An assessment of the sportfishery on artificial "Liberty Ship" reefs off Port Aransas, Texas

The concept of using surplus World War II Liberty Ships for the construction of artificial reefs to increase the availability of sportfish off the Texas coast was originally suggested in 1974. It became a reality, under the guidance of the Texas Coastal and Marine Council, when three ships were sunk off Port Aransas in the winter of 1976. Since that time, the ships have rapidly become encrusted with algae, anemones, sea urchins, gorgonian coral and other attached marine life. These in turn have provided refuge and food source for a host of small invertebrates and fishes. In June of 1977, one and a half years after ·sinking the first ship, the Texas Coastal and Marine Council commissioned this study to evaluate the impact of the Liberty Ship reefs on sportfishing in the Port Aransas area. For a project such as the Liberty Ship reefs to be successful, there are two criteria: the ships must increase the supply of desirable sportfish and fishermen must be willing to utilize the new resource. The present study is an attempt to evaluate both aspects of the project. A user survey was conducted to determine the amount and type of recreational usage the Liberty Ships receive.A report to the Texas Coastal and Marine Council in fulfillment of Contract No. IAC(76-77)-2149Submitted September 1977Marine Scienc

The icthyofaunal composition and trophic interactions of the artificial "Liberty Ship" reefs off Port Aransas, Texas

This study is an assessment of the biological effects resulting from the construction of an artificial reef consisting of three surplus Liberty Ships that were sunk off Port Aransas, Texas in 1976. ... Systematic monthly assessment of the Liberty Ship Reefs presented a unique sampling problem. Snagging problems made trawling and other methods of netting unfeasible while depth, turbidity and currents precluded diver transects, baited camera recorders, or hook and line assessments, at least during the winter sampling periods. Fish traps were proposed as a reliable and cost effective means of sampling in all types of weather and sea conditions. Fish traps allow concurrent sampling of open bottom areas and reef with the same ship, making possible a true comparison of the relative productivity of artificial reefs. They also allow consistent day-night sampling and seasonal replication without the inherent variations in skill that bias diver transects and hook and line assessments. This initial report describes the construction and deployment of traps and summarizes the data collected during January-February sampling cruises. These initial sampling cruises indicate that fish traps are a practical method of assessing the productivity of the artificial "Liberty Ship" reefs.Winter seasonal report submitted to the Texas Coastal and Marine Council in partial fulfillment of IAC (78-79)--0869Submitted March 1978Marine Scienc

Species composition and ecological relationships of icthyofauna on artificial Liberty Ship reefs off Port Aransas, Texas : final report submitted to the Texas Coastal and Marine Council in partial fulfillment of IAC (78-79)-0869

Submitted August 1978Five cruises were made to the Liberty Ship Reef off Port Aransas, Texas in June and July 1978. Collecting procedures, which included sampling by fish trap, hook and line, and long line, were relatively unchanged from previous trips. Increased diver participation allowed more reliable placement of the traps onto the deck of the ships. Diver observations of fish greatly supplemented other data collecting methods. Fishes collected or observed on the ship reef were divided into four ecological groups: 1) obligate reef fishes which are demersal and almost always associated with natural or artificial structures, 2) coastal pelagic species which are attracted to structures for orientation, 3) estuarine-dependent opportunistic species which exploit the reef for food and shelter but are not confined to that habitat, 4) typical continental shelf species which occur near the ship reef but are not actually associated with it. At this time of year the Liberty Ship reefs support a large and diverse fish fauna, composed of both predator and prey species, and appears to have many characteristics of a complete reef habitat with an abundance of catchable sportfish.Marine Scienc

Decline in Amphibian Health in Local Stream

Many local streams of the Santa Monica Mountains are populated by the native California Newt, Taricha torosa, a species of special concern. Arroyo Sequit is one of these streams, the upper and lower portions of which are split by a culvert and the Mulholland Highway. This stream and the surrounding areas burned during the Woolsey fire of 2018. Since the fire, construction has been ongoing in and around the stream. Two years post-fire (during the summer of 2020) significantly more newts were found in the stream than years prior. A large proportion of these newts were unhealthy in appearance, presenting with symptoms including emaciation, cloudy eyes, infected vents, and necrotic and bleeding tails. A higher incidence of infection was noted at Lower Arroyo (below the culvert, where construction activity is concentrated) than at Upper Arroyo. Pathology studies by the National Wildlife Health Center found that these newts tested negative for ranavirus and B. salamandivorans but positive for B. dendrobatidis, a chytrid fungus to which newts are not typically susceptible. Although the final pathology report came back inconclusive, it is clear that the newt population of Arroyo Sequit is exhibiting concerning health abnormalities. We suggest that a combination of environmental stressors, including wildfires and construction, may have an immunocompromising effect. We speculate that this may be a factor in the health decline of this newt population

RETENTION OF LARVAL ROCKFISHES, SEBASTES, NEAR NATAL HABITAT IN THE SOUTHERN CALIFORNIA BIGHT, AS INDICATED BY MOLECULAR IDENTIFICATION METHODS

