Morphometric comparison of yellowfin tuna from Southeast Polynesia, Central America and Hawaii.

ENGLISH: It is important to the Inter-American Tropical Tuna Commission to determine whether or not the yellowfin tuna (Neothunnus macropterus) which support the large commercial fishery along the American West Coast are distinct from populations of this species further to the westward. Previous research has shown that there are marked differences in morphometric characteristics of specimens from Hawaii and from the West Coast. In the present study there are compared biometric data from specimens from Southeast Polynesia (Marquesas, Society, and Tuamotu Islands) with data from specimens from Central America and from Hawaii. SPANISH: Es importante para la Comisión Interamericana del Atún Tropical determinar si los atunes "aleta amarilla" (Neothunnus macropterus) que mantienen las grandes pesquerías comerciales a lo largo de la costa occidental americana, son diferentes de los atunes de la misma especie que se hallan más al Oeste. Investigaciones previas han indicado que las características morfométricas de los atunes de Hawaii y las de los que se encuentran en la costa occidental difieren notablemente. En el presente estudio se comparan datos biométricos de especímenes de la Polinesia sudoriental (Islas Marquesas, Society y Tuamotu) con datos de especímenes de América Central y de Hawaii. (PDF contains 48 pages.)

Morphometric comparison of skipjack from the Central and Eastern Tropical Pacific Ocean

ENGLISH: One of the important problems in the current investigations of the Inter-American Tropical Tuna Commission is the determination of the racial affinities of the stocks of yellowfin and skipjack inhabiting the Eastern Tropical Pacific fishing region. The nature of the problem is twofold. Primary concern is elucidation of the inter-regional relationship of stocks between the Eastern Tropical Pacific fishing region and those further to the westward. Hardly less important, however, is the intraregional relationship of stocks within the regions, particularly the Eastern Pacific region. This latter relationship must be at least partially understood in order properly to approach investigation of the former. SPANISH: Dentro de las las investigaciones que al presente efectúa la Comisión Interamericana del Atún Tropical, uno de los importantes problemas consiste en la determinación de las afinidades raciales de los stocks de atún aleta amarilla y barrilete que se encuentran en las regiones de pesca del Pacífico Oriental Tropical. La naturaleza del problema es doble. El interés primario es la elucidación de la relación inter-regional entre los stocks de la región pesquera del Pacífico Oriental Tropical y los de aquéllas más hacia el oeste de dicho océano. Apenas menos importante, sin embargo, es la relación intra-regional de los stocks dentro de las regiones, particularmente la del Pacífico del Este. Esta última relación debe ser por lo menos parcialmente conocida, a fin de abordar con propiedad la anteriormente citada. (PDF contains 63 pages.)

Biometric comparison of the anchoveta, Cetengraulis mysticetus (Gunther), from ten localities of the Eastern Tropical Pacific Ocean

ENGLISH: It is important to the Inter-American Tropical Tuna Commission to know whether the anchoveta (Cetengraulis mysticetus), the principal tuna bait species in the Eastern Tropical Pacific Ocean, is composed of one or several populations. Earlier research indicated that, on the basis of significant differences in certain meristic counts, populations of this species in six of the major baiting localities between Mexico and Peru, should provisionally be considered as separate stocks. Since that time, additional collections of anchovetas have been obtained from these and other intervening localities. Purpose of the present study was to confirm the results of the earlier work, and to determine whether the differences in the meristic counts persisted from year to year, as well as to examine certain morphometric characters of the fish from these areas, and to learn whether the populations from the other localities are also separate entities. SPANISH: La Comisión Interamericana del Atún Tropical está interesada en saber si la anchoveta (Ceteugrautís mvsticetus}, la principal especie usada como cebo para la pesca del atún en el Océano Pacífico Oriental Tropical, está compuesta de una o de varias poblaciones. Investigaciones previas indicaron que, a base de diferencias significativas encontradas en ciertos caracteres numéricos, las poblaciones de esta especie en seis de las principales localidades entre México y Perú, podían ser consideradas provisionalmente como pertenecientes a "stocks'' separados. Desde entonces se han venido haciendo recolecciones adicionales de anchovetas en éstas y otras localidades intermedias. El propósito del presente trabajo ha sido confirmar los resultados obtenidos previamente, y determinar si las diferencias en los caracteres numéricos han persistido de un año a otro, así como examinar ciertos caracteres morfométricos en los peces de estas áreas, y resolver si las poblaciones de las nuevas localidades muestreadas son también entidades diferentes. (PDF contains 76 pages.)

