Growth analysis of nine multipurpose woody legumes native from southern Mexico

The growth of nine multipurpose woody legumes was evaluated in nursery conditions. These species, belonging to the genera Acacia, Leucaena, Lysiloma, Prosopis and Pithecellobium, inhabit both primary and secondary tropical deciduous and thorn forests. The total length of the experiments was 165 days. At a variable frequency, the following four variables were measured: (1) relative growth rate (RGR), (2) root/shoot ratio (R/S), (3) root length/root dry weight ratio (RL/RDW), and (4) stem length (SL). The temporal behavior of these variables differed greatly among species. A direct relationship between seed weight and initial biomass production was initially found; however, the effect of seed size on biomass production was lost as plants aged. At the initial harvest, RGR values did not differ significantly among species, but they did at the end of the experiment; Pithecellobium dulce had the lowest final RGR. The three Acacia species had the highest biomass productions and highest R/S ratios but the lowest RL/RDW ratios; A. farnesiana and Lysiloma divaricata had the largest mean SL, whereas the smallest mean SL corresponded to the two Leucaena species and to Lysiloma acapulcensis. Several recommendations concerning the management of plants in the nursery and the optimal timing for transplanting the seedlings to reforestation sites are provided.     

Reproductive cycle of the sea cucumber <Emphasis Type="Italic">Holothuria floridana</Emphasis> in the littorals of Campeche,Mexico

The reproduction of Holothuria floridana in Campeche bay, southern Gulf of Mexico, was investigated over a period of 12 months by macroscopic and histological examination of the gonad and gametogenesis. A total of 1938 specimens were collected. Their body gutted weight and body gutted length ranged from 15 to 225 g and 5 to 21 cm, respectively. Percentage of the gonad weight to the gutted body weight (gonad index, GI) increased steadily from December to April, rapidly declined in May, and remained low during the following months. GI displayed a negative correlation with temperature of the habitat and no correlation with salinity. The gonad maturity scale with five stages was developed from macroscopic and microscopic observations; I, recovery; II, growing; III, early mature; IV, mature and V, spent. Stages III to V were observed all around the year, suggesting that this species displays continuous reproduction with two peaks of spawning events; from March to April and in September. The presence of viscera regurgitated individuals caused high variability in GI. The sex-ratio varied from 1:1 (December 2013 to June 2014), to 1.37:1 (November 2013); we suggest that this may be the consequence of unintentional selective fishing. The body length and body weight at the first maturity were calculated to be 13.4 cm and 87.0 g, respectively. For resource management it will be necessary to address some reference points like harvest season and avoidance of catches shorter than length at first maturity.     

Phenotype of Aeromonas salmonicida sp. salmonicida cyclic adenosine 3′,5′‐monophosphate receptor protein (Crp) mutants and its virulence in rainbow trout (Oncorhynchus mykiss)

Precise deletion of genes related to virulence can be used as a strategy to produce attenuated bacterial vaccines. Here, we study the deletion of the cyclic‐3′,5′‐adenosine monophosphate (cAMP) receptor protein (Crp) in Aeromonas salmonicida, the aetiologic agent of furunculosis in marine and freshwater fish. The Crp protein is a conserved global regulator, controlling physiology processes, like sugar utilization. Deletion of the crp gene has been utilized in live attenuated vaccines for mammals, birds and warm water fish. Here, we characterized the crp gene and reported the effect of a crp deletion in A. salmonicida virulent and non‐virulent isolates. We found that A. salmonicida Δcrp was not able to utilize maltose and other sugars, and its generation time was similar to the wild type. A. salmonicida ?crp showed a higher ability of cell invasion compared to the wild type. Fish challenges showed that A. salmonicida ?crp is ~6 times attenuated in Oncorhynchus mykiss and conferred protective immunity against the intraperitoneal challenge with A. salmonicida wild type. We concluded that deletion of A. salmonicida crp influences sugar utilization, cell invasion and virulence. Deletion of crp in A. salmonicida could be considered as part of an effective strategy to develop immersion live attenuated vaccines against furunculosis.     

A method for applying fluvial geomorphology in support of catchment‐scale river restoration planning

• 1. This paper reports on an extension to the use of Fluvial Audit survey to include a subjective and adaptive multi‐criteria assessment (MCA) process that integrates scientific literature and observational data to develop three reach‐scale indices of: (a) channel modification; (b) channel function (sediment store or source); and (c) naturalness. These indices are nested within an overall conceptual model of channel evolution and used to underpin catchment scale river restoration.
• 2. The approach is described and applied to a small groundwater dominated river in the UK. The results show that over 48% of the total main river was in a degraded state relative to a conceptual model of a natural reference state. Only 23% of the river was in a near‐natural state.
• 3. MCA classifications were translated into a set of management actions necessary to return each reach to a near‐natural condition. These are described.
• 4. The method offers a transparent decision support for stakeholders that can incorporate differing scientific evidence. The use of MCA enables flexibility in terms of the relative importance of scores and weights placed upon factors in the final classification. This makes the approach amenable to stakeholder and public consultation.

