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Policy and management implications of large-scale, interdisciplinary studies of the California Current large marine ecosystemorganized by Mark Carr and Cinamon Vann (Partnership for Interdisciplinary Studies of Coastal Oceans)MANAGEMENT AND CONSERVATION IMPLICATIONS OF MULTI-SCALE PATTERNS OF VARIATION IN KELP FOREST ECOSYSTEMS MARK CARR, Jennifer Caselle, Craig Syms, Mark Readdie, and Dan Malone, Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA (MC), Marine Science Institute, University of California, Santa Barbara, CA, USA (JC, MR), Marine Biology Department, Cook University, Townsville, QLD, Australia (CS), Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA (DM), carr@biology.ucsc.edu Forests of the giant kelp, Macrocystis pyrifera, are among the most productive and species-rich ecosystems on earth. High rates of primary production and a continuous influx of energy and nutrients fuel their species rich food webs. Combined with their accessibility, these ecosystems provide a variety of human services (e.g., recreational and commercial fisheries, non-extractive values) and are subject to a variety of anthropogenic impacts that can alter their structure and functions. Central to the management and conservation of these systems is knowledge of how the structure (e.g., species composition) and function of these forest ecosystems varies across broad spatial and temporal scales. We have initiated long-term (since 1999), large-scale (> 400 km) surveys of the fishes, invertebrates, and macroalgae that constitute these ecosystems to describe their spatial and temporal patterns of variation. Community structure (species composition and relative abundance) is shown to vary predictably along the coast in response to regional (e.g., temperature regimes, geologic formations) and local (e.g., key species interactions, exposure to ocean swell) processes. System dynamics is shown to vary less predictably at smaller (local) spatial scales. As shown by example (evaluation of marine protected areas), knowledge of these scales and sources of variation is key to interpreting human influences on these ecosystems and developing spatially explicit approaches to management and conservation. LONG-TERM MONITORING OF INTERTIDAL RESOURCES AND IMPLICATIONS FOR THE MANAGEMENT OF COASTAL ECOSYSTEMS MARK READDIE, Pete Raimondi, Carol Blanchette, and Bruce Menge, University of California, Santa Barbara, CA, USA (MR, CB), University of California, Santa Cruz, CA, USA (PR), Department of Zoology, Oregon State University, Corvallis, OR, USA, readdie@lifesci.ucsb.edu Informed management of coastal resources requires an understanding of the basis of management policy and of the data relevant to that policy. For example, if the basis of management policy is to protect distinct biological communities then spatially explicit characterization of those biological communities is needed. Too often there is incomplete understanding of the bases for policy and no appropriate data to inform decisions. In this talk we discuss the interaction between policy bases and data requirements. In particular we discuss how data from existing long-term and spatially expansive monitoring programs can inform management of coastal resources. DETERMINING CONNECTIONS AMONG MARINE POPULATIONS: IMPLICATIONS FOR MANAGEMENT ROBERT WARNER, Marine Science Institute, University of California, Santa Barbara, CA, USA, warner@lifesci.ucsb.edu Evidence from a variety of sources suggests two important features of marine larval dispersal that can strongly affect management. First, larval dispersal distances appear to be much shorter than previously thought, and include substantial amounts of self-recruitment. Second, larval recruitment into coastal habitats appears to be intermittent and heterogeneous on annual time scales, driven by advection in turbulent coastal circulation. The stochastic nature of larval transport in particular will create unavoidable uncertainty that complicates the management of nearshore ecosystems. Short dispersal paths and self-recruitment suggest that management may be more effective if carried out on a local scale, and that the effects of spatial management approaches (such as marine reserves) may be limited in their extent. The pulsed aspect of recruitment, even at long distances from a source, may alleviate the Allee effects that limit the success of long-distance colonization. High variation in recruitment, especially occasional large pulses of recruitment, may enhance the contribution of the storage effect on species persistence and coexistence. On the other hand, local rates of larval settlement may be largely decoupled from local stock abundances, even if self-recruitment is substantial. This provides an unexplored source of uncertainty in stock-recruitment relationships. Finally, the stochastic nature of connectivity may make it difficult to assess the effects of spatial fisheries management policies because it is likely to take long periods of sampling in order to detect recruitment responses to a management change. THE GEOGRAPHY OF RECRUITMENT IN THE COASTAL OCEAN: THE CHALLENGES FOR MANAGEMENT STEVEN GAINES, Bernardo Brotiman, Brian Kinlan, and Carol Blanchette, Marine Science Institute, University of California, Santa Barbara, CA, USA, gaines@lifesci.ucsb.edu Recent large-scale studies of marine populations are providing new views on the geographical patterns of the recruitment of young. The emerging findings pose new challenges for the management of marine populations. The recruitment of larvae to adult populations often varies enormously among locations and the spatial pattern typically does not mirror corresponding variation in the production of larvae, as assumed in most fisheries models. Temporal variation in larval recruitment has long plagued fisheries management and has received considerable attention in management strategies. By contrast, spatial variation in larval recruitment has been largely ignored in marine management, primarily because data were scarce. Although much of the variation in recruitment appears inherently stochastic, striking patterns are often present. For example, abrupt regional breaks in larval recruitment along the west coast of the United States near Cape Blanco, Oregon separate coastal populations that receive orders of magnitude different recruitment rates. Failure to incorporate such predictable demographic variation into the management of populations that span this break undoubtedly leads to decisions that place fished populations at risk. Similarly, even with large variation from one site to the next, the spatial pattern is often predictable. For coastal populations a substantial