Marine extinctions revisited

In recent years, more than 130 extinctions have been estimated to have occurred in the marine realm. Here we review this body of evidence and show that this figure may actually be overestimated by as much as 50%. We argue that previous estimates have not fully taken into account critical uncertainties such as naturally variable geographical distributions, and have misinterpreted documentary evidence. However, current evidence indicates that some sharks, rays and reef‐associated species, although not necessarily geographically restricted, are particularly vulnerable to anthropogenic impacts and now occur in very low numbers. Overestimating extinctions is of concern because it could reduce confidence in the credibility of the ‘extinct’ category in threatened species lists and, ultimately, be used to question the integrity of conservation and management policies. We suggest that when integrating future checklists of marine extinct species, there needs to be a more rigorous use of the terminology of extinction, and participation by specialists in each of the particular taxonomic groups involved.     

Quantitation of cotton fibre-quality variations arising from boll and plant growth environments

Crop growth simulation models used to manage cultural inputs and to improve yields of cotton, Gossypium hirsutum L., do not address fibre quality, a major determinant of cotton fibre price and end-use. Fibre maturation simulations require rapid, reproducible methods for fibre quality quantitation at the boll or locule level. Combination of fibre quality mapping by fruiting site with quality quantitation by an electron-optical particle sizer provided replicated, reproducible data suitable for use in predictive models and quantitative studies of fibre quality variations attributable to genotype and growth environment. The efficacy and potential of this unique fusion of agronomic and textile technologies were examined through comparisons of three 1992 fibre quality database subsets from the US Southeastern Coastal Plain and Mississippi Delta. Comparisons of ‘Pee Dee 3’ fibre quality, on a locule-by-locule basis at positions 1 and 2 on main-stem nodes 5 through 18, revealed that fibre length, cross-sectional area, and physical maturity varied among fruiting sites. Subsurface microirrigation applied during an early-season drought increased fibre yield by 40%, significantly increased fibre fineness, and decreased fibre maturity indicators. Fibre length variations were compared between ginning methods and among nine genotypes grown in the Coastal Plain. Irrigation-related reductions in physical fibre maturity, found in the Coastal Plain, were contrasted with chronological maturities of ‘DPL5415’ and ‘DES119’ fibre harvested 21, 28, 35, 42, or 56 days post-anthesis in the Mississippi Delta. Fibre-quality mapping with particle-sizing represents a powerful, new tool for constructing fibre development simulations essential for improving cotton fibre quality and processing outcome.     

A basal dinosaur from the dawn of the dinosaur era in southwestern Pangaea

Upper Triassic rocks in northwestern Argentina preserve the most complete record of dinosaurs before their rise to dominance in the Early Jurassic. Here, we describe a previously unidentified basal theropod, reassess its contemporary Eoraptor as a basal sauropodomorph, divide the faunal record of the Ischigualasto Formation with biozones, and bracket the formation with (40)Ar/(39)Ar ages. Some 230 million years ago in the Late Triassic (mid Carnian), the earliest dinosaurs were the dominant terrestrial carnivores and small herbivores in southwestern Pangaea. The extinction of nondinosaurian herbivores is sequential and is not linked to an increase in dinosaurian diversity, which weakens the predominant scenario for dinosaurian ascendancy as opportunistic replacement.     

The evolution of modern eukaryotic phytoplankton

The community structure and ecological function of contemporary marine ecosystems are critically dependent on eukaryotic phytoplankton. Although numerically inferior to cyanobacteria, these organisms are responsible for the majority of the flux of organic matter to higher trophic levels and the ocean interior. Photosynthetic eukaryotes evolved more than 1.5 billion years ago in the Proterozoic oceans. However, it was not until the Mesozoic Era (251 to 65 million years ago) that the three principal phytoplankton clades that would come to dominate the modern seas rose to ecological prominence. In contrast to their pioneering predecessors, the dinoflagellates, coccolithophores, and diatoms all contain plastids derived from an ancestral red alga by secondary symbiosis. Here we examine the geological, geochemical, and biological processes that contributed to the rise of these three, distantly related, phytoplankton groups.     

One-port video assisted laparoscopic kidney biopsy in standing steers

The purpose of this study was to simplify the two-port laparoscopic renal biopsy technique used in support of pharmacokinetic studies through the application of a one-port system. Twelve Holstein steers were fasted for 24 h and sedated with acepromazine and xylaxine in preparation for laparoscopic surgery in standing stocks. Lidocaine 2% was injected to provide local anesthesia for introduction of the trocar-cannula assembly. The operating endoscope was inserted and the abdomen was insufflated with CO₂. A biopsy forceps was introduced into the channel of the operating endoscope to obtain a 100 mg kidney cortex sample. Eighteen laparoscopic procedures provided 18 kidney samples suitable for pharmacokinetic studies. No complications were encountered. The one-port laparoscopic kidney biopsy is feasible and safe, and advanced skill required for triangulation is not necessary for its performance.     

Monitoring of alcoholic fermentation of onion juice by NIR spectroscopy: valorization of worthless onions

The valorization of vegetable byproducts is one of the main objectives of industry today. The project on which this study is based examined the potential usefulness of worthless onions (Allium cepa L. sp.) and overproduction to obtain several functional products with different applications in the food industry. Near-infrared (NIR) spectroscopy, combined with multivariate calibration, has been used to monitor the alcoholic fermentation of onion juice. Good results were obtained, revealing the suitability of NIR spectroscopy for controlling and optimizing this process in real time.     

