W&M ScholarWorks
Virginia Marine Resource Bulletin Virginia Sea Grant
Spring 3-1-2000
Marine Resource Bulletin Vol. 32, No. 1
Virginia Sea Grant
Virginia Institute of Marine Science
Follow this and additional works at: https://scholarworks.wm.edu/vimsmrb
Part of the Aquaculture and Fisheries Commons
Recommended Citation Virginia Sea Grant and Virginia Institute of Marine Science, "Marine Resource Bulletin Vol. 32, No. 1" (2000). Virginia Marine Resource Bulletin. 71. https://scholarworks.wm.edu/vimsmrb/71
This Book is brought to you for free and open access by the Virginia Sea Grant at W&M ScholarWorks. It has been accepted for inclusion in Virginia Marine Resource Bulletin by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. RESOURCE BULLETIN
Spotlight on Cobia .
Virginia Sea Grant College Program Virginia Institute of Marine Science College of William and Mary Volume 32 • Number 1 • Spring 2000
Copy of Page 1.max T\.1~s; ~s,s;ue of t\.1~ 15-v.Lleti.vc nLgV!L~(?\.1r::s; the sco-pe of '(ts.wvch (;lv~-Gl s-potLLgVlt CvcltvcvLvcg (;lchvLr::tJ t!AK?.~vo-g -pl!Ace (;It vr MS ovc t\.1e FvvfLs.h, coiJi-C! . T V1e cobi-o \1·/0VR Ls 1-v"--pD'(b? vet fo'( w,CJ V~-!:j vt(;!S.Ovcs. bet Vi 1-vcs.Lc;le !A V'-Gl ou: sLGle tV\e VIM.S COv1AV'A.U~v~t!:j.
OV'v H ere ovc ww.nvzs, tne e>cpeV:.Ls.e of severc.JL rle;JClYtV'VI.evcts. V1rs beevv brousnt tooetV\er, V'VI.OS:: V'-cr::rblv, Adv~sorv sev•;Lce.s, Ft.snevi.es., C-lvcd tV1e AqurcuL- ~ <) u tuve c,evcet i-cs C-lvc-DI r;~eeclLvcg r ecVivccLog!:j c evctev. Tne resuLti-vcg StJ vctYS!:j V\(;ls V'VI.vztuC'LlH bev.e{i.ted tne veservchev.s i-A·;oLverl C-lV'-d ovee~tLv v ~ v 'AcceLev!Aterl cvx , sevevi/!L ves;er vc n i. vvst~ :.v..t es C'vvd s':.!A:es •r~L t Vii-"'- t V!e .Se!A c;vO.V'vt CoLLege 'PYOoYC!V'VI....., Cobi.C' !tws lov,o"-" tJ eevc !A vese'Avc!r, -pv~DYLtt.-1u V~t tn~ V\vc~'JtrsL:~..-~u o-,r .Soutv,evvc- tv'li.ss~ss~-p-p~'s C1v1:lf Co!Ast ~esei:lYcn l rboro.tov·ij C So Lr Ls M•t sv.r-pri.s.LV'-8 tn!A':. dA.ti.V'-g (;! vecevvt. ;tvt.e~z ~vcg tne ~cieCl r>f llC"Li.vvg ti:llt vets !A v'vd ex.-pn t. eV'-ces :n roug \.1 o veg i.o veil l, cco-peve>ti.ve cc fji.fl nrciect s~cv1:L?. .suviV~ce . A D·Ucen::> ~ V'VI.eet~v.. o ':lOS. VieLe! e>t r.:v,e vvovlcl J ~ ~ Aquoculture .Soc~e::tJ vKee:cvvg i.vc New DvLef7.V'-S, chs -pos'.: Feb YuOr tJ llvc-~1, CL rVie bevvefi.ts. rJ v;ovlzL vvg co:::;et V!er- ilve vcot LV'-si.g"'-l,fLc'A"'-:. rnvougn -plClvcV'-Lvcg, ccnvev.. t 'Avvd. fu:vzve -p-1ojects. c!Avc- be :!ALlored. to fLt togetV.ev, :"' cov-A.-plevA.e"'-t ere VI otnev. 1/l "'-d : o (;! :/lvcMce cuv sV!Mec! lzl'\,ov;le?.ge tJos,e Reswvcltl cloLlV~Y.S 'di.lL be s;tvetcV.e?. fuvtllev L"'- :ne precess, CJV'-d vesei:lvcV! resuLts wi.LL be wcove wi.DielCA Clvcrl vo.ni.dl r--1 chssewvLvcr:ed . Pos.ctLve e+-rec'::s v r U ' I vevwL r.:neV'VI.selves Lvc od·m· 'N!A!:jS teo. .sci.ev~-hsts DYe leo vvcL"'-S to toLR to wen ctV\ev ClV'-CI to .s hi:lv~ tnei.v wo v~ for tV!e t:~evcef~t of tne vesouvce. The whoLe i.s, i."'-d eed, greotev tn(:lvc the svzw, of tne -pnvts. AV'od th(;lt, i.t seeV'VI.s, tV1-C!Apsv1:LV!tes wnr.t .SeiA Cjn:l "'-':: does so 'NelL. E!:j ?YO'J~c\Lvvg Cf/'(, uV'VI.bveLLr fo v· veser.vcV! 'i!nLLe r.lLOc'/l"'-0 lV'vdivl-duilL str.'.::es to set -pvo~vC'w, -pv[ovLnes, .sw c,viAv.. t -pvoV'VI.otes {Lex.~bi.l~ ::. tJ (;lvcrl, !A: tne .SO.V'VI.e tt.w,e, s-p~ri.:ecl cco'!Jevr. : ~O"'- . wLtV! such 9. -posLti.ve o-p-pvoDc h IAV'-d. oLi.cvv .,A.tV'-7- of (eSDuvces fvow, vi.vgLvc~Cl, to fv\Lssi.ssL-p-pL, to 1 ex.V!s, tV.e cob~o effovt Ls. sure to V'VI.!ARe grwt stvi.cte.s. 1 Copy of Page 1.max DR. L. DONELSON WRIGHT Dean and Director Virginia Institute of Marine Science School of Marine Science MARINi£ RESOURCE The College of William and Mary DR. WILLIAM RICKARDS Director Virginia Sea Grant College Program BULLETIN DR. WILLIAM D. DUPAUL Director Marine Advisory Program Volume 32 · Number 1 • Spring 2000 SALLY H. MILLS CONTENTS Editor and Graphic Designer All photographs and illustrations within are FEATURES copyrighted. Permission to use art work must be obtained from the originators of the art A Cobia By Any Other Name. .. 2 work. Art on cover by Duane Raver; inside cover and p age 1 I by Kent Forrest; page 16 by Susanna Musick. Maps on pgs. 2 and 13 by Cobia Diet 11 Kay Stubblefield; on page 15 by Jason Romine. Graphs on pgs. 3, 7, 10 by John Olney, Sr; pg. 11 by Mike Arendt. Photograph on pg. 4 by Tagging Efforts Provide Insight 12 Todd Mathes; on pgs. 7, 17-19 by Charlie Petrocci; page 8, by Sharon Miller; page 14 by Cobia in the Bay: A Moving Target? 14 John Olney, Jr.; others by Sally Mills. byjohn Olne~jr. The Virginia Marine Resource Bulletin is a publication of the Marine Advisory Program Th e Old Fish Dock 16 of the Virginia Sea Grant College Program, which is administered by the Virginia Gradu by Charlie Petrocci ate Marine Science Consortium with mem bers at the College of William and Mary, the Old Dominion University, the University of Virginia, and the Virginia Polytechnic Insti OUTREACH & ANNOUNCEMENTS 20 tute and State University. Subscriptions are available without charge upon writteR re quest. Comments and questions abou.i the Bulletin may be directed to the editor at (804) NATURALIST'S CORNER 2 1 684-716 7, or bye-mail to [email protected]. The Bulletin is intended as an open forum for ideas. The views expressed do not imply en dorsement, nor do they necessarily reflect the official position of Sea Grant of the Virginia Institute of Marine Science. Sea Grant is a partnership of university, government, and industry focusing on marine research, edu cation, and advisory service. Nationally, Sea WILLIAM& MARY Grant began in 1966 with passage of the Sea Grant Program and College Act. ~ This work is the result ofresearch supported in part Smlifu.t VIRGINIA INSTITUTE OF MARINE SCIENCE by the NOAA Office ofSe a Grant, U.S. Departmellf Virginia SCHOOL OF MARINE SCIENCE ofCommerce, under Grant No. NA56RGO 14/to the Virginia Graduate Marine Science Consortium and the Virginia Sea Grant College Program. Copy of Page 1.max A Cobia B~ An~ Otber Name ... By Sally Mills Few fish elicit such animated the International Game Fish As its along the U.S. East Coast or reactions among recreational sociation was founded. According about the status of cobia stocks anglers as mention of the elusive to those records, the largest re in the Atlantic and Gulf of cobia. Known here in the states corded fish was caught in Shark Mexico. Ongoing research funded as crab-eater, lemonfish, and ling, Bay, Australia in 1985, and by Sea Grant and VIMS contin across the globe cobia (Racby weighed 135 lbs., 9 oz. T he larg ues to fill in the gaps. cmtron canadum) are commonly re est recorded catch in Virginia oc ferred to as sergeant fish or king curred near Mobjack Bay in 1980 A fish proftle fish. Regional nomenclature aside, and weighed in at 103 lbs., 8 oz. The cobia is an elongated fish, the excitement of the pursuit is Cobia represent the single with a pronounced dorsal fin pre of universal appeal to anglers species of the fa m ily Rachy ceded by a series of single, sharp who've tried their hand at cobia centridae, but are believed to be spines. It has a slightly depressed fishing. It is the fighting nature of closely related to the dolphinfishes head and extended lower jaw. Its their personality that has propelled (Corypbaena spp.). The fish are mouth is large and wide; its eyes, the cobia to popularity, especially found in temperate zones world small. With its small, plate-like among tournament fishers along wide from Indo-Pacific waters to teeth, it clamps down wi th ex the Gulf and Florida coasts. the southern Atlantic Ocean. Un tremely powerful jaws that will Worldwide cobia citations date til recently, little was known about quickly crush a crab or draw an back to the year 1939, the year that their life history or migration hab- angler's blood. A fast-growing Cobia Distribution Worldwide 2 •!