Morphometric study of Megalaspis cordyla (Linnaeus, 1758) along the northwest coast of India

Megalaspis cordyla obtained from the landings in and around Bombay, Maharashtra, India, were analysed for the study of their morphometric and meristic characteristics. The various morphometric and meristic characteristics did not indicate any variation within the population. The data provided are intended to facilitate comparison with similar data for other locations, and thereby, to establish the homogeneity or heterogeneity of the populations in the distributional range of this species.

Morphometric and meristic studies of the spotted estuarine prawn, Macrobrachium equidens (Dana) of Vembanad Lake, Kerala State

The paper reports on the statistical analysis of growth pattern and meristic studies of body parts of the spotted estuarine prawn, Macrobrachium equidens (Dana) of Vembanad Lake, Kerala State. The results showed that the growth pattern of carapace length, telson length, ischium length and dactylus length in relation to total length were significantly different between the sexes at slope itself (at 1% level) and growth pattern of abdominal length, merus length, carpus length, propodus length and palm length were significant at elevations (5%, 1% levels). The average sizes of all these characters were greater in males than in females. Regression equations have been calculated for the characters and presented in the text. Among the characters of the carapace, rostrum length, post-orbital length showed significant difference between sexes at 1% level (slope value) and width of carapace at 1% level (elevations). The average sizes of all these characters were higher in males. Among the meristic characters studied, the species exhibited sexual dimorphism with regard to dorsal teeth, post-orbital teeth and ventral teeth. The fundamental data generated is essential for establishing the species status as well as it is useful for making comparison with other species.

Report of the 2005 Workshop on Ocean Ecodynamics Comparison in the Subarctic Pacific

I. Scientific Issues Posed by OECOS II. Participant Contributions to the OECOS Workshop A. ASPECTS OF PHYTOPLANKTON ECOLOGY IN THE SUBARCTIC PACIFIC Microbial community compositions by Karen E. Selph Subarctic Pacific lower trophic interactions: Production-based grazing rates and grazing-corrected production rates by Nicholas Welschmeyer Phytoplankton bloom dynamics and their physiological status in the western subarctic Pacific by Ken Furuya Temporal and spatial variability of phytoplankton biomass and productivity in the northwestern Pacific by Sei-ichi Saitoh, Suguru Okamoto, Hiroki Takemura and Kosei Sasaoka The use of molecular indicators of phytoplankton iron limitation by Deana Erdner B. IRON CONCENTRATION AND CHEMICAL SPECIATION Iron measurements during OECOS by Zanna Chase and Jay Cullen 25 The measurement of iron, nutrients and other chemical components in the northwestern North Pacific Ocean by Kenshi Kuma The measurement of iron, nutrients and other chemical components in the northwestern North Pacific Ocean by Kenshi Kuma C. PHYSICAL OCEANOGRAPHY, FINE-SCALE DISTRIBUTION PATTERNS AND AUTONOMOUS DRIFTERS The use of drifters in Lagrangian experiments: Positives, negatives and what can really be measured by Peter Strutton The interaction between plankton distribution patterns and vertical and horizontal physical processes in the eastern subarctic North Pacific by Timothy J. Cowles D. MICROZOOPLANKTON Microzooplankton processes in oceanic waters of the eastern subarctic Pacific: Project OECOS by Suzanne Strom Functional role of microzooplankton in the pelagic marine ecosystem during phytoplankton blooms in the western subarctic Pacific by Takashi Ota and Akiyoshi Shinada E. MESOZOOPLANKTON Vertical zonation of mesozooplankton, and its variability in response to food availability, density stratification, and turbulence by David L. Mackas and Moira Galbraith Marine ecosystem characteristics and seasonal abundance of dominant calanoid copepods in the Oyashio region by Atsushi Yamaguchi, Tsutomu Ikeda and Naonobu Shiga OECOS: Proposed mesozooplankton research in the Oyashio region, western subarctic Pacific by Tsutomu Ikeda Some background on Neocalanus feeding by Michael Dagg Size and growth of interzonally migrating copepods by Charles B. Miller Growth of large interzonal migrating copepods by Toru Kobari F. MODELING Ecosystem and population dynamics modeling by Harold P. Batchelder III. Reports from Workshop Breakout Groups A. PHYSICAL AND CHEMICAL ASPECTS WITH EMPHASIS ON IRON AND IRON SPECIATION B. PHYTOPLANKTON/MICROZOOPLANKTON STUDIES C. MESOZOOPLANKTON STUDIES IV. Issues arising during the workshop A. PHYTOPLANKTON STOCK VARIATIONS IN HNLC SYSTEMS AND TROPHIC CASCADES IN THE NANO AND MICRO REGIMES B. DIFFERENCES BETWEEN EAST AND WEST IN SITE SELECTION FOR OECOS TIME SERIES C. TIMING OF OECOS EXPEDITIONS D. CHARACTERIZATION OF PHYSICAL OCEANOGRAPHY V. Concluding Remarks VI. References (109 page document)

