Microalgal blooms in a eutrophic estuary (Golden Horn, Sea of Marmara) following a remediation effort

The present work describes microalgal blooms that occurred in a eutrophic estuary (Golden Horn, Sea of Marmara, Turkey) between October 2013 and September 2014 following a remediation effort. The relationships between bloom-forming microalgal species and environmental factors were investigated during the study period. The changing environmental conditions (e.g. increasing water transparency and salinity) after seawater transfer to the Golden Horn Estuary stimulated phytoplankton growth with dense algal blooms. Annual average values of Secchi depth, salinity and dissolved oxygen increased in comparison with those in an earlier study in 2009–2010. Nine microalgal species, which consisted of four diatoms, two dinoflagellates, one cryptophycean, one raphidophycean and one euglenophycean, formed the blooms with water discolorations during spring and summer. The species that reached the highest bloom density were Plagioselmis prolonga (62.4 × 106 cells l−1) among crytophyceans, Heterocapsa triquetra (21.8 × 106 cells l−1) among dinoflagellates and Skeletonema marinoi (39 × 106 cells l−1) among diatoms. The abundance of dinoflagellates and phytoflagellates increased particularly in the upper estuary when compared to diatoms and their rapid growth and bloom formation revealed that they have a wide range of tolerance to changing environmental conditions and a strong ability to compete with other species in this study area.

Subsurface Oil and Waves in The Coastal Zone

Over the last decade, there have been more and more oil spill responses effected by subsurface waves in the coastal zone. These have ranged from oil leaking from sunken ships to heavy oils that have sunk to the bottom. A primary example is the DBL 152 incident on the Gulf of Mexico coast in November, 2006. The incident resulted in approximately 70,000 barrels of Slurry Oil (API 4) being released and sinking to the bottom. Waves played a significant role in the mobilization of the oil on the bottom, in addition to effecting sediment loading in the subsurface, often restricting visibility and making ROV operations difficult. Waves can also play a major role disturbing sunken ships, and evidenced by the SS Jacob Luckenbach, sunken off San Francisco during WWII. The ship was a source of occasional incidents of oiled birds washing ashore after certain winter storms. The oil on the ship was removed as part of a major remediation effort in the summer of 2002.The oil spill response community will be more effective, particularly with subsurface oils, with a better understanding of the role of waves on the mobilization of sediment and other deposited substances (such as subsurface oil). This paper provides an overview of wave mechanics and the implications for subsurface oil movement and spill response activities, using examples from the DBL 152, SS Jacob Luckenbach, and other recent incidents. Shortcomings of current understanding will be highlighted, with suggestions for future research offered.

Estimating changes in river faecal coliform loading using nonparametric multiplicative regression

Faecal coliform (FC) concentration was monitored weekly in the Tangipahoa River over an eight year period. Available USGS discharge and precipitation data were used to construct a nonparametric multiplicative regression (NPMR) model for both forecasting and backcasting of FC density. NPMR backcasting and forecasting of FC allowed for estimation of concentration for any flow regime. During this study a remediation effort was undertaken to improve disinfection systems of contributing municipal waste water treatment plants in the watershed. Time-series analysis of FC concentrations demonstrated a drop in FC levels coinciding with remediation efforts. The NPMR model suggested the reduction in FC levels was not due to climate variance (i.e. discharge and precipitation changes) alone. Use of the NPMR method circumvented the need for construction of a more complex physical watershed model to estimate FC loading in the river. This method can be used to detect and estimate new discharge impacts, or forecast daily FC estimates.

Naval Shipyard Base Realignment and Closure: The Environmental Remediation Effort

Mare Island Naval Shipyard was placed on the "Fast Track" toward military base closure as of October 1993. All ship projects will end by April 1995. The base will close in April 1996. This paper discussesthe cooperative efforts of the Federal, state and local authorities, and the shipyard, to quickly turn over the yard for effective civilian reuse; andthe shipyard effort to train and utilize the existing workforce as a major element in the environmental remediation effort—to both prepare the facility for reuse and to prepare the workforce for reemployment.