• Virginia Marine Resource Bulletin Copy of Page 1.max ber of Virginia cita ot far away in the Mindanao tions are awarded, region of the Philippines, juvenile and recent years have cobia are being grown in cages in produced record a promising aquaculture venture numbers of large fish under development by the Pili (see graph). Though pi no-Taiwanese governments. they tend to move According to the trade newspa ab out as individuals per, "Fish Farming International," and occasion ally in about 150 tons of whole fish av small pods of two or eraging 6 kg were marketed in three, cobia appear to 1998 in Japan. The fish fetched favor structures such prices between $4.80 and $5.70 a as pilings and wrecks kg (which translates to $2.20 to and choose to con- $2.60 a pound). Success in grow gregate in the shade ing cobia out to 6-10 kg (13.2-22 Cobia being measured by Mike Oesterling of these settings. lbs.)over a period of just 12 to 18 Cobia are good months is attracting the attention fish, adults frequently reach 110 tasting fish, with firm white meat of a growing number of private em FL (fork length) by the end similar in flavor to wahoo. The investors, who are now looking to o f the second year, and can grow fish is eaten around the world, and expand their export markets. to 2 meters (or 6.6 feet) FL at ma is especially popular in Pakistan, In the United States, landings turity. The cobia's black-brown T aiwan, India, Australia, and are a bit easier to come by, but dorsal side and creamy-white ven throughout the Philippines. compiled for com mercial fishers tral side are complemented in Worldwide data are scant, but sev only. That is because of the na juveniles by two bands of white eral sources cite Pakistan as the ture of the recreational fishery. that run the full length of the fish, leader in annual landings. Charter boats going out for other from snout to tail, and are easily observed shimmering in the wa 700 ~------, ter. The bands disappear in older 600 fish. Cobia forage on bottom VIRGINIA SALTWATER FISHING dwelling (demersal) prey-prima TOURNAMENT Volume 32, Number 1 •!• Spring 2000 •!• 3 Copy of Page 1.max spec1es often come back with cobia on board, but the COMMERCIAL LANDINGS OF COBIA information is hard to track Along the Atlantic & Gulf Coasts because success is highly 800.000 variable. Recreational catch 700.000 is speculated to b e much r---- •Pounds greater than commercial 800.000 r---- ~ Dollars harvests, however. In Vir ginia, for example, the Ma 500.000 rine Resources Commission calculates that commercial 400.000 f- f- landings from haul seines 300.000 r-:: f- f- f- f- and pound nets comprise less than 4% of total land 200.000 f- f- f- ings. Virtually all of the cobia activity comes from 100.000 f- recreational fishers on char- lL[(c- ter trips and party boats and fishing from piers and jet- ues. Commercial data compiled by ued at $613,242, or $1.87 per available, ex-vessel commercial the National Marine Fisheries Ser pound. That comp ares to a $.48 landings dro pped to 11 ,710 vice for the Gulf and Atlantic per pound value in 1981. pounds (1997) and climbed coasts show a steady increase in Virginia-specific data reveal slightly to 13,419 pounds in 1998. both weight and value of cobia mixed results in landings since Landings data aside, little was landings over the period 1981 to 1950. After a relatively healthy known about the nature of the 1998. The ex-vessel, or dockside, supply during the 1950s and early cobia stock in Virginia, and re numbers in 1998 were totaled for ' 60s, landings plummeted searchers at the Institute launched the region at 327,448 pounds val- throughout most of the next two a series of focused studies aimed d ecades. The at building a more detailed com past ten years posite. Because it is a fast grower have witnessed with worldwide distribution and higher landings appeal, it has piqued the interest in general, and of several scientists here as a during 1995 and potential aquaculture species. 1996, landings reached 22,011 Aquaculture beginnings and 20,796 In the early '90s, a pair of cobia pounds respec was introduced into the VIMS tively-the high aquarium. Within months, the fish est numbers had nearly doubled in size, and since 1963. D ur they continued to grow steadily. ing the las t two They appeared to be hearty and Cobia often associate with sharks and rays and years for which quite adaptable to their captive resemble the sharksucker (genus Remora). numbe rs are environment. 4 •:• Virginia Marine Resource Bulletin Copy of Page 1.max A few bells started to go off Once sex has been de among not-so-casual observers. termined via a biopsy, Would the fish make a suitable females that are close to candidate for the marine finfish spawning will be encour aquaculture movement under way aged to do so in captivity. at the Institute? If so, how could Other females, less ready brood stock be obtained? How to spawn, will be held in should the fish be handled and tanks and fed prey based how could they best be kept alive? upon natural foods, includ Among the many conversa ing squid and capelin. Fe tions that ensued, it became clear males will be given a hor that any cobia research would rely monal implant to acceler heavily upon Virginia watermen as ate gametogenesis (th e a reliable provider of brood stock. onset of reproduction) and maintained for several weeks until spawning oc curs. Oesterling notes that Researcher Jef(Tellock examines the ideal capture this year copepod culture (abo ve), a potential would involve one ripe fe food source for cobia larvae. male for every two males. Here, he works with assistant John Anywhere from 5 to 20 Olney, J1: (left) at the cobia tank. specimens would be used be moved in coolers if available, to accommodate vary or buckets and ing stages of spawning readiness placed in a holding among the captures. tank back at the In stitute. In years two The next step and three, managers If spawning is successful, eggs will Haul seine and pound net fishers targeted slightly larger fish, and be moved to the larval facility on were contacted for potential in adapted their transport scheme campus and the captured fish, re terest in the project, and a timeline accordingly. This coming season, leased back into the wild. The ul for learning how to manage and in late May/ early June, research timate objective is the production raise the fish was established. ers will attempt to rear the largest of cobia larvae raised to finger According to Mike Oesterling, specimens ever: 20- to 30- pound ling size that can eventually be chief architect of the cobia cul fish. To accomplish this, they will returned to a culture system for ture project, the underlying goal use research vessels to meet the further grow-out. The final des has been to move forward incre fi shers on site, trans fer the fish to tination and size of captive fish mentally while learning all that we a holding tank on the vessel, and depends entirely upon planned could about the fish along the way. return them to the aquaculture lab. use: fi ngerlings would be held in During the first year, researchers These larger fish will initially be a flow-through system until they went after young-of-the-year fish, placed in a flow-through system become young juveniles (in cobia, a mere 6-10" long, in an attempt that more closely mimics their about 3 months) and potentially, to learn how to handle, transport, natural environment and therefore released into the wild in early fall and care for them. That proved reduces stress, and later transferred to enhance existing stocks; larger straightforward, since they could to a 7,500-gallon holding tank. specimens raised to become food Volume 32, Number 1 •!