Conference Abstracts:

1)Introduction To The Symposium Its Purpose And Plan.

K.M. Kelley and C.G. Lowe, Marine Biology Program, Department of Biological Sciences, California State University, Long Beach, Long Beach, CA 90840

Catch & release regulations for both recreational and commercial fishing, mandated by state and federal agencies, are intended to protect both marine and freshwater fisheries. Do they? In this symposium, experts from around the United States and region focused their attention on the biological impacts of fishing-induced stress, as well as stress derived from other sources such as long-term captivity or pollution. What is presently known about the secondary impacts of stress responses was emphasized, particularly how induced stress factors (especially hormones) impact important aspects of physiology and behavior. The potential meaning of scientific findings to fish, fisheries, and fisheries management was a lso considered. The flow of the symposium was as follows. Stress specifically stress responseswas introduced as a vertebrate phenomenon that is highly conserved and relevant in fish. The discussion then moved into fish and field, with a variety of re search findings on fish presented, and ended with a more management-oriented perspective. At the conclusion of the symposium, an open forum afforded the opportunity for interested participants to provide input and to contribute to a discussion on the over all conclusions taken from the speakers, on future questions and issues in need of attention, and on possible management recommendations. For details on these discussions, we encourage you to go to


2)The Fish Case-study Of The Vertebrate Stress Response And Its Relevance To Human-derived Impacts In Marine Fishes

K.M. Kelley1, M.M. Galima1, J.A. Reyes1, K. Sak1, D. Topping1, K. Goldman2, and C.G. Lowe1. 1Marine Biology Program, Dept. Biological Sciences, California Stat e University, Long Beach, Long Beach, CA 90840; 2Jackson State Univ., Dept. of Biology, P.O. Box 18540, Jackson, MS 39217.

Corticosteroid hormones (cortisol, corticosterone) play highly conserved roles among vertebrates as stress hormones. These steroids (fish produce cortisol) mediate a variety of physiological changes that are generally adaptive for successful short-term responses to stressors, including mobilization of fuels to support greater energy utilization by muscle and other tissues, and re d uction of energy-expensive processes including growth, reproduction, and immune function. Long-term stress responses (more than several days), on the other hand, become significantly maladaptive, as inhibition of the latter physiological processes cannot be prolonged without serious consequences to well-being and survival. Upon encountering a stressor from the environment, such as catching-&-releasing or exposure to an abnormal environment (e.g., contamination, captivity, human activities), fish typicall y exhibit a rapid (<1 min) but transient elevation in circulating levels of epinephrine (adrenalin) which is followed by a prolonged surge in plasma cortisol levels (initiated within several minutes). The cortisol surge is often profound (>50-fold in most fish) and will be sustained so long as the stressor remains; once the stressor is removed, cortisol returns toward baseline levels at a rate that differs among species. Importantly, the cortisol surge sets into motion other changes, among them alteration s in endocrine regulators of tissue growth & repair. Studies done in our laboratory and in some others have demonstrated that an insulin-like growth factor-binding protein (IGFBP) is increased by cortisol and in several physiological conditions when corti s ol is elevated and growth is inhibited. The highly consistent presence of this IGFBP in growth-inhibited fish has led to the proposal that it serves effectively as a biomarker for the growth impacts of stress. Interestingly, we have seen that the IGFBP r emains elevated in plasma of stressor-exposed fish even after the surge in cortisol has subsided, suggesting that the physiological impacts of cortisol in fish outlast the initial stress-induced surge in cortisol. Thus, the secondary effects of stress (e .g., on growth) are likely to be of significant importance when considering the greater biological impacts of catch-&-release or other human-derived stressors. [Funded by CA Sea Grant College Prog. NOAA NA06RG042 2002-03, proj. # R/F-192, & NSF grant IBN0115975.]


3)Regulation Of Stress Steroids In Mammals And Fish: Common Mechanisms And Differences.

(M.E. Baker, Department of Medicine - 0693, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0693. )

A key hormone in the resp onse to stress in vertebrates, from humans to fish, is the steroid cortisol, a glucocorticoid. This steroid acts by binding to a receptor, which undergoes a conformational change leading to binding of the cortisol-receptor complex to DNA and the regulati on of transcription of genes involved in the glucocorticoid response. These responses include increased glucose metabolism hence the name glucocorticoid- as well as suppression of the immune response, loss of calcium from bones and programmed cell death, apoptosis, and several other changes. For a long time, the glucocorticoid receptor (GR) was the main focus of research on the stress response. However, it is now clear that enzymes that regulate the concentration of cortisol that can reach the GR also are important in the stress response. One of these enzymes, 11b-hydroxysteroid dehydrogenase-type 2 (11b-HSD-2) catalyzes the oxidation of the C11-hydroxyl on cortisol to a ketone, yielding cortisone, an inactive steroid. This is a convenient on-off switch that conserves the steroid and allows it to be used. The recent cloning of 11b-HSD-2 from fish provides new insights into the regulation of cortisol levels in fish. Interestingly, 11b-HSD-2 also converts 11b-hydroxytestosterone to 11keto-testosterone, the active androgen in fish. Thus, 11b-HSD-2 is a key regulator of androgen and cortisol action in fish. Environmental chemicals that inhibit 11b-HSD-2 will have profound disruptive effects on endocrine physiology in fish.


