablemente el tamaño de la población. Estos resultados reflejan probablemente lo inadecuados que son aún los métodos de marcación, pero ellos podrían, quizá, poner en tela de juicio las conclusiones de Shimada y Schaefer. Por lo tanto,es deseable examinar otras fuentes de evidencia independientes, relacionadas con el efecto que la pesca tiene sobre la población. En efecto, si los altos índices de pesca sugeridos por Shimada y Schaefer son correctos, es de esperar que, además de los cambios en la magnitud de la población, se hayan producido otros, concomitantes y sensibles, en la calidad de los stocks de atún aleta amarilla, puesto que tanto el promedio de edad como el de tamaño de los individuos habrían disminuído debido a las elevadas tasas de mortalidad inherentes a las altas intensidades de pesca. En 1954 la Comisión inició un programa ininterrumpido para tomar muestras y determinar en ellas las frecuencias de tallas y evaluar de este modo los cambios correlativos que tuvieran lugar en los stocks pero, infortunadamente, este sistema de evaluación directa no fué practicado en el período anterior, que fué precisamente el de rápida expansión de la pesquería. En tal virtud, hubo de ser necesario buscar indicios más generales referentes a los cambios posibles en la composición de tamaños. (PDF contains 20 pages.)

Influence of the Azores high on sea level pressure and wind, and on precipitation, in the Eastern Tropical Pacific Ocean

ENGLISH: Intensification of the Azores high pressure cell in mid-year, with concomitant air flow from the Caribbean into the Pacific, is shown to be responsible for a secondary minimum of precipitation observed along the tropical Pacific coast of the Americas, and to have a measurable effect on wind and precipitation several hundred kilometers offshore. SPANISH: La intensificación de la célula de alta presión de las Azores a mediados del año, y la corriente de aire concomitante que entra al Pacífico procedente del Caribe, se demuestra que es la causante de un mínimo secundario de precipitación observado a lo largo de la costa tropical de las Américas en el Pacífico y que tiene un efecto mensurable sobre el viento y la precipitación varios cientos de kilómetros mar afuera. (PDF contains 23 pages.)

Population dynamics of the skipjack tuna (Katsuwonus pelamis) of the Eastern Pacific Ocean