• Spring 2000 •!• 5 Copy of Page 1.max fish would be grown out in a re circulating system for a year or Cobiq Reseqt-ch in the GulF longer. The ideal size for this, ac cording to Oesterling, is about five As <1 biologist working 6 •!• Virginia Marine Resource Bulletin Copy of Page 1.max ecology. They were assisted in this a maximum length of 160 em and effort by a handful of individuals weigh t of 37 kg, while males throughout the lower Chesapeake reached a maximum length of 130 Bay: Captain Jim Jenrette from em and weight of 20 kg (see Cape Charles, D onnie Wallace in graph). Males from their sample Foxhill; Jimmy Lewjs 1n did not reach trophy size, which Gloucester Point, and over 100 an was, at the time, 45 lbs. for a cita glers who responded to local ads. tion issued by the Virginia Saltwa What Denny has discovered ter Fishing Tournament. Also, fe in her work with Dr. Olney is of males outnumbered males by a interest to cobia fishers in Virginia ratio of 2:1 during the sampling and throughout the southeast. By period. examining growth rings in cobia otoliths, scientists h:we aged all of Reproduc tive status the fish sampled at 12 years and Another strand of the project in under. In their survey of more volved examining the gonads of than 500 fish over two fishing sea mature cobia to gain an under Heavy -weight rods are a necessity when .fishing for cobia. sons, Olney's team confirmed that standing of their reproductive sta females grow both faster and big tus while in the Chesapeake Bay. Cobia ecology ger than their male counterparts. Through histological analysis of Understanding more about the They found that females attained oocytes (developing female repro- ecology of the cobia is critical to the success of ongoing work in the VARIATIONS IN COBIA WEIGHT & LENGTH aquaculture lab. And ob taining specimens for such 40 research happens where • Females the action is - at the dock 0 Males at Wallace's Bait & Tackle 30 in Foxhill, Virginia. Dur n= 362 • c:n ing the summers of 1996 -Jl: • and 1997, Susan D enny -.c.. 20 and assistants from the c:n VIMS Department of ~ Fisheries Science exam ..ii 10 ined cobia specimens from ...0 recreational fishers as they came off their boats. Spe 0 -. Legal size cifically, they collected 37'" TL otoliths (ear bones) and gonads (sex organs) from 0 20 40 60 80 100 120 140 160 180 fresh cobia in order to conduct histological analy- Total Length (em) ses to learn more about growth and reproductive Volume 32, Number 1 ·:· Spring 2000 ·:· 7 Copy of Page 1.max ductive cells), Olney and others characterized as large, at 1.1-1.5 ing phase. These fish are of suf learned that females are reproduc mm in diameter. ote the large, ficient size to be taken, however, tively active while in the bay and dark oil globule in each egg yolk and therein lies the rub. It is hy spawn here during several events in the micrograph shown b elow. pothesized that these large, highly -as many as six to eight. It is this oil globule that renders fecund females are targeted by Concurrent with this work, the eggs buoyant in the water recreational fishers in the lower the research team was involved in column. Several larvae were also bay as the fish begin to migrate delineating spawning grounds at captured, but only at offshore sta off the Virginia coast. But other the bay's entrance, where a plume tions. than citation records, little data created by fast-moving currents exist on the recreational aspect of appears to be a favored spot for Management implications Virginia's cobia fishery. ripe females to feed. Using two At this point in time, the rate at research vessels to conduct which anglers remove reproduc Estimating fishing effort ichthyoplankton surveys during tively-active cobia from the In order to get at that informa the summers of 1996 and 1997, population is not known. Young tion, Olney's team devised a clever females (3-5 years) that have plan to estimate recreational pres sp awned remain in the Ch esa sure on cobia stocks. They con peake during the summer months ducted a series of fly-overs in the and have the capacity to reach 37 lower bay and, through low-level inches (the current minimum size flight, were able to identify the limit for taking) by September, trademarks of cobia fishers in when they begin to move out of known "hotspots." Signs such as the region - some to southern lo chumming, anchoring, using bait cations and others, to deeper wa slicks and heavy-weight rods, for A bongo frame holding two nets is ters off the coast. At about this example, indicate cobia fishing pulled behind the research vessel to same time, an unknown percent on board. Working in tandem wi th capture cobia eggs. age of even younger females ( <3 the fly-over is a research vessel D enny collected cobia eggs in the years) has reached sexual maturity performing "ground-truthing." lower bay and offshore. The pro but not yet gone through a spawn- Researchers on the vessel move cedure uses a "b ongo frame" holding two extremely fine itex nets, dragged behind a vessel mov This collapsed follicle indicates ing at very slow speed. At pre rece/11 spawning: specimen was collected in early swnme1: scribed intervals, the net is pulled up, washed down, and the con The fertilized eggs shown he/ow were tents are removed to a seive for captured in a plankton net. Large oil globules (dark spots) in the eggs render subsequent p reservation and them buoyant in the water column. study. The nets move throughout the .water column, capturing eggs at varying depths. Cobia eggs were in fact caught Micrograph Above: This photograph of a microscopic in plankton nets throughout the slide depicts oocytes in a gonad, obtained through entire study period (mid-June histological preparation ofa thi11 section ofovary. through mid-August) at both in Micrographs courtesy of the shore and offshore stations and Department ofFish eries Science. 8 •!