Tissue‐specific stable isotope ratios of shortfin mako (Isurus oxyrinchus) and white (Carcharodon carcharias) sharks as indicators of size‐based differences in foraging habitat and trophic level

We evaluated whether the trophic level and feeding grounds (coastal versus offshore) of white and shortfin mako sharks captured in the northern Mexican Pacific varied as a function of size using carbon (δ¹³C values) and nitrogen (δ¹⁵N values) stable isotope analysis of soft tissues. A step increase in δ¹⁵N values was observed at approximately 85 cm TL and 150–170 cm TL for shortfin mako and white sharks, respectively, consistent with the dilution of the maternal isotopic signal following the incorporation of exogenous food. Shortfin mako and white shark muscle tissue and whole blood were enriched in ¹⁵N as a function of size, which is consistent with increasing trophic level, but this pattern may be confounded by differences in habitat. To infer differences in foraging habitat throughout life, we compared isotope ratios of liver and blood fractions with those of white muscle tissue; these tissues have relatively faster and slower isotope turnover rates, respectively. Whole blood and muscle δ¹³C values of small white sharks (<200 cm total length) caught near the coast suggested benthic foraging. Very limited differences between δ¹³C values of muscle tissue and whole blood from small and medium mako (<196 cm TL) and small white sharks indicated equilibrium to local feeding grounds. In contrast, differences in the δ¹³C values of liver tissue from small and medium mako and small white sharks indicated changes in diet or feeding grounds. The δ¹³C values of plasma and muscle tissue of large white sharks (>350 cm total length) caught offshore indicate feeding in coastal and oceanic areas and are consistent with recent migration to pelagic feeding grounds. Our study provides insight into size‐based habitat use and migration patterns of two species of migratory sharks for which there is limited information, particularly in their nursery grounds in Mexican waters.     

Effects of conjugated linoleic acid and curcumin on growth performance and oxidative stress enzymes in juvenile Pacific white shrimp (Litopenaeus vannamei) feed with aflatoxins

Aflatoxicosis is a growing problem in aquaculture. A 42‐day study was designed to evaluate the efficacy of conjugated linoleic acid (CLA) and curcumin (CUR) to protect juvenile Pacific white shrimp (Litopenaeus vannamei) from aflatoxins. Growth parameters along with alkaline phosphatase (ALP) and glutathione S‐transferase (GST) activities were measured. Shrimps (36) with an average weight of 76 ± 0.9 mg were randomly allocated in eight experimental groups. Non‐contaminated diet (NCD) and aflatoxin‐contaminated diet (ACD) at 200 μg/kg were prepared. ACD was used to prepare six diets supplemented with CLA (4, 5 or 6 g/kg) and CUR (0.15, 0.2 and 0.3 g/kg). ACD reduced feed intake, growth rate and nitrogen retention efficiency, and increased ALP and GST activity. Improved nitrogen retention was observed for all groups feed with CLA. CUR supplementation at 0.2 g/kg increased feed intake and growth rate while at 0.15 g/kg increased nitrogen retention. ALP activity was reduced in all CUR groups and in 5 and 6 g/kg CLA groups. Reduction in GST activity was observed in 0.15 and 0.2 g/kg CUR groups and 4 g/kg CLA group. CLA supplementation and CUR supplementation can be beneficial to protect juvenile shrimp against aflatoxins.     

Geographical information systems-based models for offshore floating marine fish cage aquaculture site selection in Tenerife, Canary Islands

The present study focuses on the development of a standard methodology for selection of suitable sites for offshore (exposed) marine fish‐cage farming (floating cages) of seabream (Sparus aurata) and seabass (Dicentrarchus labrax) in an island environment, using Tenerife as an example. Site selection is a key factor in any aquaculture operation, affecting both success and sustainability and can solve conflicts between different activities, making a rational use of the coastal space. Site selection was achieved by using geographical information systems (GIS)‐based models and related technology to support the decision‐making process. The framework for spatial multicriteria decision analysis used in this study began with a recognition and definition of the decision problem. Subsequently, 31 production functions (factors and constraints) were identified, defined and subdivided into eight submodels. These were then integrated into a GIS database in the form of thematic layers and later scored for standardization. At this stage, the database was verified by field sampling to establish the quality of data used. The decision maker's preferences were incorporated into the decision model by assigning weights of relative importance to the evaluation under consideration. These, together with the thematic layers, were incorporated using multicriteria evaluation techniques and simple overlays to provide an overall assessment of possible alternatives. The integration, manipulation and presentation of the results by means of GIS‐based models in this sequential and logical flow of steps proved to be very effective for helping the decision‐making process of site selection. Tenerife has very favourable environmental conditions for culture of marine fish and there are no totally unsuitable sites for cage farming identified in this study. On the other hand, there are few very suitable sites (high scores) either, principally due to the heavy use of the coastline and the conflicts between different users. From the 228 km² of available area for siting cages in the coastal regions with depth less than 50 m, the total area suitable for siting cages (scores 6–8) was 37 km². There are only 0.51 km² of very suitable areas (score 8) and approximately 5.37 km² of suitable (score 7), most of these being located in the southeast of the island. These relatively small areas of suitability should be put into the context of the wider use of the coastal environment around Tenerife.