The intense exploitation since 1972 of the formerly only slightly exploited protogynous hermaphroditic fish
Pagrus pagrus
(L.) in southern Brazil has led in less than a decade to the collapse of the ...fishery, with no recovery four decades later. In this study we analized the age structure, growth, reproduction and mortality of the species were studied based on samples collected from 1976 to 1985 to provide a baseline before the onset of overexploitation. Maximum estimated ages were 21 and 26 years based on scale and otolith readings, respectively. Mean total length (TL) at age did not differ between males and females, while hermaphrodites were smaller. The von Bertalanffy growth coefficients for all fish (immature, females, hermaphrodites and males) were
L
∞
= 447 mm,
k
= 0.204 and
t
0
= −1.134 yr. Change in growth was observed during the study period. Females were dominant at all sizes, hermaphrodites were only present up to intermediate sizes, and males, despite being infrequent at small sizes, made up over 40% among the larger specimen (TL > 400 mm). Spawning took place mainly in late spring and condition factors were lower after spawning. Natural mortality was estimated as
M
= 0.173 yr
−1
based on the von Bertalanffy growth parameters. Total mortality (
Z
) and exploitation rate (
E
) estimated from catch curves of fully recruited red porgies aged five to ten years increased from 0.24 yr
−1
and 28% before 1973 to 0.49 yr
−1
and 63% in the following years. Two distinct scale and otolith patterns, one with well-marked
annuli
and another with faint or absent
annuli,
suggested that the red porgy stock off southern Brazil might not be homogeneous and may include subpopulations that do not fully mix.
The life cycle, fisheries and management of the main fishing resources of the Patos Lagoon and adjacent coastal waters are reviewed. Over recent decades, fish landings in Rio Grande have decreased by ...over 60%. The stocks of the large-sized, slow-growing fishes Genidens barbus and G. planifrons, Pogonias cromis and Rhinobatos horkelii collapsed in the early 1980s. The pink shrimp Penaeus paulensis stock was reduced by intense fishing of subadults in the estuary and of adults at sea. The sciaenid fishes Micropogonias furnieri, Macrodon atricauda, Umbrina canosai and Cynoscion guatucupa, which together represent more than half of local marine fish landings, are overexploited. These sciaenids are more resilient to intense fishing when compared with other families because of their early maturation and high fecundity, but high exploitation rates are unsustainable in the long run. The pelagic migrant fishes Pomatomus saltatrix and Mugil liza and the blue crab Callinectes sapidus are at the limit of exploitation. The recovery of these stocks will depend on diminishing the fishing pressure they have suffered in recent decades. Despite legal protection, the present enforcement has proven to be insufficient and intense fishing by a large number of industrial and small-scale fishing boats still goes on. Overall, the future of the estuarine and coastal fishing resources is uncertain and the recovery of the large long-living species of the higher trophic levels is unlikely.
ABSTRACT Cashew gummosis is one of the main diseases of the cashew in the semi-arid region of the northeast and is characterised by a decline in the plants and a reduction in stand. Lasiodiplodia ...theobromae, the causal agent, is an endophytic fungus that eventually takes on pathogenic characteristics; however, the environmental conditions that cause this change in behaviour are still unknown. It is assumed that stress in the host caused by environmental changes stimulate pathogenicity. The aim of this study was to define the relationship between climate and geographical factors and the occurrence of gummosis. Rainfall data, maximum and minimum temperature, thermal amplitude, and the altitude of 14 micro-regions in the northeast were compared and classified into five frequencies of disease occurrence: 0 (no occurrence), 1 (rare occurrence), 2 (frequent occurrence), 3 ( generalised occurrence) and 4 (generalised high-severity occurrence). The data were submitted to the Doornik-Hansen test for multivariate normality, and principal component analysis was carried out using the correlation matrix between the climate and geographical variables and occurrence of the disease. Areas of disease severity were correlated (Pearson’s correlation). Only thermal amplitude, altitude and latitude were associated with the different areas of gummosis occurrence. The districts of Buíque, in the state of Pernambuco, and São Raimundo Nonato, Canto do Buriti and Pio IX, in Piauí, with the highest incidence of the disease, had the highest values for thermal amplitude, altitude and latitude. Whereas the districts of Pacajus and Beberibe had a lower occurrence of gummosis, with lower values for thermal amplitude, altitude and latitude.
