The diversity of life in the ocean is being dramatically altered by the rapidly increasing and potentially irreversible effects of activities associated with human population expansion. Biodiversity is defined as the collection of genomes, species, and ecosystems occurring in a geographically defined region. The most critical (current or potential) contributors to changes in marine biodiversity are now recognized to be the following: fishing and removal of the ocean's invertebrate and plant stocks, many of which are overexploited; chemical pollution and eutrophication; physical alterations to coastal habitat; invasions of exotic species; and global climate change, including increased ultraviolet radiation and potentially rising temperatures, resulting in possible changes to ocean circulation (and thus nutrient supply and distribution). These stresses to the marine environment have affected and may yet affect life from the intertidal zone to the deep sea.

These activities and phenomena have resulted in clear, serious, and widespread social, economic, and biological impacts including:

• dramatic reductions in most of the preferred edible fish and shellfish species in the world's oceans;
• reduction or loss of species with important potential for biomedical products;
• altered aesthetic and recreational value of many coastal habitats, such as coral reefs, bays, marshes, rocky shores, and beaches;
• vast changes in the species composition and abundance of the ecologically important animals and plants within and between impacted ecosystems; and
• changes in the basic functioning of ecosystems, including the rates and

• sources of primary production, the stability of populations, the amount and directions of energy flow, and biogeochemical cycling.

Evaluating the scale and consequences of changes in the ocean's biodiversity due to human activities is, however, seriously compromised by critically inadequate knowledge of the patterns and the basic processes that control the diversity of life in the sea.

The basic description of marine biodiversity trails that of the terrestrial realm, particularly as it relates to the extraordinary diversity of higher taxa in the marine compared to the terrestrial environment. Continuing discoveries of new families, orders, and even phyla of marine organisms foretell a wealth of biodiversity yet to be realized.

Like terrestrial habitats, there are vast numbers of undescribed species in familiar oceanic habitats, such as coral reefs and temperate bays and estuaries. There are environments, like the deep sea and polar regions, that are so under-sampled that numerous new species are discovered during each expedition to a new area. Newly recognized biological habitats that contain novel species assemblages—such as hydrothermal vents, whale carcasses, brine seeps, and wood debris—continue to emerge, especially in deep water. Moreover, understanding of the mechanisms responsible for the creation, maintenance, and regulation of such habitat-specific marine biodiversity is incomplete, fragmentary, or entirely lacking.

Yet exciting new information, novel techniques, and heightened awareness now permit dramatically improved sampling and species identifications and process-oriented research at increasingly larger geographic scales. Such studies have been previously intractable, but are fundamentally required to understand the consequences of anthropogenic changes to the diversity of marine life.

This report identifies the urgent need for a national research program on Biological Diversity in Marine Systems and outlines a research agenda. This research agenda proposes a fundamental change in the approach by which biodiversity is measured and studied in the ocean by emphasizing an integrated regional-scale research strategy within an environmentally relevant and socially responsible framework. This is now possible because of recent technological and conceptual advances within the ecological, molecular, and oceanographic sciences.

Propelled by the need to understand the effects of human activities on biodiversity, this research program would require studies conducted at appropriately large temporal and spatial scales. Given the open nature of marine systems, a regional-scale approach must be taken, one that involves studying multiple, separate sites within a large geographic region. Biological and physical criteria would be used to define this region—that is, to set the maximum spatial and temporal scales required to characterize those processes that control local biodiversity. This decadal-time-scale research program would integrate ecological

and oceanographic research spanning a broad range of spatial scales, from local to regional, and over appropriate time scales for distinguishing changes in biodiversity due to effects of human activities from natural phenomena.

A well-defined set of research questions would be addressed in studies of several different kinds of regional-scale marine ecosystems. These studies would permit meaningful comparisons of the causes and consequences of changes in biodiversity due to human activities in different habitats.

This agenda would require significant advances in taxonomic expertise for identifying marine organisms and documenting their distributions, in knowledge of local and regional natural patterns of biodiversity, and in understanding of the processes that create and maintain these patterns in space and time. This would provide, in fact, an exciting opportunity to develop the interface between taxonomy and ecology and between the ecological and oceanographic sciences.

The five fundamental objectives of this first national research agenda on marine biodiversity are:

• to understand the patterns, processes, and consequences of changing marine biological diversity by focusing on critical environmental issues and their threshold effects, and to address these effects at spatial scales from local to regional and at appropriate temporal scales;
• to improve the linkages between the marine ecological and oceanographic sciences by increasing understanding of the connectivity between local, smaller-scale biodiversity patterns and processes and regional, larger-scale oceanographic patterns and processes that may directly impact local phenomena;
• to strengthen and expand the field of marine taxonomy through training, the development of new methodologies, and enhanced information dissemination, and to raise the standard of taxonomic competence in all marine ecological research;
• to facilitate and encourage the incorporation of (1) new technological advances in sampling and sensing instrumentation, experimental techniques, and molecular genetic methods; (2) predictive models for hypothesis development, testing, and extrapolation; and (3) historical perspectives (geological, paleontological, archaeological, and historical records of early explorations) in investigations of the patterns, processes, and consequences of marine biodiversity; and
• to use the new understanding of the patterns, processes, and consequences of marine biodiversity derived from this regional-scale research approach to improve predictions of the impacts of human activities on the marine environment.

As envisioned by the committee, this national research agenda for marine biodiversity would lead to novel, integrated, multiple-scale studies that would improve understanding of how human activities alter marine biodiversity and of why and how such alterations change the functioning of ecosystems. In turn, this understanding would provide valuable information for policymakers regarding the preservation and conservation of marine life, and for identifying those path-

ways that might save and restore the sea. The ultimate benefit to science and society of this research program would be an enhanced ability for long-term sustained use of the oceans and marine organisms for food, mineral resources, biomedical products, recreation, and other aesthetic and economic gains, while conserving and preserving the diversity and function of life in the sea.

In summary, this marine biodiversity initiative would be:

• An environmentally responsible and socially relevant basic research program on the causes and consequences of changes in marine biological diversity due to effects of human activities.
• A research agenda guided by well-defined research questions that will be addressed concurrently in several different regional-scale systems.
• A program that focuses on large-scales that were previously intractable but are absolutely required to address the most compelling biodiversity research questions.
• A partnership between the ecological and oceanographic sciences, both conceptually and methodologically, for explaining biodiversity patterns, processes, and consequences.
• A partnership between ecology and taxonomy, with a major focus on reinvigorating the field of marine taxonomy and systematics.
• A research program with the ultimate goal of improving predictions regarding future effects of human activities on marine biodiversity, thus facilitating the use of the sea for societal needs while minimizing impacts on nature.