• Virginia Marine Resource Bulletin Copy of Page 1.max Sr. and John Hoenig de COBIA SPAWNING GROUNDS veloped models relating cobia growth and egg in the Lower Chesapeake Bay production to fishing mortality (based upon fishing effort) at two dif ferent size restrictions. T he model shown on page 10 is complex, and best explained by Dr. Olney: "Egg production per recruit is a declining function of fishing mor .,,;" tality. The trade-off be , / tween egg production I • I Bluefish I and yield can be visual I ------..... Rock . ' I ' ized by plotting egg pro ' \ '', \ ' \ duction per recruit ' ' \ • . I against yield per recruit ' 700-1 700-11 I I I Going from left to right, I General Area I each point on the curve I of Spawning I I represents a level of I I fishing mortality (F). I I • • I Each curve pertains to 650-1 650-11 I a particular size regula- \ ' ..... , ______tion. In the absence of fishing (when yield per Key: recruit is zero), egg pro • duction per recruit is • = VIM$ Sampling Station 640-11 ~~' maximaL Thus, each curve in the example has the same origin. "If we compare two throughout a designated area and tures footage of cobia activity at types of fishing with different size interview fishers about what they the dock, and by follow-up phone regulations, we can conclude that are catching, the number of co calls with anglers participating in o ne is uniformly superior to an bia on board, how many hours the survey. other if, for any level of yield, the they've been at it, and other data The cumulative knowledge one provides greater egg produc that can be used to construct a gained from these studies and sur tion than the other; likewise, for dearer picture of fishing effort. veys provides a qualified basis any level of egg production, that Fishing effort is further docu upon which to estimate fishing ef one provides higher yield than the mented by information collected fort and think about ap-propriate other. from a video-camera placed at management responses. Building "In the case of cobia," Dr. Wallace's Bait & Tackle that cap- on these data, D rs. John Olney, Olney notes, "our modeling re- Volume 32, Number 1 •!• Spring 2000 •!• 9 Copy of Page 1.max veals that when fishing mortality Directed Fishing Effort on Cobia, 1998 is low, a smaller minimum size 1600 provides a higher egg production 1600 for a given level of harvest per re 1400 cruit. However, when fishing Boat Hours= 7,786 (area under the curve) (/) 1200 mortality is high, the situation ...... ::J reverses. When F is high, the 0 1000 I larger minimum size is beneficial 800 ctl -0 because it conserves egg produc f1) 600 tion and produces a greater yield 400 (see pointsZ Y & ). In other words, at high fishing mortality, 200 the larger minimum size provides 0 140 a higher egg production and a 160 180 200 220 240 higher yield for a given level of Julian Day fishing effort. The product ofthe instantaneous counts (boats obsel"l'ed perjly-o>'er) is an estimate ofseasonalfishing effort. represented here as the area under the cun·e. "We conclude that if we can Julian Day= numerical ordering of365 -day year: June I =Julian Day /52. be certain that fishing mortality on cobia will be kept low, then the smaller minimum size, currently per recruit. However, if one be efforts to monitor the cobia fish 37 inches, will provide a higher lieves that the fishing mortality ery in Chesapeake Bay, there are yield than the 44-inch minimum may be or become large, then the no current estimates of fishing size, while maintaining a reason higher minimum size is safer." mortality. We do not know what ably high level of egg production Since there are no ongoing F is for cobia stocks. Thus, a pas sive management strategy, such as raising the minimum size, could 12 ~------. protect our stocks if F is high. Current Levels of Fishing Mortality In considering a higher mini - 10 ...... ~ are Unknown mum size restriction, Olney and Hoenig add an important caveat: COST 8 "Since cobia are a highly migra I I tory species that travel along the ...... I I Q) 6 I I entire southeastern coast and a. I I c throughout the Gulf of Mex.ico, 0 ~ Current :;::; () 4 I minimum size any attempts to impose size restric ::J I "0e tions in Virginia must be accom 0... 2 minimum size panied by equal restrictions in other 0) 0) coastal states along their migration w path in order to be effective." 0+-----.-----.---~.----,----~~---r-----r--~ 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 Harvest per Recruit (kg) fn g raphing egg production against yield, or harvest. per recruit, a model ojjishing mortality can be established. Based on this model, when fishing mortality becomes high. the higher minimum size is safet: 10 •!• Virginia Marine Resource Bul letin Copy of Page 1.max Cobia Diet In an analysis of stomach contents of cobia captured in the lower Chesapeake Bay in 1997, graduate student Mike Arendt uncovered some interesting data that underscores the variability of results observed thus far on the species. Arendt examined the stomach con tents of 114 cobia collected at weigh stations and tournaments. Of the total collected, 78 stomachs contai ned identifi able, non-bait prey items. In contrast to results from prior stud ies that examined the cobia's diet, A rendt found the following: + As many as 28 different species were consumed by the cobia examined, but swimming crabs domi nated the diet; + Swimming crabs dominated the diet of all sized cobia in the sample, by both number and volume (vs. an earlier study that found finfish to be the dominant prey item in the largest size class examined, which was 115-153 em FL); + Pipefish and seahorses appeared important only in the diet of smaller cobia (vs. their importance to all sizes examined in a study conducted in orth Carolina waters); and + Cownose rays, previously unseen in the cobia diet, were observed in sampled cobia Monthly Comparison of the Index of Relative greater than 100 em FL. Importance (iri) for Major Prey Groups (I) u 1: t~"' ou.. 7000 I r------~-.~c 6000 ->< 5000 (I)~ 4000 Percent Volumetric Contribution of Major Prey -~ > ; ~ 3000 Groups for Overall Sample (N=78) Jaw Volume only I Gi + 2000 O::z 1000 0~ •Blue crab )(~ 0 (I) - D lady crab "0 - -- • Other Invertebrates = • Flatfish 0 Pipefish/Seahorse • Cownose ray 121 Other Finfish 57% Volume 32, Number 1 ·:· Spring 2000 ·:· 11 Copy of Page 1.max ging Efforts ProviDe Insight By Sally Mills & Jon Lucy Inherent to any fisheries opment Fund, administered by will illuminate the data shown management plan is a basic under the Virginia Marine Resources here. Of the fish recaptured one standing about species growth and Commission. The study set out time (single recaptures), two gen reproduction, diet, habitat needs, to identify migratory habits of co eral trends were seen: and migration. In the case of bia along the East Coast, through + Larger fish caught initially in the cobia, very little was known about a well-publicized tagging effort by lower Chesapeake Bay near the such behaviors or habitat needs; trained recreational fishers. Bay Bridge-Tunnel in early to mid yet a growing number of citations Tagging of cobia has occurred summer were most often recap were being awarded for large fish every year since, and has received tured within the lower bay at or taken during the Virginia Saltwa strong support from the Marine near the same tagging site the fol ter Fishing Tournament. Advisory Services D epartment at lowing year. One fish returned two In fact, little time had b een VIMS and the Virginia Sea Grant consecutive years. Same season invested in studying cobia since College Program. Money