There is a limited number of established ovarian cancer cell lines matching the low-grade serous histotype available for research purposes. Three-dimensional (3D) culture systems provide in vitro ...models with better tissue-like characteristics than two-dimensional (2D) systems. The goal in the study was to characterize the growth of a given low-grade serous ovarian carcinoma cell line in a 3D culture system conducted in a magnetic field. Moreover, the culture system was evaluated in respect to the assembly of malignant cell aggregates containing lymphocytes. CAISMOV24 cell line alone or mixed with human peripheral blood mononuclear cells (PBMC) were cultured using a commercially available 3D culture system designed for 24 well plates. Resulting cell aggregates revealed the intrinsic capacity of CAISMOV24 cells to assemble structures morphologically defined as papillary, and reflected molecular characteristics usually found in ovarian carcinomas. The contents of lymphocytes into co-cultured cell aggregates were significantly higher (
< 0.05) when NanoShuttle-conjugated PBMC were employed compared with non-conjugated PBMC. Moreover, lymphocyte subsets NK, T-CD4, T-CD8 and T-regulatory were successfully retrieved from co-cultured cell aggregates at 72h. Thus, the culture system allowed CAISMOV24 cell line to develop papillary-like cell aggregates containing lymphocytes.
We analysed the long-term changes in the population dynamics and life history of whitemouth croaker (Micropogonias furnieri) off Southern Brazil, to understand how four decades of heavy fishing ...(1976–2017) has affected its population dynamics. In the first three decades, size and age structure were eroded with the loss of the larger (> 60 cm total length) and older (>20 yrs. old) individuals. Individual growth increased sharply until the early 2000s and stabilized thereafter. The age at first maturity decreased by one year for females, the total mortality (Z) increased three-fold, and the stock size decreased approximately 90 %. Despite changes in the population structure due to intense fishing and high exploitation rates, the landings remained high until the late 2000s and in the last decade decreased less than expected by a former stock assessment. The resilience of the stock can be explained by its life history traits: (i) high fecundity, (ii) multiple spawning events during a protracted reproductive season in coastal waters, (iii) large estuarine nursery grounds unaffected by industrial fishing and (iv) faster growth and earlier sexual maturation due to the reduction in food competition and possibly evolution via gear selectivity. However, the stabilization of individual growth rates, the high rate of exploitation and the low spawning potential warn of the risk of further population decline and fishery collapse if intense fishing pressure continues.
Prevent bottom trawling in southern Brazil Cardoso, Luís Gustavo; Haimovici, Manuel; Abdallah, Patrízia Raggi ...
Science (American Association for the Advancement of Science),
04/2021, Volume:
372, Issue:
6538
Journal Article
Identifying changes in the population structure and dynamics for fish stocks is important to support its management. Data obtained from 1976 to 2019 allowed to follow up long more than four decades ...the changes in the population structure and life-history of
Umbrina canosai
, an intensely exploited demersal sciaenid fish in southern Brazil. Intense fishing caused the truncation of the length/age structure with the loss of most of the bigger/older fishes and the sex ratio change, with increasing frequencies of males. A considerable increase in individual growth was observed and attributed to the lower competition for food due to the reduction in the density of the overall coastal benthic-feeding fish community caused by intense fishing. The large increase in the mortality and the exploitation rate resulted in a drastic decrease in the reproductive potential despite some anticipation in the sexual maturation. Despite the adaptative response to intense fishing, the high exploitation rates and the drastic reduction of the spawning potential ratio in recent years, are clear evidences that
U. canosai
could be reaching its adaptive capacity for resilience. Therefore, an urgent necessity for a drastic reduction of the fishing mortality to avoid the economic collapse of the fishery is required.
Microbiological quality of colonial cheese sold in Porto Alegre-RS Ausani, Thais de Campos; Lopes, Graciela Volz; Costa, Eduardo de Freitas ...