ENGLISH: Catches of skipjack tuna supporting major fisheries in parts of the western, central and eastern Pacific Ocean have increased in recent years; thus, it is important to examine the dynamics of the fishery to determine man's effect on the abundance of the stocks. A general linear hypothesis model was developed to standardize fishing effort to a single vessel size and gear type. Standardized effort was then used to compute an index of abundance which accounts for seasonal variability in the fishing area. The indices of abundance were highly variable from year to year in both the northern and southern areas of the fishery but indicated a generally higher abundance in the south. Data from 438 fish tagged and recovered in the eastern Pacific Ocean were used to compute growth curves. A least-squares technique was used to estimate the parameters of the von Bertalanffy growth function. Two estimates of the parameters were made by analyzing the same data in different ways. For the first set of estimates, K= 0.819 on an annual instantaneous basis and L= 729 mm; for the second, K = 0.431 and L=881. These compared well with estimates derived using the Chapman-Richards growth function, which includes the von Bertalanffy function as a special case. It was concluded that the latter function provided an adequate empirical fit to the skipjack data since the more complicated function did not significantly improve the fit. Tagging data from three cruises involving 8852 releases and 1777 returns were used to compute mortality rates during the time the fish were in the fishery. Two models were used in the analyses. The best estimates of the catchability coefficient (q) in the north and south were 8.4 X 10- 4 and 5.0 X 10- 5 respectively. The other loss rate (X), which included losses due to emigration, natural mortality and mortality due to carrying a tag, was 0.14 on an annual instantaneous basis for both areas. To detect the possible effect of fishing on abundance and total yield, the relation between abundance and effort and between total catch and effort was examined. It was found that at levels of intensity observed in the fishery, fishing does not appear to have had any measurable effect on the stocks. It was concluded therefore that the total catch could probably be increased by substantially increasing total effort beyond the present level, and that the fluctuations in abundance are fishery-independent. The estimates of growth, mortality and fishing effort were used to compute yield-per-recruitment isopleths for skipjack in both the northern and southern areas. For a size at first entry of about 425 mm, the yield per recruitment was calculated at 3 pounds in the north and 1.5 pounds in the south. In both areas it would be possible to increase the yield per recruitment by increasing fishing effort. It was not possible to assess potential production of the skipjack stocks fished in the eastern Pacific, except to note that the fishery had not affected their abundance and that they were certainly under-exploited. It was concluded that the northern and southern stocks could support increased harvests, especially the latter. SPANISH: Las capturas de atún barrilete que sostienen las pesquerías principales de la parte occidental, central y oriental del Océano Pacífico han aumentado en los últimos años; así que es importante examinar la dinámica de la pesquería para determinar el efecto que pueda tener sobre la abundancia de los stocks. Se desarrolló un modelo hipotético, lineal para standardizar el esfuerzo de pesca a un solo tamaño de barco y tipo de arte. Luego se usó el esfuerzo standardizado para computar un índice de la abundancia que pueda dar razón de la variabilidad estacional en el área de pesca. Los índices de la abundancia variaron mucho de un año a otro tanto en el área septentrional como en el área meridional de la pesquería, pero indicaron una abundancia generalmente superior en el sur. Se emplearon los datos de 438 peces marcados y recuperados en el Océano Pacífico oriental para computar las curvas de crecimiento. Una técnica de mínimos cuadrados fue usada para estimar los parámetros de la función de crecimiento de van Bertalanffy. Se hicieron dos estimativos de los parámetros mediante el análisis de los mismos datos, de diferente manera. Para el primer juego de estimativos, K=0.819 sobre una base anual instantánea y L∞=729 mm; para el segundo, K=0.431 y L∞=881. Estos se correlacionaron bien con los estimativos obtenidos usando la función de crecimiento de Chapman-Richards, que incluye la de von Bertalanffy como un caso especial. Se decidió que la última función proveía un ajuste empírico, adecuado a los datos del barrilete, ya que la función más complicada no mejoró significativamente el ajuste. Los datos de marcación de tres cruceros incluyendo 8852 liberaciones y 1777 retornos, fueron usados para computar las tasas de mortalidad durante el tiempo en que los peces estuvieron en la pesquería. Se usaron dos modelos en los análisis. Los mejores estimativos del coeficiente de capturabilidad (q) en el norte y en el sur fueron 8.4 X 10-4 y 5.0 X 10-5 , respectivamente. La otra tasa de pérdida (X), la cual incluyó pérdidas debidas a la emigración, mortalidad natural y mortalidad debida a llevar una marca, fue 0.14 sobre una base anual instantánea para las dos áreas. Con el fin de descubrir el efecto que posiblemente pueda tener la pesca sobre la abundancia y el rendimiento total, se examinó la relación entre la abundancia y el esfuerzo y entre la captura total y el esfuerzo. Se encontró que a los niveles de la intensidad observada en la pesquería, la pesca no parece haber tenido ningún efecto perceptible en los stocks. Por lo tanto se decidió que mediante un aumento substancial del esfuerzo total, más allá del nivel actual, la captura total probablemente podría aumentarse, y que las fluctuaciones de la abundancia son independientes de la pesquería. Los estimativos del crecimiento, mortalidad y esfuerzo de pesca fueron usados para computar las isopletas del rendimiento por recluta del barrilete, tanto en las áreas del norte como del sur. Para una talla de primera entrada de unos 425 mm, el rendimiento por recluta fue calculado en 3 libras en el norte y 1.5 libras en el sur. En ambas áreas sería posible aumentar el rendimiento por recluta mediante un aumento del esfuerzo de pesca. No fue posible determinar la producción potencial de los stocks del barrilete pescado en el Pacífico oriental, excepto para observar que la pesquería no ha afectado su abundancia y que ciertamente se encuentran subexplotados. Se concluyó que los stocks norte y sur pueden soportar un aumento en el rendimiento, especialmente este último. (PDF contains 274 pages.)

Investigations on the vertical migration of planktonic Crustacea in the Bodensee-Obersee. [Translation from: Schriften des Vereins fur Geschichte des Bodensees und seiner Umgebung, 87, 177-187, 1969.]

The vertical zoning of the planktonic Crustacea in a lake is the expression of a complex set of different factors. Besides the measurable, external influences such as light, temperature, acid and C02 stratification, a particularly large part is played by internal factors, which co-ordinate a specific reaction in each species depending on state of development, age and sex. Supporting this extensive, predictable, annual course of diurnal depths and the daily vertical migrations, whose extent is again dependent on external conditions, primarily of course on the amount of light. The individual factors mentioned, however, are here also of great significance. Within the scope of a long-term study of the planktonic Copepoda of Lake Constance, some day and night series were in 1963 also carried out in the Obersee, in order to obtain at least volumetric data on the extent of the daily migrations of these creatures.

