Ill 



expanded to shelf-wide cruises in subsequent years during critical periods of hypoxic water mass 

 formation, during the summer when strongest, and during breakup. 



Question #7: Variation Due to Storm Effects - What is the role of hurricanes on the biology of the 

 shelf? 



Background : Hurricanes have a frequent and drastic effect on the shelf, stirring up pollutants, 

 restructuring the ecosystem, distributing water masses, and causing enormous exchanges of shelf and 

 estuarine waters in short time periods. Important questions are: How deep into the water column and 

 into the sediments does mixing occur? What is a hurricane's effect on hypoxia? How long does it take 

 for recovery after storms? How significant is organism burial or removal? 



Approach : Opportunistic sampling just before and after hurricanes, that "hitchhike" onto existing efforts 

 by other parts of the study. 



3.1.5 Biological - Physical Studies Linkages 



Whether biological processes are being influenced by the river plume at the eastern edge of the TEXLA region 

 or by decaying rings at the western edge, it is critical to the success of a process oriented study that biological- 

 physical links be as well understood as possible. The existence of separate physical and biological components 

 is unfortunate in that such separation discourages the needed coordination. So that the ecological utility of 

 physical oceanography results be maximized, it is necessary for the following coordination to be undertaken. 



3.1.6 Field Sampling 



• Spatial Coverage - conduct about 10 regional scale surveys annually on a 'regular' grid, with special 

 emphasis on coastal boundary layers, riverine and oceanographic fronts, and upwelling, with the below 

 parameters measured continuously while underway between stations. Extended scale information can 

 be obtained through the use of remote sensing (visual and thermal, image, retrospective analysis) to 

 follow, for example, eddies and cross shelf features. 



light measurements - measure insolation/total photosynthetically active radiation (PAR), split into 



upwelled and downwelled components of PAR; 



micronutrient distributions, including urea and dissolved inorganic nitrogen (DIN), silicate, 



phosphate with a sampling resolution possible for every 15 minutes while underway and vertically 



at about 12 depths per station; 



general parameters - measure temperature, salinity, nutrients, light transmission, and pigments 



continuously while underway during all biological data collecting surveys; 



particle flux - sediment trap measurement concurrently with current meter moorings of the Physical 



Oceanography Program to quantify the flux of sinking particulate matter across the shelf, including 



particulate organic carbon (POC), particulate organic nitrogen (PON), and pigments. 



3.1.7 Coordinating Analysis 



Large MMS and similar studies have a history of fragmenting during the final analysis phase to the extent that 

 very little effort goes into seeking linkages among system components. This must be avoided if a process 

 oriented study is to be successful. Therefore, the analyses of the physical and biological components must be 

 linked in the following manner: 



• integrate the biological modeling with physical modeling, i.e., at gridded, vertically resolved simulations 

 of long-term circulations and associated parameters of biological importance (>10 years); 



• using both system state estimates and transport information, estimate the flux of N from the system 

 through their transport off the shelf, through denitrification and burial. 