Semina. Ciências agrárias : revista cultural e científica da Universidade Estadual de Londrina,
03/2019, Volume:
40, Issue:
2
Journal Article
Peer reviewed
Open access
Colonial cheese is a traditional dairy product in southern Brazil and is commonly purchased by the citizens of Porto Alegre. However, there is still a lack of technical regulation of colonial cheese, ...and there is little information about the microbiological quality of this product at the retail level. Thus, the objectives of this study were to (i) evaluate compliance with the legal microbiological standards of colonial cheese sampled from street fairs and the central market of the city of Porto Alegre; (ii) statistically test the hypothesis of an association between noncompliance with the standards and local purchasing (street fairs or central market); (iii) estimate the number of Listeria spp. and Listeria monocytogenes in the positive samples; and (iv) characterize the L. monocytogenes strains by serotyping and macrorestriction (PFGE). For this purpose, 205 cheese samples belonging to 17 different brands were analyzed. The microbiological analyses were conducted according to ISO standardized protocols for the detection of L. monocytogenes and Salmonella spp. or by enumeration of coagulase-positive Staphylococcus and coliforms at 45°C. Among the samples, 47.31% did not comply with at least one of the microbiological standards established by the Brazilian legislation and were thus unsuitable for human consumption. Regarding the coliforms at 45ºC and coagulase-positive Staphylococcus, 10.73% and 40.48% of the samples presented higher counts than the legal parameter, respectively. There was no association between the frequency of samples with coagulase-positive Staphylococcus counts above the legal parameter and local of purchasing; however, the commercial brand influenced the frequency of unsuitable samples. This may indicate failures of hygiene during cheese production. Salmonella spp. were not detected. Listeria monocytogenes was isolated from 2.9% of the samples. The estimated average populations of Listeria spp. and L. monocytogenes were low in the positive cheese samples at -3.3 log CFU g?1 and -2.26 log CFU g?¹, respectively. The strains of L. monocytogenes belonged to serovars 1/2a, 1/2b and 1/2c and could be grouped into five pulsotypes with no evident epidemiological relation among them. The results demonstrate the need to improve the hygiene procedures during colonial cheese production and to strengthen monitoring at the dairy plants and retail levels.
Ecological niche models (ENMs) and species distribution models (SDMs) have been widely applied to various studies relevant to biogeography, conservation biology, and ecology. These modelling ...techniques seek to develop spatial maps for projecting, among others past, current, and future species distributions. Born in the field of terrestrial ecology, only in recent years have these models been applied to marine environmental issues, especially to improve the forecasting of the distribution of occurrences and capturing of fishery resources. This study aimed to present through bibliometric analysis the characteristics of articles related to the use of ENMs and SDMs in marine fishery resources considering three main points: (1) state of the art: number of articles over the years, journals, countries, collaborations, and focus of research; (2) characteristics linked to fishery resources: marine biogeographic realms, taxonomic groups, life phases, oceanographic zones, and behaviours; (3) characteristics linked to methods: type of method, type of biological and, environmental data. We provide a list of 378 articles (derived from 930 screened ones), the results, and a discussion of our findings, which represent a baseline for the current status (strengths, limits, and gaps) of the interface between ENMs/SDMs and fishery resources.
Worldwide overfishing has caused the collapse of populations of excessively exploited marine fish. The coastal demersal sciaenid fish “pescadinha”, Macrodon atricauda, has been intensely fished since ...the 1960s along the southern Brazilian coast, resulting not only in decreasing abundance but also in increasing growth rates and decreasing age and length at first maturity. We analyzed the time series of several population indicators, such as catch per unit effort (CPUE), age composition of the stock, total and natural mortality and exploitation rate to investigate the long-term impact of fishing on the mortality, age structure and biomass of M. atricauda. Furthermore, we modeled the time-trajectory of the total biomass under an assumption of constant recruitment and discuss the limits of resilience and the risk of collapse of the fishery. The CPUE (kg/day at sea) has decreased almost 50%. Total mortality increased from 0.5yr−1 in the almost unexploited stock in the 1950s to around 1.9yr−1 in the 2000s, while the age structure changed dramatically: fishes in the landings were not older than 9 years old in the 1960s, 7 years old in the 1970s and no fish over 5 years old has been observed since the 1990s. Taking into account the growth changes, a deterministic model estimated a reduction of 67% in total biomass over five decades. In the last 30 years, the stock has withstood high exploitation rates (between 0.5 and 0.7yr−1) and has suffered a steady decline in biomass but has not collapsed, probably due to life-history traits that favor resilience: early maturation and rapid individual growth. However, the stock is at risk of collapse, taking into consideration the present non-stabilized level of high mortality, changed age structure and life history, low biomass and high exploitation rates. A precautionary approach suggests the need to reduce fishing effort.
PDF