4)Catch-and-release Stress: Impacts On The Endocrine Physiology Of The California Sheephead, Semicossyphus Pulcher.

M.M. Galima, C.G. Lowe, and K.M. Kelley. Department of Biological Sciences, California State University Long Beach, Long Beach, CA, 90840.

A catch-and-release policy was implemented several years ago by the state of California for undersized ( 30.5 cm TL) California sheephead, Semicossyphus pulcher, with the objective of reducing impacts of fishing pressures on this economically important species. It has not yet been established, however, whether the stress associated with cat ching and releasing has subsequent maladaptive effects. The impacts of catch-associated stressors on the endocrine physiology of S. pulcherwere therefore examined, with an emphasis on how metabolism and growth may be altered. S. pulcherwere caught offs hore near Catalina Island using standard hook and line or commercial trapping. Controls (baseline) consisted of fish blood-sampled within 3 min of initial disturbance, which included catching and rapid retrieval to the surface as well as catching directl y underwater while diving. Fish were subjected to the following stress-inducing protocols: 1) increasing angling fight times up to 20 min, 2) line-catching and confinement in tanks for 10 min to 30 d, 4) trap-catching with up to 5 h soak times, and 5) catching, releasing to the environment for varying periods, and then sampling of recaptured fish. In all experiments, plasma cortisol concentrations increased significantly and often dramatically in response to catch-associated experiences, in a manner com m ensurate with the time and intensity of the treatments. Following the elevations in cortisol were sustained increases in plasma glucose, while increases in lactate were more transitory. Plasma levels of a putative growth-inhibitory protein (IGFBP) were increased in stressed fish, along with alterations in IGF-I concentrations, yet no differences in plasma IGF bioactivity were detected in these experiments. Our data thus far indicate that captured S. pulcher experiences a profound stress response with associated metabolic impacts, while effects on growth regulatory factors are complex and not yet understood. [Support by CA Sea Grant College Program NOAA NA06RG042 2002-03, project # R/F-192 and NSF grant IBN-0115975]


5)Parasites Of Fishes Associated With Wastewater Discharge And The Potential Of Infestation And Stress On Host Fishes

J.E. Kalman. University of California Los Angeles, Department of Organismic Biology, Ecology and Evolution, Los Angeles, CA 90095 and Orange County Sanitation District, Environmental Compliance and Monitoring Division, Fountain Valley, CA 92708.

During the Southern California Bight 2003 Regional Marine Monitoring Survey, select demersal fishes were collected and inspected for ectoparasites. While it is widely known that th e southern California marine environment has been subjected to numerous inputs of pollution, such as wastewater effluent, storm runoff, DDTs and PCBs, little is known about the effects of pollution on infestation of parasites on marine fishes. Exposure t o pollution may result in stress, which may potentially decrease the immune response in fishes and increase their susceptibility to diseases and parasites. This study evaluates the conditions around wastewater outfalls in terms of infestation (e.g., prevalence and mean intensity) of ectoparasites on demersal fishes and examines if specific parasite and/or host species can be used as bioindicators of environmental stress in the Southern California Bight. A variety of marine organisms have been evaluated as potential biological indicators of various forms of pollution in the aquatic environment. However, due to the range of contaminants to which marine organisms are exposed, it is unclear which organisms and which anomal ies are best used as indicators. The hornyhead turbot, Pleuronichthys verticalis, has been used as a model organism for indicating environmental stress. Levels of the stress hormone cortisol and infestation levels of ectoparasites were compared in groups of fish collected at various predeter mined stations in the Southern California Bight. Preliminary results suggest an abnormal response in cortisol levels in groups of fish with high parasite prevalence.


6)Altered Endocrine Physiology Of Southern California Flatfish Collected Near Wastewater Treatment Plant (wwtp) Outflow - Stress And Growth.

J.A.Reyes1, K. Sak1, M.M. Galima1, J.L Armstrong2, and K.M. Kelley1

1)Endocrine Laboratory & Marine Biology Program, Dept. Biological Sciences, California State University, Long Beach, Long Beach, CA 90840; 2)Orange County Sanitation District, Fountain Valley, CA, 92708.

