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Menge B.A.,Oregon State University | Hacker S.D.,Oregon State University | Freidenburg T.,MPA Monitoring Enterprise | Lubchenco J.,Oregon State University | And 4 more authors.
Ecological Monographs | Year: 2011

Detection of ecosystem responsiveness to climatic perturbations can provide insight into climate change consequences. Recent analyses linking phytoplankton abundance and mussel recruitment to the North Pacific Gyre Oscillation (NPGO) revealed a paradox. Despite large increases in mussel recruitment beginning in 2000, adult mussel responses were idiosyncratic by site and intertidal zone, with no response at one long-term site, and increases in the low zone (1.5% per year) and decreases in the mid zone (1.3% per year) at the other. What are the mechanisms underlying these differential changes? Species interactions such as facilitation by barnacles and predation are potential determinants of successful mussel colonization. To evaluate these effects, we analyzed patterns of barnacle recruitment, determined if predation rate covaried with the increase in mussel recruitment, and tested facilitation interactions in a field experiment. Neither magnitude nor season of barnacle recruitment changed meaningfully with site or zone from the 1990s to the 2000s. In contrast to the relationship between NPGO and local-scale mussel recruitment, relationships between local-scale patterns of barnacle recruitment and climate indices were weak. Despite differences in rates of prey recruitment and abundance of sea stars in 1990-1991, 1999-2000, and 2007- 2008, predation rates were nearly identical in experiments before, during, and after 1999-2000. The facilitation experiment showed that mussels M. trossulus only became abundant when barnacle recruitment was allowed, when abundance of barnacles reached high abundance of ∼50% cover, and when mussel recruitment was sufficiently high. Thus, in the low zone minimal changes in mussel abundance despite sharply increased recruitment rates are consistent with the hypothesis that change in adult mussel cover was buffered by the relative insensitivity of barnacle recruitment to climatic fluctuations, and a resultant lack of change in facilitation strength. Facilitation of mussels is likely important in the mid zone as well, but the dynamics of the longer-lived M. californianus at our two long-term sites appeared to be driven primarily by differential regimes of disturbance. Although rocky intertidal ecosystems may be sensitive to major climatic perturbations, predicting community responses will be difficult due to complex individualistic responses of key taxa during the recruitment stage and their influences on subsequent species interactions. © 2011 by the Ecological Society of America. Source


Krenz C.,Oregon State University | Menge B.A.,Oregon State University | Freidenburg T.L.,MPA Monitoring Enterprise | Lubchenco J.,Oregon State University | And 3 more authors.
Journal of Experimental Marine Biology and Ecology | Year: 2011

Through bottom-up inputs and larval transport, benthic-pelagic links can have an important effect on benthic community structure. Recent work on community structure of northeast Pacific rocky shores has focused on latitudinal differences in recruitment of intertidal invertebrates as a driver of variation in community structure. Recruitment differences are associated with a transition in upwelling near Cape Blanco in southern Oregon. Here we examine the transition in recruitment along an unstudied gap on the northern California and Oregon coasts, document a latitudinal gradient in bottom-up factors, and examine if major coastal promontories associated with upwelling plumes potentially separate benthic-pelagic coupling into regions. We monitored the recruitment of intertidal invertebrates, chlorophyll a concentrations in coastal waters, and the growth rates of mussels at numerous sites along the northern California and Oregon coasts. The transition in recruitment of intertidal invertebrates from north to south changed from very high levels north of Cape Blanco, to intermediate levels between Capes Blanco and Mendocino, to very low levels south of Cape Mendocino. The specific shape of the recruitment cline varied among species. Chlorophyll a concentrations and mussel growth rates were higher north of Cape Blanco than south of Cape Blanco, indicating that bottom-up factors may also drive regional differences in rocky shore community structure. Distinctive timing between regions of recruitment and plankton pulses suggests that benthic-pelagic coupling may be somewhat independent between these regions, which are separated by major coastal promontories. Our results highlight the large variability in spatially coupled ecosystems along the northern California and Oregon coasts that drive the latitudinal gradient in rocky shore community structure in the northeast Pacific. © 2011 Elsevier B.V. Source


Menge B.A.,Oregon State University | Gouhier T.C.,Oregon State University | Freidenburg T.,Oregon State University | Freidenburg T.,MPA Monitoring Enterprise | Lubchenco J.,Oregon State University
Journal of Experimental Marine Biology and Ecology | Year: 2011

