TheBack Pa 



"The Back Page" is an update on Sea 

 Grant activities— on research, marine 

 education and advisory services. It's also 

 a good place to find out about meetings, 

 workshops and new publications. For 

 more information on any of the projects 

 described, contact the Sea Grant offices in 

 Raleigh (919/737-2454). For copies of pub- 

 lications, write UNC Sea Grant, Box 8605, 

 NCSU, Raleigh, N.C. 27695-8605. 



In late March, Sea Grant 

 agent Jim Bahen and Var- 

 namtown netmaker Steve 

 Parrish tested four turtle ex- 

 cluder device designs at 

 the U.S. Navy's David Taylor 

 Research Center in Bethesda, Md. 



The TEDs were tested in the Navy's 

 flume tank, a long trough that circulates 

 water. The Navy uses the tank to test ship 

 hull and submarine designs. Bahen and 

 Parrish were using the tank to see how 

 TEDs worked underwater and to deter- 

 mine how shrimp loss could be minimized. 

 The project was funded by the National 

 Marine Fisheries Service. 



Parrish had built scaled-down versions 

 of four TEDs: the Georgia Jumper with an 

 accelerator, a modified Matagorda TED, 

 the original Parrish TED and a modified 

 Parrish TED with an accelerator. 



NMFS had approved the use of the ac- 

 celerators, funnels made of webbing that 

 increase the speed at which shrimp pass 

 through the main body of the net to the 

 tailbag. It was believed that accelerators 

 shot shrimp past the TED opening created 

 to extrude turtles. 



Many Florida shrimpers had been in- 

 stalling the accelerators in their nets and 

 claimed they reduced the loss. 



The duo worked with Cliff Goudey, a 

 marine engineering specialist of the Mas- 

 sachusetts Institute of Technology Sea 

 Grant College Program, and a New 

 England netmaker to run the tests and 

 exchange ideas. 



"We learned a lot," Bahen says. "We 

 learned some techniques for fine-tuning 

 the [excluder] opening and ways to mini- 

 mize loss." 



For bottom-extruding excluders, Bahen 

 and Parrish found that floats need to be 

 added to the headrope to lift the tailbag 

 and extruder opening off the bottom. This 

 change could make for an easier escape 

 by the cumbersome sea turtles. 



And, they found that exit holes could be 

 sewn tighter to reduce shrimp loss but still 

 allow turtles to exit. 



Overall, Bahen and Parrish observed 

 that top-extruding TEDs allowed too much 

 shrimp loss. The force of water that swept 

 across the top of the net gapes open the 

 extruder hole, permitting shrimp to escape. 



Now Bahen and Parrish will make some 

 modifications in the TED designs to test 

 this summer aboard The Georgia Bulldog, 

 a boat operated by the Georgia Sea Grant 

 College Program. 



The National Marine 

 Fisheries Service's Beaufort 

 Laboratory is conducting 

 research on sea turtles, 

 and they need your help. 

 NMFS has distributed 

 posters requesting beachgoers to report 

 any sea turtle sightings. The posters con- 

 tain pads of removable postcards for 

 noting the date, location and species of 

 turtle you see, whether the turtle was alive 

 or dead, and whether it had been tagged. 



If you're at the coast, look for the 

 posters in the N.C. Aquariums, the N.C. 

 Maritime Museum, dive shops, fish houses 

 and bait and tackle shops. 



Six species of Atlantic sea turtles are en- 

 dangered. They include the Kemp's ridley, 

 leatherback, hawksbill, olive ridley and the 

 Florida breeding population of green sea 

 turtles. All but the olive ridley have been 

 spotted in North Carolina waters. 



But the role of North Carolina's waters in 

 sea turtle ecology is poorly understood. 

 The NMFS project to obtain data on sea 

 turtles here began in 1988. They want to 

 know what turtle species inhabit Tar Heel 

 waters and where they are commonly found. 



If you see one of the NMFS posters, be 

 sure to take one of the postcards. And if 

 you see a sea turtle, dead or alive, and 

 don't have one of the data cards, make 



some notes about the sighting, then call 

 the NMFS Sea Turtle Project Coordinator 

 at 919/728-3595. 



If it's May, fishermen 

 must be shedding blue 

 crabs in coastal North 

 Carolina. May is the month 

 when virtually all blue 

 crabs slip out of their hard 

 exoskeleton. For a few hours, the crab be- 

 comes entirely soft and edible when cooked. 



Blue crabs shed their shells to grow, but 

 females must molt to mate. Females only 

 reach sexual maturity during the last molt 

 of their life. It's this mating response that 

 makes soft crabs so numerous in May, espe- 

 cially around the full moon, crabbers say. 



First the males shed in late April or early 

 May. Then the females molt one to two 

 weeks later, and the pair mates. If all goes 

 as scheduled, the female carries the re- 

 sulting eggs during the summer and 

 releases them near the inlets in the early fall. 



But some crabs don't adhere to the 

 schedule. They mate later during the sum- 

 mer. Then, the female often carries the 

 eggs throughout the fall and winter until 

 the next spring before releasing them. 



Although May is usually the month 

 when shedding is at its peak, Mother 

 Nature can rush the schedule if the 

 weather warms earlier. And molting usually 

 peaks a week to 10 days earlier in the 

 southern and central coastal areas, says 

 Wayne Wescott, a Sea Grant Marine Ad- 

 visory Service agent. 



But no matter when North Carolina 

 crabs shed, they are always ahead of their 

 northern neighbors in the Chesapeake. 

 And this affords crabbers a top-dollar 

 value for their soft crabs. 



North Carolina crabbers also get the 

 jump on another soft crab market— the 

 one for "roaches." Small soft-shell crabs 

 from V/2 to 3 inches wide are called 

 roaches, and they are used in an exclusive 

 hors d'oeuvres market in the North. 



Crabbers find these roaches, also called 

 "walk-ins," in their unbaited peeler pots 

 during the very first days of spring. After 

 crabbers shed the small crabs, they ship 

 continued on next page 



