Polychaete (Marphysa mosambica) Morphometrics, and their use in the Estimation of Whole Polychaete Size and Breeding Values of Bait Exploited by Artisanal Fishers at the Kenyan Coastline
Kihia CM*, Waigwa SW, Munyaka JM
Department of Biological Sciences, Egerton University, Egerton, Kenya.
Abstract: Polychaetes, such as Marphysa mosambica, are extensively used as bait in tropical artisanal fisheries, while, cultured polychaetes are exploited as fishfeed in mariculture. In order to monitor exploited wild and cultured polychaetes populations, metrics that predict growth and reproductive condition, are needed. Adult polychaete specimen were collected from mudflats at three locations along the Kenyan coastline. Measurements of the head, trunk and tail length were obtained and correlated to whole polychaete dimension. Breeding values monitored were condition factor and gonadosomatic index. Regression between morphometrics and whole polychaete dimension, and also breeding values, were obtained and the best variable estimator identified. Results indicate, adult polychaete along the Kenyan coastline are 97 mm long, with 170 segments and weigh 2.36g, with an average egg load of 106 eggs. Polychaete morphometric and condition factor differed among the locations, but GSI were similar. Differences were attributed to habitat characteristics and bait exploitation patterns. Polychaete trunk length and width, were best estimators (r2<0.4) of whole polychaete dimension, condition factor and GSI. Upon further validation, trunk dimensions may be used for rapid estimation of the total length, weight and reproductive condition of polychaetes.
Keywords: Morphometrics, whole polychaete, Condition factor, Gonado Somatic Index.
Pages: 1 – 13 | Full PDF Paper
The Impact of Air Pollution on the Occurrence of Bioindicator Rhytisma Acerinum L. and Its Potential Use in the Production of Biomass
Grammar school of St. Nicholas , Duklianska 16, 080 01, Prešov, Slovakia.
Abstract: The aim of our project was to find the association between the intensity of bioindication demonstrations of Rhytisma acerinum L. (size and number of spots) and selected meteorological factors (precipitation, SOx), compare the content of selected biogenic elements in the leaves and soil of affected seedlings of Acer platanoides L. and Acer pseudoplatanus L. In 2014 and 2015 we recorded 100 % infection rate in both species of maple in the mountains of Bukovské mountains and Slánske mountains. The major manifestation of the bioindication of fungi was recorded in the highest areas (protected areas). We observed differences in infection of the monitored species of maples: Acer pseudoplatanus L. had a greater number of smaller spots compared to Acer platanoides L. In 2014 with more precipitation the number of spots was higher (Bukovské mountains by 27,62 % more and Slanské mountains by 30,11 %), the size of spots was also larger than in 2015 (Bukovské mountains by 8,34 % and Slanské mountains by 52,31 %). In the experimental stage we found out that the more intense pH of the watering solution, the higher number and size of spots. The largest number and size of spots were recorded on the seedlings watered with the solutions of pH from 6,00 – 7,60 and on seedlings growing in the forest. The content of nitrogen increased with a decreasing pH, higher contents of carbon, hydrogen and oxygen were recorded in the maples remarkably infected with the fungus, the presence of sulfur was recorded only in the leaves of Acer platanoides L. (more sensitive to SOx). The highest content of calcium, magnesium, potassium and phosphorus was recorded in the soil under the maple trees intensely affected by Rhytisma acerinum L. After evaluating the calorific value and gross combustion heat we did not record any significant differences in the production of maple biomass. We propose to use the monitoring of occurrence of Rhytisma acerinum L. bioindicator as a suitable method for detection of air pollution caused by sulphur pollutants. The results are as well significant for the finding about faster defoliation of maple leaves which causes more rapid humification of soil, which in the replanting process of trees results in a less serious land degradation.
Keywords: Rhytisma acerinum L., Acer pseudoplatanus L., Acer platanoides L., bioindicator, SOx, air pollution, acid rain.
