scholarly journals Artisanal fishing characterization and spatio-temporal occurrence of marine shrimp (Crustacea, Decapoda, Penaeidae) in the littoral of Lucena, Paraíba, Brazil

2018 ◽  
Vol 40 ◽  
pp. 47 ◽  
Author(s):  
Glória Cristina Cornélio do Nascimento ◽  
Dimitri De Araújo Costa ◽  
Raquel Ferreira de Sá ◽  
Martin Lindsey Christoffersen ◽  
Maria Cristina Basilio Crispim

The present study distinguishes types of fishing activities. It records the most economically exploited shrimps in the municipality of Lucena, Paraíba, Xiphopenaeus kroyeri (“espigudo”), and Penaeus schmitti (white shrimp). From October 2014 to October 2015, samples containing 700 gr of shrimp were collected at three sites of artisanal fishing. Data on temperature, ammonium, nitrate, nitrite, chlorophyll-a, salinity, pH, and dissolved oxygen were recorded.  Two different shrimp species are commercially used in the region, of 2,628 sampled individuals, X. kroyeri predominated, with 1,957 individuals, followed by P. schmitti, with 671 individuals. At localities 1 (in Lucena beach) and 2 (Fagundes beach) both species were present, the X. kroyeri being predominant, but at locality 3 (Costinha beach) only the P. schmitti was recorded. The regional wet season influenced salinity during the months of the year, producing positive or negative correlations among species found at each locality depending on what was analysed. It is relevant to understand the relationship between fishing resources and environmental variables which provide information about fishing dynamics and permits the development of strategies for the maintenance of stocks and fishing areas, as well as permitting the establishment of public regulations for the better preservation and conservation of marine areas and estuaries on which many species depend for the completion of their life cycles. 

2011 ◽  
Vol 68 (3) ◽  
pp. 528-536 ◽  
Author(s):  
Miguel Bernal ◽  
Yorgos Stratoudakis ◽  
Simon Wood ◽  
Leire Ibaibarriaga ◽  
Luis Valdés ◽  
...  

Abstract Bernal, M., Stratoudakis, Y., Wood, S., Ibaibarriaga, L., Uriarte, A., Valdés, L., and Borchers, D. 2011. A revision of daily egg production estimation methods, with application to Atlanto-Iberian sardine. 2. Spatially and environmentally explicit estimates of egg production. – ICES Journal of Marine Science, 68: . A spatially and environmentally explicit egg production model is developed to accommodate a number of assumptions about the relationship between egg production and mortality and associated environmental variables. The general model was tested under different assumptions for Atlanto-Iberian sardine. It provides a flexible estimator of egg production, in which a range of assumptions and hypotheses can be tested in a structured manner within a well-defined statistical framework. Application of the model to Atlanto-Iberian sardine increased the precision of the egg production time-series, and allowed improvements to be made in understanding the spatio-temporal variability in egg production, as well as implications for ecology and stock assessment.


2005 ◽  
Vol 56 (5) ◽  
pp. 609 ◽  
Author(s):  
T. S. Elsdon ◽  
B. M. Gillanders

Elemental concentrations within fish otoliths can track movements and migrations of fish through gradients of environmental variables. Tracking the movements of fish relies on establishing links between environmental variables and otolith chemistry, with links commonly made using laboratory experiments that rear juvenile fish. However, laboratory experiments done on juvenile fish may not accurately reflect changes in wild fish, particularly adults. We tested the hypotheses that: (1) the relationship between ambient (water) and otolith chemistry is similar between laboratory-reared black bream (Acanthopagrus butcheri) and wild black bream; and (2) ontogeny does not influence otolith chemistry. Field-collected and laboratory-reared fish showed similar effects of ambient strontium : calcium (Sr : Ca) on otolith Sr : Ca concentrations. However, ambient and otolith barium : calcium concentrations (Ba : Ca) differed slightly between laboratory-reared and field-collected fish. Importantly, fish reared in stable environmental variables showed no influence of ontogeny on Sr : Ca or Ba : Ca concentrations. Natural distributions of ambient Sr : Ca showed no clear relationship to salinity, yet, ambient Ba : Ca was inversely related to salinity. The distribution of ambient Sr : Ca and Ba : Ca in estuaries inhabited by black bream, suggest that these elements can answer different questions regarding environmental histories of fish. Reconstructing salinity histories of black bream using otolith Ba : Ca concentrations seems plausible, if adequate knowledge of Ba : Ca gradients within estuaries is obtained.


2021 ◽  
Author(s):  
Tomos Potter ◽  
Anja Felmy

AbstractIn wild populations, large individuals have disproportionately higher reproductive output than smaller individuals. We suggest an ecological explanation for this observation: asymmetry within populations in rates of resource assimilation, where greater assimilation causes both increased reproduction and body size. We assessed how the relationship between size and reproduction differs between wild and lab-reared Trinidadian guppies. We show that (i) reproduction increased disproportionately with body size in the wild but not in the lab, where effects of resource competition were eliminated; (ii) in the wild, the scaling exponent was greatest during the wet season, when resource competition is strongest; and (iii) detection of hyperallometric scaling of reproduction is inevitable if individual differences in assimilation are ignored. We propose that variation among individuals in assimilation – caused by size-dependent resource competition, niche expansion, and chance – can explain patterns of hyperallometric scaling of reproduction in natural populations.


