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CRD 04-13 Ninth Flatfish Biology Conference, December 1-2, 2004, Water's Edge Resort, Westbrook, Connecticut Abstracts - Oral Presentations
Session I	9:00 a.m.
Movement of Yellowtail Flounder: A Cooperative Tagging Study Steve Cadrin1, Azure Westwood1, Larry Alade1, Nathan Keith1, Rodney Rountree2, Dave Martins2, Ross Kessler2, Darin Jones2, April Valliere3, Jeremy King4, John Boardman4, Heath Stone5, and New England Fishermen 1NMFS/NEFSC/Woods Hole Laboratory, 166 Water Street, Woods Hole, MA 02543 2School for Marine Science and Technology, 706 Rodney French Boulevard, New Bedford, MA 02744-1221 3Rhode Island Division of Fish and Wildlife, 3 Fort Wetherill Road, Jamestown, RI 02935 4Massachusetts Division of Marine Fisheries, 50A Portside Drive, Pocasset, MA 0255 5Canada Department of Fisheries and Oceans, 531 Brandy Cove Road, St. Andrews, New Brunswick E5B 2L9 During 2003 and 2004, New England fishermen and fishery scientists collaborated to tag approximately 25,000 yellowtail flounder (Limanda ferruginea) in the Gulf of Maine, Cape Cod, Georges Bank, southern New England and mid-Atlantic areas using conventional disc tags and data-storage tags.  The principle objectives were to 1) estimate movement among stocks, 2) determine fishing mortality rates within stock areas, and 3) assess growth.  The project coordinates several concurrent field studies with a common tagging protocol, a single experimental design and tag return system as well as comprehensive outreach efforts.  The study was planned to reduce uncertainty in yellowtail flounder stock assessments, thereby improving fishery management.  Preliminary results indicate frequent movements within stock areas, and infrequent movements among stocks.  Data-storage tags indicate distinct off-bottom behavior, typically in evening hours, lasting an average of about four hours.  The frequency of off-bottom movements does not appear to vary seasonally, but vertical movements are more frequent on Georges Bank than on the Cape Cod grounds.  Further details on the project design and results are available online at cooperative-tagging.org.
Session I	9:20 a.m.
Variation in Growth of Juvenile Plaice on a British Nursery Beach: How Homogenous are Flatfish Habitats at Small Temporal and Spatial Scales? Benjamin J. Ciotti and Timothy E. Targett University of Delaware, College of Marine Studies, Lewes, DE 19958 Although there is evidence of a link between growth rate and survival through the ‘critical’ nursery stage, it is uncertain which environmental factors control growth in juvenile plaice (Pleuronectes platessa).  It is often assumed that temperature alone dictates growth rate and that prey is not limiting.  However, previous studies have taken measurements at scales that may be inappropriate to link growth with environmental factors, such as benthic prey communities, that vary over smaller spatial and temporal scales.  Evidence of site fidelity in juvenile plaice suggests that finer resolution growth measurements are required to understand the link between growth of juvenile plaice and such features of the nursery environment. We are using RNA:DNA ratio-based growth indices to examine small-scale variation in individual growth of juvenile plaice collected from a single Scottish nursery beach. Growth rate (estimated from RNA:DNA) and diet characteristics (prey-type, gut fullness)  were quantified and related to environmental features of the nursery environment measured at the time of sampling.  Comparisons were made between variations over smaller (100’s of meters, days) and larger (500’s of meters, weeks) spatial and temporal scales using a fully nested, orthogonal design. Measuring variability in the growth of juvenile plaice over these small spatial and temporal scales and testing the degree of habitat heterogeneity allows a) an evaluation of the occurrence of prey limitation, b) an understanding of the potential importance of growth heterogeneity for overall nursery productivity, and c) development of more powerful predictive relationships between growth and features of the nursery habitat.
Session I	9:40 a.m.
Annual Movement-Site Fidelity Patterns of Summer Flounder within Virginia and from State to Mid-Atlantic Waters (2000-2004) Jon A. Lucy1 and Claude M. Bain III2 1College of William and Mary, Virginia Institute of Marine Science, PO Box 1346, Gloucester Point, VA 23062 2Virginia Saltwater Fishing Tournament, Virginia Marine Resources Commission, 681 Oriole Drive, Virginia Beach, VA 23451 Summer flounder, Paralichthys dentatus, is consistently among the top-ranked fish targeted by Virginia’s recreational and commercial fisheries. Using trained anglers, the Virginia Game Fish Tagging Program (VGFTP) began tagging flounder in spring 2000. Through 2004 over 20,000 flounder (279-559 mm TL) have been tagged using Hallprint T-bar tags (65 mm streamer). Since 2002, recapture rates remained around 9 %; 1-1.5% of recaptures occurred the year following initial tagging. Within-year recaptures were largely concentrated at Chesapeake Bay structure sites (piers, bridges, tunnels, jetties), however, during cooler months, flounder consistently moved out of the bay and onto the continental shelf. During subsequent spring months, fish moved back inshore into the bay, but also to beaches, sounds, and inlets from New York to the NC/SC border. Single and multiple recaptures of fish demonstrated flounder seasonally remaining 2-15 weeks around structure sites and certain inlets where first tagged. Patterns were consistent year- to-year for fish tagged during both early and mid summer periods. Recaptures documented some instances of year-to-year site fidelity for certain Chesapeake Bay sites and Virginia coastal inlets. Results significantly expand upon, and provide stronger support for, inshore-offshore and coastal dispersal patterns observed by VIMS flounder tagging studies conducted during 1987-89 and 1995-96. Multiple recaptures of flounder over periods of weeks to months at certain structure sites in Chesapeake Bay, coupled with year-to-year returns, indicate the importance of such sites as annual foraging areas. Equally important, the tagging program provides hard evidence to anglers that their efforts to carefully release sub-legal flounder result in more catches, both short-term (later during the same season), and long-term (bigger fish 1-2 years later).
Session I	10:00 a.m.
Resource Partitioning Between Four Species of Flounder in Narragansett Bay Kathryn Banahan University of Rhode Island, School of Oceanography, Narragansett, RI 02882 In this study, we investigated the diets of four species of flounder in Narragansett Bay: summer flounder (Paralichthys dentatus), winter flounder (Pseudopleuronectes americanus), fourspot flounder (Paralichthys oblongus), and windowpane flounder (Scophthalmus aquosus).  These four species are abundant in Narragansett Bay throughout the summer months and are therefore likely to be important components of the benthic food web.  Living in the same region, these flounder share the same resources and may therefore directly compete.  We investigated whether the four flounder species partition the resources by means of their diets and spatial area.  Flounder were collected at weekly intervals at two stations in the bay from June to August of 2004.  Stomach contents were sorted to the lowest taxonomic level, counted, and weighed.  While there was some prey overlap, diet composition analysis by weight showed that each species of flounder had a different prey preference.  The dominant prey categories in summer flounder were fish and mantis shrimp, winter flounder preferred worms and amphipods, fourspot flounder ate squid, and windowpane flounder ate mostly Crangon.  The only significant prey overlap between summer, fourspot, and windowpane flounder was Crangon, however, the high abundance of this prey in the summer makes competition unlikely.  The diet of summer flounder varied between stations, reflecting prey available at each location; in contrast, the winter flounder diet was the same at both stations.  Fourspot and windowpane flounder were not collected at the mid bay site, therefore their diets were not analyzed by location.
Session II	10:40 a.m.
Winter Flounder (Pseudopleuronectes americanus) Spawning and Early Life History in the New York and New Jersey Harbor Estuary Jenine Gallo1, Ron Pinzon1, John Duschang2, and Matthew J. Rattenberg2 1US Army Corps of Engineers-New York District, New York, NY 10278-0900 2Lawler, Matusky and Skelly Engineers, Pearl River, NY 10965 Winter flounder (Pseudopleuronectes americanus) populations along the Atlantic coast of the United States have declined over the last decade.  Overfishing, mortality from water withdrawals and degradation of essential spawning and nursery habitat are a few of the factors thought to have contributed to this decline.  Coastal estuaries along the Eastern United States provide spawning and nursery habitat for winter flounder.  To better understand how winter flounder use large coastal estuaries and local habitats, adult- and early-life stages of winter flounder were collected over two spawning seasons in the New York and New Jersey Harbor through trawl and epibenthic sled surveys. Bottom habitat was characterized at each sampling location.  Winter flounder were found throughout the Harbor; however adult abundance, sex ratios and egg and larval densities differed considerably among areas. Results suggest that spawning areas may be spatially separated within the estuary, likely resulting from local habitat conditions. Furthermore, spawning and nursery habitat were spatially separated suggesting that larvae migrate between spawning and nursery areas. These results parallel recent contributions to the literature that suggest that winter flounder spawn in the lower reaches of harbors and major coastal tributaries, while nursery areas occur well within the estuaries.