Aspects of the washout of salmonid eggs. 1. Observations on the physical characteristics of real and artificial eggs, their rate of fall in a water column and their pattern of settlement in an experimental channel

When salmonid redds are disrupted by spates, the displaced eggs will drift downstream. The mean distance of travel, the types of locations in which the eggs resettle and the depth of reburial of displaced eggs are not known. Investigation of these topics under field conditions presents considerable practical problems, though the use of artificial eggs might help to overcome some of them. Attempts to assess the similarities and/or differences in performance between real and artificial eggs are essential before artificial eggs can validly be used to simulate real eggs. The present report first compares the two types of egg in terms of their measurable physical characteristics (e.g. dimensions and density). The rate at which eggs fall in still water will relate to the rate at which they are likely to resettle in flowing water in the field. As the rate of fall will be influenced by a number of additional factors (e.g. shape and surface texture) which are not easily measured directly, the rates of fall of the two types of egg have been compared directly under controlled conditions. Finally, comparisons of the pattern of settlement of the two types of egg in flowing water in an experimental channel have been made. Although the work was primarily aimed at testing the value of artificial eggs as a simulation of real eggs, several side issues more directly concerned with the properties of real eggs and the likely distance of drift in natural streams have also been explored. This is the first of three reports made on this topic by the author in 1984.

Effects of trawling for ocean shrimp (Pandalus jordani) on macroinvertebrate abundance and diversity at four sites near Nehalem Bank, Oregon

Surveys with a remotely operated vehicle (ROV) at four mudhabitat sites with different histories of ocean shrimp (Pandalus jordani) trawling showed measurable effects of trawling on macroinvertebrate abundance and diversity. Densities of the sea whip (Halipteris spp., P<0.01), the flat mud star (Luidia foliolata, P< 0.001), unidentified Asteroidea (P<0.05), and squat lobsters (unidentified Galathoidea, P<0.001) were lower at heavily trawled (HT) sites, as was invertebrate diversity based on the Shannon-Wiener index. Sea cucumbers (unidentified Holothuroidea) and unidentified corals (Hydrocoralia) were observed at lightly trawled (LT) sites but not at HT sites. Hagfish (Eptatretus spp.) burrows were the dominant structural feature of the sediment surface at all sites and were more abundant at the HT sites (P<0.05), a result potentially related to effects from fishery discards. Substantial heterogeneity was found between the northern and southern site pairs, indicating high site-to-site variability in macroinvertebrate densities in these deep (146–156 m) mud habitats. Two of the study sites were closed to trawling in June 2006. The data from this study can be used in combination with future surveys to measure recovery rates of deep, mud, seaf loor habitats from the effects of trawling, thus providing a critical piece of information for ecosystem-based management.

Effects of rapid decompression and exposure to bright light on visual function in black rockfish (Sebastes melanops) and Pacific halibut (Hippoglossus stenolepis)

Demersal fishes hauled up from depth experience rapid decompression. In physoclists, this can cause overexpansion of the swim bladder and resultant injuries to multiple organs (barotrauma), including severe exophthalmia (“pop-eye”). Before release, fishes can also be subjected to asphyxia and exposure to direct sunlight. Little is known, however, about possible sensory deficits resulting from the events accompanying capture. To address this issue, electroretinography was used to measure the changes in retinal light sensitivity, flicker fusion frequency, and spectral sensitivity in black rockfish (Sebastes melanops) subjected to rapid decompression (from 4 atmospheres absolute [ATA] to 1 ATA) and Pacific halibut (Hippoglossus stenolepis) exposed to 15 minutes of simulated sunlight. Rapid decompression had no measurable influence on retinal function in black rockfish. In contrast, exposure to bright light significantly reduced retinal light sensitivity of Pacific halibut, predominately by affecting the photopigment which absorbs the green wavelengths of light (≈520–580 nm) most strongly. This detriment is likely to have severe consequences for postrelease foraging success in green-wavelength-dominated coastal waters. The visual system of Pacific halibut has characteristics typical of species adapted to low light environments, and these characteristics may underlie their vulnerability to injury from exposure to bright light.