The rate of input of new individuals into communities is a key component of community dynamics. Detection of ecosystem responsiveness to climatic perturbations such as El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and North Pacific Gyre Oscillation (NPGO) can provide insight into how ecosystems will respond to climate change. Although these climate patterns are ocean-based, understanding of their influences on key ecosystem processes in temperate coastal marine ecosystems is limited. Recent analyses documented orders-of-magnitude increases in mussel recruitment in the 2000s relative to the previous decade. To evaluate the generality of this pattern across other intertidal species with planktotrophic dispersive larvae, and determine the extent to which variation in recruitment was explained by climatic and environmental (upwelling) variation, we analyzed patterns of barnacle and mussel recruitment across space (at up to 10 sites across 250. km) and through time (up to 20-years). Compared to mussel recruitment, barnacle recruitment varied far less interdecadally, and showed minimal change in seasonality. Using three analytical approaches, multiple regression, quantile regression and wavelet analysis, we found that recruitment of the barnacles Balanus glandula and Chthamalus dalli and mussels Mytilus spp. varied in generally similar ways with climate variation as expressed in ENSO, NPGO, and PDO indices, and with upwelling, as expressed in the Bakun upwelling index. In regression approaches, NPGO and upwelling had the strongest associations with recruitment of all species, with MEI and PDO also having an influence on C. dalli. The strength of the association with the environment varied with recruitment magnitude, however, being generally stronger at intermediate and in some cases high recruitment densities and weak at low recruitment densities. Time series (wavelet) analysis showed that with all environmental indices, the most consistent strong relationships occurred at annual periodicities, but multi-year periodicities were also important with PDO and upwelling indices. Patterns were complex, however, with periods of strong and weak associations at different time periodicities varying differently among the different environmental measures, and in some cases varying from strongly positive to strongly negative associations at the same periodicities through time. These relatively consistent relationships between large-scale climate and upwelling, and recruitment explained a substantial fraction of the variance (37-40%). The ~. 60% of the variance in recruitment not explained in our analyses is likely due to myriad other factors such as shorter-scale variation in upwelling, internal tidal bores, sea breezes, wave forces, larval behavior, and post-settlement processes. Thus, our analysis adds insights into potential influences on recruitment that occur at ocean basin- to regional scales, and complements the body of work that focuses on the more local-scale and shorter-term mechanistic influences that also help determine the pace at which larvae recruit to the adult habitat. © 2011 Elsevier B.V. Source


Gleason M.,The Nature Conservancy | Fox E.,California Natural Resources Agency | Vasques J.,50 Harbor Blvd. | Whiteman E.,MPA Monitoring Enterprise | And 8 more authors.
Ocean and Coastal Management | Year: 2013

The State of California recently planned and is implementing a network of marine protected areas (MPAs) in state waters as mandated by the Marine Life Protection Act (MLPA). A public-private partnership (the MLPA Initiative) completed four regional public MPA planning processes characterized by robust stakeholder contributions and the incorporation of best readily available science. Prior to enactment of the MLPA in 1999, less than 3% of California state waters were in MPAs, and most of those MPAs were small and lacked clear objectives. By 2013, approximately 16% of state waters will be in 124 MPAs that represent and replicate most marine and estuarine habitats and are designed to be ecologically-connected. The redesigned statewide network of MPAs improves marine ecosystem protection in California, advanced the science and practice of designing MPA networks, and increased the awareness and capacity of stakeholders, scientists and decision-makers for marine spatial planning. The public planning effort took almost seven years and significant financial investment (approximately $19.5 million in private charitable foundation funds and $18.5 million in public funds). Not all stakeholders were pleased with the outcomes and the planning processes faced many challenges. While the design of the MPA network aimed to meet science and feasibility guidelines, final decisions on MPAs in each region reflected tradeoffs needed to garner public acceptance and support for implementation. The MLPA Initiative offers some key lessons about implementing policy through a public planning process. While California is developing mechanisms for assessing effectiveness of the MPA network in coming years, including establishing a MPA Monitoring Enterprise and a process for periodic review and adaptive management of MPAs, significant challenges remain for effective implementation. © 2012 Elsevier Ltd. Source

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