Seafloor Geomorphology as Benthic Habitat

GeoHAB Atlas of Seafloor Geomorphic Features and Benthic Habitats

Peter Harris, Elaine Baker

• Publisher: Elsevier
• Year: 2011
• Print ISBN:
  9780123851406
• eBook ISBN:
  9780123851413
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

The conservation of marine benthic biodiversity is a recognised goal of a number of national and international programs such as the United Nations Convention on Biodiversity (CBD). In order to attain this goal, information is needed about the distribution of life in the ocean so that spatial conservation measures such as marine protected areas (MPAs) can be designed to maximise protection within boundaries of acceptable dimensions. Ideally, a map would be produced that showed the distribution of benthic biodiversity to enable the efficient design of MPAs. The dilemma is that such maps do not exist for most areas and it is not possible at present to predict the spatial distribution of all marine life using the sparse biological information currently available. Knowledge of the geomorphology and biogeography of the seafloor has improved markedly over the past 10 years. Using multibeam sonar, the benthic ecology of submarine features such as fjords, sand banks, coral reefs, seamounts, canyons, mud volcanoes and spreading ridges has been revealed in unprecedented detail. This book provides a synthesis of seabed geomorphology and benthic habitats based on the most recent, up-to-date information. Introductory chapters explain the drivers that underpin the need for benthic habitat maps, including threats to ocean health, the habitat mapping approach based on principles of biogeography and benthic ecology and seabed (geomorphic) classification schemes. Case studies from around the world are then presented. They represent a range of seabed features where detailed bathymetric maps have been combined with seabed video and sampling to yield an integrated picture of the benthic communities that are associated with different types of benthic habitat. The final chapter examines critical knowledge gaps and future directions for benthic habitat mapping research. - Reviews and compares the different methodologies currently being used - Includes global case studies - Provides geological expertise into what has traditionally been a biological discipline

1. Why Map Benthic Habitats?

Peter T. Harris¹ and Elaine K. Baker²

¹Marine and Coastal Environment Group, Geoscience Australia, Canberra, ACT, Australia

²UNEP/GRID- Arendal School of Geosciences, University of Sydney, Australia

Habitat is the property that inherently integrates many ecosystem features, including higher and lower trophic level species, water quality, oceanographic conditions and many types of anthropogenic pressures. Thus, strengthening assessments of status and trends in habitat quality and extent will be an important priority in the development of a global marine assessment.

(Assessment of Assessments Report, UNEP and IOC-UNESCO[1])

This introductory chapter provides an overview of this book’s contents and definitions of key concepts, including benthic habitat, potential habitat, and seafloor geomorphology. It concludes with a summary of commonly used habitat mapping technologies. Benthic (seafloor) habitats are physically distinct areas of seabed that are associated with particular species, communities, or assemblages that consistently occur together. Benthic habitat maps are spatial representations of physically distinct areas of seabed that are associated with particular groups of plants and animals. Habitat maps can illustrate the nature, distribution, and extent of distinct physical environments and, importantly, they can predict the distribution of the associated species and communities.

The data sets collected for constructing habitat maps provide fundamental information that can be used for a range of management and industry applications, including the management of fisheries, spatial marine environmental management, design of marine reserves, supporting offshore oil and gas infrastructure development, port and shipping channel construction, maintenance dredging, tourism, and seabed aggregate mining. Seafloor habitat mapping provides fundamental baseline information for decision makers working in these sectors.

GeoHab (www.geohab.org) is an international association of marine scientists conducting research using a range of mapping technologies in the study of biophysical (i.e., geologic and oceanographic) indicators of benthic habitats and ecosystems as proxies for biological communities and species diversity. Using this approach, combinations of physical attributes of the seabed identify habitats that have been demonstrated to be effective surrogates for the benthic communities that they typically support. Thus, management priorities can be identified using seabed habitat maps as a guide. The work of GeoHab demonstrates how knowledge of seabed properties can be employed to guide marine environmental management, marine resource management, and conservation efforts.

Seafloor geomorphology is one of the most useful physical attributes of the seabed mapped and measured by GeoHab scientists. Different geomorphic features (e.g., submarine canyons, seamounts, atolls, and fjords) are commonly associated with particular suites of habitats. Knowledge of the geomorphology and biogeography of the seafloor has improved markedly over the past 10 years. Using multibeam sonar, submarine features such as fjords, sand banks, coral reefs, seamounts, canyons, and spreading ridges have been revealed in unprecedented detail. The 57 case studies presented in this book represent a range of seabed geomorphic features where detailed bathymetric maps have been combined with seabed video and sampling to yield an integrated picture of the benthic communities that are associated with different types of benthic habitat.

Key Words: Benthic habitats; geomorphic features; physical surrogates; biodiversity; spatial marine planning; environmental management; habitat mapping technology

General Outline of the Content of This Book

This book provides a synthesis of seabed geomorphology and benthic habitats based on up-to-date information contained in the case studies. Part 1 of the book provides an introduction in which the drivers that underpin the need for benthic habitat maps are examined, including threats to benthic habitats. The habitat mapping approach a...

