http:\/\/lenfestocean.org\/sites\/default\/files\/pollution_plume_summary_final.pdf<\/p>\n
Venayagamoorthy, S.K., H. Ku, O.B. Fringer, A. Chiu, R.L. Naylor and J.R. Koseff. 2011. Numerical modeling of
\naquaculture dissolved waste transport in a coastal embayment. Environmental Fluid Mechanics.<\/p>\n
A recent scientific study published in the journal Environmental Fluid Mechanics shows that the location of
\ncoastal and offshore aquaculture pens can dramatically influence the extent to which dissolved fish farm
\nwaste disperses from its source and reaches coastlines. This study is the first detailed look at how real
\nworld factors influence the flow of wastewater from fish farms and provides a further basis for understanding
\nthe impact of aquaculture fish-pens on coastal water quality.<\/p>\n
Marine aquaculture, or fish farming, is viewed as a means to supplement declining wild fisheries and to
\nhelp meet the rising global demand for seafood; however it can cause environmental degradation. For
\nexample, water quality can be significantly impacted because farmed fish excrete much of the nutrients
\ncontained in their feed, including nitrogen and phosphorous. In excess, these nutrients, can trigger
\neutrophication and depleted oxygen levels. Nutrients discharges are a particular concern when fish are
\ngrown in open net pens because nutrient-laden feces, undigested feed, and other fish wastes flow freely
\ninto the surrounding environment, some settling to the bottom and other waste products dissolving into
\nthe water column. The concentrations of dissolved waste from net pens are often assumed to decline
\ncontinuously in all directions as the discharge moves further from the pens, diluting the environmental
\nimpacts as the distance from the pens increases.<\/p>\n
Dr. Venayagamoorthy and colleagues, supported by the Lenfest Ocean Program, explored the influence
\nof local currents and flow conditions on the concentration and dispersal of dissolved wastes from
\nmarine aquaculture net pens. In order to test the assumption that waste products are consistently
\ndiluted as distance from the net pens increases, the scientists developed an idealized computational
\nmodel and performed simulations of dissolved pollutant plumes in variable coastal and offshore marine
\nenvironments. The simulations included representations of the local physical environment (i.e., the
\nshape and depth of the embayment containing the pens), flow conditions (i.e., tides and wind-induced
\ncurrents), and the physical locale of the pens relative to the coasts and freshwater discharges.
\nThe scientists showed that specific flow conditions around the aquaculture pens, such as tidal flow, the
\nearth\u2019s rotation, local river discharges and the drag introduced by the pens, can lead to pockets of
\nconcentrated pollution traveling considerable distances from the source, potentially affecting coastal
\nwaters and the coastlines far from the aquaculture pens themselves.<\/p>\n
The results of this study show that producers, regulators and other stakeholders cannot simply assume
\nthat fish waste discharge will be diluted consistently as it moves away from the net pens, or that dilution
\nis necessarily the solution for aquaculture wastes. Instead, they need to consider how factors such as
\ntides, river outflows, shape of embayments and other factors will influence the concentration and spread
\nof dissolved wastewater plumes. Thus, the effluent model created in this exercise can be a useful tool
\nfor predicting a site\u2019s ability to meet water quality standards before aquaculture facilities are built.<\/p>\n
Lenfest Ocean Program: Protecting Ocean Life Through Marine Science
\nThe Lenfest Ocean Program supports scientific research aimed at forging
\nsolutions to the challenges facing the global marine environment.
\nemail: info@lenfestocean.org <\/p>\n","protected":false},"excerpt":{"rendered":"
http:\/\/lenfestocean.org\/sites\/default\/files\/pollution_plume_summary_final.pdf Venayagamoorthy, S.K., H. Ku, O.B. Fringer, A. Chiu, R.L. Naylor and J.R. Koseff. 2011. Numerical modeling of aquaculture dissolved waste transport in a coastal embayment. Environmental Fluid Mechanics. A recent scientific study published in the journal Environmental Fluid Mechanics shows that the location of coastal and offshore aquaculture pens can dramatically influence the extent … Continue reading Lenfestocean.org: DILUTION CANNOT BE ASSUMED THE SOLUTION FOR AQUACULTURE POLLUTION by S. K. Venayagamoorthy, H.Ku, O.B. Fringer, A. Chiu, R.L. Naylor, & J.R. Koseff<\/span>