Comparison of Torpedograss and Pickerelweed Susceptibility to Glyphosate

Torpedograss (Panicum repens L.) is one of the most invasive exotic plants in aquatic systems. Repeat applications of (N-phosphonomethyl) glycine (glyphosate) herbicides provide limited control of torpedograss; unfortunately, glyphosate often negatively impacts most non-target native species that grow alongside the weed. This experiment studied the effect of glyphosate on pickerelweed (Pontederia cordata L.), a native plant that shares habitats with torpedograss. Actively growing plants of torpedograss and pickerelweed were cultured in 8-liter containers and sprayed to wet with one of four rates of glyphosate: 0%, 0.75%, 1.0%, or 1.5%. Each treatment included a surfactant to aid in herbicide uptake and a surface dye to verify uniform application of the treatments. All herbicide treatments were applied with a backpack sprayer to intact plants and to cut stubble of both species. Four replicates were treated for each species-rategrowth combination during each of two experiment periods. Plant dry weights 8 weeks after herbicide application suggest that torpedograss was effectively controlled by the highest rate of glyphosate applied to cut stubble. Pickerelweed was unaffected when the highest rate of glyphosate was applied as a cut-and-spray treatment. These data suggest that a cut-and-spray application of a 1.5% solution of glyphosate may be an effective strategy to control torpedograss without deleteriously affecting pickerelweed. (PDF contains 4 pages.)

Comparison of Experimental Strategies to Control Torpedograss

Studies were conducted to evaluate whether the herbicide imazapyr or a combination of imazapyr and fluridone could be used effectively to control torpedograss ( Panicum repens L.), an exotic perennial plant that has replaced more than 6,000 ha of native vegetation and degraded quality wildlife habitat in Lake Okeechobee, Florida. Torpedograss was controlled for more than one year in some areas following a single aerial treatment using 0.56, 0.84, or 1.12 kg acid equivalents (ae) imazapyr/ha. Combining imazapyr and fluridone did not increase the level of torpedograss control. In areas where plant biomass was reduced by fire prior to being treated with 0.84 or 1.12 kg ae imazapyr/ha, torpedograss was controlled for more than two years and native plant species, including duck potato ( Sagittaria lancifolia L.) and pickerelweed ( Pontederia cordata L.) became the dominant vegetation in less than one year. Although torpedograss was controlled in some areas, little or no long-term control was observed at 16 of the 26 treatment locations. To reduce the uncertainty associated with predicting long-term treatment affects, additional studies are needed to determine whether environmental factors such as periphyton mats, plant thatch, hydroperiod and water depth affect treatment efficacy. , he

The ontogeny of haematopoiesis in the marine teleost Leiostomus xanthurus and a comparison of the site of initial haematopoiesis with Opsanus tau

