Salt Marsh Ponds Research Articles

Waterbird Use of Saltmarsh Ponds Created for Open Marsh Water Management

Open Marsh Water Management (OMWM) as an alternative to pesticides for mosquito control in saltmarshes along the Atlantic Coast has created debate among biologists. We designed an experiment to determine waterbird (American black duck [Anas rubripes] and other waterfowl, wading birds, shorebirds, gulls, and terns) use (during daylight) of ponds created for mosquito control compared with use of preexisting water bodies (i.e., natural tidal ponds, creeks, old ditches) and refuge impoundments. We also evaluated the influence of pond size and depth on waterbird use of wetlands. We documented bird use of different habitats for 1 year

Species Assemblages in Saltmarsh Ponds in Western Iceland in Relation to Environmental Variables

The fauna and flora of 63 saltmarsh ponds in western Iceland were investigated. Forty-five taxa were identified. A DECORANA analysis of presence/absence of species showed salinities to be the chief determinants of species composition. Salinities were highly variable, but minimum salinities appeared to be most critical, although maximum salinities as well as elevation of ponds had additional significant effects. The majority of the species are marine species, most of which are commonly found under fully marine conditions. Minimum salinities experienced can therefore be expected to be particularly critical for such species. Some species were shown to have a distinct modal abundance pattern with the mode at intermediate salinities. Species richness was positively related to salinities. A shift in composition of dominant angiosperms indicating a reduction in salinities had taken place between 1977-78 and 1991. The species composition of the ponds shows similarities to that of estuaries although significant differences can be seen. The species composition also shows similarities to that recorded from saltmarsh ponds in Britain, Netherlands and Germany

White phosphorus poisoning of waterfowl in an Alaskan salt marsh.

The cause of the yearly death of an estimated 1,000 to 2,000 migrating dabbling ducks (Anas spp.) and 10 to 50 swans (Cygnus buccinator and C. columbianus) has remained a mystery for the last ten years in Eagle River Flats (ERF), a 1,000 ha estuarine salt marsh near Anchorage, Alaska, used for artillery training by the U.S. Army. We have gathered evidence that the cause of this mortality is the highly toxic, incendiary munition white phosphorus (P4). The symptoms of poisoning we observed in wild ducks included lethargy, repeated drinking, and head shaking and rolling. Death was preceded by convulsions. Farm-reared mallards dosed with white phosphorus showed nearly identical behavioral symptoms to those of wild ducks that became sick in ERF. White phosphorus does not occur in nature but was found in both the sediments where dabbling ducks and swans feed and in the gizzards of all carcasses collected in ERF. We hypothesize that feeding waterfowl are ingesting small particles of the highly toxic, incendiary munition P4 stored in the bottom anoxic sediments of shallow salt marsh ponds.

Feeding rhythms and food of Penaeus japonicus bate (crustacea, penaeidae) in salt marsh ponds; role of halophilic entomofauna

The feeding habits of Penaeus japonicus in aestival, semi-extensive cultivation, were studied in salt marsh ponds of the French Atlantic Coast. A bi-monthly sampling programme was carried out over 3 months: on each occasion, samples were taken hourly over a 24-h period and the stomach contents of a total of 1191 shrimps were analysed. A shift from continuous to nocturnal feeding occurred during the second month of the rearing period (i.e. between 74 and 97 days after metamorphosis). In semi-extensive shrimp culture (from 10 shrimps m −2 at the beginning to 3.4 shrimps m −2 at harvesting), naturally occurring prey were the largest food source throughout the study, despite a daily supply of pellet food. Shrimps appeared to be opportunistic carnivores since they fed on all the salt marsh fauna, with a preference for halophilic insects, especially chironomids. However, a selection of prey, related to their size, was observed over the rearing period. The choice of prey shifted in the following order: zooplankton and harpacticoids (Day 0-Day 7) — harpacticoids (D 7-D 27) — chironomids (D 27-D 62) — macrobenthos and chironomids (D 62-D 86). Feeding rhythms and food preferences are discussed in relation to data obtained in similar studies.

Saltmarsh ponds—a preferred habitat for magnetotactic bacteria?

Sediment and the overlying water samples were collected from 67 fresh and 38 salt water sites in the UK. Only 13% (five) of the samples taken from salt water sites were negative for magnetotactic bacteria compared with 47·7% (32) of the fresh water ones. Of the seven types of salt water habitats examined, saltmarsh ponds were found to be most suited to magnetotactic bacteria, 96% (25/26) of sites being positive.

δ13C signature of organic carbon in estuarine bottom sediment as an indicator of carbon export from adjacent marshes

The δ13C signature of organic carbon in estuarine bottom sediment in Louisiana Barataria Basin was used for estimating carbon flux from adjacent marsh. The stable carbon isotope composition of plants, soils and sediments from the basin were determined. The δ13C content of marsh vegetation ranged from -26.3 to -27.8% for C3 freshwater vegetation in the upper basin to -13.0 to -13.3% for C4 vegetation in the lower basin. The δ13C content of the highly organic marsh soils were similar to δ13C content of vegetation present. The δ13C content of organic carbon from bottom sediment of open water bodies ranged from 27.3 in the upper basin (freshwater) to 16.4 in bottom sediment of salt marsh ponds. The13C signature of organic carbon in bottom sediment from saline regions corresponded to the size of the body of water. The smaller salt marsh ponds contain sediment with δ13C values close to that of the C4 plantSpartina alterniflora. Results suggest that phytoplankton rather thanSpartina alterniffora is the likely organic source in bottom sediment of the larger bay near the coast (e.g. Caminada Bay).

Laboratory and field evaluations of industrial formulations of Bacillus thuringiensis serovar. israelensis against some mosquito species of central Italy

Two wettable powder formulations (Bactimos and Vectobac) and a flowable concentrate (Teknar) formulation of Bacillus thuringiensis serovar. israelensis were evaluated as larvicides of Culex pipiens, Aedes caspius, and Aedes detritus. In the laboratory, the levels of susceptibility of these species to the test formulations were essentially similar and corresponded to their relative potencies; the LC 90 values ranged from 0.042 to 0.37 ppm. C. pipiens, A. caspius, and A. detritus, in that order, were susceptible to the biocide. Under field conditions in central Italy. Bactimos at 0.5 kg/ha gave 98% control of C. pipiens in an irrigation canal. Teknar at 1.25 liters/ha gave 86–100%, and at 2.5 liters/ha gave 90–100% control of C. pipiens in two natural ponds. Against A. caspius in salt marsh habitats, Bactimos at 0.5 kg/ha and Teknar at 2.5 liters/ha yielded complete control of the larvae, while a lower rate (0.2 kg/ha) of Bactimos, and Vectobac at 0.5 kg/ha resulted in 82–94% and 67–91% control, respectively. Higher rates (0.75 and 1.0 kg/ha) of Vectobac gave 76–100% and 98–100% control of A. caspius. Bactimos at 0.15 kg/ha gave 93–98% control of A. detritus in two salt marsh ponds. B. thuringiensis serovar. israelensis is practically economical for the control of C. pipiens, A. caspius, and A. detritus in the various biotopes in central Italy.

Financial feasibility of high density oyster culture in saltmarsh ponds with artificially prolonged tidal flows

This paper is an economic analysis of an innovative approach to string culture of oysters in Narragansett Bay, R.I. The analysis indicates an internal rate-of-return ranging from 6.8 % to 26.3 % for a larger pond. The internal rate-of-return would be greatly increased if uniform oyster size could be achieved and if the anticipated price premium for quality oysters could be realized.