ABSTRACT Larval (<16 mm SL) Sebastes spp. that could not be identified visually were identified with molecular genetic methods from plankton samples collected during a California Cooperative Oceanic Fisheries Investigations (CalCOFI) cruise in April 1999. Our goals were to characterize natal habitat and to determine the abundances of individual rockfish species in CalCOFI ichthyoplankton samples. This is the first time the entire complex of Sebastes larvae collected during a CalCOFI cruise has been identified to species. For three abundant species, we found a significant association between abundance and stations within the Southern California Eddy (SCE), and a significant relationship between the distribution of 1-d-old larvae and potential adult habitat for the most narrowly distributed of the three species. These results suggest that the interplay of natal spawning habitat overlaid by the persistent SCE contributes to larval retention in this region. We also found low abundance and number of occurrences for larvae of the nearshore subgenus Pteropodus, suggesting that CalCOFI stations are too far offshore to evaluate distributions of this group

Timing and mechanism for intratest Mg/Ca variability in a living planktic foraminifer

Geochemical observations indicate that planktic foraminifer test Mg/Ca is heterogeneous in many species, thereby challenging its use as a paleotemperature proxy for paleoceanographic reconstructions. We present Mg/Ca and Ba/Ca data collected by laser ablation ICP-MS from the shells of Orbulina universa cultured in controlled laboratory experiments. Test calcite was labeled with Ba-spiked seawater for 12 h day or night calcification periods to quantify the timing of intratest Mg-banding across multiple diurnal cycles. Results demonstrate that high Mg bands are precipitated during the night whereas low Mg bands are precipitated during the day. Data obtained from specimens growing at 20 °C and 25 °C show that Mg/Ca ratios in both high and low Mg bands increase with temperature, and average test Mg/Ca ratios are in excellent agreement with previously published empirical calibrations based on bulk solution ICP-MS analyses. In general, Mg band concentrations decrease with increasing pH and/or [CO2−3] but this effect decreases as experimental temperatures increase from 20 °C to 25 °C. We suggest that mitochondrial uptake of Mg2+ from the thin calcifying fluid beneath streaming rhizopodial filaments may provide the primary locus for Mg2+ removal during test calcification, and that diurnal variations in either mitochondrial density or activity produce Mg banding. These results demonstrate that Mg banding is an inherent component of test biomineralization in O. universa and show that the Mg/Ca paleothermometer remains a fundamental tool for reconstructing past ocean temperatures from fossil foraminifers

Counteridenticals

A counteridentical is a counterfactual with an identity statement in the antecedent. While counteridenticals generally seem non-trivial, most semantic theories for counterfactuals, when combined with the necessity of identity and distinctness, attribute vacuous truth conditions to such counterfactuals. In light of this, one could try to save the orthodox theories either by appealing to pragmatics or by denying that the antecedents of alleged counteridenticals really contain identity claims. Or one could reject the orthodox theory of counterfactuals in favor of a hyperintensional semantics that accommodates non-trivial counterpossibles. In this paper, I argue that none of these approaches can account for all the peculiar features of counteridenticals. Instead, I propose a modified version of Lewis’s counterpart theory, which rejects the necessity of identity, and show that it can explain all the peculiar features of counteridenticals in a satisfactory way. I conclude by defending the plausibility of contingent identity from objections

Impact of ultraviolet radiation on marine crustacean zooplankton and ichthyoplankton: a synthesis of results from the estuary and Gulf of St. Lawrence, Canada