2015 ◽  
Vol 75 (3) ◽  
pp. 692-702 ◽  
Author(s):  
LS Andrade ◽  
M Antunes ◽  
PA Lima ◽  
M Furlan ◽  
IF Frameschi ◽  
...  

AbstractThe life cycle of the crab Callinectes danae is estuarine-dependent, and studies on aspects of their biology should also cover marine areas. The present study investigated the sexual maturity, as well as habitat preference by adults in different gonadal stages, and the crabs’ reproductive periodicity outside the estuary. Three bays on the subtropical southeastern coast of Brazil were sampled monthly for two years. For each bay, six transects were established, four of them parallel to the beach line (5, 10, 15 and 20 m depth), as well as one transect in an exposed area, and another sheltered from the action of waves. The results showed that the pattern of spatio-temporal distribution of adults C. danae was similar in three bays, although the highest abundance was found in Ubatumirim. Females with developed gonads/ovigerous females were found in greater abundance than females with rudimentary/developing gonads, mainly in deeper transects. Although the areas sampled have different environmental characteristics, the reproductive pattern of the species did not change, showing continuous reproduction throughout, with more abundance of reproductive females on spring and summer. Males reached maturity at larger sizes than females in all three bays.


2015 ◽  
Vol 87 (3) ◽  
pp. 1717-1726 ◽  
Author(s):  
JULIANA WOJCIECHOWSKI ◽  
ANDRÉ A. PADIAL

One of the main goals of monitoring cyanobacteria blooms in aquatic environments is to reveal the relationship between cyanobacterial abundance and environmental variables. Studies typically correlate data that were simultaneously sampled. However, samplings occur sparsely over time and may not reveal the short-term responses of cyanobacterial abundance to environmental changes. In this study, we tested the hypothesis that stronger cyanobacteria x environment relationships in monitoring are found when the temporal variability of sampling points is incorporated in the statistical analyses. To this end, we investigated relationships between cyanobacteria and seven environmental variables that were sampled twice yearly for three years across 11 reservoirs, and data from an intensive monitoring in one of these reservoirs. Poor correlations were obtained when correlating data simultaneously sampled. In fact, the 'highly recurrent' role of phosphorus in cyanobacteria blooms is not properly observed in all sampling periods. On the other hand, the strongest correlation values for the total phosphorus x cyanobacteria relationship were observed when we used the variation of sampling points. We have also shown that environment variables better explain cyanobacteria when a time lag is considered. We conclude that, in cyanobacteria monitoring, the best approach to reveal determinants of cyanobacteria blooms is to consider environmental variability.


2021 ◽  
Vol 880 (1) ◽  
pp. 012004
Author(s):  
H Mahidin ◽  
M T Latif ◽  
A Hamdan ◽  
J Salleh ◽  
D Dominick ◽  
...  

Abstract Sarawak Region of Malaysia is currently experiencing a high demand for capital needs such as transformation forest to plantations, economic development, and improving transportation systems. Those land cover changes will increase primary pollutant emissions and trigger surface O3 formation. Surface O3 is a secondary pollutant and a significant greenhouse gas contributing to climate change and declining air quality. In this study, variations in surface O3 concentrations at urban and suburban sites in Sarawak were explored using the Malaysian Department of Environment data spanning a two-year cycle (2018-2019). The primary aim of this study is to ascertain the variation of surface O3 concentrations reported at four monitoring stations in Sarawak, namely Kuching (SQ1) (Urban), Sibu (SQ2) (Suburban), Bintulu (SQ3) (Suburban), and Miri (SQ4) (Suburban). The study also analysed the relationship between O3 distribution and nitrogen oxides (NO and NO2). The findings showed that O3 concentrations observed in the region during the study period were lower than the maximum permissible value of 100 ppbv suggested by the Malaysian Ambient Air Quality Standard (2020). SQ4 (Miri) at suburban sites recorded the highest average surface O3 concentrations with an hourly average and daily maximum O3 concentration of 15.7 and 89.5 ppbv, respectively. Temperatures, UV exposure, and wind speed all impact the concentration of surface O3 in Sarawak. In all stations, concentrations of O3 were inversely linked with NO, NO2, and relative humidity (RH). This research will assist the relevant agency in forecast, monitor, and mitigate the level of O3 in the ambient environment, especially in the Sarawak Region.


Diversity ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 36
Author(s):  
Teckwyn Lim ◽  
Ahimsa Campos-Arceiz

Understanding the relationship between humans and elephants is of particular interest for reducing conflict and encouraging coexistence. This paper reviews the ecological relationship between humans and Asian elephants (Elephas maximus) in the rainforests of the Malay Peninsula, examining the extent of differentiation of spatio-temporal and trophic niches. We highlight the strategies that people and elephants use to partition an overlapping fundamental niche. When elephants are present, forest-dwelling people often build above-the-ground shelters; and when people are present, elephants avoid open areas during the day. People are able to access several foods that are out of reach of elephants or inedible; for example, people use water to leach poisons from tubers of wild yams, use blowpipes to kill arboreal game, and climb trees to access honey. We discuss how the transition to agriculture affected the human–elephant relationship by increasing the potential for competition. We conclude that the traditional foraging cultures of the Malay Peninsula are compatible with wildlife conservation.


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