1. Physiological and behavioral effects of hypoxia on Atlantic croaker in the Chesapeake and Coastal Bays Andrea K. Johnson University of Maryland Eastern Shore Collaborators: Dr. Mary Fabrizio (VIMS) Dr. Richard Brill (NOAA/VIMS)

2. World Hypoxic and Eutrophic Coastal Areas 415 eutrophic and hypoxic coastal systems worldwide 169 hypoxic areas 233 areas of concern 13 systems in recovery

3. HYPOXIA Result –changes in species composition – population decline – mass mortalities –production of extensive “dead zones” such as that in the Gulf of Mexico Massive Fish Kill in Gulf Caused by "Dead Zone,” Oil? Photograph courtesy P.J. Hahn, Plaquemines Parish Environmental degradation has been increasing the occurrence of hypoxia.

4. Spawning (Fall-Winter) Larvae Offshore Estuary Juveniles STUDY OBJECTIVE We proposed to use Atlantic croaker, an economically and ecologically important demersal species, as a model species to assess the sublethal effects of seasonal hypoxia on fish physiology, movement and distribution.

5. ATLANTIC CROAKER Good indicator species in which to study the effects of environmental degradation – Well researched – Hardy – Matures quickly – Found in hypoxic waters 1.6-3.7 mg/L DO in the Gulf of Mexico (Craig and Crowder, 2005; Thomas et al., 2007) < 2 mg/L DO Chesapeake Bay (Fabrizio pers. obs.)

6. SPECIFIC OBJECTIVES 1. Laboratory Study (Year 1-2) Determine the effects of hypoxia exposure on immunological, reproductive and endocrine functions of croaker under controlled laboratory conditions. 2. Field Study (Year 1) Determine the persistence (presence/absence over time) of croaker in areas that develop hypoxia in Chesapeake Bay using active acoustic telemetry.

7. SPECIFIC OBJECTIVES 3. Field Study (Years 3-5) Compare immunological, reproductive and endocrine functions in croaker collected from hypoxic and reference sites in the Chesapeake and Coastal Bays. 4. Field Study (Years 1-5) Integrate observed physiological responses determined in laboratory and field studies to behavioral responses of croaker, and to changes in water quality and other environmental variables (tested under subprojects 1 and 2) in the field.

8. HEALTH INDICATORS TIER I General Health Status TIER II Indicators of Biochemical Status TIER III Immune and Endocrine Function

9. TIER I Histo- pathology Liver, gills, heart, intestines, gonads, kidney Fecundity Organo- somatic Indices Spleno- somatic Index (SSI) Hepato- somatic Index (HSI) Gonado- somatic Index (GSI) GENERAL HEALTH STATUS

10. TIER II Plasma Chemistry WBC Counts Hematocrit BIOCHEMICAL STATUS

11. TIER III Endocrine GnRHVitellogenin Immune Phagocytosis ENDOCRINE AND IMMUNE FUNCTION

12. Sperm Production GSI Sperm development Oocyte Production GSI Ooycte development EXTERNAL STRESSORS (e.g. hypoxia, toxicants) Gonadotropins Testes Ovaries T, 11-KT T, E 2 GnRH Plasma vitellogenin Liver vitellogenesis Adrenocorticotropic Hormone (ACTH) Interrenal tissue Cortisol Muscle protein  Growth  Reproduction  Immune functions  Survival  Disease  Corticotropic Releasing Hormone (CRH) HPI AXISHPG AXIS

13. PROJECT TIMELINE

14. EDUCATION AND OUTREACH

15. THANK YOU