Session II	11:00 a.m.
Acute and Chronic Stress in Juvenile Summer Flounder Paralichthys dentatus: Effects on Plasma Cortisol Concentrations and Growth Steven Gavlik1 and Jennifer L. Specker2 1UMass-Dartmouth, Biology Department, N. Dartmouth, MA 02747 2University of Rhode Island, Graduate School of Oceanography, Narragansett, RI 02882 The summer flounder (Paralichthys dentatus) is a marine flatfish in the early stages of commercial aquaculture. However, little is known about the physiological stress response to common culture practices such as handling and crowding during size grading--a technique that reduces cannibalism. To investigate the stress response, we first used an injection of porcine ACTH1-24 to describe the magnitude and duration of the plasma cortisol (CORT) response in juvenile summer flounder. Injection of ACTH1-24 significantly elevated CORT levels (28.1 ± 4.3 ng/ml versus 0.9 ± 0.4 ng/ml in uninjected controls) within 4 h and CORT levels returned to baseline by 24 h. This information was used to design short-term experiments that tested the hypothesis that handling and crowding would increase plasma CORT concentrations. Flounder resting CORT levels were normally low (<10 ng/ml, and typically ~1-3 ng/ml), and comparable to other sedentary species. Overall, the flounder CORT response to handling and crowding (for 1 or 4 h) was variable in both magnitude (range: 4-22 ng/ml) and duration, returning to baseline within 24 h in 1 of 3 instances. Finally, long-term experiments were designed that tested the hypothesis that chronic exposure to handling and/or crowding would dampen the stress response and/or reduce growth. Long-term (5-6 weeks) weekly or daily exposure to these stressors (15 min chasing or crowding) did not consistently affect growth (measured as weight (g) and total length (cm)), reducing it on one occasion and not affecting it on another. Additionally, in 1 of 2 instances our data suggested that long-term repeated exposure to handling/crowding stress could depress the CORT response to stress. These results demonstrate that, although plasma CORT levels are low in undisturbed juvenile summer flounder, they increase significantly due to crowding and can remain elevated for at least a day. Regardless, the growth of juvenile summer flounder was unaffected by long-term chasing and crowding. In addition, flounder showed some evidence of habituation to these stressors. (This work was supported by Rhode Island Sea Grant, under NOAA Grant No NA16RG1057.)
Session II	11:20 a.m.
Environmental Gene Expression in Winter Flounder, Pseudopleuronectes americanus Peter F. Straub1,2 and Ashok D. Deshpande1 1NMFS/NEFSC/Howard Marine Laboratory, 74 Magruder Road, Highlands, NJ 07732 2Richard Stockton College, Biology Program, Pomona, NJ 08240 Environmental regulation of gene expression underlying the processes of development, growth and reproduction may be a sensitive indicator of both condition and habitat quality.  Measures of environmental gene expression may then be useful in predicting the limitations to growth and fecundity in specific environments.  To begin to test these hypotheses, this project has been collecting sets of genes, starting with liver tissue, that appear to be markers of environmental response to diverse habitats.  These genes or partial gene-transcripts have been isolated from winter flounder by subtractive hybridization, cloned, sequenced and identified by computer homology search.  The gene sets represent genes that appear to be coordinately up-regulated or down-regulated in response to anthropogenic disturbance or specific challenges such as exposure to oil spills.  Isolated genes were found to be related to detoxification, immune response, reproduction, transport, signaling and general metabolism.  Some examples of detoxification genes are the cytochrome P450s 1A, 2D, 3 and 24; glutathone-s-transferase; and alcohol dehydrogenase.  Immune responsive transcripts detected included the anti-microbial hepcidin, complement components C-3 and C-7 and differentially regulated trout protein-1.  Signaling transcripts included tumor suppressor p33ING1, Bal-643-liver regeneration protein, and hepatocyte growth factor-1.  Specific regulation of a subset of the isolated genes was confirmed by quantitative polymerase chain reaction (q-PCR).  Collection of this set of winter flounder genes, deposited as expressed sequence tags (EST) in the national database at Genbank (www.ncbi.nlm.nih.gov), is contributing to the delineation of the winter flounder genome and to the development of a winter flounder specific microarray for measurement of global gene expression.
Session II	11:40 a.m.
Winter Flounder in Western Long Island Sound: Facts, Photos, Fallacies and Fate – It Ain’t Rocket Science Arthur Glowka Fisherman, Western Long Island Sound Stamford CT 06902 The Atlantic States Marine Fisheries Commission is responsible for formulating a winter flounder management plan. Commercially fished stocks can be gauged by trawl statistics and dealer reports. ASMC needs information on inshore recreational stocks, habitat and predation. I have been documenting recreational fishing in Western Long Island Sound (WLIS) through writing and photography for more than forty years and have observed the population of winter flounder in WLIS to be less than 1% of the historical levels of the 1980’s. What now remains are a few large fish, 14” plus, with a sparse scattering of 8 to 10” fish and no juveniles 1-2”. WLIS is a contained body of water because of its geography, geology and hydrology. The winter flounder are resident species along with blackfish and cunner. There is no commercial trawling in WLIS. I, and my extensive network of fishermen, have observed that juvenile winter flounder are one of the major prey species for sea robin and fluke. We routinely examine stomach contents as we clean fish. We have also observed cormorants eating medium flounder. An over wintering population of seals in WLIS may prey on winter flounder as well. Serious recreational anglers gladly partake in tagging and volunteer angler surveys. Six-pack charter men and head boats all want to restore the winter flounder fishery. To better monitor predation, I suggest we supply 4-6 of them with small digital cameras next summer. I propose we synchronize photography during one week in early season, mid-season and late season to document stomach contents as they clean fish. This would provide a snap shot of predation to confirm anecdotal observations. Anything is better than nothing.
Session II	12:00 p.m.
Ecology and Biological Strategies of Etropus crossoyus and Citharichthys spilopterus (Pisces: Bothidae) Related to the Estuarine Plume, Gulf of Mexico Patricia Sanchez-Gil1, Alejandro Yañez-Arancibia2, Margarito Tapia Garcia3, John W. Day4, Charles A. Wilson4 and James H. Cowan4 1Doctorado en Ciencias Biolgicas, Universidad Autonoma Metropolitana, Ap. Post. 55-535, Mexico D.F. 2Coastal Ecosystem Unit, Institute of Ecology A.C. Km 2.5, Carretera Antigua Xalapa-Coatepec # 351, El Haya 91070, Xalapa Ver., México 3Departamento de Hidrobiología, Universidad Autónoma Metropolitana, Ap. Post. 55-535, Mexico D.F. 4Louisiana State University, Department of Oceanography and Coastal Sciences, Coastal Ecology Institute, School of the Coast and Environment, Baton Rouge 70803 LA Differences in the biological and ecological strategies of two dominant tropical flatfish E. crossotus (fringed flounder) and C. spilopterus (bay whiff) are discussed. The analysis is based on the relative seasonal abundance of the two species and the apparent coupling of both life history patterns with the organic matter concentration and food availability, coupled with the seasonality of estuarine plume. This contribution attempts to show that dominance (or ecological success) of coastal marine flatfish with similar biological and ecological patterns is based on the sequential use in time and space of habitats related to the estuarine plume of the Grijalva-Usumacinta mega delta onto the tropical inner shelf in the Southern Gulf of Mexico.
Session III	1:20 p.m.