from recaptures inside the bay indicate the early research performed by the fund has been used primarily cobia both staying at release sites C. E . Richards at VIMS in the late to purchase tagging equipm ent, and moving significant distances. '60s. Richards tagged 16 cobia in conduct training workshops for + Small (<14") fish caught in the the Chesapeake Bay during 1967 volunteer fishers, and compile Elizabeth River in the "hot ditch" and 1968, with six returns. Three study results. Claude Bain with the area near the Virginia Power plant returns were recorded between Virginia Saltwater Fishing Tourna and close to the Intracoastal Wa one and five years after tagging, ment and Jon Lucy with Marine terway tended to stay in the area within 32 nautical miles from the Advisory Services at VIMS co-di for significant time periods. Re release site. Cobia that returned rect the project and act as princi cap tured in the same vicinity from during the same year of tagging pal investigators, while graduate between 8 to 37 days later, these were recovered between 12 and 36 student Michael Arendt assists fish probably over-wintered here nautical miles from the release site. with special tagging studies, data (from ovember to perhaps as The information suggests that a validation, and report writing. late as April) before moving far distinct, repetitive, summer habi Results to date are presented ther north into the bay. tation occurs and that the cobia in the adjacent chart. Since 1995, Of fish caught on more than in the Chesapeake Bay may be a 362 cobia have been tagged off one occasion (multiple recaptures), distinct group or sub-population. the Virginia coast, producing 48 a few theories can be offered: The question lingers. Faced recaptures (a 13% return rate). + Several individuals were recap with no contemporary informa The recapture rate indicates good tured in or very near to the same tion about cobia movement in the tag retention in fish and, most location year after year. These oc Chesapeake, a tagging study was importantly, suggests that tagging currences suggest the importance initiated in 1995 through the Vir (and the hook and release that ac of certain areas in the bay for con ginia Game Fish Tagging P ro companies it) does not interfere gregating fish - either for eating gram, with support from the Vir with fish behavior or health. or spawrung reasons. ginia Recreational Fishing Devel- A few anecdotal observations + D ata demonstrate that spawn- 12 •!• Virginia Marine Resource Bulletin Copy of Page 1.max ing-sized females are returning That information is key to identi ferred to many other marine spe annually to the lower Chesapeake fying essential fish habitat - infor cies that m ight warrant a need for Bay, and that the same fish is ca mation that gets incorporated into study- often at moment's notice. pable of returning again and again. management plans. Jon Lucy adds, Such has been the case on several + Data also demonstrate that the "Fishers can help us by writing occasions with large, unpredicted catch and release process does not down the tag number, estimating puppy drum migrations in the bay. harm the fish; multiple recaptures the size of the fish, and then re As Claude Bain is quick to and recaptures of deeply hooked leasing it. Tag numbers can be point out, it is this team of volun fish clearly substantiate this fact. called in to (757) 491-5160." teers, approximately 140-strong in A secondary b enefit that, un Virginia, who deserves great credit The cobia tagging program is til now, has been somewhat over for the success of the program. beneficial for many reasons. First looked is the opportunity realized "The sportfishermen do this on and fo remost, it provides much by having a trained cadre of fish their own. They donate their time needed information about a ers equipped with tagging devices on the water, their fuel, and attend poorly understood marine species. along Virginia's coastline. Once workshop s regularly to stay up on When multiple recaptures are this group has mastered proper the latest tag retention studies. We made, we get unique information handling and tagging procedures, could not do this work without about fish movement over time. those skills can be readily trans- them," he emphasized. ~: white boxes =fish recaptured at site of initial release shaded boxes = fish not recaptured at site of initi al release LOWER Back R. = off Back River CHESAPEAKE BFR = Bluefish Rock CBBT =Ches. Bay Bridge-Tunnel BAY IMG = Inner Middle Ground Shoal Lat Shl = Latimer Shoal YSL York Spit Light, shoal area off York River mouth = RECAPTURED ONE YEAR white triangle = hot ditch area, power plant outfall (N=6 FISH) IMG 6/96 - Back R. 6/97 (365 d) IMG 6/98 • Back R. 6/99 (354 d) IMG 6/98 • YSL 6/99 (359 d) IMG 6/98 • YSL 6/99 (366 d) IMG 6/97 • Lat Shl 8/98 (415 d) IMG 7/98 • Lat Shl 7/99 (359 d) RECAPTURED ONE TO TWO YEARS LATER (N = 2 FISH) IMG 6/96 · IMG 7/97 (371 d) (same fish) - IMG 6198 (359 d) IMG 7197 · IMG 6/99 (718 d) SOUTHERN RECAPTURES (N=4 FISH) ONE MONTH TO FOUR YEARS LATER BFR 7195 S. Oregon lnl., NC 6/99 (1428 d) IMG 9/96 • Hatteras , NC 10 /96 (38 d) CBBT 9196 • Frisco , NC 10/96 (47 d) IMG 6/98 - Jacksonville, FL 4/99 (316 d) Source: Data compiled and analyzed by Michael D. Arendt. Volume 32, Number 1 •!· Spring 2000 •!• 13 Copy of Page 1.max Cobia in tbe Ba~: A Moving Target? By John Olney, Jr. As one of the two largest game "The cobia are caught in good Cobia hotspots fish entering the Chesapeake Bay, numbers to the Bay Bridge-Tun The most popular fishing lo the cobia predictably draws a great nel and the eastern shore later in cations for cobia in the early sum deal of interest from local the summer, though they tend to mer months are York Spit, the sportfishers. Often growing to a be a smaller class of fi sh." D avid Bluefish Rock and Poquoson Flats length of 50 inches and weighing goes on to say that in his experi area, and off of Hampton Roads. anywhere from 10 to 100 pounds, ence it's best to always have your Later, much of the fi shing pres the cobia by all reasonable esti tackle thoroughly prepared, and to sure is diverted toward the east mates is one of, if not the, pre g rind your own chum, so you ern shore and the Bridge-Tunnel mier sportfish in the Chesapeake know exactly what you are fishing fishing areas, but these haven't al Bay. Available in sizable numbers with. ways been the preferred spots. for only a few months in the sum "Man, most people just don't mer, it's re puted as a bullish know how much work it is to keep fighter, and at times can be an everything up to date. The fish awfully elusive creature. It's a fish ing is one thing, but all the work that people brag about when they to g(!t to the fishing stage is some catch one, and it's a fi sh that thing else altogether,"a he dds. people tend to tell exaggerated It may be a lot of work, but stories abou t when they lose one. whatever D avid does seems to be Cobia season in Virginia usu effective. In 1995, he and his fi sh ally begins in late May as the fi sh ing parties caught 106 cobia (in a are migrating into the bay to season that usually doesn't last 100 spawn. Chumming with ground days), and in 1996, he and his bud bunker (menhaden) is the favorite dies caught 92. local method in