Saturday, March 15, 1997
Integrated Plenary Session on Marine Biodiversity
Elliot A. Norse
Although loss of biological diversity on land (especially tropical forests) became a major global issue in the 1980s, until very recently far less attention has been given to loss of biological diversity in the marine realm. Yet, the marine realm is vastly larger: it constitutes more than 99% of the portion of the biosphere permanently inhabited by animals and plants. Not surprisingly, it is biotically rich (in some ways far richer than the land), is vitally important as a source of economic products and free ecosystem services, and is subject to the same pressures as terrestrial ecosystems. In the course of producing Global Marine Biological Diversity: A Strategy for Building Conservation into Decision Making (Island Press 1993), I identified five proximate threats to biological diversity in oceans, coastal waters and estuaries: 1) Overexploitation, both of species that are deliberately sought and non-target species taken by non-selective methods; 2) Physical alteration, from diverse sources such as mangrove forest destruction, saltmarsh draining, bottom trawling and erosion of land caused by unsustainable agricultural practices; 3) Pollution, by the addition of toxic chemicals, nutrients, radionucleides and solid wastes to the sea from discharges, dumping, runoff and aerial fallout; 4) Introduction of alien species, both intentionally and by trans- and inter-oceanic movement of ships holding large amounts of larvae in ballast water; and 5) Global atmospheric change, both stratospheric ozone depletion causing increased UV-B radiation on the Earth's surface, and the many consequences of global climatic change.
Marine protected areas, such as the Monterey Bay National Marine Sanctuary are an essential components of any strategy for conserving life on Earth, but only 0.6% of US marine waters under federal jurisdiction are protected as marine sanctuaries. The effectiveness of these areas will markedly improve as scientists learn more about their design and management; this will be one of the major topics at the first Symposium on Marine Conservation Biology, which MCBI is organizing at the Annual Meeting of the Society for Conservation Biology at the University of Victoria, Victoria, British Columbia on June 6-9, 1997. Like terrestrial protected areas, the effectiveness of marine protected areas ultimately depends on the commitment of nations and local people to protecting the resources within them and to preventing external influences from diminishing their integrity.
California's four National Marine Sanctuaries stretch nearly 600 km and protect the world's most diverse temperate coastline. Origins of this biotic richness, and the processes maintaining it are complex and varied, but many are related to the region's location in the California Transition Zone (CTZ). The CTZ, centered on Monterey Bay, represents the intergradation between biotas of the cold Oregonian-Aleutian and the warm Californian-Mexican-Panamanian biogeographical provinces. Central California contains most species from both provinces, many endemic species restricted only to the CTZ, numerous migratory or ephemeral species, and evolutionary relics that survive nowhere else. Biotic diversity is enhanced and maintained by: complex oceanographic processes (currents, upwelling); geological and tectonic processes that create innumerable habitats from coastal marshes to deep-sea canyons and abyssal plains; and by environmental fluctuations on many scales e.g. weather and upwelling (seasonal); El NiÒo (decades); climate (centuries); sea level fluctuations (millennia); longterm geological processes.
Bruce H. Robison
The deep waters of the world ocean comprise the largest living-space on Earth. Within these waters are the largest animal communities on the planet. Yet despite the obvious importance of this enormous fauna to global ecology, the deep ocean remains the least explored and least understood of Earth's major ecosystems. In the last decade technological advances have greatly improved our access to these remote and hostile habitats, particularly in the oceanic water column where the majority of oceanic life occurs. In Monterey Bay, research utilizing undersea vehicles has revealed a representative deep water fauna that is much larger and more ecologically complex than could have been determined by conventional sampling methods. Among the most significant results is the discovery that gelatinous animals comprise as much as a quarter of pelagic biomass, that was missed by traditional surveys. This diverse and fascinating group of animals constitutes an important yet undescribed branch of the oceanic food web. As we continue to work deeper into the Monterey Submarine Canyon, our measurements of diversity across all taxa, continue to expand. Deep waters on a global scale surely contain the largest remaining groups of under-described biodiversity. Continued exploration will reveal not only new species, but whole new communities and new, large-scale ecological patterns as well.
The remarkable biological richness and diversity of land and sea environments has been important in shaping human activities in the Monterey Bay region. Human activities also affect the maintenance of biodiversity, through the complex interactions of scientific knowledge, resource use and conservation. As we become more knowledgeable about the interaction of terrestrial and marine ecosystems, we must complement this with a better understanding of the connections between land and sea in regional economic activities and in the development of effective social and political institutions. This presentation will review recent research on institutional innovations that affect biodiversity and present some research themes that may be useful in analyzing the human encounter with nature in this region.
