Guy Harvey Magazine

WIN 2017

Guy Harvey Magazine is focused on fishing, boating, scuba diving, and marine conservation. Portfolios from the world's best fishing photographers, articles on gear, travel, tournaments, apparel, lifestyle, seafood recipes, sustainable fisheries.

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Page 35 of 83

36 | Oysters require that water be clean (but not lacking in nutrients) as well as having the right salinity, oxygen level, temperatures and the right amount of tidal change. And, to get started, the larval oysters need a hard substrate on which to fix—too much detritus or soft mud is a bad deal for oyster production. Oysters feed by filtering plankton and algae from the surrounding water, ejecting the filtered water back into the sea and beneficially clarifying it in the process. Researchers say a single adult oyster can filter 50 gallons of water in 24 hours, so the effect of large oyster beds on keeping water clear—which, in turn, helps underwater vegetation like turtle grass and eelgrass to grow—can be enormous where they are abundant. Reportedly, Chesapeake Bay's once- flourishing oyster population filtered excess nutrients from the estuary's entire water volume every three to four days at the time the first English settlers arrived. Now, with oyster populations at a fraction of what they were then, it takes a year. Mississippi has experienced an even more dramatic decline in oyster numbers, but not over centuries like the Chesapeake: in 2004, oystermen there harvested over 490,000 sacks of mature oysters. Since then, the resource has endured Hurricane Katrina, the BP oil spill, and the Bonnet Carré Spillway openings (the bypass structure that prevents flooding in New Orleans), which flooded the prime oyster areas with an excess of fresh water. Oysters do best at 15 to 18 ppt of salt in the water, but levels dropped to zero along much of the Louisiana and Mississippi coasts during the flush, according to MDMR. In the 2013–2014 season, oystermen harvested about 70,000 sacks of oysters. The 2014–2015 season was far worse, with production of less than 40,000 sacks. This year, it's expected to be about 35,000 sacks. "The beds were coming back strong and then this summer we had very warm weather and a lot of neap tides, and the dissolved oxygen in the western part of the bay dropped to near zero, so we lost everything that had grown back on that side—it's a process," says Jamie Miller, Executive Director of the Mississippi Department of Marine Resources. The oyster decline is affecting more than just water quality. These rapidly- disappearing creatures are also habitat builders, an important part of the food chain that creates structure and eventually results in thriving populations of spotted seatrout, red drum, sheepshead, flounder and other inshore species. Oysters also provide a lot of space for small critters like crabs and baby fish to hide in the juvenile stages—scientists estimate that fully-developed oyster beds have

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