the early months Later in the season, in July and of the season, accompanied by live August, "running the buoys" is a Cobia anglers David Hogge (R) and Timmy Brown proudly display their catch. eel or spot as preferred bait. popular fi shing method in which "You wouldn't think it, but fishers cruise from inlet buoy to If you could step back in time usually the best cobia fishing starts inlet buoy (hoping to spot a cobia and ask a bay fisherman of the on the western shore of the bay hanging underneath a surface 1960s where the best location for first, not the eastern sh ore - structure) and toss a live bait, or a cobia in the Chesapeake Bay was, places off the beach at Buckroe, bucktail to entice it. Cobia, as a you may be surprised by his an York Spit, and Bluefish Rock are general rule, are often closely as swer. Of course it wasn't the Bay usually where they show up first," sociated with a structure, whether Bridge-T unnel (constructio n says David Hogge, a long-time it is a floating buoy or a wreck on wasn't even finished until 1964), recreational cobia fisherman from the bottom; this is especially ap but it also wasn't the normally pro Gloucester. parent after spawning season. ductive places like Latimer Shoals, 14 •!• Virginia Marine Resource Bulletin Copy of Page 1.max quite different for this area of the bay. From 1995-1999, only three citation-sized cobia were reported here, and the question is, why don't the fish go north anymore? Surely, the fishers in Hampton and Poquoson don't seem to mind the shift in cobia traffic, but finding an answer to the question is not easy. Ideas floating among the rec reational angling community in clude: an unexplained change in fish behavior, changes in available habitat, or even changes in angler behavior. But with little to no data to support the change, it's cur rently anyone's guess. • QUICK FACTS • • The current h Volume 32, Number 1 •!• Spring 2000 •!• 15 Copy of Page 1.max Tbe olo Fisb Dock By Charlie Petrocci A s you walk across the dock, boom sways precariously over the ages, and where crusaders, pirates, old boards groan under each step. water's edge. H ere there are no and revolutionaries boarded ships Various sized fish scales of un computers, fax machines, or even to meet their destinies. known species cling to the boards co nveyor belts to carry fish It was from docks that explor like barnacles on a jetty. Calico shoreside. This is a fish dock that ers exposed a known world to the colored cats sit lazily in your path has remained timeless in an indus expanses of an unknown world. and make little or no effort to get try whose time demands constant D ocks were the launch pads of out of your way. And they seem change. exploration for 12 centuries. They I to peer at you from every nook, Most docks around Virginia were also the hotbeds of com fish box, and shelf that lines the today are used for commercial merce and crime, and home to the bordering, rusting wall. In the fi shing, for family sport fishing, or ill-reputed members of society. background, gulls scream and simply to tie up a pleasure craft. Docks felt the winds of trade and voices carrying distinct accents of But if we take a closer look, such the despair of war and coloniza past generations drift through the docks have served as a critical tion. It was upon their boards that air. Wooden benches, an old scale, backdrop to our cultural heritage sailors brought messages from and a couple of cleaning/ culling for centuries. They have played an around the world. Here the out tables line your passage to a small impor tant role in both creating comes of distant battles were read office and retail market. An out history and developing interna aloud to the waiting masses and dated winch, complete with tional geo-political positioning. the names of ships lost at sea an wooden block and tackle, are the For it was from docks that kings nounced. In America, they con only signs of anything resembling stepped ashore to new lan ds, trolled a new colony's wealth and high technology found here. Its where diplomats left for long voy- her destiny. 16 ·:· Virginia Marine Resource Bulletin Copy of Page 1.max Across docks lining Virginia's waterfront traveled tobacco, lumber, animal skins, seafood, and the intrepid adven turer seeking a new place to call home. Today, only seafood still travels across their ancient boards. Most of the old docks are gone, but the hand ful still dotting historic shorelines evoke to the imaginative the sights and sounds of a by-gone era. DL Edgerton's Located on the water The oldfish dock. DL Edgerton, has served the historic seafood town of Chincoteague since 1928. front of the historic sea- food town of Chincoteague Is to reminisce, to share stories, and reminisces, "We had a lot of land, Virginia, sits an old-time fish to watch for each day's catch. They pound netters fishing around dock, known as DL Edgerton's. sit with wrinkled eyelids; the lines these waters years ago, and they Edgerton's fish dock is probably on their faces reveal the harshness would come in with their catch not unlike very many other fish of years gone by. They do not standing knee-deep in fish inside docks found along the Mid-Atlan forget the dock and the safe ha those open boats. You would also tic. It buys fish, packs and co ven it represented during their see wood boxes, each holding a packs fish, sells ice, and has a small glory years as fishermen. hundred pounds of fish, piled retail market. It closes by 4 o'clock "D onnie E dgerton bought high on this dock. And then the each day. Edgerton's has seen its this old dock in 1960," says man old fish mongers who would come share of gill-netters, draggers, ager William Lee Moore. He will to get their share and peddle fish monitors, bateaus, Jersey skiffs, probably be the last to own it in a in the streets of the island and in scows, and deadrises. long line of previous owners. the small towns on the mainland." The dock has been warmed by "We don't see much of Mr. "I've seen draggers tied up to thousands of sunrises, felt the tugs Edgerton, as he lives across the this dock six boats deep and three of countless tides, and supported Chesapeake Bay in Virginia Beach, across," says waterman J ohn the weight of hundred s of so he lets me run it as I see fit. Moncheitti. Moncheitti proudly watermen and millions of fish . I've been working o n this dock for tells me he has been landing fish Though its claim to history is not 47 years now and I suspect I won't on this dock " ... since 1949, when noteworthy, it represents an era of leave until the day I die," says I moved down here from ew tough men in wooden boats - a Moore. The fish dock opened in Jersey to take advantage of the cultural centerpiece symbolizing 1928, mostly taking in ~sh such as good mackerel fishing in those the independent waterman. It mackerel and oysters and selling days. My father was a fisherman, continues to attract active ice from the adjacent ice plant, so after the war I followed in his watermen as well as those who stuck on one end of the building. footsteps." have now retired, who come daily Herman Whealton, a regular, He adds, "In the early days, I Volume 32, Number 1 •!• Spring 2000 •!