Stage-specific Effects of Cortisol on Growth and Food Consumption by Larval Summer Flounder Danielle R. Reardon1,2, David A. Bengtson2 and Jennifer L. Specker1 1University of Rhode Island, Graduate School of Oceanography, Narragansett, RI 02882 2University of Rhode Island, Department of Fisheries, Animal and Veterinary Sciences, Kingston, RI 02881 Previous research has shown that in larval summer flounder, Paralichthys dentatus, the variation in food consumption observed at 17-20 days post hatch (dph) is highly correlated with length variation noted at 26 dph. This size variation leads to post-settlement cannibalism that can result in high mortality in the hatchery. Since the endogenous levels of cortisol peak in the larvae around the time of food consumption variation, and all components of the hypothalamic-pituitary-interrenal axis are present at this time, we hypothesized that cortisol may be positively affecting the food intake of the larvae. We treated the rearing water of the larvae with cortisol, the cortisol receptor blocker RU486, and a combination of cortisol and RU486 and monitored consumption by the larvae during a week-long exposure period. Dry weights and total lengths were collected to compare any differences in growth among fish in the various treatments. Results varied depending on the developmental stage of the larvae (pre- and pro-metamorphic, late metamorphic climax). Cortisol had a negative effect on food consumption in both pre-metamorphic larvae and larvae in late metamorphic climax, while it did not affect consumption by pro-metamorphic fish. The only effect of cortisol on dry weight was noted in the pro-metamorphic group of fish.  The length of the pre-metamorphic larvae was negatively affected by the addition of cortisol, while the fish in later developmental stages were unaffected. Contrary to our hypothesis, cortisol did not increase food consumption and growth, but reduced them during some developmental stages. [Supported by U.S.D.A./NRAC Project No. 2-6/4-4.]
Session III	1:40 p.m.
Feeding in Larval Summer Flounder: Regulation by Hormones Jason P. Breves1, David A. Bengtson2, and Jennifer L. Specker1 1University of Rhode Island, Graduate School of Oceanography, Narragansett, RI 02882 2University of Rhode Island, Department of Fisheries, Animal and Veterinary Sciences, Kingston, RI 02881 Variation in growth rates of summer flounder (Paralichthys dentatus) in culture conditions presents a major hurdle in the rearing of this commercially important species due to labor associated with reducing cannibalism. Variance in food consumption and growth during the 17-25 days post-hatch window occurs simultaneously with the activation of the hypothalamic-pituitary-interrenal (HPI) axis. In the present study we investigate the role of two potentially orexigenic endocrine signals in the feeding behavior of larval summer flounder. Glucocorticoids, secreted by the interrenal, in non-stress concentrations stimulate food intake and are vital to energy balance in mammals and may potentially serve a similar function in fishes. To correlate HPI axis maturation with feeding behavior radioimmunoassay was used to measure whole body cortisol (glucocorticoid) levels of fish grouped according to amount of Artemia nauplii consumption.  Distribution of the glucocorticoid receptor and the amount of CRH and ACTH in the hypothalamus and pituitary was determined through immunocytochemistry. In addition, we report on the action of exogenous treatment with ghrelin, a peptide hormone, on the appetite of larval and juvenile summer flounder. Information regarding the hormonal regulation of feeding in larval summer flounder aims to increase knowledge regarding the growth and development of this important aquaculture species and other marine teleosts. [Supported by USDA/NRAC Project No. 2-6/4-4.]
Session III	2:00 p.m.
Abundance and Distribution of Juvenile Flatfishes in a Near-Shore Shallow Water Habitat in New Haven Harbor Jose J. Pereira, Ronald Goldberg, and Paul Clark NMFS/NEFSC/Milford Laboratory, 212 Rogers Avenue, Milford CT 06460 Stock recruitment relationships continue to be one of the most difficult problems in fisheries research. The number of larvae or juveniles often varies greatly from year to year even though the number of breeding adults may change little. A better understanding of variation in habitat use by juvenile fish would be useful in the analysis of this problem. Beginning in 1998, we initiated a long-term study to examine habitat use by juvenile fishes at small spatial scales in the near shore zone. Using a beach seine, we sampled ten locations in Morris Cove in New Haven Harbor, CT once or twice a month from May through September from 1998 to 2004.  Substrate in the study area varies from muddy sand (station 1), to sand in the middle of the sample area (2-6), to macroalgae-covered cobble (stations 7-10) at the other end of the beach. Water depths are generally around 1.5 meters or less. Five species of juvenile flatfish are represented in this near shore fish assemblage. Winter flounder (Pseudopleuronectes americanus) far outnumbered other flatfish species with nearly 900 captured since the study began. We also captured 35 windowpane flounder (Scophthalmus aquosus), 11 summer flounder (Paralichthys dentatus), 3 hogchoker (Trinectes maculatus), and 1 smallmouth flounder (Etropus microstomus). Annual winter flounder abundance varied greatly over the course of the study, with major peaks in 2000 and 2004. Flounder were more abundant at sites with softer sediments than at other sites. We have begun to examine the relationship between the annual abundance of juveniles caught in the beach seine and adult winter flounder population densities determined from trawl surveys conducted in Long Island Sound by the State of Connecticut.
Session III	2:20 p.m.
Observing Larval Supply Processes on Coastal Ocean Seascapes: Adaptive Surveys in the New Jersey Shelf Observation System and a Preliminary Description of Pelagic Habitat Associations with Special Reference to Larval Flatfishes John Manderson1, John Quinlan2, and Patricia Shaheen3 1NMFS/NEFSC/Howard Marine Laboratory, 74 Magruder Road, Highlands, NJ 07732 2 Rutgers University, Institute of Marine and Coastal Science, 71 Dudley Road, New Brunswick, NJ 08901-8521 3Wagner College, Biological Sciences Department, One Campus Road, Staten Island, NY 10301 Examination of oceanographic and behavioral processes determining patterns of larval supply and connections between adult spawning and juvenile nursery grounds is necessary for the development of spatially explicit habitat models and effective fisheries habitat management.  Traditional surveys stratified in geographic coordinate space cannot adequately describe stage-specific pelagic habitat associations and trajectories for larvae in the coastal ocean where meteorological, buoyancy, and tidal forcing produces spatially dynamic pelagic habitats and transport pathways that are frequently driven by episodic oceanographic phenomena rather than mean flows.  Integrated ocean observation systems (IOOS) that network satellite, ground and autonomous underwater sensors provide real and near real time descriptions of coastal ocean climatology that permit surveys to be adaptively stratified in oceanographic feature space.  Here we describe a series of combined hydrographic, fishery hydroacoustic and Tucker trawl surveys performed within an IOOS in the New York Bight Apex.  Broadband wireless communications were used to access near real time descriptions of coastal ocean structure.  Pelagic habitat features under several coastal ocean states (upwelling, downwelling, high and low estuarine discharge) were adaptively sampled based on the near real time information. Preliminary results suggest that specific ichthyoplankton assemblages that included several flatfishes (windowpane, yellowtail, witch flounder) show strong associations with Hudson River Plume, Cold Pool, or Shelf water, under particular ocean states.  We also describe a strategy for hypothesis driven sampling within IOOS that is likely to improve our understanding of the mechanisms determining configurations of adult spawning/ juvenile nursery ground networks on coastal ocean seascapes.
Session III	2:40 p.m.