The ontogeny of haematopoiesis in the perciform fish, spot Leiostomus xanthurus, differed from that reported as the norm for fishes, as exemplified by the cypriniform zebrafish Danio rerio, and observed in the batrachoidiform oyster toadfish Opsanus tau. Erythropoiesis in spot was first evident in the head kidney of yolk-sac larvae 3 days after hatching (DAH). No embryonic intermediate cell mass (ICM) of primitive stem cells or blood islands on the yolk were apparent within embryos. Erythrocytes were first evident in circulation near the completion of yolk absorption, c. 5 DAH, when larvae were c. 20 mm notochord length (LN). Erythrocyte abundance increased rapidly with larval development for c. 14 to 16 DAH, then became highly variable following changes in cardiac chamber morphology and volume. Erythrocytic haemoglobin (Hb) was not detected within whole larvae until they were 12 DAH or c. 31 mm LN, well after yolk and oil-globule absorption. The Hb was not quantified until larvae were >47 DAH or >7 mm standard length. The delayed appearance of erythrocytes and Hb in spot was similar to that reported for other marine fishes with small embryos and larvae. In oyster toadfish, a marine teleost that exhibits large embryos and larvae, the ICM and Hb were first evident in two bilateral slips of erythropoietic tissue in the embryos, c. 5 days after fertilization. Soon thereafter, erythrocytes were evident in the heart, and peripheral and vitelline circulation. Initial haematopoiesis in oyster toadfish conformed with that described for zebrafish. While the genes that code for the development of haematopoiesis are conserved among vertebrates, gene expression lacks phylogenetic pattern among fishes and appears to conform more closely with phenotypic expression related to physiological and ecological influences of overall body size and environmental oxygen availability.

A Comparison of Two Methods for Enhancing the Recovery of Seagrasses into Propellor Scars: Mechanical Injection of a Nutrient and Growth Hormone Solution vs. Defecation by Roosting Seabirds: Final Report.

Based on the recovery rates for Thalassia testudinum measured in this study for scars of these excavation depths and assuming a linear recovery horizon, we estimate that it would take ~ 6.9 years (95% CI. = 5.4 to 9.6 years) for T. testudinum to return to the same density as recorded for the adjacent undisturbed population. The application of water soluble fertilizers and plant growth hormones by mechanical injection into the sediments adjacent to ten propellor scars at Lignumvitae State Botanical Site did not significantly increase the recovery rate of Thalassia testudinum or Halodule wrightii. An alternative method of fertilization and restoration of propellor scars was also tested by a using a method of “compressed succession” where Halodule wrightii is substituted for T. testudinum in the initial stages of restoration. Bird roosting stakes were placed among H.wrightii bare root plantings in prop scars to facilitate the defecation of nitrogen and phosphorus enriched feces. In contrast to the fertilizer injection method, the bird stakes produced extremely high recovery rates of transplanted H. wrightii. We conclude that use of a fertilizer/hormone injection machine in the manner described here is not a feasible means of enhancing T. testudinum recovery in propellor scars on soft bottom carbonate sediments. Existing techniques such as the bird stake approach provide a reliable, and inexpensive alternative method that should be considered for application to restoration of seagrasses in these environments. Document contains 40 pages)

Long-Term Monitoring of Ecological Conditions In Gray’s Reef National Marine Sanctuary: Comparison of soft-bottom benthic assemblages and contaminant levels in sediments and biota in Spring 2000 and 2005