• 17 Copy of Page 1.max had a dragger. We also had a lot handles fish on a seasonal basis. son of a waterman, he recalls the of draggers come to this dock Shark, striped bass, trout, and past with a twinkle in his eye. "I from Hampton and orth Caro flounder are off-loaded in the started by helping my father sell lina. They would follow the fish spring; spot, croaker, bluefish, and mullet in the morning out of a fish migrations and markets. We tar Spanish mackerel in the summer; cart. We'd drive along the street geted mackerel, flounder, and trout, rockfish, kingfish, and tuna and occasionally stop and blow a bluefish back then. But as soon as in the fall; and in winter, mostly horn to let people know we were shrimp were being caught down shellfish such as oysters, although in the neighborhood with fresh south the southern boys would clams are taken year round. fish. I also remember when stur disappear. Then we had the fish "We shuck about a 1,000 gal geon were heaved upon this dock ery to ourselves." lons of oysters a year, but we only and roe spilled between the cracks Today's boats (mostly small employ three guys for that," adds in the boards. Most of the stur scows and 30- to 40-foot gill Moore. Recently spot and croaker geon went to ew York or Philly netters) leave at daybreak and re have been the steady money fish and we got five dollars a pound turn by one or two o'clock. "We for local watermen. There are also for the roe in those days, darn have about ten gill-netters work a couple of lobster boats working good money. I've also seen over a ing out of here and about ten out of Chincoteague that use the thousand boxes of mackerel on clammers who work on and off," dock to take on ice, off-load, and this dock and black drum piled up says dock foreman, Frank Reed. pack the catch for markets in like cordwood. I fished a 28-ft. "We pack out about 60 boxes of Washington, D.C., and Jessup, Jersey skiff in those days. The fish a day here now, a far cry from Maryland. These boats are fishing work was hard but the experience the days when this dock moved the southern range of the lobster was worth it." thousands of pounds of fish a grounds so their catches are mod Woose has fished from fas day." erate compared to those working sachusetts to Florida and pio Like most fish docks, Edger northern harvest areas. neered the original offshore deep ton's is open year round and "At one time this fish dock water fishing for red snapper out employed 15 workers," reports of Moorhead City, orth Caro waterman Bill Booth. "There were lina, 50 years ago. Today he still three men who did nothing all day wades for clams from his little but make boxes. ow only two skiff, using hand-sewn moccasins full-time men work the dock and on his feet to deflect the inevitable one or two seasonal helpers," he nicks and cuts that come with the added. job. And he still runs occasional wreck-fishing charters on his Lloyd "Woose" Reed larger deadrise boat, the Pine Cove, Known to everybody at the dock for his "old regular customers." simply as "Woose," Lloyd Reed at Woose is a colorful character and 92 is the oldest waterman who an important part of the cultural fishes out of Edgerton's and pos fabric that makes this old dock a sibly the oldest waterman who local landmark. fishes along the entire mid-Atlan tic coast. Though he can't recall Chincoteague where he got his nickname, he Chincoteague I sland has long Dock foreman Frank Reed unloads does remember the days gone by been synonymous with seafood, a catch ji"Oin a local g i/1-nettet: at the old fish dock. The son of a especially clams and oysters. As a 18 •!• Virginia Marine Resou rce Bulletin Copy of Page 1.max lamps first settled it in a number of 'well-to-do' seasonal 1672. Their only commu home owners who call ahead nication with the "main from, say, Washington and put in land" was made possible a big order for various types of by boat. In 1922 that all cleaned fish. I assume they use it changed when a causeway to entertain guests, since some of and bridge were built out these people have been doing it to the island. ow Chinc for years." Chincoteague also oteague is a popular tour prides itself on a number of sea ist destination with over food restaurants, and the better 400,000 visitors each year. establishments will also order But sacrificed in its fresh fish from the dock twice a zeal to embrace the week. But most of the fish ends tourism rush were up in ew York, Maryland, Phila the old fish docks delphia, and D.C. his hand-sewn mocassins and oyster shucking "We also get a number of guys houses that o nce who are 'hucksters' and sell fish matter of fact, its lined the water by the side of the road up and oysters were once front. Motels, con down the E astern Shore," adds considered the dominiums, and dock manager Moore. "aristocrats" of all town-houses h ave the nation's oysters, second onl y now replaced them. The few fish The future? to the famous Blue Points of ew docks left on the island are barely Retired watermen still return to York. Seafood was the main oc hanging on. old fish docks to see what the cupation of the island during Edgerton's is one that appears, younger guys are catching and to those years. It has been feeding for now, to be hanging on. In ad twist old stories that have been re seafood in to northern markets dition to packing out each day's told for generations. They are part since well before the Civil War. It catch, DL Edgerton's also has a of Virginia's living cultural heri is because of the lucrative connec modest down-home style retail tage, as are the deadrise boats, the tion with the north, no doubt, that fish market. Because Chinco weathered scows, and the well Chincoteague was the only town teague is a tourist town now, the worn gill-netters that leave each in Virginia to side with the Union fish market draws newcomers and dawn and return like clockwork. at the outbreak of the Civil War. seasoned visitors alike. J ulie Clammers and netters work along (Locals may have realized early on Ohylski of Baltimore tells me, side the occasional lobster boat, that Richmond was not going to "Whenever we come down here still claiming these docks their consume a lot of clams and oysters). on vacation, we like to stop by the home. And visitors get a chance Straddling the Atlantic Ocean fish market to see what they have to see a part of the past that is between Ocean City, Maryland, available. I get a kick out of walk still alive, because these men, this and Virginia Beach, Virginia, ing across these old boards. My place, and the old fish dock busi Chincoteague Island sits on the husband buys fish bait here and ness is an importan t part of the Eastern Shore, tucked behind the kids love to see the watermen Eastern Shore-and American Assateague Island National Sea walk around in their slickers. It's cultural mosaic. T heir stories, and shore Park. Fishermen and farm become part of our vacation ex the docks that breed them, are ers who lived in crude log cabins perience every year here." pieces of history surely worth and used sea clamshells as fish oiJ Frank Reed adds, "We also get holding onto. Volume 32, Number 1 ·:· Spring 2000 •:• 19 Copy of Page 1.max Folks at Virginia Sea Grant spent countless hours culling A new study underway in the Marine Advisory Program through the stack of proposals submitted in response to