Pages: 14 – 42 | Full PDF Paper
Vera Cristina de Menezes Julien1, Almeida Tomás Guissamulo2, Armindo Filipe da Silva3, Adriano Afonso Macia Júnior1
1. Department of Biological Sciences, University Eduardo Mondlane, CP. 257, Maputo, Mozambique.
2. Natural History Museum, University Eduardo Mondlane, CP. 257, Maputo, Mozambique.
3. Department of Mapping Sciences, National Statistics Institute, CP.493, Maputo, Mozambique.
Understanding the temporal variation of sea turtles nests and the processes driving those variations is of extreme importance to improve the efficiency of the monitoring and management measures at the nesting beaches. In that perspective the present study aimed to describe the temporal nesting activity of two sea turtle species at Inhaca island based on the long-term database on sea turtle nidification (~27 years).
A total of 530 loggerhead and leatherback nests were recorded, of which approximately 64% (equivalent to 340 nests) were loggerhead’s (15.45 ± 10.41 per year) and 36% (equivalent to 190 nests) were leatherback’s (8.64 ± 7.72 per year). the mean annual nest numbers between both species were significantly different (t = 2.467, df = 42 and p < 0.05). loggerhead turtles laid more nests than leatherback turtles.
Results showed that the number of nests was not equally distributed along the nesting seasons. Inter-annual variability in the number of nests laid by loggerhead and leatherback turtles was observed during the study period.
Loggerhead and leatherback nesting activities were restricted to the summer months (October-March). The nesting peaks of loggerhead turtles occurred a month later and were shorter (November and December) than those of leatherback turtles which spanned through October, November and December.
Keywords: Nesting activity, temporal nest distribution, annual nest distribution, seasonal nest distribution, re-migration intervals, sea turtles, Inhaca Island.
Pages: 43 – 55 | Full PDF Paper
Paulo José Sigaúque1, Paulo Cesar Rosman2, Eduardo González-Gorbeña3
1. Departamento de marés e correntes, Instituto Nacional de Hidrografia e Navegação (INAHINA), Avenida Karl Max, 153 C.P. 2089, Maputo, Moçambique.
2. Instituto Alberto Luiz Coimbra de Pós Graduação e Pesquisa de Engenharia, Programa de Engenharia Oceânica, Universidade Federal do Rio de Janeiro. Centro de Tecnologia Bloco C Sala 209, Ilha do Fundão, Rio de Janeiro C.P6850.
3. Instituto Alberto Luiz Coimbra de Pós Graduação e Pesquisa de Engenharia, Programa de Engenharia Oceânica, Universidade Federal do Rio de Janeiro.Centro de Tecnologia Bloco C Sala 209, Ilha do Fundão, Rio de Janeiro C.P 6850.
In Maputo Bay, located in south of Mozambique, it is important to know the hydrodynamics circulation due to tides and local winds, as well as the sediment dynamics processes, to auxiliary the maritime navigation.For this work, a finite element modelling system has been adopted, this being employed SisBaHiA®, which is the acronym for Base System for Environmental Hydrodynamics in Portuguese. Simulations have been done using a 2DH hydrodynamic model coupled with a sediment transport model, forced with local winds, river discharges and tides.
This work presents results foran environmental hydrodynamic and sediment transport study, focused on the Maputo harbor area and close to the border open(near the Inhaca Island) in order to assess the trend of the drift of sediment.
The results showed that the tides are the physical process that dominates the circulation on the bay. The tidal current is highest in the central part of the bay than in eastern and western. As expected, current velocitiesare more intense during spring tidesthan during neap tides.It has not been identified any seasonal variations in tidal current intensities. In most parts of the bay,variations in bathymetry due to sediment transport showed small differences from summer to winter.
Keywords: Tidal waves, Tidal currents, Hydrodynamic and Sediment Transport Model.
Pages: 56 – 68 | Full PDF Paper