Quantifying intrapopulation variability in stable isotope data for Spotted Seatrout (Cynoscion nebulosus)

Stable isotope (SI) values of carbon (δ13C) and nitrogen (δ15N) are useful for determining the trophic connectivity between species within an ecosystem, but interpretation of these data involves important assumptions about sources of intrapopulation variability. We compared intrapopulation variability in δ13C and δ15N for an estuarine omnivore, Spotted Seatrout (Cynoscion nebulosus), to test assumptions and assess the utility of SI analysis for delineation of the connectivity of this species with other species in estuarine food webs. Both δ13C and δ15N values showed patterns of enrichment in fish caught from coastal to offshore sites and as a function of fish size. Results for δ13C were consistent in liver and muscle tissue, but liver δ15N showed a negative bias when compared with muscle that increased with absolute δ15N value. Natural variability in both isotopes was 5–10 times higher than that observed in laboratory populations, indicating that environmentally driven intrapopulation variability is detectable particularly after individual bias is removed through sample pooling. These results corroborate the utility of SI analysis for examination of the position of Spotted Seatrout in an estuarine food web. On the basis of these results, we conclude that interpretation of SI data in fishes should account for measurable and ecologically relevant intrapopulation variability for each species and system on a case by case basis.

Evaluation of the economic costs and benefits of methods for reducing nutrient loads to the Gulf of Mexico: Topic 6 Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico.

In this report we analyze the Topic 5 report’s recommendations for reducing nitrogen losses to the Gulf of Mexico (Mitsch et al. 1999). We indicate the relative costs and cost-effectiveness of different control measures, and potential benefits within the Mississippi River Basin. For major nonpoint sources, such as agriculture, we examine both national and basin costs and benefits. Based on the Topic 2 economic analysis (Diaz and Solow 1999), the direct measurable dollar benefits to Gulf fisheries of reducing nitrogen loads from the Mississippi River Basin are very limited at best. Although restoring the ecological communities in the Gulf may be significant over the long term, we do not currently have information available to estimate the benefits of such measures to restore the Gulf’s long-term health. For these reasons, we assume that measures to reduce nitrogen losses to the Gulf will ultimately prove beneficial, and we concentrate on analyzing the cost-effectiveness of alternative reduction strategies. We recognize that important public decisions are seldom made on the basis of strict benefit–cost analysis, especially when complete benefits cannot be estimated. We look at different approaches and different levels of these approaches to identify those that are cost-effective and those that have limited undesirable secondary effects, such as reduced exports, which may result in lost market share. We concentrate on the measures highlighted in the Topic 5 report, and also are guided by the source identification information in the Topic 3 report (Goolsby et al. 1999). Nonpoint sources that are responsible for the bulk of the nitrogen receive most of our attention. We consider restrictions on nitrogen fertilizer levels, and restoration of wetlands and riparian buffers for denitrification. We also examine giving more emphasis to nitrogen control in regions contributing a greater share of the nitrogen load.

National Centers for Coastal Ocean Science (NCCOS) research highlights in the Chesapeake Bay

The Chesapeake Bay is the largest estuary in the United States. It is a unique and valuable national treasure because of its ecological, recreational, economic and cultural benefits. The problems facing the Bay are well known and extensively documented, and are largely related to human uses of the watershed and resources within the Bay. Over the past several decades as the origins of the Chesapeake’s problems became clear, citizens groups and Federal, State, and local governments have entered into agreements and worked together to restore the Bay’s productivity and ecological health. In May 2010, President Barack Obama signed Executive Order number 13508 that tasked a team of Federal agencies to develop a way forward in the protection and restoration of the Chesapeake watershed. Success of both State and Federal efforts will depend on having relevant, sound information regarding the ecology and function of the system as the basis of management and decision making. In response to the executive order, the National Oceanic and Atmospheric Administration’s National Centers for Coastal Ocean Science (NCCOS) has compiled an overview of its research in Chesapeake Bay watershed. NCCOS has a long history of Chesapeake Bay research, investigating the causes and consequences of changes throughout the watershed’s ecosystems. This document presents a cross section of research results that have advanced the understanding of the structure and function of the Chesapeake and enabled the accurate and timely prediction of events with the potential to impact both human communities and ecosystems. There are three main focus areas: changes in land use patterns in the watershed and the related impacts on contaminant and pathogen distribution and concentrations; nutrient inputs and algal bloom events; and habitat use and life history patterns of species in the watershed. Land use changes in the Chesapeake Bay watershed have dramatically changed how the system functions. A comparison of several subsystems within the Bay drainages has shown that water quality is directly related to land use and how the land use affects ecosystem health of the rivers and streams that enter the Chesapeake Bay. Across the Chesapeake as a whole, the rivers that drain developed areas, such as the Potomac and James rivers, tend to have much more highly contaminated sediments than does the mainstem of the Bay itself. In addition to what might be considered traditional contaminants, such as hydrocarbons, new contaminants are appearing in measurable amounts. At fourteen sites studied in the Bay, thirteen different pharmaceuticals were detected. The impact of pharmaceuticals on organisms and the people who eat them is still unknown. The effects of water borne infections on people and marine life are known, however, and the exposure to certain bacteria is a significant health risk. A model is now available that predicts the likelihood of occurrence of a strain of bacteria known as Vibrio vulnificus throughout Bay waters.