is looking at ways to reduce impacts to the horseshoe the Fishery Resource Grant Program (FRCP) announcement. crab (Limuius po!Jphm1is) - a preferred bait in widespread The idea behind the grant program originated within the use among conch pot fishers. The objective of the study fishing industry, and funds were secured through the Vir is to determine if reducing the amount of bait placed in ginia legislature. According to marine business specialist a mesh bag will affect the number of conch caught per Tom Murray, who acts as field manager for the FRGP, trap. It is hypothesized that, if scavenger animals are "The program solicits ideas that arise from a fisher's actual kept away from the bait through the use of mesh bags, harvesting experience. Modeled after a similar program less bait will be needed and the bait used will continue to in North Carolina, the FRGP is based on the simple attract conch during the full time that traps are in the approach that experienced fishers come up with ideas to water. Whole crabs have been tested against crab halves, improve their productivity or reduce costs every day. But cut and placed in the mesh bags. One whole female or typically, attempting such an idea or change entails a cash two whole males were used as the control groups for the outlay that is too big a risk for an individual fisherman to first experiment. justify, particularly if any benefits of the idea would also Preliminary results from the first experiment site, be realized by his competition." The FRGP funds such conducted 35 miles off Cape Henry, Virginia, in 24.4 to associated costs, with the belief that what benefits one 30.4 m of water, indicate no significant difference in catch member will eventually improve productivity through =350) between using a whole female or two whole out the industry. males (which is standard commercial practice) versus a "Getting the program underway has been a great half-female or rwo halves of male crabs per bag. Results success and Sea Grant is pleased to be involved," stated from other resource areas in Virginia are currently being Bill Rickards, director of the Virginia Sea Gr~nt College evaluated to explore the potential of reducing the amount Program. "The FRGP is similar to many functions rou of bait used to one-third or one-fourth of a horseshoe tinely handled by Sea Grant and, as such, we are uniquely crab per pot. positioned to route the funds and get them quickly into the hands of watermen who will use them judiciously." Among the ideas chosen for funding this year were proposals to: 0 Explore the viability of soft clam culture and, in Teachers from 5th grade through high school are invited so doing, compare the grow-out success of soft clams in to apply for a course entitled "Floyd and the Flood," to trays deployed in open water versus those placed in a be held at East Carolina University in Greenville, North land-based alternative; Carolina. The course is being coordinated by the Sea D Compare oyster seed growth rates using a float Grant programs in North Carolina and Virginia and other ing upweller system to growth rates achieved through a partners. traditional fl oat/ Following the model of the 1999 Mid-Atlantic re bag system; and gion Operation Pathfinder / COAST course, participants 0 Employ will take part in field and classroom activities that the use of deck include current scientific research and technology. Course mats and trip dates are June 26-29, with a follow-up session on Octo lines for more ber 7, 2000. Participants will be chosen through a com efficient culling petitive process, and will receive one graduate credit upon and unloading completion, from North Carolina State University. Tu of oyster seed ition and expenses will be paid for by course sponsors. from boats. The application deadline is May 1, 2000. For informa Linda Vigliotta from Ward Oyster Company at the site ofa project tion, go on-line to http:/ /www.vims.edu/adv/ mamea. designed to compare two methods ofsoft clam culwre. 20 ·:· Virginia Marine Resource Bulletin Copy of Page 1.max N~'4 ~------ Late March in a salt marsh... Spring appears to have taken a temporary pause in Virginia after a cold snap that snuffed the flowering life out of our daffodils and violets. And so it presented an opportune time to visit a salt marsh and catch an early peak at what's beginning to stir. As anticipated, marshland along the lower Chesapeake is only now beginning to green up. Familiar cordgrasses- big and saltmarsh-are just now breaking ground with new shoots that have reached a mere 3 or 4 inches. No eelgrass is evident in the shallows yet; instead, the charcoal hues of water and muddy shore lines prevail. Immediately beyond the lowest elevations, in the fastlands that soon will be home to thick tangles of saltmeadow hay and saltbush shrubs, are even fewer signs of life today. The stark, brittle branches of groundsel trees hold their form against the chilling winds off the water. At first blush, nothing appears to be happening here. A closer view of the ground, however, reveals mo.re. Scattered among the new growth at the water's edge in the intertidal zone is a healthy community of marsh periwinkle. No larger than three-quarters of an inch across, the snail sheDs can be distinguished from similar-looking saltwater molluscs by rows of tiny red dots aligning each ridge of the shell. Inside, a set of antennae withdraws quickly upon my inspection. The periwinkles share this marsh with a large assemblage of Atlantic ribbed mussels, burrowed in the mud and often found in groups of 2 or 3. About half of each elongated, brown shell remains under the surface, and what juts out is tightly closed during this low tide. Each is firmly embed ded and not about to give up its hold to gentle prying. Clumps of byssal threads looking like fine strands of grass spill out of its shell and attach to roots in the mud. Filtering more than a gallon of water hourly when submersed, the mussels thrive on organic matter and diatoms washing over them during the incoming tide. This salt marsh will soon be in full swing. Over the next month or so, adult blue crabs will emerge from their wintering grounds in the deep mud of the bay bottom and use the underwater grasses adjacent to the marsh to molt. Marsh and fiddler crabs will fmd shelter in the protective cordgrasses here, and scuffie about with their young. Mating horseshoe crabs will make calcu lated trips with the high, spring tides to the farthest edge of the intertidal zone to lay and fertilize their eggs away from vigilant predators. Great blue and green-backed herons will soon wade in these shallows, feeding on young fish and assorted burrowing invertebrates. The occasional red winged blackbird will perch upon a wax myrtle for a spell, before moving farther upriver. And with each incoming tide, waves of nutrients will flush over the ground and be takeJl up by await ing filter feeders. This generous buffet"'of "Vegetation pulsing with coastal life will perform its cleansing and nursery duti~ (or yet another year, without fanfare and at no expense. all these fo«es take hold, how v, .-, the ospreys flying overhead each day with young ti~ in talons will seJVe as tcblindets tl1at spring ha.s, indeed, arrived. Copy of Page 1.max Copy of Page 1.max