Table of contents

• Cover image
• Table of Contents
• Front-matter
• Copyright
• Foreword
• Preface
• Contributors
• 1. Why Map Benthic Habitats?
• 2. Habitat Mapping and Marine Management
• 3. Anthropogenic Threats to Benthic Habitats
• 4. Biogeography, Benthic Ecology, and Habitat Classification Schemes
• 5. Surrogacy
• 6. Seafloor Geomorphology—Coast, Shelf, and Abyss
• 7. Phanerogam Meadows
• 8. Predictive Modeling of Dominant Macroalgae Abundance on Temperate Island Shelves (Azores, Northeast Atlantic)
• 9. Methane-Related Carbonate Cementation of Marine Sediments and Related Macroalgal Coralligenous Assemblages in the Northern Adriatic Sea
• 10. Coastal Kelp Forest Habitat in the Baie des Chaleurs, Gulf of St. Lawrence, Canada
• 11. The Wadden Sea in the Netherlands
• 12. Sand Wave Field
• 13. Benthic Habitat Variations over Tidal Ridges, North Sea, the Netherlands
• 14. Fine-Scale Geomorphological Mapping of Sandbank Environments for the Prediction of Macrobenthic Occurrences, Belgian Part of the North Sea
• 15. Large Submarine Sand Waves and Gravel Lag Substrates on Georges Bank Off Atlantic Canada
• 16. The Yongala’s “Halo of Holes”—Systematic Bioturbation Close to a Shipwreck
• 17. Submarine De Geer Moraines in the Kvarken Archipelago, the Baltic Sea
• 18. Habitats and Benthos of an Evolving Fjord, Glacier Bay, Alaska
• 19. Geomorphic Features and Benthic Habitats of a Sub-Arctic Fjord
• 20. Seabed Character and Habitats of a Rocky Antarctic Coastline
• 21. Fringing Reefs of the Seychelles Inner Granitic Islands, Western Indian Ocean
• 22. Coral Reefs and Reef Islands of the Amirantes Archipelago, Western Indian Ocean
• 23. Hyperspectral Remote Sensing of the Geomorphic Features and Habitats of the Al Wajh Bank Reef System, Saudi Arabia, Red Sea
• 24. Mesophotic Coral Reefs of the Puerto Rico Shelf
• 25. Geomorphic Features and Infauna Diversity of a Subtropical Mid-Ocean Carbonate Shelf
• 26. Geomorphology of Reef Fish Spawning Aggregations in Belize and the Cayman Islands (Caribbean)
• 27. Submerged Reefs and Aeolian Dunes as Inherited Habitats, Point Cloates, Carnarvon Shelf, Western Australia
• 28. Seafloor Morphology and Coral Habitat Variability in a Volcanic Environment
• 29. Habitats and Benthos at Hydrographers Passage, Great Barrier Reef, Australia
• 30. Two Shelf-Edge Marine Protected Areas in the Eastern Gulf of Mexico
• 31. Nontropical Carbonate Shelf Sedimentation. The Archipelago Pontino (Central Italy) Case History
• 32. Habitats of the Cap de Creus Continental Shelf and Cap de Creus Canyon, Northwestern Mediterranean
• 33. Rock Ridges in the Central English Channel
• 34. Characterization of Shallow Inshore Coastal Reefs on the Tasman Peninsula, Southeastern Tasmania, Australia
• 35. Rocky Reef and Sedimentary Habitats Within the Continental Shelf of the Southeastern Bay of Biscay
• 36. Rock Reefs of British Columbia, Canada
• 37. Seabed Habitats of the Southern Irish Sea
• 38. Habitats and Demersal Fish Communities in the Vicinity of Albatross Bank, Gulf of Alaska
• 39. Seabed Habitat of a Glaciated Shelf, German Bank, Atlantic Canada
• 40. Identifying Potential Habitats from Multibeam Echosounder Imagery to Estimate Abundance of Groundfish
• 41. Open Shelf Valley System, Northern Palaeovalley, English Channel, UK
• 42. Benthos Supported by the Tunnel-Valleys of the Southern North Sea
• 43. Benthic Habitats and Benthic Communities in Southeastern Baltic Sea, Russian Sector
• 44. Inland Tidal Sea of the Northeastern Pacific
• 45. Cold-Water Coral Distribution in an Erosional Environment
• 46. Habitat Mapping of a Cold-Water Coral Mound on Pen Duick Escarpment (Gulf of Cadiz)
• 47. Habitats at the Rockall Bank Slope Failure Features, Northeast Atlantic Ocean
• 48. Evaluating Geomorphic Features as Surrogates for Benthic Biodiversity on Australia’s Western Continental Margin
• 49. Habitats of the Chella Bank, Eastern Alboran Sea (Western Mediterranean)
• 50. Habitat Heterogeneity in the Nazaré Deep-Sea Canyon Offshore Portugal
• 51. Banks, Troughs, and Canyons on the Continental Margin off Lofoten, Vesterålen, and Troms, Norway
• 52. Distribution of Hydrocorals Along the George V Slope, East Antarctica
• 53. The Cook Strait Canyon, New Zealand
• 54. The Ascension–Monterey Canyon System
• 55. A Study of Geomorphological Features of the Seabed and the Relationship to Deep-Sea Communities on the Western Slope of Hatton Bank (NE Atlantic Ocean)
• 56. Seafloor Habitats and Benthos of a Continental Ridge
• 57. Habitats and Benthos of a Deep-Sea Marginal Plateau, Lord Howe Rise, Australia
• 58. Seamounts, Ridges, and Reef Habitats of American Samoa
• 59. Mapping Condor Seamount Seafloor Environment and Associated Biological Assemblages (Azores, NE Atlantic)
• 60. Cold-Water Coral Colonization of Alboran Sea Knolls, Western Mediterranean Sea
• 61. Fluid Venting Through the Seabed in the Gulf of Cadiz (SE Atlantic Ocean, Western Iberian Peninsula)
• 62. Habitats of the Su Su Knolls Hydrothermal Site, Eastern Manus Basin, Papua New Guinea
• 63. Southern Kermadec Arc–Havre Trough Geohabitats and Biological Communities
• 64. GeoHab Atlas of Seafloor Geomorphic Features and Benthic Habitats
• Glossary