Effects of Dredging on the Functional Role of Nursery Habitats for Juvenile Flatfishes. Part I: Distribution of Juvenile Summer and Winter Flounder in the Pre-dredged Assawoman Canal, Delaware, with Reference to Bottom Type Brian P. Boutin and Timothy E. Targett University of Delaware, Graduate College of Marine Studies, Lewes, DE 19958 Assawoman Canal is a man-made canal connecting Indian River Bay to Little Assawoman Bay, near Indian River Inlet, Delaware.  Fish sampling occurred weekly from mid-May through October 2004 at four stations in the canal and biweekly at two stations in each of two adjacent creeks, for comparison with results from the canal.  Fish were collected in standardized hauls using a 1-m beam trawl and a 7.6-m seine.  Sampling to-date (mid-May through August) has shown highest juvenile winter flounder (Pseudopleuronectes americanus) abundance at northern Assawoman Canal sites (sand bottom with sparse organic matter) where they were captured from May 12-July 8, had a 78% frequency of occurrence, and =0.3-3.6 per10m².  Winter flounder abundance at the two sites in White Creek (mud bottom with macroalgae) was much lower, with fish captured only on May 12, 20% frequency of occurrence, and =0.2-0.3 per 10m². None were captured in southern Assawoman Canal (mud bottom with wood or leaf litter) or Miller Creek (mud bottom with no litter) south of the canal. Winter flounder densities in northern Assawoman Canal are comparable to those found in several previous studies in New Jersey and Connecticut estuaries.  Juvenile summer flounder (Paralichthys dentatus) were more widespread than juvenile winter flounder but were not abundant at any site (captured May 12-August 26, 67% frequency of occurrence, and =0.1-0.2 per 10m²). These densities are lower than those found in several studies in North Carolina.  Hogchokers (Trinectes maculatus) were the only other flatfish species to be captured (5 individuals).  Young winter flounder densities are higher in the northern Assawoman Canal than in the southern portion of the canal, in the natural creeks adjacent to the canal or in the natural creeks farther inland from Indian River Inlet (based on results from DNREC sampling). Juvenile summer flounder densities, on the other hand, are higher in the natural creeks farther inland. The proposed dredging of Assawoman Canal is therefore likely to have greatest immediate negative impact on juvenile winter flounder in the northern canal.  Longer-term impacts (positive or negative) on juvenile flatfish habitat will depend, at least in part, upon post-dredging changes in current regimes and associated sediment characteristics.
Session III	3:00 p.m.
Assessment of Power Plant Entrainment in Comparison to Long-Shore Ichthyoplankton Transport Donald Galya1, Michael Scherer2, James Herberich1, Stephanie Kelly1, and Jacob Scheffer3 1ENSR Corporation, 2 Technology Park Drive, Westford, MA 01886l  2Marine Research, Inc., 141 Falmouth Heights Road, Falmouth, MA 02540 3Pilgrim Nuclear Power Station, 600 Rocky Hill Road, Plymouth, MA 02360 Winter flounder are commercially important in Cape Cod Bay and are a dominant species collected by the entrainment monitoring program at the Pilgrim Nuclear Power Station (PNPS). This study evaluated the impact of winter flounder larvae entrainment at PNPS through direct field measurements. Previous studies have indicated a general counterclockwise circulation in the Massachusetts/ Cape Cod Bay system, with net transport to the south along the Massachusetts shoreline from Newburyport into Cape Cod Bay.  This net transport has a significant potential effect on transport of ichthyoplankton and may effect the life cycle of fish in the coastal ecosystem.  This study applied an approach whereby field measurements were collected to determine the relative amount of net volumetric flow and winter flounder larvae entrained into the PNPS cooling water system compared to the net volumetric flow and amount of winter flounder larvae transported past PNPS in offshore Cape Cod Bay waters.  The field program, conducted during May 2000 and May 2002, consisted of water velocity and tidal height measurements, and sampling of winter flounder larvae along offshore transects in Cape Cod Bay near PNPS.  To continuously measure water velocity and tidal height, acoustic Doppler Current Profilers and tidal gages were deployed at locations along the transects for the two one-month study periods. During each of these May study periods, larval flounder were collected at locations along transects during four 24-hour field-sampling efforts. Larval samples were obtained four times, twice during the day, and twice during the night. Concurrent sampling was performed to quantify the amount of winter flounder larvae entrained into the PNPS cooling water flow. All winter flounder larvae were classified and enumerated according to four larval stages. The field larvae data were combined with the current measurements to determine the transport or flux of winter flounder larvae along the coast of Cape Cod Bay, for each of the daily measurement periods. These values were then compared to the amount of winter flounder larvae entrained into the PNPS cooling system, as determined from the entrainment study, during the same daily measurement periods. Similar results were obtained in the 2000 and 2002 studies.  These results (1) confirmed that there is a southerly net flow and flux of winter flounder ichthyoplankton along the Massachusetts coast, and (2) indicated that PNPS entrains a relatively small percentage of the net larval transport—conservatively estimated at less than 1%.
Session IV	3:40 p.m.
Observations on the Systematics of Etropus crossotus Jordan & Gilbert 1882 Alicia Long NMFS/National Systematics Laboratory, Smithsonian Institution, National Museum of Natural History, MRC 153, P.O. Box 37012, Washington, DC 20013-7012 The fringed flounder, Etropus crossotus Jordan and Gilbert, 1882, was first described from eastern Pacific waters.  Subsequently, populations identified as E. crossotus have also been recorded in the western Atlantic from Virginia to southern Brazil.  Previous researchers have found only slight morphological differences between Atlantic and Pacific populations of E. crossotus.  However, with the surfacing of the Isthmus of Panama some 3-5 million years ago possibilities ended for migration and genetic mixing of fish populations between eastern Pacific and western Atlantic waters, including those of E. crossotus.  As a result of this interruption in gene flow, geminate species of fishes (and other organisms) evolved on either side of the Isthmus of Panama.  It is hypothesized that such speciation has also occurred between Atlantic and Pacific populations of flatfishes currently referred to as E. crossotus.  The goal of this project is to determine if any detectable morphological differences (including meristic and/or morphometric characteristics) exist among flatfishes presently referred to as E. crossotus that will reveal a western Atlantic and eastern Pacific geminate species pair.  Results of this study will further clarify the taxonomic diversity of species of Etropus.
Session IV	4:00 p.m.
Developmental Changes in Gut, Skin, and Gill Epithelial Glycoconjugates in Summer Flounder (Paralichthys dentatus L): A Lectin Histochemical Study Bruno Soffientino1, Marta Gomez-Chiarri2, and Jennifer L. Specker1 1University of Rhode Island, Graduate School of Oceanography, Narragansett, RI 02882 2University of Rhode Island, Department of Animal and Veterinary Science, Kingston, RI 02881 This study asked whether the glycoconjugates of gut, skin, and gills change during metamorphosis in summer flounder.  Larvae and juveniles were assayed histochemically with a battery of 15 biotinylated lectins, and scored for differences in staining intensity and spatial pattern between the two developmental stages.  All of the epithelia showed some developmental changes, but most were associated with the gut and skin epithelia and their mucous secretions. In the stomach, the mucus increased in staining with DBA, ECL, GSA II, PNA, and SBA lectins, while the epithelium changed little.  A developmental decrease in the binding intensity of the intestinal brush border was noted for DSL, RCA 120, VVA, SNA, and UEA I lectins, while intestinal goblet cells underwent a large increase in binding for GSA II.  The changes in the gut glycoconjugates correlate developmentally with shifts in bacterial flora composition found by other studies, and therefore might be relevant to the study of bacteria-host relationships in summer flounder.  The skin mucous cells of the larvae were negative for DBA, DSL, ECL, PNA, RCA 120, and SNA, but became positive in the juveniles.  The gills exhibited fewer developmental changes than the other tissues, increasing in labeling with SBA DBA, and PNA.  In the juveniles, SBA labeled the gill-filament junction where chloride cells are usually found in summer flounder.  In conclusion, this study showed that changes in glycoconjugate expression occur during metamorphosis in the gut, skin, and gills of summer flounder. Two lectins were identified as potentially useful cytological markers in this and possibly other species: UEA I for mucous cells, and SBA for chloride cells.
Session IV	4:20 p.m.
The Cortisol Antagonist, RU486, Inhibits Salinity Tolerance in Larval Summer Flounder Philip A. Veillette, Maricruz Marino, Misty M. Garcia, and Jennifer L. Specker University of Rhode Island, Graduate School of Oceanography, Narragansett, RI 02882-1197 Cortisol is the major corticosteroid secreted by the teleost interrenal. It stimulates seawater adaptation and is thought to be critical for maintaining water and electrolyte balance.  However, a role for cortisol in salinity tolerance of marine larval fish is not clear. We report here, several experiments that were designed to test whether cortisol is necessary for larvae of the euryhaline summer flounder (Paralichthys dentatus) to tolerate their native seawater milieu. The actions of cortisol are largely accomplished through binding to its receptors in target tissues. We therefore used the synthetic cortisol-receptor blocker, RU486, to determine the effect of cortisol deficiency on survival rates. In the first experiment, larvae were exposed to 10 (near isoosmotic) or 30 (hyperosmotic) ppt seawater containing 0-3.6 mM concentrations of RU486. Survival rate over 5 days was near 100% at 0-0.12 mM RU486 in both 10 and 30 ppt, although at higher concentrations of RU486 (1.2 and 3.6 mM), larval survival was significantly lower at 30 ppt compared to 10 ppt. Next, larvae were exposed to salinities from 0-65 ppt with, or without, 1.2 mM RU486. RU486 inhibited survival rate at 30 ppt and above (within 2 days), but not at lower salinities. Finally, exposure of larvae to 10 or 100 mM cortisol with 1.2 mM RU486 (at 30 ppt) prevented a decrease in survival that occurred in larva exposed only to RU486. The results demonstrate that survival of larvae in seawater is dependent on cortisol. The time frame of action of RU486 is consistent with inhibition of metabolically demanding, ionoregulatory mechanisms. [Funded by NSF IBN-0220196]
Session IV	4:40 p.m.
