Microflora population in mangrove sediments of Cross River estuary

Edu, E. A.; Omokaro, D. N.; Holzloehner, S.; Udensi, O.

doi:10.4314/gjpas.v13i3.16716

Cited by 2 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The physical impact of tides on the leaves may also cause fragmentation and increase weight loss [13]. However, the higher rates of decomposition observed at the high tide level where there is less frequent tidal inundation may be attributed to the high density of microbial populations as observed in previous studies [42,43]. Overall, tidal level had a greater effect on decomposition rate than species suggesting that external factors may contribute more in determining the decomposition rate in this study.…”

Section: Fig 1 Map Of Cross River Estuarymentioning

confidence: 46%

“…It has been observed that litter decomposing in forest sites with higher soil nitrogen concentration has higher rates of accumulation of nitrogen [55]. Similar study in the area showed that the high tide level was observed to be characterised by higher soil nitrogen concentration relative to other tidal levels [42,56,57]. The increase of nitrogen concentration and nutritional content of mangrove leaves during decomposition may have been mediated by microbial and fungal populations which colonize and carry out saprophytic decomposition.…”

Section: Leaf Litter and Nutrient Dynamicsmentioning

confidence: 77%

See 1 more Smart Citation

Monitoring and Assessment of Leaf Litter Dynamics in a Mixed Mangal Forest of the Cross River Estuary, Nigeria

B¹

2014

IJEMA

View full text Add to dashboard Cite

The leaf litter decomposition of Nypa fruticans, Rhizophora racemosa and Avicennia africana were studied across a tidal gradient in a mixed mangrove forest of the Cross River estuary Nigeria. Leaf litter decomposition was measured along the tidal gradients (low, mid, high) using litter bags. A single exponential model was used to study the decomposition rates of the leaves. Leaf decomposition varied significantly (P < 0.001) among species and spatially across tidal gradients over the study period. Decomposition was fastest in A. africana and slowest in N. fruticans and spatially, it was fastest at the low tide level and slowest at the high tide level. Tidal effects were much larger than species differences in the decomposition rates. The time (days) required for the loss of half the initial dry mass (T 50) of the decomposing leaves at the low, mid and high tide levels were A. africana, 46, 57 and 77, R. racemosa 69, 86 and 115, and N. fruticans 86, 99 and 115 respectively. Estimates of leaf litter turnover rates showed that the actual litter turnover based on the relative measure of leaf litterfall and biomass on the forest floor (K t) were much shorter than the projected litter turnover based on the leaf decomposition rates (K d). The estimated actual residence times were less than one day while the projected residence times ranged from 83 to 142 days across tidal gradients, suggesting involvement of other ecological processes in litter loss and their possible transport into the Cross River estuary. The nitrogen contents and nutritional value of the decomposing leaves increased with time during the study. The increase varied significantly (P <0.001) among species, as well as temporally (P < 0.001) and spatially (P ≤ 0.05). The average C:N ratio decreased from 27.7 to 22.1 in A. africana, 26.4 to 23.9 in R. racemosa and 32.8 to 23.6 in N. fruticans. The overall changes in nutrients during decomposition indicated net mineralization. Mangrove leaf litter dynamics, trophic value and organic matter exchange of the system have implications on the productivity of the Cross River estuary and ultimately the Gulf of Guinea. Knowledge of these processes is critical for the maintenance and long term sustainability of the mangrove and surrounding ecosystems.

show abstract

Section: Fig 1 Map Of Cross River Estuarymentioning

confidence: 46%

Section: Leaf Litter and Nutrient Dynamicsmentioning

confidence: 77%

Monitoring and Assessment of Leaf Litter Dynamics in a Mixed Mangal Forest of the Cross River Estuary, Nigeria

B¹

2014

IJEMA

View full text Add to dashboard Cite

show abstract

“…Nigeria has the largest mangrove forest cover in Africa which ranks fourth in the world after Indonesia, Brazil and Australia. Cross River system (in which Calabar River is one of its tributaries) has about 950 km 2 mangrove area (largest in Nigeria; Edu, Omokaro, Holzolehner, & Udensi, 2007). In order to extend the data available for tropical mangrove zones, a study of PAHs in sediment-dwelling biota from the Calabar River was undertaken.…”

Section: Introductionmentioning

confidence: 99%

Anthropogenic PAHs in Sediment-Dwelling Biota from Mangrove Areas of the Calabar River, SE Niger Delta, Nigeria

Ekpo¹,

Ita²,

Offem³

et al. 2012

ENRR

View full text Add to dashboard Cite

Polycyclic aromatic hydrocarbons (PAHs) in mangrove sediment-dwelling biota (crabs and molluscs) from the Calabar River, SE Niger Delta of Nigeria were analyzed using GC-MS in order to assess the degree of contamination of the river by anthropogenic activity. The associated sediment samples (where these biota were collected) showed much higher total PAH (TPAH) concentration (16,028.3 ng/g dry weight (dw)) at the upper mangrove area (UMA) than that found toward the river mouth (MR; 1,667.5 ng/g dw). However, the mean TPAH levels were higher in molluscs (16,749.8 ng/g ww) and crabs (29,325.1 ng/g ww) at theMR, and in molluscs (28,580.8 ng/g ww) and crabs (71,782.6 ng/g ww) at the UMA than in the associated sediments, indicating occurrence of bio-accumulation/bio-concentration of PAHs in tissues of these organisms. The results revealed that molluscs are safer to consume than crabs. One way analysis of variance (ANOVA) indicated no significant relationship between lipid content or body size of organisms and contaminant load probably because of non-equilibrium situation: smaller animals accumulated more PAHs than their larger counterparts, suggesting different uptake and elimination rates for these compounds. Biota-sediment accumulation factors (BSAFs) varied among the organisms (4.84-14.98) and were generally lower for highly polluted site (UMA; fresh water area) and higher for area of low anthropogenic pressure (MR- brackish water area). Risk assessment against USEPA standard show the biota to be highly contaminated with carcinogenic PAHs and may pose life-time cancer risk, especially to residents of the riverine/coastal communities who often consume more of these organisms than those living hinterland.

show abstract

Microflora population in mangrove sediments of Cross River estuary

Cited by 2 publications

References 0 publications

Monitoring and Assessment of Leaf Litter Dynamics in a Mixed Mangal Forest of the Cross River Estuary, Nigeria

Monitoring and Assessment of Leaf Litter Dynamics in a Mixed Mangal Forest of the Cross River Estuary, Nigeria

Anthropogenic PAHs in Sediment-Dwelling Biota from Mangrove Areas of the Calabar River, SE Niger Delta, Nigeria

Contact Info

Product

Resources

About