Preliminary studies on food and feeding habits of Polypterus endlicheri and Polypterus senegalus in Lake Chad

The food and feeding habits of Polyprerus cncllicheri and Polypterus senegalus was carried out in the months of September to October. The food of 33 Polypierus endlicheri as observed include Tilapia species (89.3%), Eutropius niloticus (28.6%), Mayfly nymph (39.3%), Dragon fly larva (56.6%) fish remains (21.4%) and detritus (7.1%). The food of27 Polypterus senegalus as observed include Tilapia sp (88.4%), Eutropius niloticus (27.9%), may fly nymph (23.3%), Dragonfly nymph (34.9%) remains (21.1%) detritus (23.3%). (9 page document) The percentage occurrence of food item found in the stomach of Polypterus endlieheri is 93.3% while that of Polyprerus senegalus is 67.4%. The dominance of Tilapia sp was establish in the study, and there is no significant difference between the feeding habit of Polypterus endlicheri and Polyprerus senegalus.

PICES-GLOBEC International Program on Climate Change and Carrying Capacity: Summary of the 1998 MODEL, MONITOR and REX Workshops, and Task Team Reports.

This volume summarizes the results of three workshops organized by the PICES-GLOBEC Climate Change and Carrying Capacity Program that were held just prior to the PICES Seventh Annual Meeting in Fairbanks, Alaska, in October 1998. These workshops represent the efforts of the REX, MODEL, and MONITOR Task Teams to integrate the results of national GLOBEC and GLOBEC-like programs to arrive at a better understanding of the ways in which climate change affects North Pacific ecosystems. (PDF contains 91 pages)

Cruise report: regional assessment of ecosystem condition and stressor impacts along the northeastern Gulf of Mexico shelf; NOAA Ship Nancy Foster NF-10-09-RACOW (August 13-21, 2010)

This cruise report is a summary of a field survey conducted along the continental shelf of the northeastern Gulf of Mexico (GOM), encompassing 70,062 square kilometers of productive marine habitats located between the Mississippi Delta and Tampa Bay, August 13–21, 2010 on NOAA Ship Nancy Foster Cruise NF-10-09-RACOW. Synoptic sampling of multiple ecological indicators was conducted at each of 50 stations throughout these waters using a random probabilistic sampling design. At each station samples were collected for the analysis of benthic community structure and composition; concentrations of chemical contaminants (metals, pesticides, TPHs, PAHs, PCBs, PBDEs) in sediments and target demersal biota; sediment toxicity; nutrient and chlorophyll levels in the water column; and other basic habitat characteristics such as depth, salinity, temperature, dissolved oxygen, turbidity, pH, CDOM fluorescence, sediment grain size, and organic carbon content. Discrete water samples were collected just below the sea surface, in addition to any deeper subsurface depths where there was an occurrence of suspicious CDOM fluorescence signals, and analyzed for total BTEX/TPH and carcinogenic PAHs using immunoassay test kits. Other indicators of potential value from a human-dimension perspective were also recorded, including presence of any vessels, oil rigs, surface trash, visual oil sheens in sediments or water, marine mammals, or noxious/oily sediment odors. The overall purpose of the survey was to collect data to assess the status of ecosystem condition and potential stressor impacts throughout the region, based on these various indicators and corresponding management thresholds, and to provide this information as a baseline for determining how such conditions may be changing with time. In addition to the original project goals, both the scientific scope and general location of this project are relevant to addressing potential ecological impacts of the Deepwater Horizon oil spill. While sample analysis is still ongoing, a few preliminary results and observations are reported here. A final report will be completed once all data have been processed.

Effect of nitrite, ammonia, and temperature on P. monodon larvae

P. monodon larvae were studied for the effects of temperature, ammonia, and nitrite on survival. Toxicity levels of nitrite were found to vary with larval stage. Larvae could tolerate ammonia up to about 10 ppm, with the effect more clearly shown by the zoea stage. Survival and growth were not significantly affected by temperature, although moulting was enhanced at temperatures higher than 29 C. Larvae of P. monodon have lower tolerance toward nitrite and ammonia compared to postlarvae. Although high survival was obtained at low levels of nitrite and ammonia, it is still necessary to know their effects on metabolism, in order to examine possible biochemical parameters for diagnosing sublethal toxicity or stress.