In Situ Effects of Suspended Particulate Loads Produced by Dredging on Eggs of Winter Flounder (Pseudopleuronectes americanus) Grace Klein-MacPhee1, William K. Macy1, and Walter Berry2 1University of Rhode Island, Graduate School of Oceanography, Narragansett, RI 02882-1197  2U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Laboratory, Atlantic Ecology Division, 27 Tarzwell Drive, Narragansett, RI 02882 In March of 2002, the U.S. Army Corps of Engineers began dredging in the Providence River to deepen shipping channels leading to the Port of Providence. We studied the impact of increased sediment loading on the early life stages of winter flounder, primarily on eggs and newly hatched larvae, by doing exposures in the field in areas adjacent to the dredging operations. In 2003 and 2004, we exposed newly spawned flounder eggs in weighted arrays holding 9 chambers with 100 winter flounder eggs per chamber. We placed one array adjacent to the dredging operation and one far away. Divers retrieved the arrays just at hatch time. Numbers of eggs and larvae, amount of sediment settled in the chambers, and size of larvae were compared. There was a significant difference in the amount of sediment deposited in the experimental vs. the control chambers (3.59 vs. 0.69g dry weight). There was no statistical difference in the numbers of live eggs and larvae between the treatment and the controls, although there was slightly greater survival in the controls (14.1% vs. 15.5 % eggs and larvae). Larvae were observed hatching and wriggling up through the sediment in both treatments. Survival of eggs exposed to different amounts of sediment at the EPA laboratory showed similar results- higher survival in controls but results not statistically significant.
Session IV	5:00 p.m.
Impacts of Hypoxia on Juvenile Fish Growth: Evidence From Laboratory and Field Studies Kevin L. Stierhoff and Timothy E. Targett University of Delaware, Graduate College of Marine Studies 700 Pilottown Rd, Smith Laboratory, Lewes, DE 19958 For estuarine-dependent fishes, physicochemical factors such as temperature, salinity and dissolved oxygen (DO), which vary temporally and spatially, can have substantial effects on larval and juvenile growth rates and, consequently, on nursery habitat quality.  The objectives of this study were to investigate the impacts of hypoxia (low DO) on growth rates of young-of-the-year (YOY) of two estuarine-dependent fishes: summer flounder (Paralichthys dentatus) and weakfish (Cynoscion regalis).  We conducted controlled laboratory experiments over a range of chronic and diel-cycling DO conditions.  From these results we made predictions of growth rates under a variety of conditions experienced in the field and tested these predictions using fishes collected in estuarine nursery grounds. Our laboratory growth data show that moderate (<50% saturation) levels of chronic (<7 d) hypoxia and diel-cycling (30-160% saturation over 24 h) hypoxia significantly reduce growth of juvenile summer flounder but not weakfish.  Summer flounder growth rate is reduced by 50-90% at 2 mg O2 l-1, compared with the rate at 7 mg O2 l-1,with the greatest reduction being at higher temperatures.  We are currently using RNA:DNA ratios to quantify growth rates of these fishes in the wild in response to short-term (2-4 d) changes in DO.  RNA:DNA data from field-collected fishes will provide further insight into the impacts of low DO on growth of YOY summer flounder.  The overall goal is a better understanding of the linkage between hypoxia, growth, and nursery habitat quality.
Session V	8:40 a.m.
Predatory Impact of the Green Crab (Carcinus maenas) on Post-settlement Winter Flounder (Pseudopleuronectes americanus) as Revealed by Immunological Dietary Analysis David L. Taylor Rutgers University, Marine Field Station, Institute of Marine and Coastal Sciences 800 c/o 132 Grant Bay Blvd, Tuckerton, NJ  08087-2004 Predation on flatfish during the early juvenile stage could be an important factor regulating year-class strength and recruitment.  In this study, immunological dietary analysis was performed on green crabs (Carcinus maenas) collected from the Niantic River, Connecticut, in an effort to evaluate the predatory impact of this species on post-settlement winter flounder (Pseudopleuronectes americanus).  Through the use of species-specific antiserum, winter flounder proteins were identified in 4.8% of the green crab stomachs analyzed (n = 313, size range = 14-74 mm carapace width; CW); revealing that crabs >29 mm CW are predators of post-settlement winter flounder in natural populations.  The most significant factor underlying the predator-prey interaction was the relative size relationship between species, such that the incidence of winter flounder remains in the stomach contents of green crabs was positively correlated with predator-to-prey size ratios.  Results from dietary analysis were incorporated into a deterministic model to estimate the average daily instantaneous mortality and cumulative mortality of winter flounder owing to green crab predation.  Accordingly, green crabs accounted for 1.5 to 4.7% of the daily mortality of winter flounder, and consumed 10.7% of the flounder year-class.  Relative to other macro-crustacean predators, however, predation by green crabs has a minimal effect on winter flounder survival, due in large part to the low densities of these crabs in temperate estuaries.
Session V	9:00 a.m.
Study of Class-0 Benthic Fish Species in Norwalk Harbor, CT, Concentrating on Winter Flounder Elise Brzuska1, Tom Gethin-Jones1, Liz Conover1, Liz Boggs1, Margot Schloss1, Aj Pikal1, Jim Lucey1, and Richard B. Harris2 1Wilton High School, Wilton, CT 08970 2Earthplace-The Nature Discovery Center, PO Box 165, 19 Woodside Lane, Westport, CT 06881 Class zero benthic fish species were studied in Norwalk Harbor, Norwalk, CT, concentrating on the population of winter flounder (Pseudopleuronectes americanus).  The relative abundance and species diversity of these species captured were analyzed using trawling data gathered from the Norwalk Harbor.  All organisms caught in the beam trawl were counted, identified, and released.  In order to use comparable numbers of trawls in the harbor, data were analyzed from 1991 through 1994, and then compared to 2003.  The data indicated that species abundance of juvenile benthic fish remained constant throughout the five years.  However, overall species relative abundance decreased in juvenile benthic fish species examined, particularly winter flounder (P. americanus), with the exception of an increase for northern sea robins (Prionotus carolinus).  Further examination of the distribution of P. americanus within the Norwalk Harbor, indicated cyclical population trends from 1991 through 1994, and generally lower population densities in 2003.  Possible causes for these trends may include the effects of reduced dissolved oxygen levels, increased bottom temperature, and increased predation.  The variety and range of these possible variables prevent the selection of a single factor as the cause for the shift in relative abundance.
Session V	9:20 a.m.
Investigations into the Growth of Yellowtail Flounder In and Around a Closed Area Kathy L. Lang1, Christopher M. Legault1, Andrew J. Applegate2, Heath H. Stone3, Jay Burnett1, and Vaughn M. Silva1 1NMFS/NEFSC/Woods Hole Laboratory, 166 Water Street, Woods Hole, MA 02543 2Northeast Fisheries Management Council, 50 Water Street, Newburyport, MA 01950 3Department of Fisheries and Oceans, Biological Station, 531 Brandy Cove Road, St. Andrews, New Brunswick E5B Canada There is some indication that yellowtail flounder, Limanda ferruginea, are growing to larger sizes and older ages in areas closed to commercial fishing on Georges Bank.  Recent assessments for the Georges Bank transboundary stock of yellowtail flounder have demonstrated retrospective patterns that could be due to these differences in age structure inside and outside of Closed Area II.  These observations could be due to the effect of Closed Area II and the U.S.-Canada boundary on sampling associated with data collection programs or due to biological responses to reduced fishing mortality. To test the latter, we examined data from 1986-2004 collected by the Northeast Fisheries Science Center’s bottom trawl survey, commercial sampling, and fishery observer programs as well as comparable data from Canada’s Department of Fisheries and Oceans.  These data were divided into two time periods: 1986-1994 represents the period prior to the establishment of Closed Area II in December 1994, and 1996-2004 that afterwards (1995 was considered a transitional year).