Connections between environmental contamination and impairment of endocrine mechanisms regulating stress responses and growth in marine fish are not understood. Our studies a re beginning to identify potential alterations in the endocrine physiology of local flatfish captured near the WWTP outflow of the Orange County Sanitation District (OCSD). Hornyhead turbot, Pleuronichthys verticalis, and English sole, Parophrys vetulus, are emphasized in these studies, as these species are typically present at depths and locations where the outflow pipes exist, thereby increasing their potential to be exposed to contaminants associated with effluents. Fish were caught by trawling at sites immediately proximal to the outflow and compared with fish caught at sites at varying distances therefrom. In comparison with fish from outside locations, individuals sampled near the outflow exhibited an impaired stress response, as they exhibited significantly blunted plasma cortisol surges in response to trawling and handling stressors. In addition, fish from the outflow locations have significantly reduced plasma concentrations of the growth-stimulatory hormone, insulin-like growth factor-I (IGF-I) . The connections between cortisol, IGF-I, growth, and contaminants will be discussed. In conclusion, our data suggest that essential endocrine systems, namely those regulating the ability to respond to stress and regulating growth and anabolism, are significantly impaired in fish putatively exposed to WWTP effluents. [Supported by NSF grant IBN-0115975 & CA Sea Grant College Program NOAA NA06RG042 2002-03, project # R/F-192]


7)Integrating Physiological And Behavioral Responses Of California Sheephead Exposed To Fishing-related Stressors And Its Implications Towards Management.

C.G. Lowe1, D.T. Topping1, M.M. Galima1, K.J. Goldman2, and K.M. Kelley1.

1Dept. of Biological Sciences, CSU Long Beach, 1250 Bellflower Blvd., Long Beach, CA 90840,, 562-985-4918. 2Jackson State Univ., Dept. of Biology, P.O. Box 18540, Jackson, MS 39217.

Many sport and commercial fisheries require release of undersized fish. However, often little is known about post -release survivorship or non-lethal effects on physiology and behavior. We compared the physiological and behavioral responses of California sheephead (Semicossyphus pulcher) caught on hook & line or traps. Small blood samples were taken from each fish e xposed to different fishery methods to measure the level of cortisol (stress hormone) and metabolites (glucose and lactate). Behavioral effects were determined by monitoring the rate of movement and area use using acoustic telemetry. Fish caught via either method and rapidly blood sampled (< 3 min) showed basal levels of cortisol and metabolites. However, fish exposed to standard hook & line angling techniques showed time-dependent increases in these parameters, which were greater than those caught in t r aps. Fish that were caught on hook & line and then tagged with acoustic transmitters showed slower rates of movement and they covered less area in the first 6 hrs after release, as compared with than fish fed transmitters underwater. These results sugge s t that sport angling of sheephead induces stress-associated alterations in both physiological and behavioral parameters. However, fish released after stressful angling and trapping events may begin to recover from the physiological and behavioral alterat ions within 24 hrs. Results indicate that both fisheries induce similar, but differing magnitudes of physiological stress, yet immediate post-release survivorship is high. [Support by CA Sea Grant College Program NOAA NA06RG042 2001-02, project # R/F-192].


8) Growth And Survival In Juvenile White Seabass Caught-and-released On Offset Circle And J-type Hooks.

S.A. Aalbers,1G.M. Stutzer,2and M.A. Drawbridge1

1Hubbs-SeaWorld Research Institute 2595 Ingraham St. San Diego, CA. 92109 2CSU San Marcos, 333 S. Twin Oaks Valley Rd. San Marcos CA 92096

The catch rate of juvenile white seabass, Atractoscion nobilishas recently increased following an apparent increase in recruitment throughout Southern California, yet no information is available on the incid ental hooking mortality of sub-legal (<711 mm) fish following catch-and-release. We captured juvenile white seabass (430-577 mm total length [TL]) from a net pen on 4/0 offset circle hooks (n = 113), 4/0 J-type hooks (n = 108), and with a net (control, n = 30) to investigate fish performance following release. The effects of hook type on the location of hook penetration, and how hook location affected growth and mortality were examined over the 130 day study. Circle hooks penetrated the lip region signif icantly more frequently (73%) than J-type hooks (41%). All white seabass mortalities sustained damage to the viscera, confirming that post-release mortality is directly correlated with the location of hook penetration. A 10% mortality rate was observed f or fish caught-and-released on both circle and J-type hooks. All mortalities occurred within 5 d post-release. Mortality was reduced when deeply embedded hooks were left in place rather than being removed from the visceral tissue. Hook caught fish show e d no reduced growth when compared with control fish, but deeply-hooked fish grew significantly less than fish hooked in the mouth. There was no significant difference in the angler success rates between hook types. We recommend that catch-and-release mo rtality be incorporated into the management plan for white seabass.