amount of this predictable variation may be tied to the topography of coastlines and its influence on coastal circulation. SPATIAL AND TEMPORAL PATTERNS OF OCEANOGRAPHIC PROCESSES ACROSS THE CALIFORNIA CURRENT LARGE MARINE ECOSYSTEM: IMPLICATIONS FOR SCALES OF MANAGEMENT JOHN BARTH, College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA, barth@coas.oregonstate.edu The California Current Large Marine Ecosystem (CCLME) spans from the split of the west wind drift in the north to the equatorial current systems in the south. The region is connected by swift, large-scale, alongshore surface and subsurface flows. The CCLME experiences temporal variability over a huge range of scales from diurnal to interdecadal. In some regions of the CCLME, seasonal variability is strong and of prime importance to the ocean ecosystem. For example, late arrival of usually springtime upwelling and primary production had a devastating effect on the marine food web in 2005. Interannual and interdecadal variability in oceanic water properties (temperature, salinity, nutrient and dissolved oxygen content) directly influences marine ecosystems. In some regions of the CCLME, marine systems are experiencing more frequent hypoxia and harmful algal bloom events. Prominent coastline features interact with oceanic flows to break up the CCLME into a few biogeographic regions. On smaller scales, flow-topography interaction (capes, bays, submarine canyons, and banks) sets the scale of ecosystem response. As climate variability affects the timing of seasonal transitions, seawater properties, and the degree of flow-topography interaction, the connectivity and success of marine populations will be affected. IMPACT OF CLIMATE CYCLES ON SUPPLY OF FOOD AND RECRUITS TO ROCKY INTERTIDAL HABITATS BRUCE MENGE, Department of Zoology, Oregon State University, Corvallis, OR, USA, mengeb@oregonstate.edu The inevitability of anthropogenic climate change poses new challenges to ecologists, a major one being the response of ecological communities. In marine systems, climate cycles such as El Niño-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) exhibit periodic changes that might be useful as a proxy to inform how longer-term change might influence marine ecosystems. Long-term study of ecological processes is rare, but in 1989 we began studies of the supply of mussel and barnacle recruits to rocky intertidal communities along the Oregon coast. In 1993, we initiated sampling of phytoplankton and nutrient supply to these systems. Using these data on intertidal community “subsidies,” we examined how each varied with ENSO and PDO cycles along the Oregon coast. To determine how these patterns vary with latitude along the coast, we compared these results with those from a shorter dataset available from the California coast. Results showed that in Oregon, ENSO and PDO cycles interacted to influence phytoplankton and recruitment. During warm phase PDO, El Niño (warm water) decreased both phytoplankton concentration and mussel and barnacle recruitment, probably through bottom-up effects. During cold phase PDO, El Niño had no effect but phytoplankton and recruitment were elevated during “normal” conditions, again likely due to elevated bottom-up inputs, and were actually reduced during La Niña (cold water) conditions, probably due to stronger offshore transport. In contrast to the Oregon results, no effects of either climate cycle were detected on phytoplankton and recruitment in California. We conclude that climate cycle influences on subsidies are complex and context-dependent, acting through both bottom-up and transport mechanisms, and varying with latitude. EFFECTS OF WARMING WATERS ON MARINE SPECIES: AN ECOPHYSIOLOGY APPROACH TO ASSESSING EFFECTS OF CLIMATE CHANGE GRETCHEN HOFMANN, Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA, hofmann@lifesci.ucsb.edu Coastal marine ecosystems are impacted worldwide as climate change places physiological stress on resident organisms. A key step in understanding the impact of warming coastal oceans is to know the degree of change in the physiological status and health of marine organisms. Towards that end, we have used physiological (e.g., thermotolerance), and molecular-level metrics (e.g., genomics-based assessments of gene expression patterns) to examine the response of purple sea urchins to variation in temperature. In these studies, early life history stages showed variation in thermotolerance that correlated with thermal history in the field. Specifically, larvae resulting from spawnings of adults collected in Baja California tolerated warmer temperatures than larvae of adults from northern populations from Santa Barbara Channel and Puget Sound. Similarly, adult sea urchins displayed alterations in gene expression that mapped onto their geographic distribution. The results of these studies demonstrate the degree and nature of physiological plasticity in adult and larval sea urchins with respect to temperature, and further, suggest how influential temperature is for setting distribution limits for this particular species. Such physiological data, collected across ecologically relevant temperatures, is a key component to understanding the impact, both lethal and sublethal, of expected climate change on marine populations. SPATIAL STRUCTURE AND CLIMATE CHANGE: ACCOUNTING FOR SPATIAL PATTERNS IN MARINE RESERVE DESIGN Ben Halpern and BRIAN KINLAN, Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA, kinlan@lifesci.ucsb.edu Climate change is happening and is having detectable and in some cases dramatic effects on the biology and sustainability of many ecosystems and the species that inhabit them. The design of marine reserves must at least consider the reality of climate change, if not incorporate it into the actual design and implementation of reserve networks. At both large and small scales, however, the impacts of climate change will likely be highly spatially heterogeneous. This spatial structure in response creates management challenges but also important opportunities. To help predict the patterns in this spatial structure we develop a variety of new tools and guidelines and use them to evaluate kelp forest dynamics along the coasts of southern and Baja California in the past and under future climate scenarios. We then apply these tools and guidelines to a case study in the Channel Islands, California to demonstrate how reserves can be designed to account for climate change. We argue that for reserves to be successful in the long-term they need to be designed to meet conservation and resource management goals under both present and future climate conditions. | |||||||||||||||||
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