Session V	9:40 a.m.
The Winter Flounder Gender Bender: What Are We Culturing? Elizabeth A. Fairchild, W. Huntting Howell, Nathan Rennels and James Sulikowski University of New Hampshire, Department of Zoology Durham, New Hampshire 03824 Studies have shown that sexual differentiation, and therefore male:female sex ratio in some flatfish species, can be influenced by juvenile incubation temperature. This also may be true for winter flounder, whose juveniles are quite eurythermal, but sexual differentiation and the sex ratio of cultured winter flounder have never been investigated. This is significant for both aquaculture and stock enhancement programs. In aquaculture, it may be desirable to culture female genotypes for production of larger fish. In stock enhancement, the sex ratio of fish used for releases can affect the wild population by altering the sex ratio and population dynamics of the wild population. Because the sex ratio of cultured winter flounder, and the factors that may influence it, are completely unknown, we studied the sexual differentiation and cultured fish sex ratio as part of a larger study evaluating the effectiveness of a winter flounder stock enhancement program. To accomplish this, we sampled 385 fish from the general culture population at approximately 10 mm total length (TL) intervals, starting shortly after metamorphosis and continuing through the first year. On each sampling occasion, we randomly collected 30 fish. Tissues were fixed and stored in modified Davidson’s solution for at least 48 hrs. Prior to histological processing, the samples were washed in freshwater and stored in 70% alcohol. Histological processing involved embedding the tissues, sectioning (6 microns), and staining with hematoxylin and eosin. Slides were examined to view structures and cells associated with gonadal tissue. By examining the size series of fish collected, we were able to determine the size and age when sexual differentiation is visible histologically, as well as the sex ratio of the cultured population. Results of these studies will be discussed. Analysis of this study continues, and initial findings suggest that the sex of winter flounder as small as 40 mm TL can be determined histologically.
Session V	10:00 a.m.
Spatially Explicit Modeling of the Effects of a Thermal Discharge and Ambient Temperatures on Winter Flounder, Pseudopleuronectes americanus Robert J. O’Neill, Thomas L. Englert, and Jee K. Ko Lawler, Matusky & Skelly Engineers LLP (LMS), One Blue Hill Plaza, Pearl River, NY 10965 Trawl finfish surveys conducted in the Narragansett Bay Estuary over the past three decades reveal steep declines in the abundance of several groundfish species since the late 1970s.  Of particular concern is the decline in winter flounder, a species important to the local commercial and recreational fisheries.  To determine whether heat introduced to the system from Brayton Point Station’s thermal discharge could be contributing to the decline of Mount Hope Bay winter flounder, a biothermal modeling assessment was performed by LMS.  The model was based on predictions of the temporal and spatial location of the BPS thermal plume, as provided by Applied Science Associates, Inc.  The biothermal assessment was performed for a range of biological functions, including critical growth, reproduction, avoidance, migratory blockage, and thermal mortality. The analysis evaluated the thermal effects of a variety of BPS operating conditions including ambient temperatures (no plant), historical plant operation, and proposed future operational alternatives.  A temperature tolerance polygon was developed to depict how winter flounders’ performance envelope varied with acclimation temperature. This figure, in conjunction with the results of the plume model, permitted a quantitative evaluation of the effects of the plant’s thermal discharge, including: (1) refined spatial resolution making it possible to pinpoint the location of any predicted thermal effects, (2) delineation of the species-specific habitats by life stage, and (3) the inclusion of a unique assessment of chronic thermal mortality. The analysis concluded that the BPS thermal discharge is not causing appreciable harm to the winter flounder population within Mount Hope Bay.
Session VI	10:40 a.m.
Flatfishes of Chesapeake Bay: An Overview of Species Diversity, Abundance and Occurrence Thomas A. Munroe1, Hank Brooks2, and Wendy Lowery2 1NMFS/National Systematics Laboratory, Smithsonian Institution,PO Box 37012, NHB, WC 57, MRC-153, Washington, DC 20013   2College of William and Mary, Department of Fisheries Science, Virginia Institute of Marine Science, PO Box 1346, Gloucester Point, VA 23062 Chesapeake Bay is uniquely positioned among western North Atlantic estuaries in being situated close to a major biogeographic boundary between a northern, cold temperate province and a warm temperate province to the south.  Since 1968, the Virginia Institute of Marine Science has conducted juvenile fish surveys in lower Chesapeake Bay and major tributaries (James, York and Rappahannock rivers).  Thirteen flatfish species have been reported from Chesapeake Bay.  Of these, 12 are valid species.  Neoetropus macrops, known from a single specimen purportedly captured in Chesapeake Bay, is not a valid species; rather it is a reversed specimen of Gulf Stream flounder with questionable locality data.  Among 12 species constituting the flatfish assemblage, 6 are common, 2 uncommon, and 4 species are rare in the Bay.  Common, abundant species include summer flounder, smallmouth flounder, hogchoker and blackcheek tonguefish; common, less abundant species are windowpane and fourspot flounders.  Uncommon species occurring in low abundance are winter and fringed flounders.  Rarely occurring species are halibut, yellowtail and southern flounders, and bay whiff.  The Chesapeake Bay flatfish assemblage is a unique mix of species with some at or near southern (winter flounder; yellowtail flounder, halibut) or northern limits of their distributions (blackcheek tonguefish, southern flounder, bay whiff).  Summer flounder, hogchoker, blackcheek tonguefish and smallmouth flounder are abundant, estuarine-dependent species; winter flounder is an estuarine-dependent species occurring in low abundance (more abundant in northern estuaries).  Southern flounder and bay whiff are estuarine-dependent species that occur in greater abundance in more southern estuaries.  Coastal species commonly utilizing lower Chesapeake Bay are windowpane, fourspot flounder and fringed flounder.
Session VI	11:00 a.m.
Scale Formation in Selected Western North Atlantic Flatfishes Kenneth W. Able and Jennifer C. Lamonaca Rutgers University Marine Field Station, Institute of Marine and Coastal Sciences, 800 c/o 132 Great Bay Boulevard, Tuckerton, NJ 08087-2004 We examined the patterns of scale formation (onset, completion, spatial pattern) for five species in four families of flatfishes (Bothidae: Etropus microstomus, Paralichthys dentatus; Scopthalmidae: Scophthalmus aquosus; Pleuronectidae: Pseudopleuronectes americanus; Soleidae: Trinectes maculatus) to determine if the patterns are a useful indicator for the transition from the larval to the juvenile stage.  In all species the ontogenetic pattern was very similar, with onset of scale formation occurring on the lateral surface of the caudal peduncle, then spreading anteriorly along the lateral line, then laterally over the body, on to the head, and eventually on to the medial fins, a characteristic of Pleuronectiform fishes.  The timing of scale formation, relative to fish size, was late relative to other morphological characters (i.e., fin ray formation, eye migration, settlement).  Onset of scale formation, across all species, occurred at 9.0 - 13.5 mm TL, at the same approximate size as eye migration and settlement.  Completion of scale formation on the body occurred at 22 - 54 mm TL, but completion of scale formation on the fins did not occur until 44 - 88 mm TL.  Thus, completion of scale formation in these flatfishes is apparently the last morphological change to occur during the larval to juvenile transition and, as a result, is not completed until approximately one third (Scophthalmus aquosus, Paralichthys dentatus) to one fourth (Pseudopleuronectes americanus) or at the same time (Etropus microstomus, Trinectes maculatus) as the size at first reproduction.  We continue to examine these patterns, especially with regard to ecological correlates (e.g., general habitat use, burial, etc.).
Session VI	11:20 a.m.
