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Research about Indian River

Source-linked reports with geographic coverage including Indian River.

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Field performance evaluation of a bayluscide 20-percent suspension concentrate formulation

Petromyzon marinus (sea lamprey) is a parasitic, invasive fish of the Laurentian Great Lakes. Since the late 1950s, the Great Lakes Fishery Commission has implemented an integrated Sea Lamprey Control Program (SLCP) that relies on two lampricidal chemicals: 3-(trifluoromethyl)-4-nitrophenol (TFM) and niclosamide. Niclosamide is applied using a bayluscide 20-percent emulsifiable concentrate; however, a solvent in this formulation, N -methyl-2-pyrrolidone, has been linked with worker safety concerns and has contributed to equipment degradation and clogging. To address these limitations, the U.S. Geological Survey, in collaboration with Battelle UK, developed a bayluscide 20-percent suspension concentrate (SC) as a potential alternative formulation. In this study, we evaluated the field performance of SC on the Indian River in Schoolcraft County, Michigan. The objective was to assess the formulation’s compatibility with SLCP application procedures and equipment, and to determine its ability to deliver precise lampricide concentrations in a timely manner. SC was found to dilute easily with stream water and readily combined with TFM. As a result, target lampricide concentrations in the stream were achieved within 1 hour of initiating delivery. Moreover, concentrations remained within 9 percent of target values, with less than 2 percent variation across the width of the stream, demonstrating consistent and uniform distribution. These findings indicate that SC can support accurate and timely lampricide applications. When considered alongside previous research highlighting its favorable selectivity for sea lamprey and improved environmental safety, the results support the pursuit of registration and adoption of SC as a new tool for controlling invasive sea lamprey.

Michigan

Interactions of nutrients, plant growth and herbivory in a mangrove ecosystem

The effect of nutrient enrichment of red mangroves ( Rhizophora mangle ) was studied by comparing two mangrove—covered islands in the Indian River at Ft. Pierce, Florida, USA, one (high nutrient) with and one (low nutrient) without a breeding colony of pelicans and egrets. Repeated measurements taken on > 100 tagged branches in each area revealed higher growth rates at the high nutrient site. Trees at the high nutrient site showed greater additions of (1) leaves; (2) reproductive parts; (3) new lateral branches; and (4) larger increments to existing stems. Growth in the fertilized stand also began earlier in the year and had a second maximum not shared by the low nutrient area. Both leaves and fruits at the high nutrient site were richer in nitrogen. More striking than the effects on plant growth, however, was the proportionately much greater stimulation of herbivory by insects in response to nutrient enrichment. Larvae of the five lepidopteran species that we observed feeding on buds or leaves were either more abundant or only present in the high nutrient area, as was the scolytid beetle that infested seedlings before they dropped from the parent tree. This difference in herbivory between sites disappeared when the birds seasonally migrated away from their nesting areas at the high nutrient site. This observation and the demonstration that the mangrove skipper Phocides pigmalion attains a higher growth efficiency on high nutrient leaves are both consistent with the hypothesis that increased nutritive value of vegetation (correlated with the increased concentration of nitrogen) is responsible for the 4x greater losses to herbivores in the high nutrient. Implications for environmental management and in more complex communities are discussed.

Florida