HABITAT REQUIREMENTS AND EXPECTED DISTRIBUTION OF ALASKA CORAL by Robert L. Cimberg VTN Oregon, Inc. Tim Gerrodette Scripps Institution of Oceanography Katherine Muzik Harvard University Final Report Outer Continental Shelf Environmental Assessment Program Research Unit 601 October 1981 207 TABLE OF CONTENTS List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 I. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 11. BACKGROUND REVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 III. DISTRIBUTION, HABITATS, AND PROBABLE LOCATIONS . . . . . . . . . . . . . . . . . 221 A. Purpose and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 B. Results and Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 222 1. Commercial Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 2. Distribution, Abundance, Habitat, and Probable Location . . 227 a. Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 IV. IMPACTS OF OIL AND GAS EXPLORATION AND DEVELOPMENT . . . . . . . . . . . . . 248 A. Purpose and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 B. Results and Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 1. Physical Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 2 . Chemical 3. Recolonization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 v. RECOMMENDED STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 A. Distribution and Taxonomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 B. Habitats and Ecology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 Gas Exp” oration and Deve opment . . . . . . . . . . 264 C. Impacts of Oil and VI. SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 VII. ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 VIII. LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 IX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 APPENDIX 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 APPENDIX 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 APPENDIX 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 APPENDIX 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 LIST OF FIGURES Figure 1. Index Map. Figure 2. Distribution of Primnoa the Gulf of Alaska. in Figure 3. Distribution of Primnoa near Kodiak Island. Figure 4. Distribution of coral in the Bering Sea. Figure 5. Distribution of Primnoa with depth. Figure 6. in the Mean bottom temperatures from April through June Gulf of Alaska. Figure 7. Predicted distribution of Primnoa in the Gulf of Alaska. Figure 8. the Gulf of Alaska. Distribution of coral in Figure 9. Distribution of corals with depth. Figure 10. Distribution of coral in the Chukchi Sea. in the Beaufort Sea. Figure 11. Distribution of coral Figure 12. Proposed lease areas. 211 LIST OF TABLES Table 1. Coelenterate systematic. Table 2. Systematic of Alaskan corals and their estimated value. Table 3. Reported and predicted distributions of corals in Alaska, by region. 213 I. INTRODUCTION Proposed leasing of Alaskan Outer Continental Shelf (OCS) areas for oil and gas exploration and development has resulted in the need to gather and synthesize information which can be used by the Bureau of Land Management (BLM) to make decisions necessary for protection of the marine environment. One particular aspect of the marine environment BLi’4 has been required by law to protect is the coral resource (OCS that Lands Act of 1953; Public Law 94-265; Fisheries Conservation and Management Act of 1976; and Federal Register Notes 43 CFR 6224, Protec- tion and Preservation of National Values). In addition, during the past ten years a commercial coral industry has developed in Alaska. These corals are harvested by fishermen who either selectively seek them out or make incidental catches while fishing for other commercial species. The objectives of this study are to provide the Alaskan OCS office of the Bureau of Land Management with: 1) a compilation and synthesis of information from the literature and other sources regarding the distribution, abundance, habitat requirements, and probable locations of corals along the Alaskan OCS waters; 2) a discussion of the potential effects of oil and gas exploration and development on corals; and 3) recommendations for further studies of corals and the effects of oil and gas exploration and development on these organisms. All Alaskan OCS waters are reviewed in this report. Areas within the Gulf”of Alaska are emphasized for two reasons. One, this region is the first area of Alaska available for oil and gas exploration and development, and two, most of the commercial harvesting-of coral takes place in this area. This study will focus on specific areas within the Gulf of Alaska proposed for oil and gas development (Lower Cook Inlet, Shelikof Strait, Kodiak Island, and Northeast Gulf of Alaska), as well as the inland waters of southeast Alaska. The latter region is presently not contemplated for oil development, but includes areas rich 215 in commercial coral and thereby provides a major source of coral information. The following chapter (Chapter 11) presents a review of coral taxonomy, life history, and ecology which may assist In understanding subsequent III-V address specific objectives of portions of the report. Chapters the study, while Chapter VI presents a summary of information generated in the report. .,., , . . . . . . . 