Biomass, litterfall and decomposition rates for the fringed rhizophora mangle forest lining the Bon Accord Lagoon, Tobago

The mangrove forest that fringes the Bon Accord Lagoon measures 0.8 km(2) and is dominated by red mangrove (Rhizophora mangle). This forest forms the landward boundary of the Buccoo Reef Marine Park in Southwest Tobago, and is part of a mangrove-seagrass-coral reef continuum. Biomass and productivity, as indicated by litterfall rates, were measured in seven 0.01 ha monospecific plots from February 1998 to February 1999, and decomposition rates were determined. Red mangrove above-ground biomass ranged between 2.0 and 25.9 kg (dry wt.) m(-2). Mean biomass was 14.1+/-8.1 kg (dry wt.) m(-2) yielding a standing crop of 11 318+/-6 488 t. Litterfall rate varied spatially and seasonally. It peaked from May to August (4.2-4.3 g dry wt. m(-2) d(-1)) and was lowest from October to December (2.3-2.8 g dry wt. m(-2) d(-1)). Mean annual litterfall rate was 3.4+/-0.9 g dry wt. m(-2) d(-1). Leaf degradation rates ranged from 0.3% loss d(-1) in the upper intertidal zone to 1% loss d(-1) at a lower intertidal site flooded by sewage effluent. Mean degradation rate was 0.4+/-1% loss d(-1) . The swamp produces 2.8 t dry wt. of litterfall and 12 kg dry wt. of decomposed leaf material daily. Biomass and litterfall rates in Bon Accord Lagoon were compared to five similar sites that also participate in the Caribbean Coastal Marine Productivity Programme (CARICOMP). The Bon Accord Lagoon mangrove swamp is a highly productive fringed-forest that contributes to the overall productivity of the mangrove-seagrass-reef complex

The structure and productivity of the Thalassia testudinum community in Bon Accord Lagoon, Tobago

The Thalassia testudinum dominated seagrass community in the Buccoo Reef/ Bon Accord Lagoon Marine Park, measures 0.5 km(2) and is part of a contiguous coral reef, seagrass bed and mangrove swamp system in southwest Tobago. 7 testudinum coverage, productivity and percent turnover rates were measured from February 1998 to February 1999 at four sample locations, while total T. testudinum biomass was measured at two locations in the lagoon from 1992-2002. Productivity and turnover rates varied spatially and seasonally. They were higher in the back-reef area than in the mangrove-fringed lagoon, and were lowest at locations near to a sewage outfall. 7 testudinum coverage ranged from 6.6% in the lagoon to 68.5% in the back-reef area while productivity ranged from 3.9 to 4.9 g dry wt m(-2) d(-1) . Productivity and percentage turnover rates were higher in the dry season (January-June) than in the wet season (July-December). Productivity ranged from 3.0 in the wet season to 5.0 g dry wt m2 d-' in the dry season while percentage turnover rates ranged from 4.2% to 5.6%. Total Thalassia biomass and productivity in Bon Accord Lagoon were compared to six similar sites in the Caribbean that also participate in the Caribbean Coastal Marine Productivity Program (CARICOMP). This seagrass community is being negatively impacted by nutrient-enriched conditions

Acquired cystic disease of kidney in chronic renal failure in jordan.

Acquired cystic disease of the Kidney (ACDK) is a well documented complication of end stage renal failure in patients managed conservatively or supported by dialysis. The aim of the present study is to highlight the scope of the problem among our patients, and to evaluate the clinical characteristics of the disease. A Total of 124 patients with chronic renal failure (106 on dialysis, 18 non-dialyzed) were studied with ultrasonography by the same radiologist. ACDK was defined as the presence of four or more cysts in each kidney. The cysts should have sharp smooth wall with acoustic enhancement. In non-dialyzed patients, 5.5% had ACDK, 33.5% had one to three cysts and 61% had no cysts. Among dialysis patients 42.5% had ACDK, 26% had one to three cysts and 31.1% had no cysts. During of dialysis therapy and age were greater in patients with ACDK (74 +/- 30 months. 58 +/- 3 years respectively) compared to those with no cysts (11 +/- 8 months. 26 +/- 4 years). The major clinical complications were intracystic hemorrhage in three cases and stones in seven cases. No correlation was noted between the presence of cysts and the original kidney disease, gender, hematocrit or adequacy of dialysis. We conclude that, ACDK occurs commonly in patients with chronic renal failure; however, patients are generally older and have been on dialysis longer than patients without cysts. Ultrasound, in the hands of an experienced radiologist, is a relatively adequate screening tool for ACDK and its complications.