The biota of the rocky intertidal within the boundaries of the Sanctuary is among the most diverse in the world, and local researchers have been exploring that diversity for over a century. Most of the early work was done by students and staff at Stanford University's Hopkins Marine Station, but the past several decades have seen increasing attention from other institutions around the Bay, especially Moss Landing Marine Laboratories and the University of California, Santa Cruz. Accumulating evidence indicates that species diversity and abundance have undergone considerable change over this century, partly in response to global warming. On the other hand, despite droughts, floods, earthquakes, and increasing impacts by humans and pinnipeds, the overall diversity remains high, reflecting the strong resilience of this spectacular biota. Well-designed, long-term monitoring programs are needed now so we can better understand how the system responds to both short-term and long-term environmental change.
Rikk G. Kvitek, California State University Monterey Bay
The spatial and temporal patterns of invertebrate species found in the Elkhorn Slough reflect the dynamic history of the natural and anthropogenic factors that continue to shape the slough's physical habitat and biotic communities. Today, the Elkhorn Slough is strongly influenced by daily tidal flushing, seasonal and decadal drought cycles, and a long history of extensive anthropogenic modifications. This condition is typical of most of the few remaining estuaries and tidal embayments along the west coast of the United States. Prior to the opening of the Moss Landing Harbor mouth in 1946, however, the slough was not exposed to daily tidal flushing and was a much more protected, shallow, brackish appendage of the Salinas River channel.
Here we present a quantitative description of spatial and temporal patterns of intertidal infaunal species found along the length of the Elkhorn Slough spanning a fifteen year period. In addition, we describe the spatial distribution of the major subtidal bivalve species along the seaward half of the main channel, before the occupation of this area by foraging sea otters during the late 1980's and early 1990's. We discuss these patterns in terms of the four major factors that most likely modified the invertebrate communities of the Elkhorn Slough during recent history: 1) construction of Moss Landing Harbor and resulting tidal scour, 2) invasion by exotic invertebrate species, 3) occupation of the slough by sea otters, and 4) human exploitation of invertebrates for food and bait.
Judith L. Connor
From a historical perspective, studies of deep-sea biodiversity are relatively recent. The HMS Challenger expedition of the 1870s laid the groundwork for our present exploration of deep sea life. Modern day researchers still make use of nets, trawls, and other tools similar to those used in the days of the Challenger, but they have a variety of high-tech tools available, too.
New technologies for deep-sea science include moorings, submersibles that carry scientists down into the ocean depths, remotely-operated vehicles (ROVs) and autonomous underwater vehicles (AUVs). These vehicles are often equipped with video and still cameras, sample collecting devices, instruments to analyze the physical and chemical components of the ocean, and navigational equipment to determine exact positions. The information gathered from these devices combine to produce detailed portraits of deep sea communities including knowledge of which animals live in each niche, who are their nearest neighbors, and what climates characterize particular sites.
At the Monterey Bay Aquarium Research Institute (MBARI), we use moorings, ships and two remotely-operated vehicles to study Monterey Bay and the ocean beyond. Having a deep submarine canyon so close to shore provides opportunities to study the deep sea on a daily basis, and that means a tremendous amount of information to track. There are samples and data on rocks, sea water, and animals to analyze, archive and share. One of our most exciting projects is the development of a data archive and retrieval system that will work like a recipe from a team of the finest chefs. Start with the best ingredients (high-quality video images from the ROVs and data collected from a variety of instruments), add expertise (descriptions and opinions from scientists), and make the final product appealing and accessible.
Jim A. Estes
Sea otters, after having been hunted to near extinction, made a spectacular recovery following the cessation of hunting. Numerous island populations in the west-central Aleutian archipelago reached what is thought to be pre-exploitation levels at carrying capacity between the mid-1940s and late 1960s. Local extinction and recovery of the sea otter was accompanied by dramatic changes in kelp forest communities, due in large part to strong top-down interactions in the kelp-sea urchin-sea otter food chain. Thus, in many areas sea otters are necessary for the maintenance of kelp forest ecosystems, and therefore the stability of these systems is closely linked to the persistence of sea otters. We have documented a steady decline in the sea otter population at Adak Island from >2500 individuals in the early 1990s to <700 in 1996. Evidence obtained from radio-tagged otters indicates that the decline is due to elevated adult mortality. Three possible causes are currently being explored--food limitation, environmental pollutants, and predation. Presently, our findings point most strongly to predation by killer whales, which may be the result of redirected hunting in this species following recent declines of once-abundant pinniped populations. Whatever the cause, these result demonstrate that sea otter populations can decline very rapidly. Long-term conservation tactics for sea otters and kelp forests must include the expectation that such perturbationswill be both likely and unpredictable.