9) Molecular Indicators Of Capture Related Stress In Sharks.

D. Bernal and J. Smith. Weber State University, Department of Zoology, Ogden, UT, 84408

The post-release survivorship of hooked fishes is a key assumption underlying many fishing practices and the reduction of bycatch of non-targeted fishes. However, little is understood about how cellular stress-threshold-indicator levels correlate with the post-release survivability. Although, most fishes can recover from acute bouts of exhaustive exercise, intense and repeated struggling during capture may lead to significant tissue damage and critical disruptions to homeostasis resulting in higher rates of long-term (>30 days) post-release mortality. This study quantified the presence of specific molecular indicators of cellular stress (i.e., Hsp, heat shock proteins 70 and 90) in the blood of sharks with different levels of swimming activity (i.e., the active shortfin mako shark and the sluggish blue shark) in responses to capture with sportfishing gear and commercial longline gear. Preliminary results for sportcaught sharks show an increase in the levels of Hsps as a function of angling time (i.e., struggle stress) in the mako shark and relatively smaller response in the blue shark. No apparent pattern has emerged for the longline caught specimens. Taken together, this preliminary study provides an initial assessment of molecular stress response in sharks and will serve as the foundation for future studies on the long-term molecular responses to capture related stress in fishes.


10) The Physiological Effects of Capture Stress in Tunas, Billfishes, and Sharks with inferences on Post-release recovery.

G.B. Skomal. Massachusetts Division of Marine Fisheries, Marthas Vineyard Research Station, P.O. Box 68, Vineyard Haven, MA, 02568.

Sharks, tunas, and billfishes are exploited by recreational and commercial fisheries worldwide, but quotas, minimum sizes, and bag limits result in the mandated release of large numbers of these fishes annually. Little is known of post-release mortality in large pelagic fishes and increased capture-induced mortality has important implications in quota management. To elucidate the physiological consequences of capture-induced stress in pelagic fishes, blood was sampled from 249 tuna, 217 sharks, and 6 marlin comprising 26 species captured on rod and reel, in gillnets, or on longlines. Changes in blood chemistry were correlated to parameters associated with the capture event and compared to baseline estimates derived from free-swimming fish. Blood gases, lactate and cortisol levels, and serum electrolyte, metabolite, and protein profiles exhibited significant quantifiable changes associated with the capture event. The magnitude and nature of these disturbances varied interspecifically with tunas exhibiting the greatest disruption. To investigate short and long term post-release behavior and survivorship, blood sampled fish were tagged with conventional and/or ultrasonic telemetry tags. To date, nine fish have been recaptured and seven bluefin tuna (Thunnus thynnus), three yellowfin tuna (T. albacares), three blue sharks (Prionace glauca), and two white marlin (Tetrapturus albidus) have been tracked. With the exception of one bluefin tuna, all the tracked fish survived the duration of the tracks, exhibiting behaviorally distinct recovery periods of 2hr. These observations support the hypothesis that pelagic fishes are capable of physiological recovery when handled properly and not subjected to extensive physical trauma.


11) Catch And Release Stress Impacts On Fish: Intergrating Research Findings Into Management Decisions And Angler Catch And Release Practices.

S.F. Theberge.Oregon Sea Grant, Clatsop County Extension Office, OSU Seafood Laboratory, Astoria, OR, 97103

How can we incorporate research information on the impacts of catch and relea se stress on fish into effective management decisions and improvements in release methods? Researchers, managers and fishermen can work collaboratively to develop less stressful release techniques and improve fishery catch and release management rules. Anglers are great innovators whose expertise can be used in designing release devices and methods. Researchers can test how effective the methods are in reducing mortality and stress in fish. Managers can then incorporate the results into effective rules and regulations. Fishermen also should be included in the decision making process for developing catch and release regulations. They can provide important input into what regulations will be enforceable, effective and most likely to gain support among anglers . Buy in by the fishermen can increases compliance and reduce enforcement costs and is necessary for wide acceptance of voluntary catch and release practices. There are many important considerations to consider when designing catch and release methods incl u ding sub lethal effects (slow growth, predation vulnerability and reproduction disturbances), long term mortality (from infections, stress, predation), and the experience and fishing methods of fishers. Handling techniques may need to be specific to speci es and size of fish, environmental conditions, equipment and boats being used, and water depth. Yet the regulations and practices need to be enforceable (if mandatory) and easy to teach and use.