216 11. BACKGROUND REVIEW The term “coral” is applied to several diverse orders within the urn Coelenterata (Table 1). This study covers those orders of Phyl Coelenterates having corals found in Alaska. These include the orders Alcyonacea (soft corals), Gorgonacea (sea fans or horny corals), and Scleractinia (cup corals, stony corals, or hard corals) in the class Anthozoa, and the order Stylasterina (hydrocorals) in the class Hydrozoa. The morphology of corals varies. The living tissues are composed of polyps, each with a mouth surrounded by tentacles. Some species are composed of a single polyp, others are colonies of many polyps. Certain corals are upright and display varying degrees of branching, while others are low growing, encrusting forms. Corals vary in size from less than 1 cm to over 1 m. The skeletons of corals consist of spicules which are embedded within or are deposited outside the living tissues. The chemical composition (hardness) and size of the skeleton are important in determining the commercial value of each species. Sexual reproduction usually takes place between individual polyps or colonies, since sexes in most corals are separate (Lacaze-Duthiers 1864; Bayer and Weinheimer 1974; Grigg 1977; Weinberg and Weinberg 1979). Female colonies harbor the eggs, which are fertilized by sperm from male colonies. Fertilized eggs develop within the female polyps into planula larvae. The planula larva of many species has never been observed (Stimson 1978); those that have been studied are usually large (between 0.5 and 2.5 mm long), pink, ciliated, and slightly negatively buoyant (Sevens 1981). The larvae usually live between 2 and 10 days (Lacaze-Duthiers 1864; Gohar 1940; Kinzie 1973; Grigg 1977; Weinberg and Weinberg 1979) although some have been reported to survive up to 90 days in the laboratory (Vaughan and Wel 1s 1943; Grigg 1979). 217 Table 1. Coelenterate Systematic. Orders covered in this study are asterisked (*). . Phylum Coelenterata Common Name; Distribution Class Anthozoa Subclass Octocorallia (Alcyonaria) * Order Alcyonacea Soft corals, sea strawberries; found in Alaska. Order Coenothecalia Blue coral; found in tropical Pacific reefs. * Order Gorgonacea Sea fans, fan coral; found in Alaska. Sea pens, sea pansies; found in Order Pennatulacea Alaska. Subclass Hexacorallia (Zoantharia) Order Actinaria Sea anemones; found in Alaska. Order Antipatharia Thfirny corals, black coral; found in tropics, subtropics. Order Ceriantharia Cerianthids; possibly in Alaskal. * order Scleractinia Stony corals, cup corals; found ( =Madreporari a) in Alaska. Order Zoanthidae Zoanthids; not in Alaska. Class Hydrozoa Order Hydroida Hydroids and jelly fish; found in Alaska. Order Milleporina Fire coral, millepores; not found in Alaska. Order Siphonophora Jellyfish; found in Alaska. * Order Stylasterina Hydrocorals, hard corals; found in Alaska. Order Trachylina Jellyfish; found in Alaska. Class Scyphozoa Jellyfish; found in Alaska. ? Covered in this study 1 Dr. Bruce Wing, personal communication 218 Planula larvae either swim, crawl, sink and perhaps float after being released. Planula of most corals are not usually dispersed very far CO1 oni es ( Gerrodette 1981). The 1 arva of from parent Frl tchman 1974; one species creeps down the parent colony and settles nearby (Kinzie 1973). Larvae of other species can crawl and settle up to 40 m away (Weinberg and Weinberg 1979). There is one report of planula larvae floating (Butler 1980), but this observation has not been substantiated. The planulae settle, often on current-swept solid substrates, and undergo metamorphosis into the primary polyp stage. Only a very small fraction of the larvae reach this stage; many are lost by landing on unfavorable substrates, others are eaten by predators, while still others are abraded and smothered by sediment and algae. In colonial species, subsequent budding (asexual reproduction) of the primary polyp stage produces additional polyps, each with a mouth surrounded by tentacles; these polyps form and share a common skeleton. The colony continues to grow by budding more polyps and secreting additional skeletal material. Growth of most corals is believed to be slow and may require over 100 years to reach maximum size. Causes of adult mortality include physical factors such as smothering by sand (Grigg 1977), toppling of large colonies by storm waves (Birkeland 1974), weakening of skeletons by boring organisms (Dr. Richard Grigg, personal communication), freshwater runoff, and exposure to air during extreme low tides. Biological factors include inter- specific competition with other coral species, and predation. Corals compete with each other for space and light by overgrowing one another and/or by digesting adjacent colonies. Coral predators include snails (Kinzie 1973, Birkeland 1974), fish (Randall 1967; Clarke 1968), polychaetes (Dr. R. Kinzie, personal communication), starfish and nudibranchs (Sebens, personal communication). Recently man has caused mortalities as a result of thermal and chemical pollution from power plants, sewage (Smith et al. 1973), and oil and gas exploration and development (Dept. of Commerce 1979; Loya and Rinkevich 1980). 219 Coral distribution and abundance is affected by substrate size, cur- rents, depth, and temperature. Most coral species require a solid, rocky substrate to survive, however, a few can live on sandy and muddy bottoms. Currents bring food, reduce sedimentation, and may assist in larval dispersal. Depth is important because of its relationship with other factors such as light, temperature, salinity, oxygen, and wave action. Light is necessary to many tropical, reef-building corals harboring commensal algae, which produce the necessary food for the host coral. Temperature is known to control the distribution of reef forming corals and the reproductive activity of certain temperate species (Grigg 1979). Corals are often found in association with other species and can provide a habitat for fish and invertebrates that fish might feed on. 220