Copyright © 2009 John Wiley & Sons, Ltd.     

Something old,something new: Historical perspectives provide lessons for blue growth agendas

The concept of “blue growth,” which aims to promote the growth of ocean economies while holistically managing marine socioecological systems, is emerging within national and international marine policy. The concept is often promoted as being novel; however, we show that historical analogies exist that can provide insights for contemporary planning and implementation of blue growth. Using a case‐study approach based on expert knowledge, we identified 20 historical fisheries or aquaculture examples from 13 countries, spanning the last 40–800 years, that we contend embody blue growth concepts. This is the first time, to our knowledge, that blue growth has been investigated across such broad spatial and temporal scales. The past societies managed to balance exploitation with equitable access, ecological integrity and/or economic growth for varying periods of time. Four main trajectories existed that led to the success or failure of blue growth. Success was linked to equitable rather than open access, innovation and management that was responsive, holistic and based on scientific knowledge and monitoring. The inability to achieve or maintain blue growth resulted from failures to address limits to industry growth and/or anticipate the impacts of adverse extrinsic events and drivers (e.g. changes in international markets, war), the prioritization of short‐term gains over long‐term sustainability, and loss of supporting systems. Fourteen cross‐cutting lessons and 10 recommendations were derived that can improve understanding and implementation of blue growth. Despite the contemporary literature broadly supporting our findings, these recommendations are not adequately addressed by agendas seeking to realize blue growth.     

Monitoring infection with Piscine myocarditis virus and development of cardiomyopathy syndrome in farmed Atlantic salmon (Salmo salar L.) in Norway

An epidemiological study was carried out in Norway in 2015–2018, investigating the development of infection with Piscine myocarditis virus (PMCV) and development of cardiomyopathy syndrome (CMS) in farmed Atlantic salmon. Cohorts from 12 sites were followed and sampled every month or every other month from sea transfer to slaughter. PMCV was detected at all sites and in all sampled cages, and fish in six sites developed clinical CMS. The initial infection happened between 1 and 7 months post‐sea transfer, and the median time from infection with PMCV until outbreak of CMS was 6.5 months. Generally, fish from sites with CMS had higher viral titre and a higher prevalence of PMCV, compared to sites that did not develop clinical CMS. The virus persisted until the point of slaughter at most (11 out of 12) of the sites. The detection of PMCV in all sites suggests that PMCV is more widespread than previously known. Screening for PMCV as a tool to monitor impending outbreaks of CMS must be supported by observations of the health status of the fish and risk factors for development of disease.     

The role of pendimethalin in the integrated management of propanil-resistant Echinochloa colona in Central America

Pre-emergence activity of pendimethalin on propanil-resistant jungle rice (Echinochloa colona) was demonstrated in glasshouse trials. Both susceptible and resistant populations, collected from Costa Rica, were controlled by 1·25 kg ha^-1, the usual application rate used in the field where Rottboellia cochinchinensis is also a problem. When applied post-emergence, propanil performance was improved by the addition of low doses of pendimethalin to the herbicide mixture. A propanil-resistant selection was controlled by 0·23 kg ha^-1 pendi-methalin+0·54 kg ha^-1 propanil at the one-to-two leaf stage, and 0·23 kg ha^-1 pendimethalin+1·08 kg propanil at the three-to-four leaf stage compared to 1·08 kg and 2·16 kg ha^-1 respectively when propanil was applied alone. This suggests that pendimethalin improves post-emergence control in the field compared to the standard propanil treatment and can provide residual pre-emergence control of late-germinating individuals, so reducing the propanil selection pressure. For effective jungle rice control, growers apply propanil (3·84 kg ha^-1) at 10 and 20 days after planting (DAP) followed by one application of fenoxaprop-P-ethyl (0·045 kg ha^-1) at 35 DAP. Field experiments, conducted in dry-seeded upland rice in southern Costa Rica, demonstrated that under high jungle-rice population pressure, one application of pendimethalin at 1·5 kg ha^-1 provided an effective replacement for propanil, resulting in reduced weed-control costs. ©1997 SCI