As part of an ongoing program of benthic sampling and related assessments of sediment quality at Gray’s Reef National Marine Sanctuary (GRNMS) off the coast of Georgia, a survey of soft-bottom benthic habitats was conducted in spring 2005 to characterize condition of macroinfaunal assemblages and levels of chemical contaminants in sediments and biota relative to a baseline survey carried out in spring 2000. Distribution and abundance of macrobenthos were related foremost to sediment type (median particle size, % gravel), which in turn varied according to bottom-habitat mesoscale features (e.g., association with live bottom versus flat or rippled sand areas). Overall abundance and diversity of soft-bottom benthic communities were similar between the two years, though dominance patterns and relative abundances of component species were less repeatable. Seasonal summer pulses of a few taxa (e.g., the bivalve Ervilia sp. A) observed in 2000 were not observed in 2005. Concentrations of chemical contaminants in sediments and biota, though detectable in both years, were consistently at low, background levels and no exceedances of sediment probable bioeffect levels or FDA action levels for edible fish or shellfish were observed. Near-bottom dissolved oxygen levels and organic-matter content of sediments also have remained within normal ranges. Highly diverse benthic assemblages were found in both years, supporting the premise that GRNMS serves as an important reservoir of marine biodiversity. A total of 353 taxa (219 identified to species) were collected during the spring 2005 survey. Cumulatively, 588 taxa (371 identified to species) have been recorded in the sanctuary from surveys in 2000, 2001, 2002, and 2005. Species Accumulation Curves indicate that the theoretical maximum should be in excess of 600 species. Results of this study will be of value in advancing strategic science and management goals for GRNMS, including characterization and long-term monitoring of sanctuary resources and processes, as well as supporting evolving interests in ecosystem-based management of the surrounding South Atlantic Bight (SAB) ecosystem. (PDF contains 46 pages)

A comparison of animal abundance and distribution in similar habitats in Rookery Bay, Marco Island and Fakahatchee on the southwest coast of Florida, 1971 - 1972

The three areas in Rookery Bay, near Marco Island and Fakahatchee Bay were sampled from July 1971 through July 1972, and 1,006,640 individual animals were collected, of which the majority (55%) came from the Marco area. The large disparity between the catches at Marco and the remaining study areas was due mainly to the appearance of high numbers of species of polychaetes and echinoderms that were of very minor importance or absent from the catches in Rookery Bay and Fakahatchee Bay. When only the major classes of animals in the catch are considered (i.e., crustaceans, fish and mollusks) the total counts for Fakahatchee (298,830) and Marco (275,075) are quite comparable but both exceed Rookery Bay (119,388) by a considerable margin. The effects of the red tide outbreak in the summer of 1971 were apparently restricted to the Rookery Bay Sanctuary and may account for some of the observed differences. For the purposes of making controlled comparisons between the study areas, three common habitats were selected in each area so that a mud bottom habitat, a sand-shell bottom habitat and a vegetated bottom habitat were located in each of the study areas. Total catches by habitat types for crustaceans, fish and mollusks and certain of the more abundant species show clearly the overwhelming importance of the vegetated bottom as a habitat for animals. By habitat the vegetated areas had the most "indicator species" with five, the mud habitat was next with three and the sand-shell habitat third with two. Thus the vegetated habitat would be the best choice if a single habitat were to be used to detect environmental changes between study areas. (PDF contains 137 pages)

Pilot investigation of remote sensing for intertidal oyster mapping in coastal South Carolina: a methods comparison

South Carolina’s oyster reefs are a major component of the coastal landscape. Eastern oysters Crassostrea virginica are an important economic resource to the state and serve many essential functions in the environment, including water filtration, creek bank stabilization and habitat for other plants and animals. Effective conservation and management of oyster reefs is dependent on an understanding of their abundance, distribution, condition, and change over time. In South Carolina, over 95% of the state’s oyster habitat is intertidal. The current intertidal oyster reef database for South Carolina was developed by field assessment over several years. This database was completed in the early 1980s and is in need of an update to assess resource/habitat status and trends across the state. Anthropogenic factors such as coastal development and associated waterway usage (e.g., boat wakes) are suspected of significantly altering the extent and health of the state’s oyster resources. In 2002 the NOAA Coastal Services Center’s (Center) Coastal Remote Sensing Program (CRS) worked with the Marine Resources Division of the South Carolina Department of Natural Resources (SCDNR) to develop methods for mapping intertidal oyster reefs along the South Carolina coast using remote sensing technology. The objective of this project was to provide SCDNR with potential methodologies and approaches for assessing oyster resources in a more efficiently than could be accomplished through field digitizing. The project focused on the utility of high-resolution aerial imagery and on documenting the effectiveness of various analysis techniques for accomplishing the update. (PDF contains 32 pages)

