Outdoors

Outdoors column: Upwelling along Grand Strand gives chill

jblackmon@thesunnews.com

On the afternoon of July 11, local angler Matt Conrad was combing the beach from the Pier at Garden City southward to Pawleys Island looking for bait aboard Reel Dirty, a 27-foot Regulator.

Conrad and crew found only one school of menhaden off Pawleys Island and didn't catch any kings or Spanish that day, but he did notice something unusual.

The water temperature along the entire stretch was in the 75-76 degree range, right in the middle of one of the hottest summers in memory. Mere days earlier the beach water temperature had been in the lower-to-mid 80s.

“We saw nothing and caught nothing,” recalled Conrad. “Once back in (Murrells Inlet), the water (temperature) was 85-86 degrees. It was around 100 degrees (air temperature) that day.”

With little fanfare, the Myrtle Beach area experienced an upwelling event from about July 11-13.

Upwelling is an interesting but harmless phenomena that occasionally occurs in coastal waters when winds persist in the same direction for a prolonged period, pushing away warm surface water and pulling cooler, deeper water to the surface.

Westerly winds during the recent hot weather pushed the balmy surface water in place along the beach offshore toward the east, allowing deeper, cooler water to rotate up and settle in.

In late June, the water temperature was in the mid-80s, but dropped to the lower-80s by July 4. A week later it had cooled to the upper 70s, even the mid-70s, as Conrad experienced.

“It was (a cool down of) at least five degrees but it didn't last long,” said Sandy LaCorte, a meteorologist with the National Weather Service in Wilmington. “It wasn't substantial but it was enough to notice.”

The upwelling occurred in various locations along the Southeast coast, especially on east-facing beaches, LaCorte said. A surface water temperature as low as 72 degrees was recorded in St. Augustine, Fla.

Based on data provided by water data stations present at three Myrtle Beach area piers (2nd Ave., Apache, Cherry Grove), Dr. Susan Libes, Professor of Marine Science and Chemistry at Coastal Carolina University, detected solid signs of upwelling.

“We did pick up a period of low bottom (temperatures) that coincided with a somewhat low (dissolved oxygen),” said Libes. “The relatively high salinities (recorded) are suggestive of the presence of a marine water mass close to shore as compared with the usual coastal waters that have lower salinity due to the influence of land-based runoff.

“This closer approach of the marine waters to our coast is mostly seen in the summer, probably due to the seasonal occurrence of the wind-driven upwelling.”

Within a few days, the ocean water temperatures returned to a more normal 82-83 degrees.

Now, it's back to the Dog Days of Summer. As of Thursday afternoon at 2nd Ave. Pier, the most east-facing of the three piers with data stations, the surface water temperature had returned to a reading of 86.6 degrees at 2:15 p.m.

Pier Data Stations

Libes, who is also Director of the Waccamaw Watershed Academy, keeps tabs on near-shore water conditions - especially for signs of hypoxia events - through data provided by the sensors located on the three piers - 2nd Ave., Apache and Cherry Grove.

The substantial data provided by the sensors is available online, but the website has changed.

To access the data, go to http://www.sutronwin.com/sutron/. Then click on the menu icon on the top left of the page, click on custom reports and then Long Bay Hypoxia Monitoring Consortium to get started.

Student Angler League Tournament Trail

Registration is open for the middle school and high school tournament trail, dubbed SALTT. The trail targets red drum in saltwater and bass in freshwater and will kick off this fall.

For more information, visit www.salttfishing.com.

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