The objectives of the research program reported upon here were (1) to measure ambient levels of UV radiation and determine whichvariables most strongly affected its attenuation in the waters of the estuary and Gulf of St. Lawrence, Canada; and (2) to investigate the potential direct impacts of W radiation on species of crustacean zooplankton and fish whose early life stages are planktonic. In this geographic region, productivity-determining biophysical interactions occur in the upper 0 to 30 m of the water column. Measurements of the diffuse attenuation coefficients for ultraviolet-B radiation (W-B, 280 to 320 nm) at various locations in this region indicated maximum 10% depths (the depth to which 10% of the surface energy penetrates at a given wavelength) of 3 to 4 m at a wavelength of 310 nm. Organisms residing in this layer-including the eggs and larvae of Calanus finmarchicus and Atlantic cod Gadus morhua-are exposed to biologically damaging levels of W radiation. As a result of these physical and biological characteristics, this system offered a relevant opportunity to assess the impacts of UV on subarctic marine ecosystems. Eggs of C. finmarchicus were incubated under the sun, with and without the W-B and/or UV-A (320 to 400 nm) wavebands. W-exposed eggs exhibited low percent hatchmg compared to those protected from W : W radiation had a strong negative impact on C. finmarchicus eggs. Further, percent hatching in W-B-exposed eggs was not significantly lower than that in eggs exposed to UV-A only: under natural sunlight, UV-A radiation appeared to be more detrimental to C. finmarchicus embryos than was UV-B. In analogous experiments with Atlantic cod eggs, exposure to UV-B produced a significant negative effect. However, UV-A had no negative effect on cod eggs. Additional experiments using a solar simulator (SS) revealed high wavelength-dependent mortality in both C. finmarchicus and cod embryos exposed to UV. The strongest effects occurred under exposures to wavelengths below 312 nm. At the shorter wavelengths (<305 nm) UV-B-induced mortality was strongly dose-dependent, but (for both C. finmarchicus and cod) not significantly influenced by dose-rate. Thus, at least within the limits of the exposures under which the biological weighting functions (BWFs) were generated, reciprocity held. The BWFs derived for UV-B-induced mortality in C. finmarchicus and cod eggs were similar in shape to the action spectrum for UV-B effects on naked DNA. Further, the wavelengthdependence of DNA damage was similar to that for the mortality effect. These observations suggest that W-induced mortality in C. finmarchicus and cod eggs is a direct result of DNA damage. There was no evidence of a detrimental effect of UV-A radiation in these SS-derived results. A mathematical model that includes the BWFs, vertical mixing of eggs, meteorological and hydrographic conditions, and ozone depletion, indicates that W-induced mortality in the C. finmarchicus egg population could be as high as 32.5 %, while the impact on the cod egg population was no more than 1.2%. Variability in cloud cover, water transparency (and the variables that affect it), and vertical distribution and displacement of planktonic organisms within the mixed layer can all have a greater effect on the flux of UV-B radiation to which they are exposed than will ozone layer depletion at these latitudes. Our observations indicate that C, finmarchicus and cod eggs present in the first meter of the water column (likely only a small percentage of the total egg populations) are susceptible to W radiation. However, although exposure to UV can negatively impact crustacean zooplankton and ichthyoplankton populations, these direct effects are likely minimal within the context of all the other environmental factors that produce the very high levels of mortality typically observed in their planktonic early life stages. The impact of indnect effects-which may well be of much greater import-has yet to be evaluated

Analysis of the Development of the Nasal Septum according to Age and Gender Using MRI

ObjectivesThis study was designed to evaluate the normal development of the nasal septum in Koreans using sagittal MRI for the valuable clinical information on septal procedures.MethodsTwo hundred eighty patients who had their whole nasal septum visualized in the midline sagittal view were selected among the 3,904 patients with brain MRI from January, 2004 to December, 2006 at Dankook University Hospital. The patients who had a history of nasal septal surgery or nasal trauma were excluded. Following parameters are calculated and analyzed: lengths of bony and cartilage dorsum and septal cartilage-nasal bone overlap, total septal area, septal cartilage area and, the proportion of the cartilage area to septal area and the maximal harvestable cartilage for grafting were calculated using the PAC™ program.ResultsAll the parameters were increased until adolescence. Thereafter, bony dorsal length, cartilage dorsal length, total dorsal length, total septal area and maximal harvestable cartilage for grafting have not changed significantly with age, while SC-NB overlap length, septal cartilage area, and proportion of the cartilage area to the total septal area were significantly decreased with age. The SC-NB overlap length was positively correlated with the septal cartilage area and the proportion of the cartilage area to the total septal area.ConclusionThe small septal cartilage area and its proportion to the total septal area were significantly correlated with a short overlap length of the septal cartilage under the nasal bone. Septal procedures should be carefully performed in the elderly due to the risk of incurring saddle nose

Does fish larval dispersal differ between high and low latitudes?

Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of The Royal Society for personal use, not for redistribution. The definitive version was published in Proceedings of the Royal Society B Biological Sciences 280 (2013): 20130327, doi:10.1098/rspb.2013.0327.Several factors lead to expectations that the scale of larval dispersal and population connectivity of marine animals differs with latitude. We examine this expectation for demersal shorefishes, including relevant mechanisms, assumptions, and evidence. We explore latitudinal differences in: 1) biological (e.g., species composition, spawning mode, pelagic larval duration (PLD)), 2) physical (e.g., water movement, habitat fragmentation), and 3) biophysical factors (primarily temperature, which could strongly affect development, swimming ability, or feeding). Latitudinal differences exist in taxonomic composition, habitat fragmentation, temperature, and larval swimming, and each could influence larval dispersal. Nevertheless, clear evidence for latitudinal differences in larval dispersal at the level of broad faunas is lacking. For example, PLD is strongly influenced by taxon, habitat, and geographic region, but no independent latitudinal trend is present in published PLD values. Any trends in larval dispersal may be obscured by a lack of appropriate information, or use of ‘off the shelf’ information that is biased with regard to the species assemblages in areas of concern. Biases may also be introduced from latitudinal differences in taxa or spawning modes, as well as limited latitudinal sampling. We suggest research to make progress on the question of latitudinal trends in larval dispersal.TK was supported by the Norwegian Research Council through project MENUII #190286. JML was supported by ARC Discovery Grant DP110100695. JEC and RRW were supported by the Partnership for the Interdisciplinary Study of Coastal Oceans, funded by The David and Lucille Packard Foundation and the Gordon and Betty Moore Foundation.2014-03-2