The Importance of Freshwater Riverine Habitat, Particularly as a Nursery for Paralichthys lethostigma, in the Atchafalaya River Delta, Louisiana Bruce A. Thompson1, Gary W. Peterson2, and Jason K. Blackburn1,3 1Louisiana State University, Coastal Fisheries Institute, Baton Rouge, LA 70803  2Louisiana State University, Coastal Ecology Institute, Baton Rouge, LA 70803 3Louisiana State University, Department of Geography, Baton Rouge, LA 70803 The southern flounder, Paralichthys lethostigma, is a common flatfish, ranging on the Atlantic coast of the U.S. from northern North Carolina to southern Florida, and in the Gulf of Mexico from south Florida to north-central Mexico.  Although it spawns in coastal waters, it spends much of its life cycle in nearshore and coastal estuarine habitats.  In Louisiana it is the only Paralichthys found in estuaries and often resides in lower salinity and freshwater habitats.  It is our most sought-after flatfish. We have been examining fish assemblages in low salinity [< 3 ppt] and freshwater areas of the Atchafalaya River delta and have taken all life stages of this species from small YOY [<15 mm] to adults [360mm+, 4-5 yrs].  These riverine habitats are particularly important nursery areas. We have collected hundreds of YOY [35-90 mm] during late winter and early spring, found in soft- mud bottom, protected vegetated habitats.  Nearly all of these are found in freshwater, associated with highly turbid waters from the Atchafalaya River.  It is interesting to note that much of this southern flounder habitat has been constructed with dredge materials as part of the reconstruction program presently attempting to offset coastal erosion in coastal Louisiana.    Previously we suggested that male southern flounder spend much of their mature life cycle offshore (Fischer and Thompson, In Press), but our present findings suggest that life history movements are more complicated with perhaps multiple movements across a wide range of salinity regimes.  Some of these seem to be independent of spawning migrations since they involve immature fish. The hypothesis of these movements is supported by some preliminary studies examining Sr:Ca ratios in southern flounder otoliths.  Additional work examining Sr:Ca ratios and tracking tagged flounder are planned to provide additional details of their life history in Louisiana.
Session VI	11:40 a.m.
Temporal Trends in Distribution and Abundance of Flatfishes in Lower Chesapeake Bay and its Major Tributaries Wendy A. Lowery1, Hank Brooks1, and Thomas A. Munroe2 1College of William and Mary, Department of Fisheries Virginia Institute of Marine Science, Gloucester Point, VA  23062 2NMFS/National Systematics Laboratory, Smithsonian Institution PO Box 37012, NHB, WC 57, MRC-153, Washington, DC  20013-7012 From 1979 to 2003, eight species of flatfishes and 150 other species of demersal fishes have been identified from the 21,508 trawls conducted by the Virginia Institute of Marine Science juvenile finfish bottom trawl survey of Chesapeake Bay and its three major Virginia tributaries.  Hogchoker, blackcheek tonguefish, and summer flounder occur widely over the lower Bay and throughout the major rivers during spring through fall, moving to deeper waters in winter.  Smallmouth flounder are abundant in the Bay mouth and lower rivers in summer and fall.  Windowpane have a more scattered distribution near the Bay mouth and lower rivers in winter and spring, become more abundant in summer, and move toward higher salinity waters along the eastern shore of the Bay in fall.  Winter flounder occur infrequently in the Bay and lower rivers, and disappear from catches in the fall.  Fringed flounder and fourspot flounder are rare catches in the lower Bay.  Of demersal fishes captured, 38.4 % were flatfishes.  Hogchokers were most abundant at 35.9 % of the demersal total.  Blackcheek tonguefish ranked second in abundance among flatfishes, but constituted only 1.3 % of the total demersal fish catch.  Other flatfishes (summer flounder, smallmouth flounder, windowpane, winter flounder, fringed flounder, and fourspot flounder) together accounted for only 1.2 % of the demersal fish total. Overall catch per unit effort (CPUE) per 5-minute tow were:  79.14 for hogchoker, 2.87 for blackcheek tonguefish, 1.45 for summer flounder, 1.09 for smallmouth flounder, and 0.122 to 0.003 fish per tow for other flatfishes.
Session VI	12:00 p.m.
Metabolic Acidosis Stimulates Renal Tubular Sulfate Secretion in Winter Flounder, Pseudopleuronectes americanus Ryan M. Pelis and J. Larry Renfro University of Connecticut, Department of Physiology and Neurobiology Storrs, CT 06269 Active SO42- secretion by the renal proximal tubule of marine teleosts eliminates the plasma SO42- burden that would otherwise occur from the continuous ingestion of SO42- -rich (~25 mM) seawater.  The model of tubular SO42- secretion includes pH-dependent uptake of SO42- across the basolateral membrane of proximal tubule cells (SO42-/2OH-) and the exchange of intracellular SO42- for either luminal HCO3- or Cl- (SO42-/2HCO3- or SO42-/2Cl-).  The requirement of HCO3- and OH- ions as substrates for SO42- transport has led to the hypothesis that changes in interstitial pH would alter the rate of tubular SO42- secretion.  Flounder renal proximal tubule epithelium in primary culture (fPTCs) mounted in Ussing chambers actively secreted SO42- at a net rate of 80 ± 7.7 nmoles x cm-2 x h-1 when flounder saline of normal pH (7.7, control) bathed the interstitium.  Reduction of interstital pH to 6.8 (metabolic acidosis) significantly increased net secretion 41%, and elevation of interstitial pH to 8.8 (metabolic alkalosis) decreased net secretion 32%.  For whole animal studies (in vivo), reduction of environmental pH from 7.5 to 4.3 was used to induce metabolic acidosis.  Metabolic acidosis caused a decrease in serum pH (7.7 ± 0.01 to 7.3 ± 0.05), and significant increases in serum osmolality (338 ± 4.3 to 358 ± 8.6 mOsmol x kgH2O-1) and tubular SO42- secretion rate (3.2 ± 0.76 to 5.5 ± 0.84 mmol x kg body wt-1 x h-1).  Furthermore, there was a significant linear relationship between serum pH and tubular SO42- secretion rate (R2 = 0.57).  Supported by NSF.
Session VII	1:20 p.m.
Behavioral Responses of Summer Flounder and Weakfish to Declining Dissolved Oxygen: Inter- and Intraspecific Comparisons Damian C. Brady and Timothy E. Targett University of Delaware, Graduate College of Marine Studies, Lewes, DE 19958 Understanding how fish respond behaviorally to environmental stress is vital to predicting consequences of exposure, and ultimately, the impact of stressors on distribution.  Flatfishes are particularly susceptible to hypoxia because dissolved oxygen (DO) tends to decrease with depth and flatfishes are generally less mobile than pelagic fishes.  The objectives of this study were to characterize and compare the swimming behaviors of juvenile summer flounder and weakfish during exposure to and recovery from severely low DO, such as is commonly experienced in estuarine nursery habitats. Swimming activity (body lengths s-1) was recorded in a 2-m diameter mesocosm tank and quantified every second over 6.5 h trials.  Dissolved oxygen was decreased from 7 mg O2 l-1 (normoxia) to 1.4 mg O2 l-1 (20% sat.) at 1.4 mg O2 l-1 increments, then further reduced to 0.8 mg O2 l-1 (15% sat.) and finally to 0.4 mg O2 l-1 (10% sat.).  DO was then increased at the same rate during a ‘recovery’ period to determine latent effects of hypoxia on swimming activity.  Fish remained at each DO level for 30 minutes. Both species exhibited an initial active response (increase in activity) until DO dropped to ~2.8 mg O2 l-1, beyond which both species exhibited a passive response (decrease in activity).  During subsequent exposure to increasing DO, summer flounder did not recover normal swimming speed over the 3 h ‘recovery’ period.  Furthermore, individual fish maintained rank-order of swimming speeds throughout trials, suggesting that intraspecific variability plays a role in population-level responses to hypoxia.  In conclusion, subtle increases in activity at DO levels above those that impair growth or cause mortality may result in fish avoiding some detrimental hypoxia conditions.  However, when summer flounder are exposed to very low DO, long recovery times may have significant consequences in terms of predation risk and decreased foraging.
Session VII	1:40 p.m.