Photolysis of iron–siderophore chelates promotes bacterial–algal mutualism

Marine microalgae support world fisheries production and influence climate through various mechanisms. They are also responsible for harmful blooms that adversely impact coastal ecosystems and economies. Optimal growth and survival of many bloom-forming microalgae, including climatically important dinoflagellates and coccolithophores, requires the close association of specific bacterial species, but the reasons for these associations are unknown. Here, we report that several clades of Marinobacter ubiquitously found in close association with dinoflagellates and coccolithophores produce an unusual lower-affinity dicitrate siderophore, vibrioferrin (VF). Fe-VF chelates undergo photolysis at rates that are 10–20 times higher than siderophores produced by free-living marine bacteria, and unlike the latter, the VF photoproduct has no measurable affinity for iron. While both an algal-associated bacterium and a representative dinoflagellate partner, Scrippsiella trochoidea, used iron from Fe-VF chelates in the dark, in situ photolysis of the chelates in the presence of attenuated sunlight increased bacterial iron uptake by 70% and algal uptake by >20-fold. These results suggest that the bacteria promote algal assimilation of iron by facilitating photochemical redox cycling of this critical nutrient. Also, binary culture experiments and genomic evidence suggest that the algal cells release organic molecules that are used by the bacteria for growth. Such mutualistic sharing of iron and fixed carbon has important implications toward our understanding of the close beneficial interactions between marine bacteria and phytoplankton, and the effect of these interactions on algal blooms and climate.

Control charts: an application in shrimp canning

Control chart is a statistical tool which can be employed with advantage to learn the situation in the process (whether it is under control or not). There are different kinds of control charts but one which is most commonly used is the control chart for variables, known as X-R chart. This chart can be used for measurable characteristics in food industry like appearance, colour, sizes and dimensions for chemical properties such as moisture, fat and many other analytical counts and measurements. Since construction and maintenance of such charts involve a recognizable amount of time and effort, they should not be used indiscriminately but only where it can be definitely shown that their use improves the overall operation. Since one control chart can be used for only one quality attribute, those for which the charts are used should be selected with care (Kramer and Twigg, 1962). In this article, the procedure of setting up a variable control chart is described with observations taken on filling operation of cans in a shrimp canning factory.

Investigation on reproduction process in two species of crab, Eriphia sebana and Ocypode saratan in the intertidal zone of Chabahar area

