Population dynamics of periwinkle Tympanotonus fuscatus var fuscatus (Linnaeus, 1758) in the Bonny Estuary, Niger Delta, Nigeria

The growth, mortality and recruitment pattern of Tympanotonus fuscatus var fuscatus were investigated using shell length (SL) - frequency data obtained from the mangrove swamps of the Bonny River, population. Computer based software package FiSAT (FAO - ICLARM Fish Stock Assessment tool) were used for the analysis. Sampling was done between January to December, 2004. Results obtained showed relatively high growth, low mortality and recruitment pattern with two peaks annually

Meiofauna Occurrence and Distribution in Different Substrate Types of Bonny Brackish Wetland of the Niger Delta

The meiobenthic community of different sediment types was studied for 12 months between January and December 1997 in the Bnny estuarine environment. Five replicates core samples were collected from three sediment types (Muddy, Sandy and Chikoko sediments). Meiofaunal densities in order of magnitude are muddy (356 to 899 cm3), sandy (278 to 866 cm3) and chikoko (133 to 252 cm3). Most of the taxa groups had higher densities in dry season than in wet season with significant seasonal variations observed for Sandy sediment and Muddy sediment while Chikoko sediment densities did not show significant seasonal variation (t – test < 0.5). The meiofaunal densities for the different sediment types showed marked significant variation (ANOVA, p < 0.05). @ JASE

Meiofauna Occurrence and Distribution in Different Substrate Types of Bonny Brackish Wetland of the Niger Delta

The meiobenthic community of different sediment types was studied for 12 months between January and December 1997 in the Bnny estuarine environment. Five replicates core samples were collected from three sediment types (Muddy, Sandy and Chikoko sediments). Meiofaunal densities in order of magnitude are muddy (356 to 899 cm3), sandy (278 to 866 cm3) and chikoko (133 to 252 cm3). Most of the taxa groups had higher densities in dry season than in wet season with significant seasonal variations observed for Sandy sediment and Muddy sediment while Chikoko sediment densities did not show significant seasonal variation (t – test < 0.5). The meiofaunal densities for the different sediment types showed marked significant variation (ANOVA, p < 0.05). @ JASE

Comparative study of different gill net mesh sizes in the exploitation of bonga fish (Ethmalosa fimbriata) and sardines (Sardinella eba) in Brass Coastal Waters, Bayelsa State, Nigeria

A comparative study of different gill net sizes in the exploitation of bonga (Ethmalosa fimbriata) and sardines (Sardinella eba) were conducted for 3 months between January and March 1998 in Brass River. The area is located between Latitude 4o 2" and 4 o 6 " and longitude 6 o 2 " and 6o 5" stretching from Akassa at the River mouth to Doukungbene near the upper edge of Clarendou. Three Mesh size of gill nets (35mm, 60mm and 70mm) were used for Bonga and Sardine fishing. The result obtained indicated that larger size classes of fish were obtained with the increase in mesh sizes of nets. In addition, marked variation in mean values (t test > t 0.05) and distribution ( w > P0.05) of the size classes were observed (for Ethmalosa fimbriata and Sardinella eba ) irrespective of the mesh sizes. Also the Principal component analysis (PCA) showed high selection for larger fish sizes (in the component weighting) in the catch, which were favoured by the bigger mesh sizes (70mm). @JASEM ** Due to technical difficulties, figures and images associated with this article are unavailable. We apologize for any inconvenience. *

Comparative study of different gill net mesh sizes in the exploitation of bonga fish (Ethmalosa fimbriata) and sardines (Sardinella eba) in Brass Coastal Waters, Bayelsa State, Nigeria

A comparative study of different gill net sizes in the exploitation of bonga (Ethmalosa fimbriata) and sardines (Sardinella eba) were conducted for 3 months between January and March 1998 in Brass River. The area is located between Latitude 4o 2" and 4 o 6 " and longitude 6 o 2 " and 6o 5" stretching from Akassa at the River mouth to Doukungbene near the upper edge of Clarendou. Three Mesh size of gill nets (35mm, 60mm and 70mm) were used for Bonga and Sardine fishing. The result obtained indicated that larger size classes of fish were obtained with the increase in mesh sizes of nets. In addition, marked variation in mean values (t test > t 0.05) and distribution ( w > P0.05) of the size classes were observed (for Ethmalosa fimbriata and Sardinella eba ) irrespective of the mesh sizes. Also the Principal component analysis (PCA) showed high selection for larger fish sizes (in the component weighting) in the catch, which were favoured by the bigger mesh sizes (70mm). @JASE