Abundance and Distribution of Etropus microstomus and Etropus crossotus in Virginia’s Portion of Chesapeake Bay and its Major Tributaries Hank Brooks1, Wendy A. Lowery1, and Thomas A. Munroe2 1College of William and Mary, Department of Fisheries Science, Virginia Institute of Marine Science, Gloucester Point, VA 23062 2NMFS/National Systematics Laboratory, Smithsonian Institution, Post Office Box 37012, NHB, WC 57, MRC-153, Washington, DC 20013-7012 The Virginia Institute of Marine Science (VIMS) has conducted a bottom trawl survey in Virginia’s portion of Chesapeake Bay and its major tributaries (James, Rappahannock and York rivers) since 1955, with gear configuration standardized in 1979 (30’ semi-balloon otter trawl with ¼” mesh cod-end liner and a tickler chain).  Of 12 flatfish species known from Chesapeake Bay and its tributaries, eight have been captured by the VIMS juvenile finfish trawl survey, including two members of Etropus: E. microstomus (smallmouth flounder) and E. crossotus (fringed flounder).  From 1979 to 2003, both E. microstomus and E. crossotus were regularly encountered during sampling, though at very different frequencies and abundances. Among members of the flatfish assemblage, E. microstomus ranks 4th and E. crossotusis 7th in numerical abundance.  Smallmouth flounder is a common and abundant species in lower Chesapeake Bay present in some abundance during all four seasons, with highest abundances occurring in late summer and fall.  Though found throughout most of Virginia’s portion of the Bay and its tributaries, most trawl survey records for this species are from southern and eastern regions of the Bay in close proximity to the bay mouth or near downstream ends of the tributaries.  In contrast, fringed flounder is uncommon in Virginia’s portion of the Bay and occurs in considerably lower abundances than its congener.  Though fringed flounder are captured throughout the year, most occurrences are found during fall, usually in deeper portions of the survey area.
Session VII	2:00 p.m.
An Evaluation of Summer Flounder, Paralichthys dentatus, Estuarine Habitat Use Using Acoustic Telemetry Dana Rowles, Ken Able, and Thomas Grothues Rutgers University, Marine Field Station, Institute of Marine and Coastal Sciences 800 c/o 132 Great Bay Boulevard, Tuckerton, NJ 08087-2004 Summer flounder, Paralichthys dentatus, an economically important fish, is seasonally abundant in estuaries along the East Coast of the United States but a comprehensive understanding of habitat use is lacking.  The Mid-Atlantic Bight population of summer flounder migrates between continental shelf spawning habitat in fall/winter and estuarine spring/summer habitat.  Because the species is transient, measurements of habitat quality to determine essential fish habitat (EFH) is confounded by local population overturn.  Tracking individual fish throughout summers provided insight into habitat use patterns beneficial in delineating their EFH.  This research focuses on patterns of juvenile and adult summer flounder (268-535 mm) habitat utilization during 2003 and 2004 in the Jacques Cousteau National Estuarine Research Reserve (JCNERR) encompassing the Mullica River/Great Bay estuary.   Habitat use was determined by tracking summer flounder throughout polyhaline-obligohaline parts of the estuary using acoustic telemetry.  Individually coded acoustic transmitters were externally attached, allowing individuals (2003 n=30; 2004 n=40) to be tracked passively with stationary hydrophones and actively with a mobile hydrophone.  Mobile tracking included two methods of tracking.  Weekly locations of all fish in the system, from June through November in 2003 (300 hours tracking) and April through November in 2004 (250 hours tracking), addressed the distribution of tagged fish throughout summer residence.  Mobile tracks of individual fish over time provided data on tidal and diel patterns of movement (150 hours of tracking in 2003 and 2004).  Stationary hydrophones detected all tagged fish within the system and reported 176,099 hits since the first tagged fish was released in June of 2003.  700 hours of active tracking (both methods) provided data on 51 out of 70 tagged fish.  Dynamic and static variables - temperature, salinity, dissolved oxygen, pH, depth, and substrate - were correlated with fish movements to examine the effects these variables have on habitat use. The fish were found to remain within narrower ranges of temperature, salinity, and dissolved oxygen during nighttime hours.
Session VII	2:20 p.m.
Ulcerative Dermatitis in Massachusetts Bay Winter Flounder, Pseudopleuronectes americanus Michael Moore1, Roxanna Smolowitz2, Kevin Uhlinger2, Lisa Lefkovitz3, John Ziskowski4, George Sennefelder4, Jeremy King5, Maurice Hall6, Jack Schwartz5, and David Pierce5 1Woods Hole Oceanographic Institution, Biology Department, Woods Hole, MA 02543 2Marine Biological Laboratory, Woods Hole, MA 02543 3Battelle, 397 Washington Street, Duxbury, MA 02332 4NMFS/NEFSC/Milford Laboratory, 212 Rogers Ave, Milford, CT 06460 5Massachusetts Division of Marine Fisheries, 251 Causeway Street, Suite 400, Boston, MA 02114 6Massachusetts Water Resources Authority, Environmental Quality Department, 100 First Avenue, Charlestown Navy Yard, Boston, MA  02129 Prior to 2002, ulcerative dermatitis in winter flounder has been very rare in the Gulf of Maine, including the urban harbors of Massachusetts Bay. Since 2002, blind side ulcers have been recorded in up to 42% of the winter flounder sampled at any one station. Prevalence has been highest in spring surveys in western Massachusetts Bay, and rare to absent in Cape Cod Bay and the rest of the Gulf of Maine. Ulcers in the spring appear to be acute and those in June show evidence of healing, with a lower overall prevalence. Ulcers have been observed less consistently in fall surveys. Histology of sub-acute to chronic ulcers showed hemorrhagic, macrophagic, lymphocytic and fibrosing superficial and deep dermatitis. There was focal loss of epithelium, scales, superficial dermal connective tissues and muscle and necrosis of remaining exposed deeper dermal muscle.  Areas of healing that were undergoing re-epithelization showed the development of fat cells in upper dermis in place of scales and superficial dermal muscle. Gram-negative bacterial findings showed similar bacteria on ulcerated vs. un-ulcerated skin.  However, some of the bacteria identified are potentially important opportunistic disease producing bacteria.  This might indicate that there is some other primary cause for the occurrence of the ulcers that might be associated with higher levels of opportunistic bacteria in the environment resulting in the occurrence of multi-focal irregularly occurring ulcers of various sizes in the skin. Of possible significance is that the Boston Outfall was extended into Massachusetts Bay in 2000.
Session VII	2:40 p.m.
Reduction in Organic Contaminant Exposure and Resultant Hepatic Hydropic Vacuolation in Winter Flounder (Pseudopleuronectes americanus) Following Improved Effluent Quality and Relocation of the Boston Sewage Outfall into Massachusetts Bay, USA: 1987-2003 Michael Moore1, Lisa Lefkovitz2, Maury Hall3, Robert Hillman2, David Mitchell4, and Jay Burnett5 1Woods Hole Oceanographic Institution, Biology Department, Woods Hole, MA 02543 2Battelle Duxbury Operations, 397 Washington Street, Duxbury, MA 02332 3Massachusetts Water Resources Authority, 100 First Avenue, Charlestown Navy Yard, Boston, MA  02129 4ENSR International, 2 Technology Park Drive, Westwood, MA  01886 5NMFS/NEFSC/Woods Hole Laboratory, 166 Water Street, Woods Hole, MA 02543 Effluent upgrades for Metropolitan Boston have included toxicant reduction, primary and secondary treatment and outfall extension. Between 1992 and 2003, winter flounder at five stations were surveyed annually for liver and muscle burden and chronic hepatic sub-lethal impacts of polynuclear and halogenated aromatic hydrocarbons, and metals. Trends in flounder availability and fin condition were also examined. In 1988, 12% of the adult winter flounder in Boston Harbor exhibited hepatic neoplasms and up to 80% had hepatic hydropic vacuolation (HV). Tumor prevalence fell to 0 to 2% and HV to <50% by 1996. Since then tumors have been absent, while a steady prevalence of HV has persisted, consistent with lower hydrocarbon loading and tissue levels. Contaminants and HV also fell with distance from the Boston< outfall. After the outfall extension was activated in 2000, there has been no significant change in flounder liver health at the new outfall site.