Biodiversity in Action: Regional Programs on Biodiversity
The Monterey Bay National Marine Sanctuary stretches over 360 miles along California's Central Coast, and its resources can be affected by a wide variety of marine and land-based activities. The 11 major watersheds which drain to the Sanctuary contain a mixture of land uses and habitats which affect water quality and biodiversity -- urban developments, grazing and cropland, rivers, wetlands, and harbors. Clean water in the Sanctuary and its watersheds is essential for maintaining the diversity of our marine resources, and for the many organisms who use our coastal watersheds as migratory corridors and nursery grounds. It is also a key factor in sustaining a diversity of human interests within our community--the residents, tourists, landowners and businesses who use local waters for swimming, surfing, fishing, diving, irrigation and drinking water. As growth in our coastal population and land uses place increasing pressure on these resources, preventive measures must be developed to protect water quality and preserve biodiversity, while maintaining a healthy economy. The Water Quality Protection Program (WQPP) for the Sanctuary is serving as a catalyst for pooling the resources and talents of various groups to meet this goal through education, conservation and management, research and monitoring.
Currently 27 federal, state and local agencies, public and private organizations are working together as part of the WQPP to develop and carry out strategies for a range of water quality and watershed issues. These include urban and agricultural runoff, marinas and boating activities, wetland and riparian issues, sewage discharges, and regional monitoring. A prime focus is to better integrate the large number of existing programs related to these issues (over 100!), eliminate gaps and redundancies, and pool resources to address problems. Plans are completed and underway for urban runoff and boating activities, using a combination of staff from various agencies, educators, nonprofit groups, volunteers and grant support. Key efforts include regional education, technical training, development of a regional stormwater program, and convenient waste disposal facilities. Efforts are also underway to better coordinate government monitoring programs, and develop Sanctuary-wide coordination of volunteer monitoring through local nonprofit groups. While these completed plans are being carried out, planning is also underway with local growers and ranchers to address water quality issues related to agriculture and wetlands.
The long-term success of the WQPP will depend heavily on ongoing community involvement in the program, and in raising public awareness of the connection between our everyday activities in the watersheds and the ocean's health.
Most efforts to manage biodiversity have focused on enhancing, restoring, and preserving plant and animal communities on lands controlled by public agencies and non-profit organizations. This strategy works well where federal and state lands constitute the majority of land in a bioregion. However, most of the lands that drain into Monterey Bay are controlled by private landowners whose primary objective often is to earn a living from monocrop agricultural endeavors. These private lands provide a unique challenge to resource planners who seek to enhance biodiversity.
This presentation will discuss the efforts of the USDA Natural Resources Conservation Service and other collaborators who are encouraging farmers in the Elkhorn Slough Watershed to voluntarily manage their farm landscapes for multiple resource objectives. Biodiversity is beginning to be incorporated in farm operations through vegetated buffers, restored riparian corridors, and biological pest management plantings. Only when biodiverse management systems can be shown to reduce soil erosion, capture nutrients and pesticides, contain flooding, increase groundwater recharge, and control pests will farmers become advocates of biodiversity on the extensive private lands in this region.
The Return of the Natives Restoration Education Project has been involving schoolsand communities in hands-on habitat restoration around Monterey Bay for the past 5 years. Our goal is to develop and nurture an environmental pipeline from kindergarten through college while restoring native habitats. So far hundreds of teachers have participated in our training workshops, and thousands of pre-college students have participated in our planting events. Over 20,000 of the native trees, grasses and shrubs planted during community restoration events were propagated in 8 RON greenhouses in area schools. So far, RON activities have been centered mainly in Monterey County, however, the RON model is adaptable to any community nation-wide.
Paul N. Reilly
During the past several decades commercial and sport fishing effort in central California has expanded into coastal areas which previously received little or no fishing pressure and functioned as ad hoc refuges, protecting significant populations of sexually mature fishes. Recently the concept of legally established marine reserves, in which all consumptive uses are prohibited, has received increased attention, both for the intrinsic value of preserving biodiversity and spawning stocks and for the potential enhancement of fishing in adjacent and more distant areas.
The California Department of Fish and Game's Central California Marine Reserves Project, based in Monterey, has been collecting baseline data at Big Creek Ecological Reserve (BCER), 50 miles south of Monterey, since 1993, prior to its designation as a reserve. The Project focuses on important nearshore sport fish species, primarily rockfishes, and is estimating population densities and length frequencies using standardized scuba surveys. A paired laser/video system is used to measure fishes in situ without harming them or altering their habitat. The primary objective of the Project is to evaluate the feasibility of BCER relative to protecting populations of reproductively mature sport fishes and the potential enhancement of fishing outside BCER due to larval dispersal and spillover effects.
Since 1987, the Department's Central California Commercial Passenger Fishing Vessel (CPFV) Project, also based in Monterey, has conducted an on-board sampling program in northern and central California. The Project has developed a location- and species-specific data base from observing the catches of CPFV anglers on approximately 1850 trips from Eureka to Port San Luis. Forty-two rockfish species and 33 other species have been observed. By partitioning the data into six groups based on a combination of depth range and distance from port, trends in catch per unit effort and mean length by species can be examined as indicators of the health of the fishery. CPFV trips to the area adjacent to BCER are relatively infrequent, but in the near future a combined effort by the Marine Reserves and CPFV Projects plans to increase sampling efforts there in order to document any enhancement in fished areas due to the establishment of BCER.