A comparison of seafloor habitats and associated benthic fauna in areas open and closed to bottom trawling along the central California Continental Shelf

Executive Summary: A number of studies have shown that mobile, bottom-contact fishing gear (such as otter trawls) can alter seafloor habitats and associated biota. Considerably less is known about the recovery of these resources following such disturbances, though this information is critical for successful management. In part, this paucity of information can be attributed to the lack of access to adequate control sites – areas of the seafloor that are closed to fishing activity. Recent closures along the coast of central California provide an excellent opportunity to track the recovery of historically trawled areas and to compare recovery rates to adjacent areas that continue to be trawled. In June 2006 we initiated a multi-year study of the recovery of seafloor microhabitats and associated benthic fauna inside and outside two new Essential Fish Habitat (EFH) closures within the Cordell Bank and Gulf of the Farallones National Marine Sanctuaries. Study sites inside the EFH closure at Cordell Bank were located in historically active areas of fishing effort, which had not been trawled since 2003. Sites outside the EFH closure in the Gulf of Farallones were located in an area that continues to be actively trawled. All sites were located in unconsolidated sands at equivalent water depths. Video and still photographic data collected via a remotely operated vehicle (ROV) were used to quantify the abundance, richness, and diversity of microhabitats and epifaunal macro-invertebrates at recovering and actively trawled sites, while bottom grabs and conductivity/temperature/depth (CTD) casts were used to quantify infaunal diversity and to characterize local environmental conditions. Analysis of still photos found differences in common seafloor microhabitats between the recovering and actively trawled areas, while analysis of videographic data indicated that biogenic mound and biogenic depression microhabitats were significantly less abundant at trawled sites. Each of these features provides structure with which demersal fishes, across a wide range of size classes, have been observed to associate. Epifaunal macro-invertebrates were sparsely distributed and occurred in low numbers in both treatments. However, their total abundance was significantly different between treatments, which was attributable to lower densities at trawled sites. In addition, the dominant taxa were different between the two sites. Patchily-distributed buried brittle stars dominated the recovering site, and sea whips (Halipteris cf. willemoesi) were most numerous at the trawled site though they occurred in only five of ten transects. Numerical classification (cluster analysis) of the infaunal samples also revealed a clear difference between benthic assemblages in the recovering vs. trawled areas due to differences in the relative abundances of component species. There were no major differences in infaunal species richness, H′ diversity, or J′ evenness between recovering vs. trawled site groups. However, total infaunal abundance showed a significant difference attributable to much lower densities at trawled sites. This pattern was driven largely by the small oweniid polychaete Myriochele gracilis, which was the most abundant species in the overall study region though significantly less abundant at trawled sites. Other taxa that were significantly less abundant at trawled sites included the polychaete M. olgae and the polychaete family Terebellidae. In contrast, the thyasirid bivalve Axinopsida serricata and the polychaetes Spiophanes spp. (mostly S. duplex), Prionospio spp., and Scoloplos armiger all had significantly to near significantly higher abundances at trawled sites. As a result of such contrasting species patterns, there also was a significant difference in the overall dominance structure of infaunal assemblages between the two treatments. It is suggested that the observed biological patterns were the result of trawling impacts and varying levels of recovery due to the difference in trawling status between the two areas. The EFH closure was established in June 2006, within a month of when sampling was conducted for the present study, however, the stations within this closure area are at sites that actually have experienced little trawling since 2003, based on National Marine Fishery Service trawl records. Thus, the three-year period would be sufficient time for some post-trawling changes to have occurred. Other results from this study (e.g., similarly moderate numbers of infaunal species in both areas that are lower than values recorded elsewhere in comparable habitats along the California continental shelf) also indicate that recovery within the closure area is not yet complete. Additional sampling is needed to evaluate subsequent recovery trends and persistence of effects. Furthermore, to date, the study has been limited to unconsolidated substrates. Ultimately, the goal of this project is to characterize the recovery trajectories of a wide spectrum of seafloor habitats and communities and to link that recovery to the dynamics of exploited marine fishes. (PDF has 48 pages.)