The present study with headline investigation on reproduction in two species of crab Eriphia sebana and Ocypode saratan was carried out in the intertidal zone of Chabahar in thirteen month from December 2004 to December 2005. Checked samplings have been taken, 45 number Crab monthly from any four stations by manual or use trap. During this study the following subjects were measured: temperature range and salinity, measurable coast granule, determination of sex ratio, relations carapace width with carapace length, Carapace width with total body weight, Gonad weight, gonadosomatic index, condition factor, gastrosomatic index, investigation content in stomach, LM50, growth parameters, plenty distribution length and width and gonad weight and total body weight. Studied on measurable coast granule were expressed that Ocypode saratan in Desalination station, were nest in soils equable sand and this quantity were confirmed in Pozm station. Sex ratio were assign in desalination area and Pozm M: F 0/44:0/56 and in Tiss and Chabahar M:F 0/45:0/55. Carapace length and carapace width (cm) and body weight (g) Furthest were designated in Ocypode saratan within carapace width sequential: In female: 5/42-6/15-105/13 and in male: 5/53-6/25-108/91 and in Eriphia sebana within Tiss area sequential: in female: 5/12-5/94-110/21 and in male 5/14-60/01-114/37. Have been linear relationship between carapace length and carapace width and equaled CW=aCL+b. Weight growth in two species were be modal and equaled BW=aCLb And increased crab weight by built up carapace width. Maximum gonad weight in Ocypode saratan within Desalination area in female have been outcome 3/39 and in male 0/84g and in Eriphia sebana extreme within Tiss during may in female were be 4/18 and in male 1/1g. Stomach content in Eriphia sebana were involved a black until half-purplish liquid and yellowish in Ocypode saratan. Stomach contents identifiable were being in four groups: Molluscoid, Crustacean, Plankton and Fish. Carapace width during the first year of maturation have been LM50:3/77 in Desalination area and LM50:3/92 in Pozm for Ocypode saratan and LM50:4/26 in Tiss and LM50:4/62 in Chabahar. Ability spawning in Eriphia sebana within Tiss has been CW=4/17cm and in Ocypode saratan within Desalination area CW=4/23cm. Maximun value of Loo for Eriphia sebana was equal 59/67 and growth factor K=0/68 within Tiss and Loo =61/64, K=0/65 for Ocypode saratan within Desalination area. Maximun GSI and GI have been within Desalination area and Tiss and minimum within Pozm and Chabahar. The maturity stages of two species were classifed into six stages. Review on GSI, CF have been showed that relation with temperature and salinity and definer in two species have been spawned in two period that Maximun in spring premier than autumn.

Investigation on reproduction process in two species of crab Eriphia sebana and Ocypode saratan in the intertidal zone of Chabahar area

The present study with headline investigation on reproduction in two species of Crab Eriphia sebana and Ocypode saratan was carried out in the intertidal zone of Chabahar in thirteen month from December 2004 to December 2005. Checked samplings have been taken, 45 number Crab monthly from any four stations by manual or use trap. During this study the following subjects were measured: Temperature range and salinity, Measurable coast granule, Determination of sex ratio, Relations carapace width with carapace length, Carapace width with total body weight, Gonad weight, gonadosomatic index, condition factor, gastrosomatic index, investigation content in stomach, LM50, Growth parameters, plenty distribution length and width and gonad weight and total body weight. Studied on measurable coast granule were expressed that Ocypode saratan in Desalination station, were nest in soils equable sand and this quantity were confirmed in Pozm station. Sex ratio were assign in desalination area and Pozm M: F 0/44:0/56 and in Tiss and Chabahar M: F 0/45:0/55. Carapace length and carapace width (cm) and body weight (g) Furthest were designated in Ocypode saratan within carapace width sequential: female: 5/42-6/15-105/13 and male: 5/53-6/25-108/91 and in Eriphia sebana within Tiss area sequential: female: 5/12-5/94-110/21 and male 5/14-60/01-114/37. Have been linear relationship between carapace length and carapace width and equaled CW = a CL + b. Weight growth in two species were be modal and equaled BW= aCLb and increased Crab weight by built up carapace width. Maximum gonad weight in Ocypode saratan within desalination area in female have been outcome 3/39 and in male 0/84g and in Eriphia sebana extreme within Tiss during may in female were be 4/18 and in male 1/1g. Stomach content in Eriphia sebana were involved a black until half-purplish liquid and yellowish in Ocypode saratan. Stomach contents identifiable were being in four groups: Molluscoid, Crustacean, Plankton and Fish. Carapace width during the first year of maturation have been LM50:3/77 in Desalination area and LM50:3/92 in Pozm for Ocypode saratan and LM50:4/26 in Tiss and LM50:4/62 in Chabahar. Ability spawning in Eriphia sebana within Tiss has been CW=4/17cm and in Ocypode saratan within Desalination area CW=4/23cm. Maximun value of Loo for Eriphia sebana was equal 59/67 and growth factor K=0/68 within Tiss and Loo =61/64 , K=0/65 for Ocypode saratan within Desalination area. Maximun GSI and GI have been within Desalination area and Tiss and minimum within Pozm and Chabahar. The maturity stages of two species were classifed into six stages. Review on GSI, CF have been showed that relation with temperature and salinity and definer in two species have been spawned in two period that Maximun in spring premier than autumn.